HomeMy WebLinkAbout3.3.12 Parachute Field SWMP Final-07-16-2007Appendix A
Documentation of Amendments to the Field Wide SWMP
PLAN AMENDMENTS
Williams RMT
Parachute Field SWMP
Revision
Number/Date
Pages Revised
Author
Authorized
Signature
1/ July 16, 2009
All
Habitat
Management Inc.
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Appendix B
Permit Requirements
&
Guidance Documents
STATE OF COLORADO
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
Water Quality Control Division — Stormwater Program
STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY
GENERAL PERMIT APPLICATION
and
STORMWATER MANAGEMENT PLAN PREPARATION GUIDANCE
Revised 3/2009
Contact information
Colorado Department of Public Health and Environment Telephone: (303) 692-3517
Water Quality Control Division — Stormwater Program Email: cdphe.wqstorm@state.co.us
WQCD-Permits-B2 Web Page: www.cdphe.state.co.us/wq/PermitsUnit
4300 Cherry Creek Drive South
Denver, Colorado 80246-1530
CONTENTS
Applicability
Instructions for Completing the Application
General Permit Application
Appendix A — Preparing a Stormwater Management Plan (SWMP)
APPLICABILITY
This application is for use by all entities engaged in construction activities to obtain coverage under the general
permit for Stormwater Discharges Associated with Construction Activities (the Stormwater Construction Permit).
Construction activity refers to ground surface disturbing activities, which include, but are not limited to, clearing,
grading, excavation, demolition, installation of new or improved haul roads and access roads, staging areas,
stockpiling of fill materials, and borrow areas. Construction does not include routine maintenance to maintain
original line and grade, hydraulic capacity, or original purpose of the facility.
Stormwater Construction Permit coverage is required by State and Federal regulations for stormwater discharged
from any construction activity that disturbs at least 1 acre of land (or is part of a larger common plan of
development or sale that will disturb at least 1 acre). A "common plan of development or sale" is a site where
multiple separate and distinct construction activities may be taking place at different times on different schedules,
but still under a single plan. This includes phased projects, projects with multiple filings or lots, and projects in a
contiguous area that may be unrelated but still under the same contract. If the project is part of a common plan of
development or sale, the disturbed area of the entire plan must be used in determining permit requirements, and all
portions of the project must be covered.
NOTES:
Stormwater Management Plan Preparation Guidance — The guidance, available as Appendix A to this
application, has been revised and updated.
Additional Guidance — Additional information, including further discussion on permittee and operator liability, is
available in the Stormwater Fact Sheet — Construction, available from the Division's web site at
www.cdphe.state.co.us/wq/PermitsUnit. If you have questions on completing this application, you may contact the
Division at cdphe.wqstorm@state.co.us or (303) 692-3517.
Instructions — Page 1 of 5
Revised 3/2009
Water Quality Control Division – Stormwater Program www.cdphe.state.co.us/wq/permitsunit
INSTRUCTIONS
A) Submitting the Application
Application Due Date: At least ten days prior to the anticipated start of construction, the owner or operator of the
construction activity must submit an application as provided by the Water Quality Control Division (Division).
This form may be reproduced, and is also available from the Division's web site (see previous page for
address/contact information). Applications received by the Division are processed, and a permit certification and
other relevant materials will be sent to the attention of the legally responsible person (Item 9 on the application
form).
Permit Fee: Do not send any payment with this application. You will be billed once you are covered under a
permit. Current permit fees can be obtained from the Division's web site at
www.cdphe.state.co.us/wq/PermitsUnit.
Application Completeness: The application must be completed accurately and in its entirety or the application
will be deemed incomplete—processing of the application will not begin until all required information is received.
One original copy of the completed application (no faxes or e-mails) must be submitted to the Division to initiate
the application process (see page 1 above for address/contact information).
Do not include a copy of the Stormwater Management Plan, unless requested by the Division.
B) Who May Apply For and Maintain Permit Coverage
The Permit applicant must be a legal entity that meets the definition of the owner and/or operator of the
construction site, in order for this application to legally cover the activities occurring at the site. The applicant
must have day-to-day supervision and control over activities at the site and implementation of the SWMP.
Although it is acceptable for the applicant to meet this requirement through the actions of a contractor, as
discussed in the examples below, the applicant remains liable for violations resulting from the actions of their
contractor and/or subcontractors. Examples of acceptable applicants include:
• Owner or Developer - An owner or developer who is operating as the site manager or otherwise has
supervision and control over the site, either directly or through a contract with an entity such as those listed
below.
• General Contractor or Subcontractor - A contractor with contractual responsibility and operational
control (including SWMP implementation) to address the impacts construction activities may have on
stormwater quality.
• Other Designated Agents/Contractors - Other agents, such as a consultant acting as construction manager
under contract with the owner or developer, with contractual responsibility and operational control
(including SWMP implementation) to address the impacts construction activities may have on stormwater
quality.
An entity conducting construction activities at a site may be held liable for operating without the necessary
permit coverage if the site does not have a permit certification in place that is issued to an owner and/or
operator. For example, if a site (or portion of a site) is sold or the contractor conducting construction activities
changes, the site's permit certification may end up being held by a permittee (e.g., the previous owner or
contractor) who is no longer the current owner and/or operator. In this case, the existing permit certification
will no longer cover the new operator's activities, and a new certification must be issued, or the current
certification transferred.
Utilities, Other Subcontractors, etc.: A separate permit certification is not needed for subcontractors, such as
utility service line installers, where the permittee or their contractor is identified as having the operational
control to address any impacts the subcontractor's activities may have on stormwater quality. Although
separate permit coverage may not be needed in some cases, these entities are not exempt from the stormwater
regulations for all of their projects and may still be held liable if their activities result in the discharge of
pollutants.
Leases: When dealing with leased land or facilities, the lessee shall be considered the "owner" for the
purposes of stormwater permitting if they are responsible for the activities occurring at the site.
Instructions – Page 2 of 5 Revised 3/2009
Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
C) Permitting for Developments with Multiple Owners and/or Operators
For situations where multiple entities meet the definition of owners and/or operators for different portions of a
development (e.g., a single development with multiple lots owned and operated by separate entities), it is essential
that the permittees, owners, and operators at the site correctly follow the guidance on who may apply for coverage
under the Stormwater Construction Permit (see Part B, above).
When a portion of a permitted site is sold to a new owner, a permit certification must be in place that is held by an
entity meeting the definition of owner and/or operator of that sold lot. This may be accomplished in one of the
following ways:
• Coverage Under the Existing Certification — Activities at the sold area may continue to be covered under an
existing permit certification for the project if the current permittee meets the definition of operator for the sold
area. To meet the definition of operator, the current permittee must have contractual responsibility and
operational control to address the impacts that construction activities at the sold area may have on stormwater
runoff (including implementation of the SWMP for the sold area). Therefore, a legally binding agreement must
exist assigning this responsibility to the current permit holder on behalf of the new owner and/or operator for the
sold area. It is not necessary to notify the Division in such case. However, documentation of the agreement must
be available upon request, and the SWMP must be maintained to include all activities covered by the Stormwater
Construction Permit
• New Certification Issued — Reassignment — A new permit certification may be issued to the new owner and/or
operator of the sold area. The existing permittee and the new owner and/or operator must complete the
Reassignment Form (available from the Division's web page, see page 1) to remove the sold area from the
existing permit certification and cover it under a certification issued to the owner and/or operator of the sold area.
Both entities must have SWMPs in place that accurately reflect their current covered areas and activities.
A more detailed explanation is available in the Stormwater Fact Sheet — Construction, available from the Division's
web site (see page 1).
D) Instructions for the Application Form
Item 1 - Applicant Information: Provide the company name, address, phone number, email address for applicant,
and local contact information for the project. Indicate whether the applicant is the owner, the developer, or
a contractor.
Item 2 - Location of the Construction Site: Provide the following information:
• Street Address — Provide the address of the construction site. If an exact address is not available you
may use an approximate address, the nearest intersection or boundary streets including directional
identifiers (e.g., "S. of Park St. between 5th Ave. and 10th Ave.", or "W. side of C.R. 21, 3.25 miles N. of
Hwy 10") or other identifying information. A street name without an address, intersection, mile marker,
or other identifying information describing the location of the project is not adequate. For linear
projects, the route of the project should be described as best as possible with the location more
accurately indicated by a map (see Item 3).
• Project Name, City, and County — If the project is located within the unincorporated portion of a
county, write "unincorporated" in the space provided for the city name
• Latitude/Longitude - For the approximate center point of the property, to the nearest 15 seconds. The
latitude and longitude must be provided as either degrees, minutes, and seconds, or in decimal degrees
with three decimal places. This information may be obtained from a variety of sources, including:
o Surveyors or engineers for the project should have, or be able to calculate, this information.
o EPA maintains a web -based siting tool as part of their Toxic Release Inventory program that uses
interactive maps and aerial photography to help users get latitude and longitude. The siting tool can
be accessed at www.epa.gov/tri/report/siting_toollindex.htm
o U.S. Geological Survey topographical map(s), available at area map stores.
o Using a Global Positioning System (GPS) unit to obtain a direct reading.
Note: the latitude/longitude required above is not the directional degrees, minutes, and seconds
provided on a site legal description to define property boundaries.
Instructions — Page 3 of 5 Revised 3/2009
Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
Item 3 - Legal Description or Map: One of these two items must be provided:
• Legal Description of the entire site covered by the application. The description must include
subdivision(s), block(s), and lot(s) (providing the metes and bounds or just the township/section/range, is
not adequate). This information should be available for subdivided properties from documents submitted
to or maintained by the city or county, such as the subdivision plat or deed. If this information is not
available, a map must be submitted. — or —
• Site Map that defines the boundaries of the site covered by the application. The level of detail that must
be provided will depend on the nature of the project and must be adequate so that it can be determined
during a field audit what construction activities are covered under the issued certification. For typical
developments within a specific surveyed property, a map that clearly shows the property boundaries
should be obtainable. For projects located in areas with adjacent construction areas that will not be
covered by the application (such as multi -lot developments with multiple owners/operators), this detail is
essential. However, for projects such as road or utility projects, where providing this detail may not be
feasible or necessary to distinguish the project from adjacent activities, a less detailed map showing the
approximate area is adequate. Maps must have a minimum scale of 1:24000 (the scale of a USGS 7.5
minute map). Maps must be folded to 8'/2 x 11 inches. Do not submit grading plans or other blueprints
as the site map or the application will be rejected. This is not the same as the map required in the SWMP
(see Appendix A).
Item 4 - Area of Construction Site: Provide both the total area of the construction site, and the area that will
undergo disturbance, in acres. Note: aside from clearing, grading and excavation activities, disturbed
areas also include areas receiving overburden (e.g., stockpiles), demolition areas, and areas with heavy
equipment/vehicle traffic and storage that disturb existing vegetative cover (see construction activity
description under the APPLICABILITY section on page 1).
If the project is part of a larger common plan of development or sale (see the definition under the
APPLICABILITY section on page 1), the disturbed area of the total plan must also be included.
Item 5 - Nature of Construction Activities: Check the appropriate box or boxes, or if the descriptions provided
do not fit the project, provide a brief description that indicates the general nature of the construction
activities for which permit coverage is being requested. A more detailed description of the project must be
included in the Stormwater Management Plan (see Item 8).
Item 6 - Anticipated Construction Schedule: Provide the current estimated start and final stabilization dates for
the construction project as follows:
Construction Start Date - This is the day you expect to begin ground disturbing activities, including
grubbing, stockpiling, excavating, demolition, and grading activities.
• Final Stabilization Date - in terms of permit coverage, this is when the site is finally stabilized. This
means that all ground surface disturbing activities at the site have been completed, and all disturbed
areas have been either built on, paved, or a uniform vegetative cover has been established with an
individual plant density of at least 70 percent of pre -disturbance levels. Permit coverage must be
maintained until the site is finally stabilized. Even if you are only doing one part of the project, the
estimated final stabilization date must be for the overall project. If permit coverage is still required
once your part is completed, the permit certification may be transferred or reassigned to a new
responsible entity(s).
Item 7 - Receiving Water(s): Identify the receiving water of the stormwater from your site. Receiving waters are
any waters of the State of Colorado. This includes all water courses, even if they are usually dry. If
stormwater from the construction site enters a ditch or storm sewer system, identify that system and
indicate the ultimate receiving water for the ditch or storm sewer. Note: a stormwater discharge permit
does not allow a discharge into a ditch or storm sewer system without the approval of the owner/operator
of that system.
Instructions — Page 4 of 5 Revised 3/2009
Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
Item 8 - Stormwater Management Plan (SWMP) Certification: The certification of completion of a SWMP
must be signed by the applicant or their authorized agent. Appendix A contains the requirements for the
SWMP during the period of construction (as listed in the Stormwater Construction Permit). Submittal of
the SWMP with the application is not required; however, it must be developed and implemented, and
kept at the construction site. The Division reserves the right to request the SWMP at any time.
Item 9 - Signature of Applicant: The applicant must be either the owner and/or operator of the construction site.
Refer to Part B of the instructions for additional information. The application must be signed by the
applicant to be considered complete. In all cases, it shall be signed as follows:
a) In the case of corporations, by a principal executive officer of at least the level of vice-president or his
or her duly authorized representative, if such representative is responsible for the overall operation of
the facility from which the discharge described in the application originates.
b) In the case of a partnership, by a general partner.
c) In the case of a sole proprietorship, by the proprietor.
d) In the case of a municipal, state, or other public facility, by either a principal executive officer, ranking
elected official, or other duly authorized employee if such representative is responsible for the overall
operation of the facility from which the discharge described in the form originates.
This certification includes an acknowledgment that the applicant understands that the permit
coverage, and therefore the applicant's liability, will be for the entirety of the construction project
described and applied for, until such time as the application is amended or the certification is
transferred, inactivated, or expired.
Instructions — Page 5 of 5 Revised 3/2009
GENERAL PERMIT APPLICATION
STORMWATER DISCHARGES ASSOCIATED
WITH: CONSTRUCTION ACTIVITY
(Permit No. COR -030000)
For Agency Use Only COR - 0 3
Date Received: / /
Month Uay
Billing Code: 09 9B 00
Year
ALL APPLICANTS MUST FOLLOW PART D OF THE INSTRUCTIONS TO COMPLETE THIS FORM
Please print or type. All items must be completed accurately and in their entirety, or the application will be deemed incomplete
and returned to the applicant. Processing of the application will not begin until all * REQUIRED information is received.
Please refer to the instructions for information about the required items. Original Wet Ink signatures for Items 8 and 9 are
required.
1. Name and address of the permit applicant (legally responsible entity):
*Company Name
*Mailing Address
*City, State and Zip Code
*Legally Responsible Person (application signer)
*Title
*Legally Responsible Person E-mail Address
*Phone Number Who is applying? Owner 0 Developer 0 Contractor 0
*Local Contact (familiar with facility)
*Title *Phone Number
*Local Contact E-mail Address
2. Location of the construction site:
*Name of plan, project, or development
*Street Address (or cross streets)
*City (if unincorporated, so indicate) *County *Zip Code
*Latitude/Longitude (approximate center of the site) — use one of the following formats:
Latitude / / Longitude / / (e.g., 39°42'11", 104°55'57")
degrees minutes seconds degrees minutes seconds
-or-
Latitude Longitude (e.g., 39.703°, 104.933°')
degrees (to 3 decimal places) degrees (to 3 decimal places)
3. * Legal Description or Map
0 Legal Description per instructions (NOT METES AND BOUNDS)
Subdivision(s) Lot(s)
-or-
Block(s)
0 Map Indicating Boundaries of Disturbed Area - Maps must be folded to 8'/2 x 11 inches.
4. * Area of the construction site:
Total area of project site (acres)
Area of project site to undergo disturbance (acres)
Total disturbed area of Larger Common Plan of Development or Sale, if applicable (i.e., total, including all phases,
filings, lots, and infrastructure not covered by this application)
Application - Page 1 of 2
* REQUIRED ENTRY Revised 3/2009
5. *Nature of the construction activity:
Check the appropriate box(s) or provide a brief description that indicates the general nature of the construction activities.
(The full description of activities must be included in the Stormwater Management Plan.)
▪ Single Family Residential Development
El Multi -Family Residential Development
❑ Commercial Development
❑ Oil and Gas Production and/or Exploration (including pad sites and associated infrastructure)
0 Highway/Road Development (not including roadways associated with commercial or residential development)
❑ Other, Describe:
6. *Anticipated construction schedule:
Construction Start Date: / / Final Stabilization Date: / /
month day year
month day year
7. *The name of the receiving waters(s). (If discharge is to a ditch or storm sewer, also include the name of the ultimate
receiving water):
STOP! A Stormwater Management Plan (see Appendix A) must be completed prior to signing the following
certifications!
8. * Stormwater Management Plan Certification:
"I certify under penalty of law that a complete Stormwater Management Plan, as described in Appendix A of this
application, has been prepared for my activity. Based on my inquiry of the person or persons who manage the
system, or those persons directly responsible for gathering the information, the Stormwater Management Plan is, to the
best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for falsely
certifying the completion of said SWMP, including the possibility of fine and imprisonment for knowing violations."
Signature of Legally Responsible Person (submission must include original wet ink signature)
Date Signed
r
Name (printed)
9. * Signature of Applicant
Title
"I certify under penalty of law that I have personally examined and am familiar with the information submitted in this
application and all attachments and that, based on my inquiry of those individuals immediately responsible for obtaining
the information, I believe that the information is true, accurate and complete. I am aware that there are significant
penalties for submitting false information, including the possibility of fine or imprisonment.
"I understand that submittal of this application is for coverage under the State of Colorado General Permit for
Stormwater Discharges Associated with Construction Activity for the entirety of the construction site/project
described and applied for, until such time as the application is amended or the certification is transferred,
inactivated, or expired."
Signature of Legally Responsible Person (submission must include original wet ink signature)
Date Signed
Name (printed)
DO NOT include copy of Stormwater Management Plan
DO NOT include payment — an invoice will be sent after certification is issued
Application - Page 2 of 2
* REQUIRED ENTRY
Title
Revised 3/2009
Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
APPENDIX A
SWMP GUIDANCE
PREPARING A STORMWATER MANAGEMENT PLAN (SWMP)
Stormwater Construction General Permit
Contents
A. INTRODUCTION page 2
B. GENERAL GUIDANCE 2
• BMPs 2
Special topic:
Erosion Control BMPs, Sediment Control BMPs 3
• Implementation 3
• Common Sense Approach 3
• SWMP Items, Format 3
• Existing Controls 3
• Control Implemented by Other Parties 3
• SWMP Availability 4
C. STORMWATER MANAGEMENT PLAN REQUIRMENTS 4
C.1 SWMP GENERAL REQUIREMENTS 4
C.2 SWMP CONTENTS — Narrative Site Description 5
C.3 SWMP CONTENTS — Site Map 6
Special topic: Using Construction Plans, Plans Developed to Meet Local
Stormwater Requirements, or Other Plans 6
C.4 SWMP CONTENTS — Stormwater Management Controls 7
a. SWMP Administrator 7
b. Identification of Potential Pollutant Sources 8
c. Best Management Practices (BMPs) for Stormwater Pollution Prevention 10
i) Selecting and locating appropriate BMPs 10
ii) Specific BMPs for Material Handling and Spill Prevention 10
Special topics:
• BMP location 11
• Ensuring BMPs are under the Control of the Permittee 11
• Protecting Waters of the United States 11
iii) Documenting Selected BMPs in the SWMP (including phasing of BMP implementation)12
Special topic: BMP description: Level of detail 12
iv) Non-Stormwater Discharges 12
• Concrete Washout water 12
• Construction Dewatering water 12
v) Stormwater Dewatering: 13
d. Revising BMPs and the SWMP 13
C.5 SWMP CONTENTS — Final Stabilization and Long-term Stormwater Management 14
Special topic: Inactivation of permit coverage 14
Special topic: Use of Permanent Detention Ponds as BMPs during Construction 15
C.6 SWMP CONTENTS — Inspection and Maintenance Procedures 15
a. Inspection Schedules 15
b. Inspection Procedures 15
c. BMP Maintenance/Replacement and Failed BMPs 16
d. Record Keeping and Documenting Inspections 16
Appendix A - Page 1 of 19 Revised 7/07
Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
D. ADDITIONAL SWMP AND BMP RESOURCES 17
D.1. RESOURCES — BMP Design and Implementation 17
a. BMP Design Criteria Manuals: 17
b. General BMP Selection and Design Guidance 18
c. Special Applications 18
D.2. RESOURCES — Example Management Plans 19
D.3. RESOURCES — Training 19
A. INTRODUCTION
This guidance document is designed to help you develop a Stormwater Management Plan (SWMP) for your
construction project, as required for compliance with the CDPS general permit for Stormwater Discharges Associated
with Construction Activities (the Stormwater Construction Permit). It explains what each of the SWMP requirements
means, and gives some options for you to consider in developing Best Management Practices (BMPs) that are best
suited to your site during construction.
This guidance document primarily addresses the SWMP requirements in the Stormwater Construction Permit. Other
requirements and limitations, such as records retention, reporting, inspections, etc., are detailed in the Stormwater
Construction Permit itself. Also note that the SWMP and the Stormwater Construction Permit only cover discharges of
stormwater.
Stormwater Management Plan (SWMP) Goal: To identify possible pollutant sources that may contribute
pollutants to stormwater, and identify Best Management Practices (BMPs) that, when implemented, will reduce or
eliminate any possible water quality impacts. The SWMP must be completed and implemented at the time the
project breaks ground, and revised as construction proceeds, to accurately reflect the conditions and practices at
the site.
Construction activities use and produce many different kinds of pollutants which may impact water quality. The
main pollutant of concern at construction sites is sediment. Grading activities remove grass, rocks, pavement and other
protective ground covers, resulting in the exposure of underlying soil to the elements. The soil is then easily picked up
by wind and/or washed away by rain or snowmelt. For example, sediment runoff rates from construction sites are
typically 10 to 20 times greater than those from agricultural lands, and 1,000 to 2,000 times greater than those of forest
lands. During a short period of time, construction activity can contribute more sediment to streams than would normally
be deposited over several decades, causing physical and biological harm to our State's waters. The added sediment
chokes the river channel and covers the areas where fish spawn
and plants grow. Excess sediment can cause a number of other
problems for waterbodies, such as increased difficulty in
filtering drinking water, and clouding the waters which can kill
plants growing in the river and suffocate fish. A number of
pollutants, such as nutrients, are absorbed onto sediment
particles and also are a source of pollution associated with
sediment discharged from construction sites.
Uncontrolled storm water discharges from
areas of urban development and construction
activity negatively impact receiving waters by
changing the physical, biological, and chemical
composition of the water, resulting in an
unhealthy environment for aquatic organisms,
wildlife, and humans.
In addition, construction activities often require the use of toxic or hazardous materials such as petroleum products,
fertilizers, pesticides and herbicides, and building materials such as asphalt, sealants and concrete, which may pollute
stormwater. These materials can be harmful to humans, plants and aquatic life.
B. GENERAL GUIDANCE
BMPs: Best Management Practices (BMPs) encompass a wide range of erosion and sediment control practices, both
structural and non-structural in nature, that are intended to reduce or eliminate any possible water quality impacts from
stormwater leaving a construction site. The individual BMPs appropriate for a particular construction site are largely
dependant of the types of potential pollutant sources present, the nature of the construction activity, and specific -site
conditions.
Appendix A - Page 2 of 19
Revised 7/07
Water Quality Control Division — Stormwater Program
www.cdphe.state.co.us/wq/permitsunit
Nonstructural BMPs, such as preserving natural vegetation,
preventive maintenance and spill response procedures,
schedules of activities, prohibition of specific practices,
education, and other management practices are mainly
operational or managerial techniques.
Structural BMPs include treatment processes and practices
ranging from diversion structures and silt fences, to retention
ponds and inlet protection.
Most of the BMPs referenced here are widely used in the
construction industry. They generally involve a simple and low
cost approach, and can be very effective when properly
installed and maintained
The Stormwater Construction Permit requires the use of a self -
designed SWMP. This plan is based on the use of BMPs. For
construction sites, there are several types of BMPs: those that
prevent erosion, those that prevent construction materials from
introducing pollutants to stormwater, and those that remove
sediment and other pollutants before they can be discharged
(see box, to right).
Best Management Practices to prevent the
erosion and discharge of sediment typically
include:
1. Erosion Control BMPs
Practices to prevent the erosion of soil.
Examples:
• minimizing the amount of disturbed soil
through phasing, temporary stabilization, or
leaving existing vegetation
• diverting runoff around disturbed areas
2. Sediment Control BMPs
Practices to remove sediment from runoff.
Examples:
• retaining stormwater in ponds or behind silt
fence to settle out sediment
• filtering stormwater through filter fabric on
inlets
Implementation: The SWMP focus is primarily on controls used during ground surface disturbing activities. This
focus means that many sediment control BMPs, such as silt fence and inlet protection, must be installed before
disturbing activities begins, not after.
Common Sense Approach: Your SWMP is intended to be a usable document, not a paper exercise. Therefore, do not
include practices that may sound good, but are unreasonable or not feasible for your site. Failure to implement your
SWMP, even if the BMPs listed do not make sense, puts you in automatic violation of the Stormwater Construction
Permit. For example, a blanket statement that runoff from all disturbed areas will be controlled by silt fences, even if
the slope or channels are too steep/narrow for this particular BMP, would be unreasonable.
On the other hand, if a particular BMP is listed in the SWMP, but then later turns out to be impractical or ineffective,
the SWMP must be amended to reflect the changes/improvements made.
SWMP Items, Format: When preparing your plan, make sure to address each item included in this guidance. If it
is not applicable to your site, briefly explain why. A simple "Not Applicable" is not enough. Failure to address each
item is a violation of the Stormwater Construction Permit.
In addition, your SWMP should follow the same format as the SWMP requirements listed in Section C, below. That is,
even if you are using an existing document (such as plans and specs) that addresses the required SWMP items, you
should include a cross-reference for each of the SWMP items that indicates where it can be found in your existing
document. You must be able to provide all required components of the SWMP to a State, EPA, or local agency
inspector at your site, so the location and format of the information must be clear to the site personnel in charge of
SWMP implementation.
Existing Controls: Note that the SWMP should include any existing stormwater controls at your site, not just new or
proposed ones. It can also include any erosion, sediment or drainage controls which are required by other regulations,
such as local erosion and sediment control ordinances, if you are also using them to meet the SWMP requirements.
Control Implemented by Other Parties: A permittee will often have to rely on controls implemented by other parties
to ensure adequate management of stormwater runoff. For example, if a permit certification is obtained to cover a lot in
a larger development, the permittee may need to rely on BMPs implemented by an entity in charge of the larger
development, such as street sweeping, inlet protection, or a water quality detention pond that treats runoff from several
different lots. In such situations, the BMPs implemented by the other party must be fully addressed by the permittee's
Appendix A - Page 3 of 19 Revised 7/07
Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
SWMP, and written agreements must exist between the permittee and the party implementing the BMP(s) to ensure
adequate operation and maintenance of those BMPs. Additional guidance is available in the Stormwater Fact Sheet for
Construction, available from the Division's web site at www.cdphe.state.co.us/wq/PermitsUnit.
SWMP Availability: A copy of the SWMP must be kept on site, readily available to the operator, and to Division or
EPA personnel for review during inspections. City, county, and local agencies may also request the SWMP as part of a
local oversight program. If an office location is not available at the site, the SWMP must be managed so that it is
available at the site when construction activities are occurring (e.g., by keeping the SWMP in a superintendent's
vehicle.)
C. STORMWATER MANAGEMENT PLAN REQUIRMENTS
In this section, the text in italics, and marked with the Permit banner, is quoted directly from the Stormwater
Construction Permit. The text in standard typeface is provided as guidance in the preparation of your SWMP. The
references (Part I.C, for example) correspond to the location of the item in the Stormwater Construction Permit, unless it
specifically references a section in this document.
C.1 SWMP GENERAL REQUIREMENTS
Part I.B Stormwater Management Plan (SWMP) - General Requirements
1. A SWMP shall be developed for each facility covered by this permit. The SWMP shall be prepared in
accordance with good engineering, hydrologic and pollution control practices. (The SWMP need not be prepared
by a registered engineer.)
2. The SWMP shall:
a) Identify all potential sources of pollution which may reasonably be expected to affect the quality of
Stormwater discharges associated with construction activity from the facility;
b) Describe the practices to be used to reduce the pollutants in stormwater discharges associated with
construction activity at the facility; and ensure the practices are selected and described in accordance with good
engineering practices, including the installation, implementation and maintenance requirements; and
c) Be properly prepared, and updated in accordance with Part ID.5.c, to ensure compliance with the terms
and conditions of this permit.
3. Facilities must implement the provisions of the SWMP as written and updated, from commencement of
construction activity until final stabilization is complete, as a condition of this permit. The Division reserves the right
to review the SWMP, and to require the permittee to develop and implement additional measures to prevent and
control pollution as needed.
4. The SWMP may reflect requirements for Spill Prevention Control and Countermeasure (SPCC) plans under
section 311 of the CWA, or Best Management Practices (BMPs) Programs otherwise required by a separate CDPS
permit, and may incorporate any part of such plans into the SWMP by reference, provided that the relevant sections
of such plans are available as part of the SWMP consistent with Part
For any sites with permit coverage before June 30, 2007, the permittee's SMWP must meet the new SWMP
requirements as summarized in Section II.I of the rationale. Any needed changes must be made by October 1, 2007.
The General Requirements section provides the broad expectations for the preparation, contents and implementation of a
SWMP. The specific items that must be included in the SWMP are addressed in the SWMP Contents sections below.
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C.2 SWMP CONTENTS — Narrative Site Description
Part 1.C.1 Stormwater Manggement Plan (SWMP) — Contents: Site Description
The SWMP shall include the following items, at a minimum:
Site Description. The SWMP shall clearly describe the construction activity, to include:
a)
b)
c)
d)
The nature of the construction activity at the site.
The proposed sequence for major activities.
Estimates of the total area of the site, and the area and location
excavation, grading, or other construction activities.
A summary of any existing data used in the development of the site construction plans or SWMP that
describe the soil or existing potential for soil erosion.
A description of the existing vegetation at the site and an estimate of the percent vegetative ground cover.
The location and description of all potential pollution sources, including ground surface disturbing
activities (see Part I.A.2.b), vehicle fueling, storage offertilizers or chemicals, etc.
The location and description of any anticipated allowable sources of non-stormwater discharge at the site,
e.g., uncontaminated springs, landscape irrigation return flow, construction dewatering, and concrete
washout.
The name of the receiving water(s) and the size, type and location of any outfall(s). If the stormwater
discharge is to a municipal separate storm sewer system, the name of that system, the location of the storm
sewer discharge, and the ultimate receiving water(s).
expected to be disturbed by clearing,
This part requires a narrative description of the overall scope and physical characteristics of the project, as follows:
a) Include a description of the construction activities at the site (e.g., type of project, a summary of the grading
activities, installation of utilities, paving, excavation, landscaping, etc) and the final disposition of the property.
b) Describe the sequence of events involved in the construction project, such as grading, excavation, etc.
c) This information, which is also required in the application, is useful in determining the extent of control measures
needed.
d) Data describing soils or erosion potential will typically not be needed. This information only needs to be included if
it was used in development of the SWMP, such as for BMP design.
e) It is necessary to include the percentage of existing vegetative ground cover in order to determine, after
construction, when the site has been finally stabilized. See Part I.C.4 of the Stormwater Construction Permit (also
Section C.5 of this document), for final stabilization criteria. Final stabilization of the site is necessary before
coverage under the Stormwater Construction Permit can be terminated.
f) Describe all materials and activities at the site that may have an impact on stormwater. These may include such
things as: ground disturbing activities; equipment or vehicle washing; fertilizers, chemicals, or other materials
storage; vehicle maintenance or fueling; waste incineration, treatment, storage or disposal; haul roads; off-site
vehicle tracking; loading/unloading areas, etc.
Will there be any discharge from the project site during construction that is not from stormwater? If so, describe the
source and how it will be handled.
The receiving water information is also required in the permit application. For example, "runoff from the east side
of the site will go to a roadside ditch which discharges to Jimmy Smith Gulch; runoff from the west side of the site
will go to an unnamed tributary to Westerly Creek."
g)
h)
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C.3 SWMP CONTENTS — Site Map
Part 1.C.2 Stormwater Management Plan (SWMP) — Contents: Site Map
The SWMP shall include a legible site map(s), showing the entire site, identifying:
a) construction site boundaries;
b) all areas of ground surface disturbance;
c) areas of cut and fill;
d) areas used for storage of building materials, equipment, soil, or waste;
e) locations of dedicated asphalt or concrete batch plants;
fi locations of all structural BMPs;
g) locations of non-structural BMPs as applicable; and
h) locations of springs, streams, wetlands and other surface waters.
A site map must be developed for each construction project. The site map must show those items listed above. It does
not need to be drawn to scale, but it should be legible and easy to read. Maps that are part of the construction plans,
such as a grading plan, are a good base for developing the site map, if they are amended to include all required
information as discussed below. Local municipalities may also have maps suitable as bases to begin mapping
procedures. If no other suitable base maps are available, one must be developed. Regardless of the source of the base
map, the site map needs to be of suitable scale to show the construction portion of the site and the features within it.
Using Construction Plans, Plans Developed to Meet Local Stormwater Requirements, or Other Plans:
In many cases, some of the information required for the SWMP will also be included in items such as construction
plans, documents developed for a local stormwater program, material management plans, etc. These materials may
be used to meet the SWMP requirements, if they are amended and/or supplemented to include all required
information. If the SWMP will be incorporated into the construction plan, all of the required narrative
information must also be included in the plans, or developed as a separate document. If a separate document is
used for some of the information not in the construction plans, or if the information will be included in several
locations, the permittee must still be able to provide all required components of the SWMP to a State or EPA
inspector. If this approach is used, it is highly recommended that an index be provided that references the
location(s) of all information required for the SWMP.
In addition to the items specifically mentioned in the permit, above, it is useful to also indicate on the map the
following:
• Drainage basins for each outfall — Field inspection can usually accomplish this task with acceptable accuracy. Look
for high areas such as crests of hills, parking lots, roads, etc., which would form the division between drainages.
Gullies and swales are indicators of stormwater flow direction. Obviously, if runoff is observed during a storm,
most uncertainties can be eliminated. The drainage areas shown should include the portions of the site where the
activities described in I.C.1.f of the Stormwater Construction Permit (see the permit language in Section C.2, above)
occur, as well as those portions (such as upslope areas) contributing stormwater that mixes with runoff from the
construction area.
• Surface water bodies — Mark on the site map any surface water bodies, including dry water courses, lakes, streams,
springs, wetlands, detention ponds, roadside or irrigation ditches, etc. These do not necessarily need to be within
the construction portion of the site, but may be adjacent to it or impacted by stormwater runoff. Also include any
existing storm sewers.
• Existing and planned structural stormwater pollution control measures — Show on the map the location of any
structural stormwater pollution control measures, such as detention ponds, diversion ditches, covered material
storage areas, fuel farm secondary containment structures, etc. Refer to the guidance on how to "Document
Selected BMPs in the SWMP" in Section C.4, below.
• Areas where construction activities take place — for those construction activities identified in Part I.C.1.a of the
Stormwater Construction Permit (see the permit language in Section C.2, above).
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In addition, other features could be included to make the SWMP a more comprehensive and usable plan. For example,
a later section of the SWMP includes requirements for material handling and spill prevention procedures, which could
include a site map showing where materials are stored. By including materials handling, loading and storage areas on
the site map, all information would be in one place on a single base map. Also, including such items as site entrance(s),
vehicle parking areas and direction of stormwater flow on the site map adds to its overall utility
Refer to Section D of this guidance for sources of sample maps, such as the Douglas County Grading, Erosion, and
Sediment Control (GESC) Manual and the Construction Industry Compliance Assistance Center.
C.4 SWMP CONTENTS — Stormwater Management Controls
Part 1.C.3 Stormwater Management Plan (SWMP) — Contents: Stormwater Management Controls
The SWMP must include a description of all stormwater management controls that will be implemented as part of the
construction activity to control pollutants in stormwater discharges. The appropriateness and priorities of
stormwater management controls in the SWMP shall reflect the potential pollutant sources identified at the facility.
The description of stormwater management controls shall address the following components, at a minimum:
This is the key part of the SWMP — a narrative description of the appropriate stormwater management controls for the
permitted site. As further addressed below, in many cases it may be necessary to supplement the narrative description
with technical drawings in order to accurately communicate the design standards for certain structural BMPs.
Part 1.C.3 Stormwater Management Plan (SWMP) — Contents: SWMP Administrator
a) SWMP Administrator - The SWMP shall identify a specific individual(s), position or title who is responsible for
developing, implementing, maintaining, and revising the SWMP. The activities and responsibilities of the
administrator shall address all aspects of the facility's SWMP.
a. SWMP Administrator: The SWMP Administrator can be an individual(s), position or title — this entity is
responsible for developing, implementing, maintaining, and revising the SWMP. Remember that the SWMP
Administrator is the contact for all SWMP-related issues and is the person responsible for its accuracy,
completeness, and implementation. Therefore, the SWMP Administrator should be a person with authority to
adequately manage and direct day-to-day stormwater quality management activities at the site.
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Part I. C.3 Stormwater Management Plan (SWMP) — Contents: Identification of Potential Pollutant Sources
b) Identification of Potential Pollutant Sources - All potential pollutant sources, including materials and activities,
at a site must be evaluated for the potential to contribute pollutants to stormwater discharges. The SWMP
shall identify and describe those sources determined to have the potential to contribute pollutants to
stormwater discharges, and the sources must be controlled through BMP selection and implementation, as
required in paragraph (c), below.
At a minimum, each of the following sources and activities shall be evaluated for the potential to contribute
pollutants to stormwater discharges, and identified in the SWMP if found to have such potential:
1) all disturbed and stored soils;
2) vehicle tracking of sediments;
3) management of contaminated soils;
4) loading and unloading operations;
5) outdoor storage activities (building materials, fertilizers, chemicals, etc.);
6) vehicle and equipment maintenance and fueling;
7) significant dust or particulate generating processes;
8) routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, etc.;
9) on-site waste management practices (waste piles, liquid wastes, dumpsters, etc.);
10) concrete truck/equipment washing, including the concrete truck chute and associated fixtures and
equipment;
11) dedicated asphalt and concrete batch plants;
12) non -industrial waste sources such as worker trash and portable toilets; and
13) other areas or procedures where potential spills can occur.
b. Identification of Potential Pollutant Sources: The first thing to do is evaluate all pollutant sources and
activities at the site for the potential to contribute pollutants to stormwater discharges. Part I.C.3.b of the
Stormwater Construction Permit (see permit language above) lists 13 pollutant sources that must be evaluated for
the reasonable potential to contribute pollutants to runoff. During the evaluation, consider the following types of
conditions that might affect the potential for a pollutant source to contribute pollutants to stormwater:
• the frequency of the activity (i.e., does it occur every day, or just once a month; can it be scheduled to occur
only during dry weather?);
• characteristics of the area where the activity takes place, e.g., area, surface type (pavement, gravel, vegetation,
etc.), and physical characteristics such as site gradients and slope lengths;
• ability of primary and secondary containment (fuel tanks, drum storage, etc.) at product storage and
loading/unloading facilities to prevent and contain spills and leaks;
• proximity of product storage and loading/unloading facilities to waterways or drainage facilities;
• concentration and toxicity of materials which may to be found in the site's stormwater runoff
• contamination of storage facilities/containment with stored materials (e.g., used oil drums or tanks coated with
spilled oil)
Each pollutant source recognized through this process as having the potential to contribute pollutants to stormwater,
must be identified in the SWMP along with the specific stormwater management control (BMPs) that will be
implemented to adequately control the source. Note: the actual evaluation of the potential pollutant sources does
NOT need to be included in the SWMP — just the resultant pollutant sources and their associated BMPs.
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Part I. C.3 Stormwater Management Plan (SWMP) —
c) Best Management Practices (BMPs) for Stormwater Pollution Prevention - The SWMP shall identify and
describe appropriate BMPs, including, but not limited to, those required by paragraphs 1 through 8 below, that
will be implemented at the facility to reduce the potential of the sources identified in Part I. C.3. b to contribute
pollutants to stormwater discharges. The SWMP shall clearly describe the installation and implementation
specifications for each BMP identified in the SWMP to ensure proper implementation, operation and
maintenance of the BMP.
1) Structural Practices for Erosion and Sediment Control. The SWMP shall clearly describe and locate all
structural practices implemented at the site to minimize erosion and sediment transport. Practices may
include, but are not limited to: straw bales, wattles/sediment control logs, silt fences, earth dikes, drainage
swales, sediment traps, subsurface drains, pipe slope drains, inlet protection, outlet protection, gabions,
and temporary or permanent sediment basins.
2) Non -Structural Practices for Erosion and Sediment Control. The SWMP shall clearly describe and locate,
as applicable, all non-structural practices implemented at the site to minimize erosion and sediment
transport. Description must include interim and permanent stabilization practices, and site-specific
scheduling for implementation of the practices. The SWMP should include practices to ensure that existing
vegetation is preserved where possible. Non-structural practices may include, but are not limited to:
temporary vegetation, permanent vegetation, mulching, geotextiles, sod stabilization, slope roughening,
vegetative buffer strips, protection of trees, and preservation of mature vegetation.
3) Phased BMP Implementation. The SWMP shall clearly describe the relationship between the phases of
construction, and the implementation and maintenance of both structural and non-structural stormwater
management controls. The SWMP must identify the stormwater management controls to be implemented
during the project phases, which can include, but are not limited to, clearing and grubbing; road
construction; utility and infrastructure installation; vertical construction; final grading; and final
stabilization.
4) Materials Handling and Spill Prevention. The SWMP shall clearly describe and locate all practices
implemented at the site to minimize impacts from procedures or significant materials (see definitions at
Part I.E.) that could contribute pollutants to runoff. Such procedures or significant materials could
include: exposed storage of building materials; paints and solvents; fertilizers or chemicals; waste
material; and equipment maintenance or fueling procedures.
Areas or procedures where potential spills can occur must have spill prevention and response procedures
identified in the SWMP.
5) Dedicated Concrete or Asphalt Batch Plants. The SWMP shall clearly describe and locate all practices
implemented at the site to control stormwater pollution from dedicated concrete batch plants or dedicated
asphalt batch plants covered by this certification.
6) Vehicle Tracking Control. The SWMP shall clearly describe and locate all practices implemented at the
site to control potential sediment discharges from vehicle tracking. Practices must be implemented for all
areas of potential vehicle tracking, and can include: minimizing site access; street sweeping or scraping;
tracking pads; graveled parking areas; requiring that vehicles stay on paved areas on-site; wash racks;
contractor education; and/or sediment control BMPs, etc.
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Part I. C.3 Stormwater Management Plan (SWMP) —
7) Waste Management and Disposal, Including Concrete Washout.
i) The SWMP shall clearly describe and locate the practices implemented at the site to control
stormwater pollution from all construction site wastes (liquid and solid), including concrete washout
activities.
ii) The practices used for concrete washout must ensure that these activities do not result in the
contribution of pollutants associated with the washing activity to stormwater runoff.
iii) Part I.D.3.c of the permit authorizes the conditional discharge of concrete washout water to the
ground. The SWMP shall clearly describe and locate the practices to be used that will ensure that no
washout water from concrete washout activities is discharged from the site as surface runoff or to
surface waters.
8) Groundwater and Stormwater Dewatering.
i) The SWMP shall clearly describe and locate the practices implemented at the site to control
stormwater pollution from the dewatering of groundwater or stormwater from excavations, wells, etc.
ii) Part ID.3.d of the permit authorizes the conditional discharge of construction dewatering to the
ground. For any construction dewatering of groundwater not authorized under a separate CDPS
discharge permit, the SWMP shall clearly describe and locate the practices to be used that will ensure
that no groundwater from construction dewatering is discharged from the site as surface runoff or to
surface waters.
c. Best Management Practices (BMPs) for Stormwater Pollution Prevention
i) Selecting and locating appropriate BMPs: When selecting BMPs, consider first those that limit the source
of the pollutant. It is much more efficient, from both a cost and environmental standpoint, to prevent the
pollution in the first place than to clean up polluted stormwater. For example, mulching disturbed ground to
reduce erosion, in most cases, is easier and more effective than trying to capture and treat sediment -laden runoff
before it reaches State waters.
ii) Specific BMPs for Material Handling and Spill Prevention: Where materials can impact stormwater
runoff, existing and planned practices that reduce the potential for pollution must be described. For example,
materials should be stored and handled in covered areas to prevent contact with stormwater, and chemicals
should be stored within berms or other secondary containment devices to prevent leaks and spills from
contacting stormwater runoff. In general, spill prevention and response procedures should include the
following:
• notification procedures to be used in the event of an accident. At the very least, the SWMP Administrator
should be notified. Depending on the nature of the spill and the material involved, the Colorado Department
of Public Health and Environment (24-hour spill reporting line — 877-518-5608), downstream water users,
or other agencies may also need to be notified;
• instructions for clean-up procedures, and identification of spill kit location(s);
• provisions for absorbents to be made available for use in fuel areas, and for containers to be available for
used absorbents; and
• procedures for properly washing out concrete truck chutes and other equipment in a manner and location so
that the materials and wash water can not discharge from the site, and never into a storm drain system or
stream.
Once source reduction BMPs have been evaluated, more costly options, such as mitigation of impacts or
stormwater treatment through detention storage, must be considered as necessary. The selection of BMPs is
subject to the judgment of the individual permittee, based on the conditions at the site. It is important to keep in
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mind that BMPs included in the SWMP and implemented at the site must be adequately designed to provide
control for all potential pollutant sources associated with construction activity to prevent pollution or
degradation of State waters. Therefore, in order to comply with your permit terms and conditions, appropriate
practices must be implemented in keeping with the pollutant(s) involved and the risk potential at the facility.
Redundant BMP use is highly recommended to eliminate reliance on any one (or two) BMPs, and is often
necessary to provide an adequate treatment train to remove pollutants in runoff.
In addition, the BMPs selected for use must be appropriately designed and implemented, following good
engineering practices. It is best to base BMP design and implementation on professionally accepted references.
Many well -accepted references are available that include guidance on proper BMP selection, design, and
implementation. Some counties, cities, and local agencies have adopted criteria manuals for stormwater BMPs.
Section D.1 of this guidance contains a discussion of additional resources for more in-depth information on
stormwater quality BMPs.
BMP location
A permittee must ensure that BMPs implemented to control stormwater pollution are located prior to the
stormwater discharge to a receiving water or a stormwater collection system. To meet this condition, BMPs may
be implemented at any location that allows for adequate treatment of stormwater pollutants, as long as all of the
following criteria are met:
• All BMPs are located:
o prior to the stormwater leaving the control of the permittee, i.e., where the permittee is capable of ensuring
the BMPs' proper operation and maintenance (see below section on Ensuring BMPs);
o prior to discharge to a receiving water defined as Waters of the United States (see below section on
Protecting Waters of the US); and
o prior to discharge into a municipal storm sewer or other stormwater collection system not owned by the
permittee (unless specific permission is granted).
• BMPs are implemented to control all pollutant sources covered by the permit certification (i.e., unmanaged
pollutant sources are not located down slope from the last BMP at a site).
• BMPs are implemented in accordance with the site's SWMP.
Although it is acceptable, and often advisable when used in conjunction with redundant BMPs, to locate structural
BMPs in areas of concentrated flow (e.g., check dams along drainage ditches, detention ponds, etc.), remember
that removing sediment from stormwater is often not as efficient a practice as preventing erosion in the first place,
and that once erosion starts, additional sediment control BMPs will almost always be necessary to prevent the
discharge of sediment from the site. The most efficient construction site BMPs are those that prevent erosion from
occurring.
Ensuring BMPs are under the Control of the Permittee
If a permittee will rely on contracts or agreements with other entities to manage BMPs (e.g., when BMPs will be
located off of the permittee's property and implemented by a second party, such as a site developer), the guidance
found in Part G.2.b of the Stormwater Fact Sheet—Construction (available from the Division's web site at
www.cdphe.state.co.us/wq/PermitsUnit) must be followed to ensure the BMPs are properly addressed in the
SWMP and implemented in the field. A permittee may not rely on a BMP owned or operated by a second party if
the permittee does not have permission to use the BMP, and/or if they do not have any agreements in place to
ensure its adequate operation and maintenance in accordance with the permittee's SWMP.
Protecting Waters of the United States
BMPs must not be located within waterways, including wetlands, that are defined as Waters of the United States,
unless specifically authorized by and in compliance with a separate 404 permit (also referred to as Dredge and Fill
permits) from the U.S. Army Corps of Engineers. Even when BMPs may be authorized in natural waterways,
such BMPs are only intended to control pollutants originating from activities within the waterway, and additional
BMPs are still necessary to prevent sediment from the remainder of the site from entering that waterway. Note
that even if a drainage has been modified by a private or municipal entity, it still may be considered Waters of the
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United States. It is the owner and/or operator's responsibility, through consultation with the Army Corps of
Engineers, to confirm the existence of any Waters of the United States at their site. More information on 404
permitting, including regional office contact information, may be obtained from the Army Corps of Engineers
regulatory programs' web page at http://www.usace.army mil/inet/functions/cw/cecwo/reg/, or by calling the
Denver Regulatory Office at (303) 979-4120.
iii) Documenting Selected BMPs in the SWMP (including phasing of BMP implementation): The SWMP
must describe the specific stormwater management controls (BMPs) that will be implemented at the site to
adequately control each identified pollutant source (see Section C.4.b, above). Estimated dates for BMP
implementation and maintenance are required, and any existing controls must also be discussed. The plan shall
identify both structural and non-structural control measures that are necessary for erosion and sediment control
at the site. Thoroughly describe how the BMP used at the site will change with the different stages of
construction activity at the site, and make sure that BMPs implemented for dedicated concrete or asphalt batch
plants, if applicable, and vehicle tracking controls, are clearly documented.
BMP description: Level of detail
BMP descriptions provided in the SWMP must contain adequate detail to ensure proper implementation at the site.
The following information must be addressed in the SWMP:
• What BMPs will be implemented?
• When will the BMPs be implemented? Many BMPs will only be implemented during specific phases of the
project. For example, silt fence and detention ponds may be installed prior to grading, while inlet protection
for a newly constructed stormwater collection system will need to be installed upon completion of the inlets.
• Where will the BMPs be implemented? The SWMP must clearly indicate the locations where BMPs will be
implemented. For structural BMPs, this will usually require including the locations on the site map discussed
in Section C.3 above.
• How will the BMPs be implemented? The installation and implementation specifications included in the
SWMP must be sufficient to ensure proper implementation, including procedures for operation and
maintenance of the BMP. For structural BMPs, in most cases this must include a technical drawing. For
example, if silt fence will be used at a site, in addition to the timing and location of installation, the SWMP
must provide information such as trenching depth, stake spacing, materials, etc. BMP installation and
implementation criteria must follow good engineering practices. Although it is not necessary to include design
calculations in the SWMP, such as those used to determine pond capacity or slope limitations for silt fence,
this information may be useful to include to assist in proper revisions to the SWMP and site BMPs if and when
necessary, as discussed below.
iv) Non-Stormwater Discharges: Except for emergency fire fighting activities, landscape irrigation return
flow, uncontaminated springs, construction dewatering and concrete wash out water, the Stormwater
Construction Permit only covers discharges composed entirely of stormwater.
Concrete Washout water can NOT be discharged to surface waters or to storm sewer systems without
separate permit coverage. The discharge of Concrete Washout water to the ground, under specific
conditions, may be allowed by the Stormwater Construction Permit when appropriate BMPs are
implemented. Additional information on this subject is available in the Stormwater Fact Sheet —
Construction, available from the Division's web site at www.cdphe.state.co.us/wq/PermitsUnit.
Construction Dewatering water can NOT be discharged to surface waters or to storm sewer systems
• without separate permit coverage. The discharge of Construction Dewatering water to the ground, under
specific conditions, may be allowed by the Stormwater Construction Permit when appropriate BMPs are
implemented. Additional information on this subject is available in the Stormwater Fact Sheet —
Construction, available from the Division's web site at www.cdphe.state.co.us/wq/PermitsUnit.
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Aside from the exceptions noted above, non-stormwater discharges must be addressed in a separate permit
issued for that discharge. Contact the Division or visit our web page at www.cdphe.state.co.us/wq/PermitsUnit
for guidance and applications.
v) Stormwater Dewatering: The discharge of pumped stormwater, only, from excavations, ponds,
depressions, etc., to surface waters, or to a municipal separate storm -sewer system (MS4) is allowed by the
Stormwater Construction Permit, as long as the dewatering activity and associated BMPs are identified in the
SWMP (including location of the activity), and BMPs are implemented in accordance with the SWMP.
Note: Pumping stormwater does not by itself render the pumped water a process water, provided that the pump
does not contribute additional pollutants to the discharge. If, however, a sheen is visible on the water leaving
the pump, a separate discharge permit is required.
d. Revising BMPs and the SWMP: At nearly every site, the implemented BMPs will have to be modified to adapt
to changing site conditions, or to ensure that potential pollutants are consistently and properly managed. The
pollutant sources and management practices at a site must be reviewed on an ongoing basis (and specifically during
the required inspections listed in Part I.D.6 of the Stormwater Construction Permit and discussed below). When
BMPs or other site conditions change, the SWMP must be modified to accurately reflect the actual field
conditions. Examples include, but are not limited to, removal of BMPs, identification of new potential pollutant
sources, addition of BMPs, modification of BMP installation and implementation criteria or maintenance
procedures, and changes in items included in the site map and/or description. SWMP revisions must be made prior
to changes in site conditions, except for Responsive SWMP Changes, as follows:
— SWMP revisions must be made immediately after changes are made in the field to address BMP
installation and/or implementation issues; or
— SWMP revisions must be made as soon as practicable, but in no case more than 72 hours, after
change(s) in BMP installation and/or implementation occur at the site that require development of
materials to modify the SWMP (e.g., design of retention pond capacity)
The SWMP should be viewed as a "living document" that is continuously being reviewed and modified as part of
the overall process of assessing and managing stormwater quality issues at the site. The following illustration
summarizes the process of evaluating, selecting, documenting, implementing, and revising BMPs.
0>
Evaluate Pollutant Sources
Implement BMPs
Document BMPs
1=,
Select BMPs
<1
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C.5 SWMP CONTENTS - Final Stabilization and Long-term Stormwater Management
Part 1.C.4 Stormwater Management Plan (SWMP) - Contents: Final Stabilization and Long-term Stormwater
Management
a) The SWMP shall clearly describe the practices used to achieve final stabilization of all disturbed areas at the
site, and any planned practices to control pollutants in stormwater discharges that will occur after construction
operations have been completed at the site.
b) Final stabilization practices for obtaining a vegetative cover should include, as appropriate: seed mix selection
and application methods; soil preparation and amendments; soil stabilization practices (e.g., crimped straw,
hydro mulch or rolled erosion control products); and appropriate sediment control BMPs as needed until final
stabilization is achieved; etc.
c) Final stabilization is reached when all ground surface disturbing activities at the site have been completed, and
uniform vegetative cover has been established with an individual plant density of at least 70 percent of pre -
disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed.
The Division may, after consultation with the permittee and upon good cause, amend the final stabilization criteria in
this section for specific operations.
Typically, the stormwater discharges associated with construction activity are eliminated when the site is finally
stabilized. As soon as practicable after construction activities have been completed in a disturbed area, permanent
stabilization should be started to prevent further erosion of soil from that area. All disturbed areas (except those
portions covered by pavement or a structure) must be finally stabilized once all construction activities are completed in
order to inactivate the permit coverage. Sediment that collects within the site's drainage system and permanent water
quality or quantity controls is also considered unstabilized soil, and must be removed prior to the site being considered
finally stabilized.
The SWMP must include a description of what measures will be taken to finally stabilize the site. The method of
stabilization must be provided for all areas that will remain pervious (i.e., vegetated or landscaped instead of paved,
built on, or otherwise structurally stabilized). Questions that may need to be addressed include: What type of cover
will be used? What are the specific seed mixtures and application rates? Are additional BMPs needed to prevent
erosion as the vegetation becomes established? Will the soil need to be amended? Will special methods be employed
on any steep slopes or areas of concentrated flow?
Inactivation of permit coverage
Coverage under the Stormwater Construction Permit may be inactivated by the permittee when the site has
attained final stabilization, all temporary erosion and sediment control measures have been removed, and all
components of the SWMP are complete.
Any planned stormwater management controls to prevent or control pollution of stormwater after construction is
completed must be addressed here. They typically include retention or detention ponds, infiltration measures,
vegetative swales, and natural depressions.
New developments, buildings, etc., will often incorporate elements of permanent stormwater quality control into their
design. The SWMP must be prepared consistent with these structural and nonstructural controls. Where possible,
permanent stormwater quality controls can be constructed at the initial stages of construction, or modified at the end of
construction. This can increase the efficiency of the controls by using them during both the building and operational
phases of the project. When a permanent structural control is initially used as a construction BMP, the SWMP must
contain the necessary information discussed in the guidance for documenting BMPs, Section C.4 above.
Appendix A - Page 14 of 19
Revised 7/07
Water Quality Control Division — Stormwater Program
www.cdphe.state.co.us/wq/permitsunit
Use of Permanent Detention Ponds as BMPs during Construction
Permanent detention ponds are allowed to be used as a temporary construction BMP, if: a) the pond is clearly
designated as a construction BMP in the SWMP; b) detention pond inspection and maintenance are described as
required in Part I.B.2, Part I.C.3, and Parts I.D.6, 7, and 8 of the Stormwater Construction Permit; and c) the pond
is designed and implemented for use as a BMP during construction in accordance with good engineering,
hydrologic and pollution control practices. In addition, stormwater discharges from the pond must not cause or
threaten to cause pollution or degradation of State waters. When a permanent detention pond is used in this
manner, redundant upgradient erosion and sediment control BMPs are still necessary in almost all cases to comply
with the permit requirements to select and design BMPs to prevent pollution or degradation of State waters.
The design and implementation of the pond may differ from what will exist upon completion of the project when
the BMP becomes a permanent water quality feature. In this case, the description of the BMP included in the
SWMP must address these differences. For example, if the outfall will be modified during construction to provide
additional filtering or settling of sediment (which may or may not be necessary, depending on the existence of
upstream BMPs, sediment loading to the pond, final outlet design, etc.), those modifications must be included in
the SWMP. If additional temporary stabilization of the pond (e.g., at points of concentrated flow into or through
the pond, unstable slopes, etc.) is needed to prevent erosion and transport of sediment from the pond during
construction, this must also be addressed.
Prior to inactivation of the permit, the pond must be stabilized in accordance with the permit requirements and
sediment removed from the site's drainage system. Although not related to compliance with the construction
stormwater permit, the pond may need to be inspected and modified following construction in order to meet local
permanent BMP design criteria.
C.6 SWMP CONTENTS — Inspection and Maintenance Procedures
Part I.C.5. Stormwater Management Plan (SWMP) — Contents: - Inspection and Maintenance
Part I.D. 6 of the permit includes requirements for site inspections. Part I.D. 7 of the permit includes requirements for
BMP maintenance. The SWMP shall clearly describe the inspection and maintenance procedures implemented at the
site to maintain all erosion and sediment control practices and other protective practices identified in the SWMP, in
good and effective operating condition.
E
a. Inspection Schedules: The minimum inspection schedule described in Part I.C.6.a of the Stormwater
Construction Permit requires that a thorough inspection of the stormwater management system be performed and
documented at least every 14 days, and within 24 hours of any precipitation or snowmelt event that causes surface
erosion (i.e., that results in stormwater running across the ground). If more frequent inspections are required to
ensure that BMPs are properly maintained and operated, the inspection schedule must be modified to meet this need.
Exceptions to the minimum inspection schedule are also provided. Any use of an exception is temporary, and does
not eliminate the requirement to perform routine maintenance due to the effects of a storm event or other conditions
that may impact BMP performance, including maintaining vehicle tracking controls and removing sediment from
impervious areas.
Additionally, this part of the SWMP must also include maintenance procedures for the BMPs, as discussed below.
You will need to set up a schedule appropriate to the activity and the BMP. Preventive maintenance should be
coupled with periodic inspections.
b. Inspection Procedures: The inspection must include observation of:
• the construction site perimeter and discharge points (including discharges into a storm sewer system);
• all disturbed areas;
• areas used for material/waste storage that are exposed to precipitation;
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Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
• other areas determined to have a significant potential for Stormwater pollution, such as demolition areas or
concrete washout locations, or locations where vehicles enter or leave the site;
• erosion and sediment control measures identified in the SWMP; and
• any other structural BMPs that may require maintenance, such as secondary containment around fuel tanks,
or the condition of spill response kits.
The inspection must determine if there is evidence of, or the potential for, pollutants entering the drainage system.
BMPs should be reviewed to determine if they still meet the design and operational criteria in the SWMP, and if
they continue to adequately control pollutants at the site. Any BMPs not operating in accordance with the SWMP
must be addressed as soon as possible, immediately in most cases, to minimize the discharge of pollutants, and the
SWMP must be updated as described in Section C.4.e, above. Inspections must be documented as discussed in the
Record Keeping section, below.
c. BMP Maintenance/Replacement and Failed BMPs: The Stormwater Construction Permit requires that all
erosion and sediment control practices and other protective measures identified in the SWMP be maintained in
effective operating condition and in accordance with good engineering, hydrologic and pollution control
practices. Therefore, site inspection procedures must address maintenance of BMPs that are found to no longer
function as needed and designed, as well as preventive maintenance to proactively ensure continued operation (e.g.,
removing collected sediment outside the acceptable tolerances of the BMP).
A preventive maintenance program should prevent BMP breakdowns and failures by proactively maintaining or
replacing BMPs and equipment. Site inspections should uncover any conditions, such as deteriorating silt fence or
water collected in fuel tank secondary containment, which could result in the discharge of pollutants to storm sewers
and surface waters. For example, sediment that has been collected by sediment controls, such as silt fence and inlet
protection, should be removed on a regular basis, to prevent failure of BMPs, and remove the potential of that
sediment from being discharged from the site if the BMP did fail. Removed sediment must be moved to an
appropriate location where it will not become an additional pollutant source, and should never be placed in ditches
or streams. Maintenance activities to correct problems noted during inspections must be documented as discussed in
the Record Keeping section, below.
The inspection process must also include procedures to ensure that, when needed, BMPs are replaced or new BMPs
added to adequately manage the pollutant sources at the site. This procedure is part of the ongoing process of
revising the BMPs and the SWMP as discussed Section C.4, above, and any changes to BMPs must be recorded in
the SWMP. The SWMP must be modified as appropriate as soon as practicable after such inspections.
BMPs that have failed, or have the potential to fail without maintenance or modifications, must be addressed as soon
as possible, immediately in most cases, to prevent the discharge of pollutants.
d. Record Keeping and Documenting Inspections: Keeping accurate and complete records serves several
functions. First, keeping records of spills, leaks, inspections, etc. is a requirement of the Stormwater Construction
Permit; therefore, enforcement action, including fines, could result if records are not adequate. Second, by keeping
accurate and detailed records, you will have documentation of events which could prove invaluable should
complications arise concerning the permit, lawsuits, etc.
The permittee must document inspection results and maintain a record of the results for a period of 3 years
following expiration or inactivation of permit coverage. These records must be made available to the Division or
EPA upon request. The following items must be documented as part of the site inspections:
i) The inspection date;
ii) Name(s) and title(s) of personnel making the inspection;
iii) Location(s) of discharges of sediment or other pollutants from the site;
iv) Location(s) of BMPs that need to be maintained;
v) Location(s) of BMPs that failed to operate as designed or proved inadequate for a particular location;
vi) Location(s) where additional BMPs are needed that were not in place at the time of inspection;
vii) Deviations from the minimum inspection schedule as provided in Section C.6.a above;
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Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
viii) Description of corrective action for items iii, iv, v, and vi, above, dates corrective action(s) taken, and
measures taken to prevent future violations, including requisite changes to the SWMP, as necessary; and
ix) After adequate corrective action(s) has been taken, or where a report does not identify any incidents requiring
corrective action, the report shall contain a signed statement indicating the site is in compliance with the
permit to the best of the signer's knowledge and belief.
In addition to inspection records, the permittee may opt to keep a log book for use in tracking other items related to
the SWMP such as those listed below. Additional information such as dated photographs, field notebooks, drawings
and maps, and the items below, etc. can also be included where appropriate.
• BMP operation and maintenance
• stormwater contamination
• contacts with suppliers
• notes on the need for and performance of preventive maintenance and other repairs
• implementation of specific items in the SWMP
• training events (given or attended)
• events involving materials handling and storage
• contacts with regulatory agencies and personnel
• notes of employee activities, contact, notifications, etc.
Records of spills, leaks, or overflows that result in the discharge of pollutants must be documented and maintained.
You may also want to record other spills that are responded to, even if they do not result in a discharge of pollutants.
Information that should be recorded for all occurrences includes the time and date, weather conditions, reasons for
the spill, etc. Some spills may need to be reported to the Division immediately. Specifically, a release of any
chemical, oil, petroleum product, sewage, etc., which may enter waters of the State of Colorado (which include
surface water, ground water and dry gullies or storm sewers leading to surface water) must be reported. More
guidance is available on the web at www.cdphe.state.co.us/hm/spillsandreleases.htm. The Division's toll-free 24-
hour number for environmental hazards and chemical spills and releases is 1-877-518-5608.
D. ADDITIONAL SWMP AND BMP RESOURCES
There are a multitude of resources available to the construction industry to assist in complying with the requirements of
the Stormwater Construction Permit. The following suggested list of resources can provide valuable tools to assist you
in developing and implementing your SWMP as effectively and efficiently as possible. However, the guidance found in
the resources listed below in no way replaces the requirements of the Stormwater Construction Permit, as described in
Sections A through C, above. Therefore, when using the following resources, especially in the case of example plans
and maps, it is essential that you ensure that all of the requirements included in this guidance document and the
Stormwater Construction Permit are being met.
Many of the resources below require access to the internet. If you are unable to obtain any resources you need due to a
lack of access to the internet, please contact the Division at (303) 692-3517 and we can try to assist you in obtaining the
information you need.
D.1. RESOURCES — BMP Design and Implementation
a. BMP Design Criteria Manuals:
Be sure to check with the local city or county to determine if they require that specific design criteria be met. The
following are some highly respected criteria manuals that can be used in designing and implementing BMPs for
your site.
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Water Quality Control Division – Stormwater Program www.cdphe.state.co.us/wq/permitsunit
• Urban Drainage and Flood Control District
Urban Storm Drainage Criteria Manual Volume 3 – Best Management Practices
o This criteria manual is commonly used by cities and counties in the Denver metropolitan area. The
manual includes discussion of stormwater quality management and BMPs for many activities, including
construction.
This manual is a highly respected across the country and a great resource for professionally accepted
design criteria for construction BMPs.
■ Available free from the "download" section of the Urban Drainage and Flood Control District
web page:
http://www.udfcd.org/
• Douglas County
Grading, Erosion, and Sediment Control (GESC) Manual
o The criteria manual for compliance with Douglas County's GESC permitting program for stormwater
quality. Includes an excellent discussion of effective stormwater management strategies, design criteria,
and several very useful sample site maps.
• Available for download free from the Douglas County Public Works web page:
http://www.douglas.co.us/publicworks/engineering/GESC.html
• Also available in print or CD-ROM from the Engineering Division office:
Douglas County Public Works Department - Engineering Division
100 Third Street
Castle Rock, CO 80104
Phone: 303-660-7490
b. General BMP Selection and Design Guidance
• Colorado Department of Transportation
Erosion Control and Stormwater Quality Guide
o Guidance on BMP selection and design applicable specifically to highway development projects, but
also useful as general guidance.
■ Available online from CDOT's MS4 Program web page at:
http://www.dot.state.co.us/environmental/envWaterQual/wqms4.asp
• EPA Menu of BMPs
Construction Site Storm Water Runoff Control
o EPA guidance for cities and counties who are required to develop programs to regulate construction
activities in their jurisdiction. The BMP fact sheets provide a good discussion of various structural and
nonstructural BMPs.
■ Available online at: http://cfub.epa.gov/npdes/stormwater/menuofbmps/index.cfm
• International Stormwater Best Management Practices (BMP) Database
o Database of monitoring results showing effectiveness of structural and non-structural BMPs. Currently,
the database and web site do not include much analysis of the data; this will be added in the future. Data
contributions are being solicited on an ongoing basis.
■ Available online at:
http://www.bmpdatabase.org
c. Special Applications
• Burn Areas:
U.S. Department of Agriculture, Forest Service, 2006. Burned Area Emergency Response Treatments Catalog.
0625 1801—SDTDC.
• Available online at: http://www.fs.fed.us/eng/pubs/pdf/BAERCAT/lo_res/TOContents.pdf
Appendix A - Page 18 of 19 Revised 7/07
Water Quality Control Division – Stormwater Program www.cdphe.state.co.us/wq/permitsunit
• Soil Bioengineering:
U.S. Department of Agriculture, Forest Service, 2000. Soil Bioengineering An Alternative for Roadside
Management. 0077 1801—SDTDC.
■ Available online at:
http://ttap.colostate.edu/Library/MISC/USDA%200077%201801 %20SDTDC.pdf
Franti, Thomas G. 2006. Bioengineering for Hillslope, Streambank and Lakeshore Erosion Control. University
of Nebraska–Lincoln Extension.
■ Available online at: http://www.ianrpubs.unl.edu/epublic/live/g1307/build/g1307.pdf
D.2. RESOURCES – Example Management Plans
• Construction Industry Compliance Assistance Center - Stormwater Pollution Prevention Plans
o A website with examples of actual stormwater plans prepared for a range of construction projects located in
various states. "The purpose of presenting these documents is to demonstrate various approaches to SWPPP
development. Please note that the examples presented here should not be excerpted or used as templates in
the preparation of a SWPPP, since each SWPPP must be designed to handle the specific needs of a particular
construction site." (Note that Colorado's plan is referred to as a `SWMP' instead of `SWPPP'.) Not all of
the example plans will meet the requirements of the Colorado General Permit. Therefore, it is essential that
this SWMP/SWPPP guidance document be used to ensure your completed plan contains all of the required
elements and is appropriate for your site.
■ Available online at: http://www.cicacenter.org/swppp.html
D.3. RESOURCES – Training
• Rocky Mountain Education Center (Located at Red Rocks Community College, Lakewood) -
Stormwater Management and Erosion Control Course
o One -day course, with an optional additional half-day in the field, on the principles and practices of
erosion and sediment control. Recommended for municipal erosion control inspectors and those
practicing erosion control in the field. This course is required for the CDOT certified erosion control
supervisor certification. Course is given at Red Rocks Community College in Lakewood. Course CETC
#150.
Stormwater Compliance Inspector Course
o Two-day course (including half-day in the field) on preparing for and conducting a comprehensive
construction site inspection. Recommended for municipal erosion control inspectors, construction site
managers, and those practicing erosion control in the field. Prerequisite: Stormwater Management and
Erosion Control Course (see above). Course is given at Red Rocks Community College in Lakewood.
Course CETC #151.
• Contact the Rocky Mountain Education Center at (800) 933-8394
• Schedule of classes available online at: http://www.rrcc.edu/rmec/cetc.html
• Keep it Clean Partnership (Boulder)
Erosion Control Training and Certification
o The Keep it Clean Partnership provides a low-cost, eight-hour erosion control training and recertification
program available for both public and private inspectors and contractors.
• Contact the Keep it Clean Partnership at 303-441-1439
• http://bcn.boulder.co.us/basin/kicp//kicp_construction.htm
Appendix A - Page 19 of 19 Revised 7/07
STATE OF COLORADO
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
Water Quality Control Division — Stormwater Program
STORMWATER FACT SHEET —CONSTRUCTION at OIL and GAS FACILITIES
Contact information
Colorado Department of Public Health and Environment Telephone: (303) 692-3517
Water Quality Control Division — Stormwater Program Email: cdphe.wastorm(&,state.co.us
WQCD-Permits-B2 Web Page: www.cdphe.state.co.us/wq/PermitsUnit
4300 Cherry Creek Drive South
Denver, Colorado 80246-1530
Contents
A. Introduction 1
B. When do you need a Permit? 2
1. Definitions Regarding Final Stabilization 2
2. Additional Final Stabilization Guidance for Oil and Gas Sites 2
a. Stabilized Unpaved Surfaces 2
b. Agricultural Land 2
c. COGCC Interim Stabilization 2
C. Is the site part of a larger common plan of development? 3
D. What if my construction site is on Federal or Indian Lands? 4
E. Obtaining Permit Coverage 4
F. Obtaining Permit Coverage: R -Factor Waiver 4
G. Permit Requirements 5
1. Stormwater Management Plan (SWMP) 5
2. Site Inspection 6
H. Field Permit Coverage and Master SWMPs 8
1. Size of Permitted Area 8
2. Applying for Field Permit Coverage 8
3. Master Stormwater Management Plan (SWMP) 8
I. Obtaining Forms and Guidance 11
A. INTRODUCTION
4. Look for this symbol for tips on saving time and money when involved in multiple oil and gas well sites!
On June 30, 2005, the State of Colorado stormwater regulation went into effect to require Colorado Discharge Permit
System (CDPS) permits from the Water Quality Control Division (the Division) for stormwater discharges from
construction activities associated with small construction activity for oil and gas sites (those that disturb between one
and five acres). Permitting for oil and gas construction sites that disturb five or more acres during the life of the project,
or are part of a larger common plan of development, has been required since 1992. Although federal permit coverage
for these discharges was conditionally exempted from the Federal Clean Water Act by the 2005 Federal Energy Bill, the
Colorado Water Quality Control Commission has maintained the requirement within Colorado's regulations, and
therefore permit coverage for these activities remains in effect in Colorado. These requirements are in addition to the
requirements of the Colorado Oil and Gas Conservation Commission (COGCC).
Therefore, the State of Colorado currently requires stormwater discharge permit coverage for all construction
activities that disturb one acre or greater (or that are part of a larger common plan of development, as discussed
in Section 2, below), including construction of well pads, roads, pipelines, pumping stations, etc.
This Fact Sheet provides specific guidance for compliance with the CDPS permitting requirements for stormwater
discharges from oil and gas related construction activities. This Fact Sheet is intended to augment the general
information relative to all construction activities, available in the Stormwater Fact Sheet for Construction and the permit
application and SWMP guidance document (see Section I, below, for how to obtain these documents.)
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B. WHEN DO YOU NEED TO GET A STORMWATER CONSTRUCTION PERMIT?
You may need a permit to discharge stormwater from any construction activity that disturbs at least one acre of land (or
is part of a larger common plan of development that will disturb at least one acre). The requirements vary slightly
depending on if your project or plan of development will disturb less than five acres (Small Construction Site) or five
acres or more (Large Construction Site). If permit coverage is required, it must be maintained until the site is finally
stabilized.
1) Definitions Regarding Final Stabilization
"Finally Stabilized" means that all ground surface disturbing activities at the site have been completed, and all
disturbed areas have been either built on, paved, or a uniform vegetative cover has been established with an
individual plant density of at least 70 percent of pre -disturbance levels, or equivalent permanent, physical
erosion reduction methods have been employed. Re -seeding alone does not qualify.
Oil and gas sites are considered finally stabilized once site preparation and interim reclamation are complete,
and the above final stabilization criteria have been met, even though the site will be disturbed again in the future
for final reclamation. However, future land disturbances that follow interim stabilization and result in
disturbance of one acre or greater would require permit coverage at that time.
2) Additional Final Stabilization Guidance for Oil and Gas Sites
As discussed below, permit coverage may be inactivated for an oil and gas construction site even if stabilized
unpaved surfaces exist (see subsection a, below) and/or disturbed land that has been restored to cropland
remains unvegetated (see subsection b, below), as long as construction activities have been completed and all
other disturbed areas revegetated in accordance with the definition of "Finally Stabilized." It may be useful for
some oil and gas construction operators to use the COGCC's definition of interim stabilization in determining
what areas at a site will require eventual revegetation to meet the Division's final stabilization requirement, as
discussed in subsection c, below.
a) Stabilized Unpaved Surfaces: Areas developed as stabilized unpaved surfaces as needed for operation of
the facility after interim reclamation, also qualify as "finally stabilized." The term "stabilized unpaved
surfaces" includes dirt road surfaces and the portions of the well pad surfaces that cannot be revegetated
due to operational necessity, but does not include slopes, ditches, and other areas where revegetation is
necessary. Stabilized unpaved surfaces must be prepared in such a way as to minimize erosion, such as
preventing rill erosion on pad surfaces or roads.
b) Agricultural Land: In most cases, when operational control of a disturbed area that has not been finally
stabilized is conveyed from the permittee to another entity, such as the surface landowner at a construction
site, permit coverage must be reassigned to the new operator. This is not usually an issue for the oil and gas
industry since, in most cases, COGCC rules require stabilization by the oil and gas industry prior to this
reassignment, unless the land will revert to cropland. Land disturbances for agricultural activities, such as
croplands, are exempt from stormwater discharge permit requirements. As a result, when portions of an oil
and gas site are restored to cropland in accordance with COGCC rules, and returned to control of the farmer
following interim reclamation, stormwater permit coverage is no longer required for these areas, and it is
not necessary for the oil and gas site operator to either stabilize or reassign permit coverage for the areas.
c) COGCC Interim Stabilization: Consistent with the guidance in this section, final stabilization at an oil
and gas facility has been met when the site has met the site preparation requirements for interim
reclamation in accordance with COGCC 1000 series rules, including restoration and revegetation of
disturbed areas as required by COGCC Rule 1003.e, and:
• all croplands have been restored and revegetated in accordance with COGCC Rule 1003.e.(1) and
returned to the surface owner for agriculture use.
• all non -cropland areas requiring restoration and revegetation in accordance with COGCC Rule
1003.e.(2) have established a uniform vegetative cover with an individual density of at least 70 percent
of pre -disturbance levels.
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Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
• areas reasonably needed for production operations that do not require restoration and revegetation in
accordance with COGCC Rule 1003.e. have been stabilized as unpaved surfaces. Stabilized unpaved
surfaces must be prepared in such a way as to minimize erosion.
C) IS THE SITE PART OF A LARGER COMMON PLAN OF DEVELOPMENT?
A "common plan of development" is a site where multiple separate and distinct but related construction activities
may be taking place at different times on different schedules. If the project is part of a common plan of
development, the disturbed area of the entire plan must be used in determining permit requirements or the
applicability of the waiver for small construction activities (see Section F, below).
For the oil and gas industry, a "common plan of development" is generally interpreted to mean development of
several well pads and/or related infrastructure (i.e., roads, pipelines, pumping stations, etc.) in a contiguous area,
either during the same time period or under a consistent plan for long-term development.
1) Well pads, pump stations, and other single site facilities: Consistent with EPA guidance, such facilities
located in close proximity to each other (within 1/4 mile) are considered "contiguous," and therefore part of a
common plan of development.
2) Pipelines and roads: Disturbed areas associated with feeder pipelines or roads that are constructed for the
purpose of serving a well pad or other single site facility are considered, together with the well pad, to be part of
a common plan of development. However, adjacent construction of trunk lines or roads that are part of a
regional network are not considered to be part of the common plan for that facility, and instead, are a separate
common plan of development that also requires permit coverage if one or more acres are disturbed.
Examples for determining if a project is part of a Common Plan of Development
The following examples discuss common scenarios for determining if a project is part of a common plan of development, and
explain how the total disturbed area of the plan should be determined. The total disturbed area in these examples is
subsequently used to determine if a Stormwater construction permit is required (area is one acre or greater), and if the waiver
discussed in Section F could apply (area is under five acres).
These examples are provided to help permittees better understand how to calculate total disturbed area, not to address all
possible scenarios when a site may be part of a larger common plan of development. Note that if separate contractors disturb
different areas that are part of a common plan, the areas must still be added together.
Example 1) Well Pad Site Connecting to a Regional Road and Pipeline Network: Site A is a well pad under construction a
short distance from a regional road and pipeline network that provides access to other well pads, which are over 1/4 mile
away. An access road must be built off of the existing road and a feeder pipeline must be constructed from the existing
trunk pipeline to the new well. The area disturbed for this example is calculated as follows:
Total Disturbed Area = Well Pad Disturbance + Access Road Disturbance + Feeder Pipeline Disturbance
Example 2) Construction of New Road and/or Pipeline Network: Site B is construction of a road or pipeline that will be
used to access more than one well pad. The construction of all sections of the road or pipeline is considered a common
plan of development. However, construction of dedicated access roads or feeder pipelines that may connect to the
primary road or pipeline network, but are used solely for the purpose of providing service to a single well pad or other
single site facility, are not considered part of the overall network's common plan of development. The dedicated road or
pipeline in this case is considered part of the well pad construction, as discussed in Example 1. In addition, if, after a
road or pipeline network has been completed and finally stabilized, an expansion to the network occurs that adds new
roads or pipelines to access multiple new sites, the new construction may be considered a separate common plan of
development since it is occurring after the first construction is completed.
Total Disturbed Area = Regional Pipeline or Road Construction Disturbance
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Example 3) Well Pad Site Located within 1/4 Mile of a Separate Well Pad Site(s): Site C is a well pad under construction;
an access road and feeder pipeline will also be constructed, as with Site A. However, a separate well is also being
constructed in the same area and will be unstabilized during the same period of time. A portion of the disturbed area of
the access road, feeder pipeline, or pad of the second site will be within 1/4 mile of the access road, feeder pipeline, or
pad for Site C. The area disturbed for this example is calculated as follows:
Total Disturbed Area = Well Pad Disturbance + Access Road Disturbance + Feeder Pipeline Disturbance
+ Pad, Access Road, and Feeder Pipeline Disturbance for Sites within 1/4 Mile.
D) WHAT IF MY CONSTRUCTION SITE IS ON FEDERAL OR TRIBAL LANDS?
Federal Lands: All private oil and gas operations on federal lands, including BLM, Forest Service, etc., are
regulated by the State of Colorado and must meet the State's stormwater permitting requirements discussed in this
document. Although the EPA does regulate federal facilities in Colorado, private operations on federal lands are
not considered federal facilities.
Tribal Lands and Non -Tribal Member Activities on Fee Lands: Construction activities occurring on Tribal
Lands in Colorado are not regulated by the State of Colorado and are therefore not subject to the permitting
requirements discussed in this document. The federal EPA regulates activities on Tribal Lands. The State of
Colorado does regulate non -tribal member activities on fee lands within the external boundary of a reservation,
and therefore Colorado's stormwater permitting requirements discussed in this fact sheet apply to those areas.
E) OBTAINING PERMIT COVERAGE
If the total area of ground disturbance, including disturbances from the entire common plan of development, is
greater than or equal to one acre, permit coverage is required (unless the waiver for small construction activities
disturbing less than five acres applies, as discussed in Section F, below). The owner or operator must apply for
coverage under the Stormwater Construction Permit at least 10 days prior to the start of construction activities. An
application and Stormwater Management Plan (SWMP) guidance document are available from the Division (see
Section I, below). The SWMP must be completed prior to application.
The Stormwater Construction Permit certification must be inactivated once the site has been finally stabilized, in
order to end permit coverage and billing. An inactivation form is supplied with the permit certification.
410. The Division strongly recommends that those involved in construction associated with oil and gas exploration
and production consider applying for coverage under a Field Permit certification, as discussed in Section H,
below. This process eliminates the need for an operator to submit separate applications and inactivation forms for
multiple sites within a well field. This process, along with streamlining the SWMP and inspection procedures as
discussed in Sections G and H, below, can considerably reduce the resources necessary for an operator to comply
with the stormwater requirements and protect State surface waters.
F) OBTAINING PERMIT COVERAGE UNDER THE R -FACTOR WAIVER (Less than five acres disturbance only)
• A site may qualify for coverage under this waiver only if less than five acres of land is disturbed at the site and
the site is not part of a larger common plan of development with greater than five acres disturbed, as
discussed in Section C, above. Sites that are within an area covered under a Field Permit certification (see Section
H) may still apply for an R -Factor waiver, if they are not otherwise part of a common plan of development.
The R -Factor waiver allows a site owner or operator to apply for a waiver from State Stormwater Construction
Permit requirements coverage when the R -Factor for a construction project, as calculated using the State approved
method, is less than five. The R -Factor is a way to measure erosion potential based on the duration of the project
and time of year. An application with instructions for using the State -approved method is available from the
Division. See Section I, below.
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In general, the only projects that will qualify for the waiver are projects that are completely stabilized within a
month or two of the start of construction. This means that projects relying on seeding for revegetation will usually
not qualify for the waiver, because the vegetation must be established before the site is considered stabilized. For
the oil and gas industry, this generally means that only projects for which all disturbed areas will be returned to
cropland (see discussion under Section B) will qualify, since other disturbed areas typically rely on seeding for
stabilization. In addition, the Division will not grant waivers for construction sites located in areas where snow
cover exists at, or up -gradient of, the site for extended periods of time, if the construction site will potentially
remain active and unstabilized during spring runoff.
This waiver does not relieve the operator or owner from the responsibility of managing the site to prevent pollution
or degradation of State waters or from complying with the requirements of other agencies, such as meeting COGCC
stormwater quality requirements.
G) PERMIT REQUIREMENTS
The specific requirements that must be met are contained in detail within the permit and SWMP guidance
document, and are further clarified specifically for the oil and gas industry within this guidance. Permittees must
read all three documents. The two most significant requirements are the development and implementation of a
SWMP, and conducting and documenting the required self -inspections, as summarized below.
1) Stormwater Management Plan (SWMP)
The Stormwater Construction Permit requires dischargers to control and eliminate the sources of pollutants in
stormwater through the development and implementation of a Stormwater Management Plan (SWMP). These
requirements are further described in the SWMP guidance document (included as an appendix to the
application), which must be read prior to developing your plan.
The purpose of a SWMP is to identify possible pollutant sources that may contribute pollutants to stormwater,
and identify Best Management Practices (BMPs) that, when implemented, will reduce or eliminate any possible
water quality impacts. For construction activities the most common pollutant sources is sediment. Other
pollutant sources include fuels, fueling practices and chemicals/materials stored on site, etc. BMPs encompass a
wide range of practices, both structural and non-structural in nature, and may include silt fence, sediment ponds,
vehicle tracking controls, good housekeeping, inspection and maintenance schedules, training, etc.
411 Because site conditions at different projects can sometimes be relatively consistent, an oil and gas
company could significantly streamline the SWMP development process through the use of boilerplates
and/or the development of a field -wide SWMP, as discussed in Section H.3, below.
a) SWMP Revisions: When BMPs or site conditions change, the SWMP must be modified to accurately
reflect the actual field conditions. Examples include, but are not limited to, removal of BMPs,
identification of new potential pollutant sources, addition of BMPs, modification of BMP
installation/implementation specifications or maintenance procedures, and changes in items included in the
site map and/or description. SWMP revisions must be made prior to changes in site conditions, except for
Responsive SWMP Changes, as follows:
SWMP revisions must be made immediately after changes are made in the field to address BMP
installation and/or implementation issues; or
SWMP revisions must be made as soon as practicable, but in no case more than 72 hours, after
change(s) in BMP installation and/or implementation occur at the site that require development of
materials to modify the SWMP (e.g., design of retention pond capacity)
b) SWMP Location: The SWMP must be on site during active construction and site inspections to ensure
accurate implementation and maintenance of BMPs, and required revisions. This can best be accomplished
by having appropriate site staff, who are consistently at the project during construction operations, keep a
copy of the SWMP with them during active construction.
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• If a construction site is covered under a Field Permit certification, as discussed in Section H, below, the
Division will generally authorize a minor exception to the SWMP location requirement. For such sites, the
permittee may request, in accordance with Part I.E.2 of the permit, that the SWMP be retained at a central
location in close proximity to the oil/gas field. All such requests must be made in writing to the Division,
explain why the permit requirement can not be met, specify the alternate SWMP location(s), and include
the associated permit certification number. If the Division does not respond to the written request within
two weeks of receipt, the exception is approved. Permittees are advised to obtain delivery confirmation of
receipt by the Division. An up-to-date copy of the SWMP must be available to a Division or EPA inspector
at the time of inspection . The intent of the SWMP must still be met—that the SWMP be available to
those directly responsible for installing and maintaining the BMPs to ensure that activities in the field
conform to the specifications in the SWMP.
2) Site Inspection
a) Required Schedules: Specific schedules for permittees to conduct inspections of their sites are prescribed
in Part I.D.6 of the permit. The schedule differs based on conditions at the site.
• A permit certification for an oil and gas construction activities operator will often cover several separate
sites that are being constructed on different schedules but under a common plan of development or a Field
Permit certification (as discussed in Section H, below). Therefore, different inspection frequencies may
apply to different portions of the permitted area, as discussed below.
1) Minimum Inspection Schedule (see Part I.C.6.a. of the permit): The minimum inspection schedule
applies those sites under active construction, which includes the period from when the ground is initially
disturbed to when construction activity is completed, and also includes the preparation of areas that will be
revegetated for interim reclamation. During this period, a thorough inspection of the site stormwater
management system must be conducted following the requirements in Part I.D.6.b of the permit, at least
once every 14 calendar days. Also, post -storm event inspections must be conducted within 24 hours after
the end of any precipitation or snowmelt event that causes surface erosion.
• Preparing and seeding the site for reclamation as soon as practical after construction is completed will help
reduce the need of frequent inspections, and is a highly effective BMP for reducing the potential for
polluting runoff.
Exceptions to the minimum inspection schedule. Any use of an exception is temporary, and does not
eliminate the requirement to perform routine maintenance due to the effects of a storm event or other
conditions that may impact BMP performance, including maintaining vehicle tracking controls and
removing sediment from impervious areas. Inspections, as described above, are required at all other times.
i) Post -Storm Event Inspections at Temporarily Idle Sites (see Part I.C.6.a.1 of the permit):
Temporarily Idle Sites are those where there are no construction activities occurring following a storm
event. At such sites, post -storm event inspections must be conducted prior to restarting construction
activities at the site, but no later than 72 hours following the storm event, and the delay noted in the
inspection report. Routine inspections still must be conducted at least every 14 calendar days.
ii) Completed Sites (see Part I.C.6.a.2 of the permit): Once construction is completed and the site
has been prepared for final stabilization (including completion of appropriate soil preparation,
amendments and stabilization practices), the site (or portion of a site) is considered a Completed Site (for
purposes of the stormwater permit). Note: only construction activities that result in a disturbance of the
ground surface must be completed. Construction activities that can be conducted without disturbance of
the ground surface, such as certain well completion activities, would not prohibit a site from otherwise
qualifying as a Completed Site. (Completed Sites still require permit coverage until final stabilization
criteria have been met.)
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Completed Sites qualify for a reduced inspection schedule, as the potential for pollution is reduced if the
site has been adequately prepared and/or seeded. However, because slopes and other disturbed areas are
not vegetated, erosion in these areas still occurs which requires maintenance activities such as regrading
and seeding of problem areas. As such, inspections must continue in order to address these situations.
During the Completed Site period, a thorough inspection of the site stormwater management system is
required at least once every month. The SWMP for the site must be amended to indicate those areas that
will be inspected at this reduced frequency.
iii) Winter Conditions Inspections Exclusion (see Part I.C.5.c of the permit): Inspections are not
required at sites where construction activities are temporarily halted, snow cover exists over the entire
site for an extended period, and melting conditions posing a risk of soil erosion do not exist. This
temporary exclusion is applicable only during the period where melting conditions do not exist, and
applies to the routine 14 -day and monthly inspections, as well as the post -storm -event inspections.
Note: it is typical that when snow cover exists, even at a Completed Site, significant potential for erosion
and BMP failure exists when melting does finally occur. Therefore, permittees should prepare the site
prior to snow cover to ensure it is as stabilized as possible, and be prepared to perform site maintenance
when melt -off occurs, to alleviate any potential problems. Inspection records must document the
following information when this exclusion is used: dates when snow cover occurred, date when
construction activities ceased, and date melting conditions began.
b) Performing Inspections: The inspection must cover the construction site perimeter, all disturbed areas,
areas used for material/waste storage that are exposed to precipitation, discharge locations, and locations
where vehicles enter and exit the site. These areas must be inspected to determine if there is evidence of, or
the potential for, pollutants leaving the construction site boundaries, entering the stormwater drainage
system, or discharging to state waters. All BMPs must be evaluated to determine if they still meet the
design and operational criteria in the SWMP and if they continue to adequately control pollutants at the site.
Any BMPs not operating in accordance with the SWMP must be addressed as soon as possible,
immediately in most cases, to minimize the discharge of pollutants, and the SWMP must be updated as
described in Section G.1.a, above.
c) Documenting Inspections: The permittee must document inspection results, and maintain a record of
the results for a period of 3 years following expiration or inactivation of permit coverage. These records
must be made available to the Division or EPA upon request. The following items must be documented as
part of the site inspections:
i) The inspection date;
ii) Name(s) and title(s) of personnel making the inspection;
iii) Location(s) of discharges of sediment or other pollutants from the site;
iv) Location(s) of BMPs that need to be maintained;
v) Location(s) of BMPs that failed to operate as designed or proved inadequate for a particular
location;
vi) Location(s) where additional BMPs are needed that were not in place at the time of inspection;
vii) Deviations from the minimum inspection schedule as provided in Sections G.2.a. 1 .i -iii, above;
vii) Description of corrective action for items iii, iv, v, and vi, above, date(s) corrective action(s)
taken, and measures taken to prevent future violations, including requisite changes to the
SWMP, as necessary; and
viii) After adequate corrective action(s) has been taken, or where a report does not identify any
incidents requiring corrective action, the report shall contain a signed statement indicating the
site is in compliance with the permit to the best of the signer's knowledge and belief.
To streamline this process, the inspection items could be included in a checklist. This is especially true
during the Completed Site phase. However, the permittee must ensure that the staff performing the
inspection is adequately trained to recognize potential pollutant sources, such as rill formation on slopes or
inadequate materials management, and to assess the adequacy and proper maintenance of BMPs.
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H) SAVING TIME & MONEY WITH FIELD PERMIT COVERAGE AND MASTER SWMPS
▪ Due to the nature of oil and gas construction activities related to exploration activities, the Division allows for
coverage to be obtained under the Stormwater Construction Permit for multiple construction activities in an oil and
gas field (Field Permit Coverage), instead of obtaining permits for each separate site or common plan of
development. The Field Permit covers all construction activities disturbing over one acre, or that are part of a
common plan of development exceeding one acre, within the applied -for field, with the exception of any specific
site that has obtained an R -Factor Waiver (see Section F). This option allows oil and gas companies to save
considerable resources by not having to apply for permit coverage and inactivation on a site -by -basis, and can
significantly streamline the SWMP development process. In addition, a permittee covered under a Field Permit
certification pays one permit fee for the area covered, instead of separate fees for each individual site.
1) Size of Permitted Area
A single permit certification may be allowed to cover all activities in an oil and gas field, although in some
cases, additional certifications may be required in order to maintain a manageable area and amount of activity
under a single permit certification. In general, the Division requires that the permitted area be discrete enough
to allow for adequate administration by the permittee and enforcement by the Division. Although the Division
has not developed specific criteria for a maximum area to be covered under one certification, it is our
expectation that the individual sites covered under a single certification will be related (e.g., within the same oil
and gas field or collection system) and will be of a manageable size, probably no larger than a USGS
quadrangle, although the there is flexibility on this issue. Based on these criteria, permit coverage for an oil and
gas field on Colorado's western slope will usually be adequately covered under a single permit certification.
However, for larger well fields on the eastern plains, such as the Wattenberg oil and gas field, multiple permit
certifications will probably be needed unless an operator is only working in a specific area within the larger
field.
2) Applying for Field Permit Coverage
The same application is used to apply for Field Permit Coverage as is used for regular Stormwater Construction
Permit coverage (Section E). However, the information provided on the application varies slightly to account
for the non -typical coverage being requested. All items on the application still must be filled out or the
application will be returned unprocessed. Follow the instructions below when completing the application.
• Location: In place of the street address, provide a general description of the proposed area to be permitted
(e.g., Southeastern Fremont County), and indicate the nearest town to the proposed permitted area. Provide
all counties that the permit coverage will be located within. The latitude and longitude provided should be for
the approximate center of the covered area.
• Map: A map must be provided. This map is in addition to the Site map(s) required in the SWMP. The map
must indicate the boundaries of the proposed permitted area. All construction activities disturbing over one
acre, or that are part of a common plan of development exceeding one acre, within the area indicated will be
covered under the permit certification until finally stabilized, with the exception of any specific site that has
obtained an R -Factor Waiver (see Section F).
• Area of the construction site: Because the area will vary over time, a rough estimate of the total area and
the area to be disturbed is acceptable.
• Anticipated construction schedule: Provide the date that activities will begin in the area to be covered, and
indicate "ongoing" for the "Final Stabilization Date."
3) Master Stormwater Management Plan (SWMP)
The master SWMP must contain the same information required for typical permit coverage and be prepared in
accordance with the Division's SWMP guidance document. However, a permittee can considerably streamline
the SWMP development process by developing a field -wide plan, i.e., a master SWMP, that summarizes
information common to all of the sites. This information would be separate from the site-specific details,
thereby eliminating the need to repeat this information in individual SWMPs. Templates (compliant with the
permit), modified to reflect specific -site conditions, may be used to ensure that all permit items applicable to the
specific sites are addressed.
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Note: Permittees are allowed to use a master SWMP, without that by itself defining a site as a common plan
of development.
a) Master SWMP format: SWMP information must be developed and maintained for all construction
activities that exceed one acre (or are part of a common plan of development exceeding one acre) conducted
within the permitted area. Instead of developing a complete separate plan for each individual site within a
permitted area, the permittee may wish to develop a single plan that addresses both the information common
to the active projects, and the site-specific information (maps, etc.). As new activities begin, required
information is added to the plan, and as areas are finally stabilized, the related information is removed.
Documentation related to areas that have been finally stabilized and removed from the active plan must be
maintained for a period of at least three years from the date that the associated site is finally stabilized.
A master SWMP format eliminates the need for operators to develop repetitive information in separate
plans. A master SWMP could contain two sections, one containing all of the information specific to each
site, and a second reference section containing information applicable to all sites (refer to the text box,
below). The master SWMP can be administered as two separate documents to ease paper work, with the
information common to the entire field contained in a document in the form of a field manual, containing
BMP installation/implementation details and generic descriptions, as discussed below.
As discussed in Section H.3.a, above,
with specific information for individual
the entire permitted area in a Reference
between these sections and how templates
SWMP guidance in Appendix A of the
41110 Possible Master SWMP Format
a permittee may want to consider formatting a master SWMP with two sections, one
sites in a Site Specific section, and one with more generic information applicable to
section. The following is an example of how the plan requirements could be divided
could be used. For details on what must be included in each section, refer to the
permit application.
SWMP/Permit
Item
Section of
SWMP
Discussion
Site Description
(Permit I.C.1)
Site Specific or
Reference
section
Much of the content here will be very similar for different projects, with only certain
specifics needed, such as the applicable schedule, location, receiving water, SWMP
administrator, etc. Items such as the description of the activity and the sequence of
events will likely be similar for many sites, and therefore can be handled with
template language developed for the Site Specific section, or even partially included in
the Reference section. Using a template and associated language for this section may
be extremely helpful in ensuring that all items are included in the site-specific
information as required by the permit.
Site Map
(Permit I.C.2)
Site Specific
section
In the majority of cases, site-specific topography and drainage patterns will
require that individual site maps be developed for each site. However in some
cases, such as when individualized BMPs are not needed because slopes and
defined drainages are not present, a generic site map may be applicable. This
would only occur when a well pad is located in a flat field and not adjacent to
a drainage way. In this case, a generic site map could be used, since each site
and associated BMPs are likely to be the same. This could significantly
decrease the resources needed for sites with less complex stormwater
management needs.
Stormwater
Management
Controls
(Permit I.C.3)
SWMP
The SWMP Administrator may differ for individual sites covered under a Field Permit
certification, and so should be identified in the Site Specific section. If the SWMP
Administrator is the same for all sites covered under a Field Permit certification, the
SWMP Administrator can be identified in the Reference section.
Administrator:
Site Specific or
Reference
section
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Stormwater
Pollutant
Potential pollutant sources will be different in type and location for specific sites
Management
Sources:
within a Field Permit certification. Template language may be useful here to ensure
Controls
Site Specific
compliance with the minimum potential pollutant sources evaluation required by the
(continued)
section
permit, as long as the resultant pollution sources reflect site-specific conditions.
Stormwater
BMP
The requirement to identify BMPs and other controls has two parts: identification of
Management
Identification:
the controls for a specific site, and descriptions of those controls. Materials Handling
Controls
Site Specific
and Spill Prevention can be handled in the Site Specific or Reference sections, and/or
(continued)
section
in SPCC Plans(s), as applicable.
(Permit I.C.3
BMP
Site-specific BMP Identification: The individual BMPs used at a site must be
Descriptions:
identified in the Site Specific section. However, in most cases, this could be
Reference
accomplished by just listing the type of BMPs used and identifying where and when
section
they will be used at the specific site. This can be done through a check list or filling
out a table and then identifying the BMPs locations on the site map. In some cases,
site specific information may still be needed, such as for a stream crossing where a
generic BMP description may not suffice.
BMP Descriptions: This includes narrative descriptions as well as technical
drawings for structural BMPs. The description will also include maintenance
requirements for that BMP, as required in Part I.D.6 and I.D.7 of the permit, discussed
below. The descriptions can be included in the Reference section as a sort of BMP
manual, and do not need to be repeated for each specific site. This will also
encourage consistent BMP implementation procedures across various sites,
simplifying implementation, inspections, and training.
Materials Handling and Spill Prevention: All BMPs implemented to minimize
impacts from procedures and significant materials handled at construction sites must
be specifically addressed in the SWMP. The SWMP must identify all significant
materials used or stored at sites covered under the permit certification, and include
applicable BMPs for those materials. Specifically, the SWMP must identify
procedures to prevent and manage spills. The materials present at separate locations
must be identified either in the Site Specific section, or in a separate plan as discussed
below.
In many cases, significant materials and/or BMPs to address those materials may be
identified in a separate Spill Prevention Control and Countermeasures (SPCC) plan.
Multiple versions of SPCC plans may be necessary for one permit because of the
uniqueness of individual drilling pads. Having multiple SPCC plans within one Field
SWMP is acceptable. However, if material handling and spill prevention content is
included in separate SPCC Plans, the permittee must cross-reference the separate
plans in the SWMP and indicate where they are located. The permittee must be able
to provide all required components of the SWMP to a State, EPA, or local agency
inspector, as discussed in Section G.1.b of this fact sheet.
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Final
BMP
As with the BMP requirements, this section could be split between the Site Specific
Stabilization
Identification:
section and the Reference section, with a boilerplate used for the Site Specific section.
Site Specific
(Permit I.C.4)
section
BMP
Site Stabilization Description: The stabilization methods used for the different
portions of the site must be identified in the Site Specific section. For example,
identify areas to be stabilized as unpaved pad or road surfaces, cropland, or vegetated
Descriptions:
with different seed mixes. The specifications on each stabilization method could then
Reference
be added to the Reference section. In some cases, site-specific information may still
section
be needed, such as for extremely steep slopes requiring a non-standard seeding
method or seed mixture.
Stabilization Methods Description: This would include the details on how each
stabilization method would be implemented, which will be heavily dependent on the
more specific standards included in the COGCC rules. The descriptions can be
included in the Reference section as part of the BMP manual discussed above, and do
not need to be repeated for each specific site. Details such as compaction and surface
standards for pad/road surfaces, seeding methodologies for different scenarios (e.g.,
drill seeding, hydro mulching, etc.), and specific seed mixtures for various vegetative
cover requirements would be included here.
Inspection and
Reference
In almost all cases, the description of the inspection and maintenance procedures will
Maintenance
section
be the same for all sites, and so can be addressed in the Reference section. Different
(except for
BMPs will have different maintenance requirements, but those requirements can be
(Permit I.C.5)
uncommon
conditions)
included in the Reference section. In addition to the BMP maintenance discussion,
this section will also include a discussion of the inspection schedule, procedures, and
documentation as discussed in Section G.2 of this fact sheet. In some cases, increased
inspection schedules or alternative maintenance practices may be needed for difficult
conditions or non -typical BMPs. In such a case, site-specific language must be added
for that site.
I) OBTAINING FORMS AND GUIDANCE
The application, SWMP guidance, and other information may be obtained from the Division's web site at
www.cdphe.state.co.us/wq/PermitsUnit, or by calling (303) 692-3517. For other questions about the Stormwater
Program, please call (303) 692-3517.
Additional reference materials and construction BMP training classes are listed in the SWMP guidance document
(included as an appendix to the permit application).
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STATE OF COLORADO
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
Water Quality Control Division — Stormwater Program
STORMWATER FACT SHEET — CONSTRUCTION
Contact information
Colorado Department of Public Health and Environment Telephone: (303) 692-3517
Water Quality Control Division — Stormwater Program Email: cdohe.wastorm(&,state.co.us
WQCD-Permits-B2 Web Page: www.cdphe.state.co.us/wq/PermitsUnit
4300 Cherry Creek Drive South
Denver, Colorado 80246-1530
Contents
A. Introduction 1
B. Obtaining Regulatory Coverage 2
1. Do you need a Permit? 2
a. Applying for a Permit 3
b. Options: Small Construction Sites 3
i. Qualifying Local Programs 3
ii. R -Factor Waiver 3
2. Who May Apply? 3
C. Permit Requirements 4
D. Local Stormwater Requirements 5
E. Amending Your Permit Certification 5
F. Ending Your Permit Coverage 5
G. Multiple Owner/Developer Sites 6
1. Permit Coverage 6
2. Permit Compliance 8
H. Sale of Residence to Homeowners 9
I. Construction Dewatering 10
J. Concrete Washout 10
A. INTRODUCTION
Look for this symbol throughout this guide for brief summaries of the most important information you need to
know about stormwater permitting for construction activities. Then read further if you want more details.
In 1992, the State of Colorado stormwater regulation went into effect to control municipal and industrial stormwater
discharges, based on EPA regulations. The regulation is meant to reduce the amount of pollutants entering streams,
rivers, lakes, and wetlands as a result of runoff from residential, commercial and industrial areas. The State regulation
(5 CCR 1002-61) covers discharges from specific types of industries including construction sites, and storm sewer
systems for certain municipalities. In Colorado, the program is under the Colorado Department of Public Health &
Environment, Water Quality Control Division (the Division). The Colorado program is referred to as the Colorado
Discharge Permit System (CDPS), and regulated stormwater discharges from construction activities are covered under
the CDPS General Permit for Stormwater Discharges Associated with Construction Activities (the Stormwater
Construction Permit).
Construction activities produce many different kinds of pollutants which may cause stormwater contamination
problems. The main pollutant of concern at construction sites is sediment. Grading activities remove grass, rocks,
pavement and other protective ground covers, resulting in the exposure of underlying soil to the elements. The soil is
then easily picked up by wind and/or washed away by rain or snowmelt. Sediment runoff rates from construction sites
are typically 10 to 20 times greater than those from agricultural lands, and 1,000 to 2,000 times greater than those from
forest lands. During a short period of time, construction activity can contribute more sediment to streams than would
normally be deposited over several decades, causing physical, chemical, and biological harm to our State's waters. The
added sediment chokes the river channel and covers the areas where fish spawn and plants grow.
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Water Quality Control Division — Stormwater Program www.cdphe.state.co.us/wq/permitsunit
Excess sediment can cause a number of other problems for waterbodies, such as increased difficulty in filtering drinking
water, and clouding the waters, which can kill plants growing in the river and suffocate fish. A number of pollutants,
such as nutrients, are absorbed onto sediment particles and also are a source of pollution associated with sediment
discharged from construction sites.
In addition, construction activities often require the use of toxic or hazardous materials such as fuel, fertilizers,
pesticides and herbicides, and building materials such as asphalt, sealants and concrete, which may also pollute
stormwater. These materials can be harmful to humans, plants and aquatic life.
This Fact Sheet provides general guidance for compliance with the CDPS permitting requirements for stormwater
discharges from construction activities. The Division reserves the right to interpret the permitting requirements on a
case-by-case basis, as necessary.
B. OBTAINING REGULATORY COVERAGE FOR CONSTRUCTION SITES
11.1 You must obtain permit coverage (or an R -Factor waiver) to discharge stormwater from any construction
activity that disturbs at least 1 acre of land (or is part of a larger common plan of development or sale that will
disturb at least 1 acre).
The owner or operator must apply for coverage under the Stormwater Construction Permit at least 10 days
prior to the start of construction activities. The application is available from the Division's web page.
1) Do you need to obtain coverage under the Stormwater Construction Permit?
Construction Sites that disturb one acre or greater, or are part of a larger common plan of development disturbing
one acre or greater, are covered under Colorado's stormwater permitting requirements. Generally, permit coverage
is required, as discussed in Part B.1.a, below. However, additional options may exist if your project or plan of
development will disturb less than 5 acres (Small Construction Site), as discussed in Part Bib, .b, below. If permit
coverage is required, or a waiver applied for, it must be maintained until the site is finally stabilized.
Is it part of a larger common plan of development or sale?
"A common plan of development or sale" is a site where multiple separate and distinct construction activities may be
taking place at different times on different schedules. Examples include: 1) phased projects and projects with multiple
filings or lots, even if the separate phases or filings/lots will be constructed under separate contracts or by separate
owners (e.g., a project where developed lots are sold to separate builders); 2) a development plan that may be phased
over multiple years, but is still under a consistent plan for long-term development; and 3) projects in a contiguous area
that may be unrelated but still under the same contract, such as construction of a building extension and a new parking
lot at the same facility. If the project is part of a common plan of development or sale, the disturbed area of the
entire plan must be used in determining permit requirements.
Disturbance associated with utilities, pipelines, or roads that are constructed for the purpose of serving a facility, are
considered together with that facility to be part of a common plan of development. However, adjacent construction of trunk
lines or roads that are part of a regional network and not directly associated with the facility construction, are not usually
considered to be part of the common plan for that facility. Note that permit coverage or an R -Factor waiver is still required
for each individual project (facility or adjacent construction activity) that disturbs one or more acres.
What is the total estimated area of disturbance?
The area of disturbance is the total area at the site where any construction activity is expected to result in disturbance of
the ground surface. This includes any activity that could increase the rate of erosion, including, but not limited to,
clearing, grading, excavation, and demolition activities, installation of new or improved haul roads and access roads,
staging areas, heavy vehicle traffic areas, stockpiling of fill materials, and borrow areas. Construction does not include
routine maintenance to maintain original line and grade, hydraulic capacity, or original purpose of the facility.
"Finally Stabilized" means that all ground surface disturbing activities at the site have been completed, and all
disturbed areas have been either built on, paved, or a uniform vegetative cover has been established with an individual
plant density of at least 70 percent of pre -disturbance levels, or equivalent permanent, physical erosion reduction
methods have been employed. Re -seeding alone does not qualify.
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a) Applying for a permit
Application for coverage under the Stormwater Construction Permit must be made at least 10 days prior to the
start of construction activities, unless the site is a Small Construction Site that qualifies for an alternative option
discussed in B.1.b, below. An application, which includes guidance on developing a Stormwater Management
Plan (SWMP), is available from the Division. The SWMP must be completed prior to application. See Section
C, "Permit Requirements," for further information. If your application is complete, it will be processed and your
permit certification mailed to you.
The Stormwater Construction Permit certification must be inactivated once the site has been finally stabilized, in
order to end permit coverage and billing. An inactivation form is supplied with the permit certification.
b) Additional Options for Small Construction Sites (at least 1 acre, but less than 5 acres of disturbance)
The following options may apply to Small Construction Sites that disturb less than 5 acres, and are not part of a
larger common plan of development exceeding 5 acres.. (Regardless of which option applies at the State level,
all local requirements must still be met as discussed in Section D, below.)
The options discussed under Parts b.i and b.ii below are not available for Large Construction Sites.
i) Obtain coverage under a State -designated Qualifying Local Program
(Available for Small Construction Sites only)
The Division may designate a local municipality's stormwater quality control program as a Qualifying Local
Program. This means that the local program's requirements are at least as stringent as the State permit. In
this case, it is not required for the owner or operator to apply for permit coverage under the Stormwater
Construction Permit. The local municipality will be responsible for notifying you that you do not need to
apply for State coverage, if this is an option. You can also view a list of the few municipalities with
Qualifying Local Programs at the Division's web page (see first page for web address).
The local program must have been formally designated by the Division to qualify. Most municipalities have
some type of local program and may require permits and fees. However, simply having a local program in
place does not necessarily mean that it is a qualifying program and that the Division's Stormwater
Construction Permit application is not required.
ii) Apply for coverage under the R -Factor Waiver
(Available for Small Construction Sites only)
The R -Factor waiver allows a site owner or operator to apply for a waiver from coverage under the
Division's Stormwater Construction Permit, if the R -Factor, calculated using the State -approved method, is
less than 5 during the period of construction. The R -Factor is a way to measure erosion potential based on
the length of the project and time of year. An application with instructions for using the State -approved
method is available from the Division's web page (see first page for web address).
In general, the only projects that will qualify for the waiver are projects that are completely stabilized
within a month or two after the start of construction. That means that projects relying on seeding for
revegetation will usually not qualify for the waiver, because the vegetation must be established before the
site is considered stabilized. During the spring and summer months, when Colorado experiences the bulk of
its rainfall, many projects will not qualify at all for the waiver. In addition, the Division will not grant
waivers for construction sites located in areas where snow cover exists at, or up gradient of, the site for
extended periods of time, if the construction site will potentially remain active and unstabilized during
spring runoff.
This waiver does not relieve the operator or owner from complying with the requirements of local agencies,
such as meeting local stormwater quality requirements, including those required by a Qualifying Local
Program as discussed in Section B.1.b.i, above.
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2) Who may apply for permit coverage?
The Permit applicant must be a legal entity that meets the definition of the owner and/or operator of the construction
site, in order for this application to legally cover the activities occurring at the site. The applicant must have day-to-
day supervision and control over activities at the site and implementation of the SWMP. Although it is acceptable
for the applicant to meet this requirement through the actions of a contractor, as discussed in the examples below,
the applicant remains liable for violations resulting from the actions of their contractor and/or subcontractors.
Examples of acceptable applicants include:
• Owner or Developer - An owner or developer who is operating as the site manager or otherwise has supervision
and control over the site, either directly or through a contract with an entity such as those listed below.
• General Contractor or Subcontractor - A contractor with contractual responsibility and operational control
(including SWMP implementation) to address the impacts construction activities may have on stormwater
quality.
• Other Designated Agents/Contractors - Other agents, such as a consultant acting as construction manager
under contract with the owner or developer, with contractual responsibility and operational control (including
SWMP implementation) to address the impacts construction activities may have on stormwater quality.
An entity conducting construction activities at a site may be held liable for operating without the necessary permit
coverage if the site does not have a permit certification in place that is issued to an owner and/or operator. For
example, if a site (or portion of a site) is sold or the contractor conducting construction activities changes, the site's
permit certification may end up being held by a permittee (e.g., the previous owner or contractor) who is no longer
the current owner and/or operator. In this case, the existing permit certification will no longer cover the new
operator's activities, and a new certification must be issued, or the current certification transferred. See Section F,
below, for additional guidance on scenarios with multiple owners and/or operators.
Utilities, Other Subcontractors, etc.: A separate permit certification is not needed for subcontractors, such as
utility service line installers, where the permittee or their contractor is identified as having the operational control to
address any impacts the subcontractor's activities may have on stormwater quality. Although separate permit
coverage may not be needed in some cases, these entities are not exempt from the stormwater regulations for all of
their projects and may still be held liable if their activities result in the discharge of pollutants.
Leases: When dealing with leased land or facilities, the lessee shall be considered the "owner" for the purposes of
stormwater permitting if they are responsible for the activities occurring at the site.
C. PERMIT REQUIREMENTS
The primary requirement of the Stormwater Construction Permit is the development and implementation
of a Stormwater Management Plan (SWMP). The permit application includes guidance that must be
followed for development and implementation of the SWMP. Permit requirements are the same for both
Small and Large Construction Sites.
The Stormwater Construction Permit requires dischargers to control and eliminate the sources of pollutants in
stormwater through the development and implementation of a Stormwater Management Plan (SWMP). The purpose of
a SWMP is to identify possible pollutant sources that may contribute pollutants to stormwater, and identify Best
Management Practices (BMPs) that, when implemented, will reduce or eliminate any possible water quality impacts.
For construction activities, the most common pollutant source is sediment. Other pollutant sources include fuels,
fueling practices and chemicals/materials stored on site, concrete washout, etc. BMPs encompass a wide range of
practices, both structural and non-structural in nature, and may include silt fence, sediment ponds, vehicle tracking
controls, good housekeeping, inspection and maintenance schedules, training, etc.
The SWMP is not submitted with the permit application unless requested. An up-to-date copy of the SWMP must be
kept on site, for use by the operator, and so that Division, EPA, or local inspectors can review it during an inspection.
If an office location is not available at the site, the SWMP must be managed so that it is available at the site when
construction activities are occurring (e.g., by keeping the SWMP in a superintendent's vehicle.)
Further information concerning the contents of the SWMP can be found in Appendix A of the application, "Preparing a
Stormwater Management Plan." This document and others can be obtained from the Division's web site or by
contacting the Division (see first page for address information).
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D. LOCAL STORMWATER REQUIREMENTS FOR CONSTRUCTION
Where local requirements exist for stormwater management, an owner/operator must comply with both
the Division's and the local agency's requirements.
In addition to the requirement to obtain and comply with the Division's Stormwater Construction Permit, it is possible
that additional government agencies (i.e., cities, counties, and special districts) may impose local requirements to
control the discharge of pollutants from construction activities. An owner or operator of a construction activity must
comply with the Stormwater Construction Permit requirements discussed in this Fact Sheet, even if they are also
covered by a local program's requirements. (However, in the case of a Qualifying Local Program, as discussed in
Section B.1.b.ii, some administrative requirements for the Stormwater Construction Permit may be simplified.)
Likewise, the Stormwater Construction Permit does not pre-empt or supersede the authority of local agencies to
prohibit, restrict, or control discharges of stormwater. Where a local program places additional restrictions on
stormwater management at a construction site within its jurisdiction, the owner/operator must comply with those stricter
requirements in addition to the Division's permitting requirements. For example, although the Division allows several
options for permitting at multiple owner/operator sites, a local authority may restrict these options and require specific
procedures to be followed for who maintains permit coverage and authority for stormwater discharges.
MS4 Permits
Many cities, counties, and special districts are covered by a Municipal Separate Storm Sewer System (MS4)
permit. These permits require the governmental entity to implement various programs to improve stormwater
quality in their jurisdiction. Included in these permits is the requirement to implement a program to manage the
discharge of pollutants from construction sites within their jurisdiction. Therefore, if a construction site located
within the jurisdiction of one of these government entities does not properly manage stormwater at that site, the
government entity may be in violation of their permit in addition to the construction site owner and operator.
E. AMENDING YOUR PERMIT CERTIFICATION
This section is only applicable if the limited information on the construction project submitted in the two-
page application form changes. In such case, it may be necessary to provide the Division with revised
information.
If the information provided by the permittee in their two-page application form is no longer accurate, the permittee
must provide the revised information to the Division. This includes such items as the planned total disturbed acreage,
and the project legal description or map originally submitted with the application. (Note: it is not necessary to revise the
anticipated final stabilization date, since the information provided was only an estimate.) To revise this information,
provide a letter to the Division's Stormwater Program (see the contact information on page 1) that includes the revised
information. The Division will not respond to this letter, so you are advised to obtain delivery confirmation from your
postal service to confirm receipt.
When the Stormwater Management Plan is revised, as required by the Stormwater Construction Permit, it is not
necessary to notify the Water Quality Control Division. When BMPs or other site details discussed in the SWMP are
modified, the SWMP must be updated to accurately reflect the actual field conditions. Examples include, but are not
limited to, removal of BMPs, addition of BMPs, modification of BMP design specifications, and changes in items
included in the site map and/or description. However, this information is not submitted to the Division, unless
requested.
F. ENDING YOUR PERMIT COVERAGE
A Stormwater Construction Permit certification remains active until inactivated, or transferred or
reassigned to a new responsible party. Forms for inactivation, transfer or reassignment of a permit
certification can be obtained from the Division's web site or by contacting the Division (see first page for
address information).
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1) Inactivation notice
Permit coverage for a site that has been finally stabilized in accordance with the SWMP (see definition in Section
B.1, above), may be inactivated by submitting a completed Inactivation Notice form. This form contains a
certification statement that must be signed in accordance with the General Requirements of the permit.
Also, the permittee may inactivate permit coverage at sites where all areas have been removed from their permit
coverage, by one or more of the methods below:
• reassignment of permit coverage (see Section F.3);
• sale to homeowner(s) (see Section H); and/or
• amendment by the permittee, as discussed in Section E, above for areas where permit coverage has been
obtained by a new operator (see Part G.1, below) or the area is returned to agricultural use (see the Division's
Oil and Gas Construction Fact Sheet).
In these cases the permittee would no longer have any land covered under their permit certification, and therefore
there would be no areas remaining to finally stabilize. Submittal of an Inactivation Notice is still required and must
discuss how the above conditions have been met.
2) Transfer of permit
Permit coverage for a construction site may be transferred to a new entity when responsibility for stormwater
discharges at the site changes from the permittee to the new entity. To transfer permit coverage, the permittee must
submit a completed Notice of Transfer and Acceptance of Terms form that is signed in accordance with the
General Requirements of the permit.
If the new entity will not complete their portion of the transfer form, the permit certification may be inactivated if
the permittee has no legal responsibility for the construction activities at the site, requests inactivation in written
correspondence to the Division, and submits a completed Inactivation Notice form.
3) Reassignment of permit
Permit coverage for a specific portion of a permitted site may be reassigned to a new entity when a permittee no
longer has control of that portion of the site, and wishes to transfer coverage of that portion to a second party. To
reassign permit coverage for a specific portion of a permitted site, the permittee must submit a completed Notice of
Reassignment of Permit Coverage form that is signed in accordance with the General Requirements of the permit.
If the new entity will not complete their portion of the reassignment form, the specific portion of the site may be
removed from permit coverage if the permittee has no legal responsibility for the construction activities at the
portion of the site, and a written request (including contact information for the new entity) is submitted to the
Division.
G. PERMITTING FOR DEVELOPMENTS WITH MULTIPLE OWNERS AND/OR OPERATORS
For situations where multiple entities meet the definition of owners and/or operators for different
portions of a development (e.g., a single development with multiple lots being owned and operated by
separate entities), extra care must be taken to ensure that proper permit coverage is maintained and that
stormwater management practices are correctly documented and implemented.
Local stormwater quality programs may have differing requirements for who must maintain permit coverage, and what
actions must occur when permitted areas and/or activities change. Construction site owners and operators must ensure
that their actions do not result in violations of local program requirements. Refer to Section D for additional
information.
1) Permit Coverage for Multiple Owner/Operator Development
When a portion of a permitted site is sold to a new owner, a permit certification must be in place that is
held by an entity meeting the definition of owner and/or operator of the sold area (see the discussion in
Section B.2, above). This may be accomplished in one of the following ways:
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a) Coverage Under the Existing Certification — Activities at the sold area may continue to be covered under an
existing permit certification for the project if the current permittee meets the definition of operator for the sold
area. To meet the definition of operator, the current permittee must have contractual responsibility and
operational control to address the impacts that construction activities at the sold area may have on stormwater
runoff (including implementation of the SWMP for the sold area). Therefore, a legally binding agreement must
exist assigning this responsibility to the current permit holder on behalf of the new owner and/or operator for the
sold area. It is not necessary to notify the Division in such case. However, documentation of the agreement
must be available upon request, and the SWMP must be maintained to include all activities covered by the
Stormwater Construction Permit.
Example: Developer Dan sells a lot to Builder Bob. Developer Dan is currently covered by a permit
certification that covers a larger area, which includes the sold lot. Developer Dan and Builder Bob may enter
into a contract that assigns the responsibility for permit coverage and stormwater management to Developer Dan
for Builder Bob's lot. Developer Dan is also responsible for making sure his SWMP includes the activities on
the sold lot. Developer Dan's permit certification will continue to cover construction activities on Builder Bob's
lot.
b) New Certification Issued — Reassignment — A new permit certification may be issued to the new owner and/or
operator of the sold area. The existing permittee and the new owner and/or operator must complete the
Reassignment Form (available from the Division's web page, see page 1) to remove the sold area from the
existing permit certification and cover it under a certification issued to the owner and/or operator of the sold
area. Both entities must have SWMPs in place that accurately reflect their current covered areas and activities.
Example: Developer Dan sells a lot to Builder Bob. Developer Dan is currently covered by a permit
certification that covers a larger area, which includes the sold lot. For this example, Developer Dan and Builder
Bob must jointly submit the Reassignment Form. Builder Bob will be issued a new permit certification for his
lot and the lot will be removed from Developer Dan's permit coverage. Prior to submittal of the Reassignment
Form, Developer Dan must revise his SWMP to reflect the changes in his covered area and activities, and
Builder Bob must develop his own SWMP to cover the area and activities he will obtain coverage for.
c) Amend Existing Permit Certifications — In some cases, both parties (the original owner/operator and the new
owner/operator of an area undergoing transfer of ownership or operation) will already both be permit holders for
their portions of the overall project (i.e., at least two permit certifications are issued for the project and cover
both the party wishing to reassign coverage and the party wishing to accept coverage). When an additional area
is transferred between the two parties, the permittees may simply amend their permit certifications instead of
completing the Reassignment Form. Both parties must separately complete the procedures discussed in Section
E to amend their permit coverage, removing the applicable area(s) from the original owner/operator's permit
coverage, and adding the area(s) to the new owner/operator's permit coverage. The requests must cite both
permit certification numbers. (Note: this request may be submitted jointly if it is signed by both entities.)
This option will likely be used in cases where a developer and an owner have already submitted a Reassignment
Form, as discussed in Part b, above, where an initial transfer of lots has occurred, and then additional lots are
transferred at a later date. Both entities must have SWMPs in place that accurately reflect their current covered
areas and activities.
Example: Developer Dan sells a lot to Builder Bob. Developer Dan is currently covered by a permit
certification that covers a larger area, which includes the sold lot. In addition, Builder Bob also holds a permit
certification for other portions of the development which he already owns, and Builder Bob wishes to cover his
new lot under this certification. Developer Dan submits a request to remove the lot from his permit certification
and provides Builder Bob's permit certification number that the lot will now be covered under. Builder Bob
also submits a request to modify his permit certification to add the lot, and provides Developer Dan's permit
certification number under which the lot was previously covered. Developer Dan and Builder Bob must revise
their SWMPs to reflect the changes in their covered area and activities.
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2) Permit Compliance for Multiple Owner/Operator Development
As a permittee, the most important concept for projects where multiple entities are involved is: if
activities within your permitted area result in pollution of stormwater, are the entity responsible for
ensuring that those pollutants are properly managed.
1Permittees are responsible for complying with the Stormwater Construction Permit requirements for the
1, areas and activities for which they have permit coverage, and for all BMPs they are relying on to comply
with the permit. Properly addressing and documenting the responsibility of various parties at a
construction site will help protect an entity from liability in the case where another party's actions result
in failure of BMPs.
a) Pollutants from Outside the Permitted Area:
A permittee may be held liable for pollutants that pass into and are then discharged from their permitted
area or that result from another entity's activities. Specifically, a permittee may have responsibility to
ensure proper implementation of BMPs to control stormwater discharges from their permitted area, even
if another entity is contributing pollutants.
The Stormwater Construction Permit requires the permittee to ensure the implementation of BMPs which will be
used to control the pollutants in stormwater discharges associated with construction activity from their permitted
area. Therefore, a permittee may be responsible for adequately implementing and maintaining BMPs that are
providing treatment for pollutants originating outside of their permitted area or from another entity's activities.
An example is when a permittee's property is being used by a separate entity for construction activities (e.g.,
loading and unloading, site access, materials storage, etc.), or BMPs located on the permittee's property are
being relied on to treat stormwater runoff from another site.
This scenario is common when a developer sells off lots to a builder. As a practical matter, what most often
occurs is that the developer must allow the builder to use the developer's infrastructure (e.g., roads, storm
drains, ponds, etc.) for activities and BMPs that cannot realistically be limited to the builder's property. In this
case, the developer remains a liable party (in addition to the builder) to ensure that proper stormwater
management is implemented for the project. Permit coverage may instead be assigned to the builder for this
infrastructure, if the builder has been designated as the operator of the area for stormwater quality purposes (See
Section B.2). However, this may not always be practical when multiple builders are operating in an area or
when the developer is still performing their own construction activities.
Refer to the Liability and Example sections, below, for further guidance.
b) BMPs Located Outside the Permitted Area:
If a permittee will be relying on BMPs that are outside of the area they own and/or operate, the specific
actions listed below must be taken to ensure compliance with the Stormwater Construction Permit. The
permittee is responsible for ensuring the proper managment all pollutants from their permitted area.
Even if the BMP are implemented by another party, the permittee may still be liable if their pollutants
are eventually discharged.
The permittee is responsible for ensuring the operation and maintenance of all BMPs that are used to control
pollutants that originate from their activities, even if the BMPs are located outside of the area owned and/or
operated by the permittee. For example, a builder may only have ownership of a single lot, but may have to rely
on BMPs that are located off of their lot and on a developer's property to adequately manage stormwater runoff,
such as inlet protection that is on the developer's streets. If a permittee will rely on BMPs that are outside the
area that they own and/or operate, the following measures must be taken:
i) Any off-site BMPs must be documented in the permittee's SWMP. This includes structural BMPs (e.g.,
inlet protection and sediment ponds) and non-structural BMPs (e.g., concrete wash out areas and street
sweeping). By including the BMPs in the SWMP, the permittee can effectively include the practices under
their permit coverage. In such cases, the same off-site BMPs may actually be included in two or more
parties' SWMPs.
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ii) The permittee must have adequate permission from the land and/or BMP owner(s) to utilize the off-site
conveyances and BMPs and to ensure proper maintenance and operation. The permittee must be able to
provide evidence of this agreement upon request.
iii) The off-site BMPs must be operated and maintained in accordance with the SWMP(s) and must control the
discharge of pollutants. It may be necessary to enter into agreements with other parties to ensure operation
and maintenance of these BMPs. Regardless of who actually carries out the operation and maintenance of a
BMP, all permittees who make use of the BMP to control pollutants from their construction activities remain
liable if the BMP is not adequately operated and maintained.
iv) All BMPs must be located prior to discharge to surface waters or municipally -owned storm sewer systems.
Liability: In the above examples, to reduce liability, the developer and builder should communicate on
stormwater management issues and document who will be responsible for specific BMPs (e.g., who will
maintain inlet protection and implement street sweeping). If BMPs are not being adequately implemented by
the party defined as responsible, the other party should take the necessary action to ensure pollutants originating
from, or passing through, their permitted area are properly controlled. It is recommended that stormwater
management responsibilities be addressed in contracts or other legal agreements between applicable owners and
operators for construction sites where one party's actions may impact another party's permit compliance. These
legal agreements will both help define roles and responsibilities at a multi owner/operator site, and also may be
used to seek damages from a contractor if monetary penalties are issued to a permittee for permit violations.
Example: Developer Dan sells a lot to Builder Bob. Following the procedures discussed in Section G.1.b or c,
above, Builder Bob obtains separate permit coverage for his new lot, ending at the curb line. Because the site
infrastructure is being utilized by several different builders at the project, Developer Dan maintains permit
coverage for the streets, storm drain system, and a large retention pond that is designed and implemented as a
BMP to manage pollutants from construction activities at the development (including Builder Bob's lot). In
addition to the large pond, inlet protection is also being used to protect storm sewer inlets located on Developer
Dan's roads, and street sweeping is occurring to control sediment tracked onto Developer Dan's roads.
Builder Bob is relying on the pond, inlet protection, and street sweeping to manage pollutants from his lot, and
therefore has included the BMPs in his SWMP, as discussed in Section G.2.b, above. The BMPs are also
included in Developer Dan's SWMP because they are being used to control pollutants from property he still
maintains control over, as discussed in Section G.2.a, above. In addition, Developer Dan and Builder Bob enter
into a contract that clearly defines Developer Dan as being responsible for implementing and maintaining the
infrastructure BMPs (i.e., the pond, inlet protection, and street sweeping BMPs), and requires Builder Bob to
implement additional BMPs on his lots, such as vehicle tracking control and construction waste management.
If the infrastructure BMPs are not properly operated and maintained, or discharges of sediment and/or other
pollutants from Builder Bob's lot are not properly controlled and overwhelm the infrastructure BMPs, both
Developer Dan and Builder Bob may be in violation of their permits. Therefore, Builder Bob and Developer
Dan must both remain diligent in ensuring that conditions of their contract are being met and BMPs operated by
both parties continue to be implemented in accordance with their SWMPs.
H. SALE OF RESIDENCE TO HOMEOWNERS
Residential lots that have been conveyed to a homeowner and that meet the specific criteria below do not
require coverage under the Stormwater Construction Permit.
In this case, the conveyed lot may be removed from coverage under the permittee's certification, and the permittee is no
longer responsible for meeting the terms and conditions of this permit for the conveyed lot, including the requirement to
transfer or reassign permit coverage. The permittee remains responsible for eventual inactivation of the original
certification (see Part F, above). The criteria for these lots are as follows:
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1) The lot has been sold to the homeowner(s) for private residential use;
2) the lot is less than one acre of disturbed area;
3) all construction activity conducted by the permittee on the lot is completed;
4) a certificate of occupancy (or equivalent) has been awarded to the homeowner; and
5) the SWMP has been amended to indicate the lot is no longer covered by permit.
Lots not meeting all of the above criteria require continued permit coverage. However, the permit coverage for the
conveyed lot may be transferred or reassigned to a new owner or operator (see Parts F and G.1, above).
I. CONSTRUCTION DEWATERING
13 Construction dewatering water can NOT be discharged to surface waters or to storm sewer systems
without separate permit coverage. The discharge of Construction dewatering water to the ground, under
the specific conditions listed below, may be allowed by the Stormwater Construction Permit when
appropriate BMPs are implemented.
Two options are available for managing uncontaminated Construction Dewatering water on a construction site.
Construction Dewatering water discharged from the project site, to surface waters or to storm sewer systems, is
considered a process water and requires an industrial process water permit. Applications for dischargers engaged in the
dewatering of uncontaminated groundwater from a construction site are available from the Division's web site or by
contacting the Division (see first page for address information).
Alternatively, Construction Dewatering water may be discharged to the ground if all of the following conditions are
met:
1) The discharge and the BMPs are included in the SWMP;
2) Adequate BMPs are included to control stormwater pollution;
3) The discharge does not leave the site as surface runoff or to surface waters/storm sewer systems; and
4) The groundwater being pumped is not contaminated so as to exceed State groundwater standards.
If the above conditions are not met, a separate permit (see above) is needed for discharges to the ground and/or
surface waters.
Further information concerning Construction Dewatering, including what constitutes contamination of groundwater, can
be found in the Stormwater Construction Permit and Rationale. These documents and others can be obtained from the
Division's web site or by contacting the Division (see first page for address information).
J. CONCRETE WASHOUT
Concrete Washout water can NOT be discharged to surface waters or to storm sewer systems without
separate permit coverage. The discharge of Concrete Washout water to the ground, under the specific
conditions listed below, may be allowed by the Stormwater Construction Permit when appropriate BMPs
are implemented.
Concrete Washout water from washing of tools and concrete mixer chutes may be discharged to the ground if all of the
following conditions are met:
1) The source is identified in the SWMP;
2) Adequate BMPs are included in the SWMP to prevent pollution of groundwater; and
3) These discharges do not leave the site as surface runoff or to surface waters/storm sewer systems.
The use of the washout site should be temporary (less than 1 year), and the washout site should be not be located in an
area where shallow groundwater may be present, such as near natural drainages, springs, or wetlands.
Concrete washout water must not be discharged to state surface waters or to storm sewer systems. Also, on-site
permanent disposal of concrete washout waste is not authorized by this permit.
Further information concerning Concrete Washout can be found in the Stormwater Construction Permit and Rationale.
These documents can be obtained from the Division's web site or by contacting the Division (see first page for address).
Page 10 of 10 Revised 7/07
Appendix C
Colorado Discharge Permit System
Certification
&
Rationale
STATE OF COLORADO
Bill Ritter, Jr., Governor
James B. Martin, Executive Director
Dedicated to protecting and improving the health and environment of the people of Colorado
4300 Cherry Creek Dr. S.
Denver, Colorado 80246-1530
Phone (303) 692-2000
TDD Line (303) 691-7700
Located in Glendale, Colorado
http:/lwww.cdphe.state.co.us
June 20, 2007
Laboratory Services Division
8100 Lowry Blvd.
Denver, Colorado 80230-6928
(303) 692-3090
Dave Cesark, .Prin Env Spec
Williams Production RMT Co.,
P.Q. Box 370
Parachute, CO 81635
970/285-9377
y.r
RE: Final Permit, Colorado Discharge Permit System — Stormwater
Certification No: COR -038541
Parachute Field
Garfield County
Local Contact: Michael Gardner, Sr. Env Spec
970/263-2760
Dear Sir or Madam:
Colorado Department
of Public Health
and Environment
Enclosed please find a copy of the new permit and certification which have been re -issued to you
under the Colorado Water Quality Control Act.
Your old permit expires on June 30, 2007. This is a renewal to the permit, and replaces the old one.
See page 2 of the Rationale (the pages in italics) for a summary of the changes to the permit.
Your Certification under the permit requires that specific actions he performed at designated times.
You are legally obligated to comply with all terms and conditions of the permit.
Please read the permit and certification. If you have any questions please visit our website at :
www.cdphe.state.co.uslwglpermitsunitlstormwater or contact Matt Czahor at (303) 692-3517.
Sincerely,
Kathryn Dolan
Stormwater Program Coordinator
Permits Unit
WATER QUALITY CONTROL DIVISION
xc: Regional Council of Governments
Local County Health Department
District Engineer, Technical Services, WQCD
Permit File
STATE OF COLORADO
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
WATER QUALITY CONTROL DIVISION
TELEPHONE: (303) 692-3500
CERTIFICATION TO DISCHARGE
UNDER
CDPS GENERAL PERMIT COR -030000
STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION
Certification Number COR038541
This Certification to Dischargt'specifically authorizesi
Williams Production RMT Co.
LEGAL CONTACT:
Dave Cesark, Prin Env Spec
Williams Production) RMT Co.
P.O. Box 370
Parachute, CO 81635
Phone # 970/285-9377
dave. cesark a williasns. coin
LOCAL CONTACT:
Michael Gardner, Sr. Env Spec,
Phone # 970/263-2760
michaeLgat dner@williams. cora
During the Construction Activity: Gas/Oil Field Exploration and/or
Development
to discharge stormwater from the facility identified as Parachute Field
which is located at:
Map In File
, Co
Latitude 39.484, Longitude 107.991
In Garfield County
to: -- Colorado River
Anticipated Activity begins 07/01/2005 continuing through 06/30/2010
On 79.2 acres (79.2 acres disturbed)
Certification is effective: 07/01/2007 Certification Expires: 06/30/2012
Annual Fee: $245.00 (DO NOT PAY NOW — A prorated bill will be sent shortly.)
Page 1 of 22
Page 2 of 22
Permit No. COR -030000
CDPS GENERAL PERMIT
STORMWATER DISCHARGES ASSOCIATED WITH
CONSTRUCTION ACTIVITY
AUTHORIZATION TO DISCHARGE UNDER THE
COLORADO DISCHARGE PERMIT SYSTEM
In compliance with the provisions of the Colorado Water Quality Control Act, (25-8-101 et seq., CRS, 1973
as amended) and the Federal Water Pollution Control Act, as amended (33 U.S.C. 1251 et seq.; the "Act"),
this permit authorizes the discharge of stormwater associated with construction activities (and specific
allowable non-stormwater discharges in accordance with Part I.D.3 of the permit) certified under this permit,
from those locations specified throughout the State of Colorado to specified waters of the State. Such
discharges shall be in accordance with the conditions of this permit.
This permit specifically authorizes the facility listed on the certification page (page 1) of this permit to
discharge, as of this date, in accordance with permit requirements and conditions set forth in Parts I and II
hereof. All discharges authorized herein shall be consistent with the terms and conditions of this permit.
This permit and the authorization to discharge shall expire at midnight, June 30, 2012.
Issued and Signed this 31st day of May, 2007
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
Janet S. Kieler
Permits Section Manager
Water Quality Control Division
SIGNED AND ISSUED MAY 31, 2007
EFFECTIVE JULY 1, 2007
TABLE OF CONTENTS
PART I
A. COVERAGE UNDER THIS PERMIT 3
1. Authority to Discharge 3
a) Applicable Sections 3
b) Oil and Gas Construction 3
2. Definitions 3
3. Permit Coverage Without Application — Qualifying Local Programs 3
a) Applicable Sections 3
b) Local Agency Authority 4
c) Permit Coverage Termination 4
d) Compliance with Qualifying Local Program 4
e) Full Permit Applicability 4
4. Application, Due Dates 4
a) Application Due Dates 4
b) Summary of Application 4
5. Permit Certification Procedures 4
a) Request for Additional Information 4
b) Automatic Coverage 5
c) Individual Permit Required 5
d) General vs. Individual Permit Coverage 5
e) Local Agency Authority 5
6. Inactivation Notice 5
7. Transfer of Permit 5
8. Reassignment of Permit 5
9. Sale of Residence to Homeowners 6
10. Permit Expiration Date 6
11. Individual Permit Criteria 6
B. STORMWATER MANAGEMENT PLAN — GENERAL REQUIREMENTS 6
C. STORMWATER MANAGEMENT PLAN — CONTENTS 7
1. Site Description 7
2. Site Map 7
3. Stormwater Management Controls 8
a) SWMP Administrator 8
b) Identification of Potential Pollutant Sources 8
c) Best Management Practices (BMPs) for Stormwater Pollution Prevention. 8
4. Final Stabilization and Long-term Stormwater Management 9
5. Inspection and Maintenance 10
D. TERMS AND CONDITIONS 10
1. General Limitations 10
2. BMP Implementation and Design Standards 10
3. Prohibition of Non-Stormwater Discharges 11
4. Releases in Excess of Reportable Quantities 11
5. SWMP Requirements 11
a) SWMP Preparation and Implementation 11
b) SWMP Retention Requirements 11
c) SWMP Review/Changes 11
d) Responsive SWMP Changes 12
6. Inspections 12
a) Minimum Inspection Schedule 12
b) Inspection Requirements 13
c) Required Actions Following Site Inspections 13
7. BMP Maintenance 13
8. Replacement and Failed BMPs 14
9. Reporting 14
-2a-
TABLE OF CONTENTS (cont.)
10. SWMP Availability 14
11. Total Maximum Daily Load (TMDL) 14
E. ADDITIONAL DEFINITIONS 15
F. GENERAL REQUIREMENTS 16
1. Signatory Requirements 16
2. Retention of Records 16
3. Monitoring 16
PART II
A. MANAGEMENT REQUIREMENTS 17
1. Amending a Permit Certification 17
2. Special Notifications - Definitions 17
3. Noncompliance Notification 17
4. Submission of Incorrect or Incomplete Information 18
5. Bypass 18
6. Upsets 18
7. Removed Substances 18
8. Minimization of Adverse Impact 18
9. Reduction, Loss, or Failure of Stormwater Controls 19
10. Proper Operation and Maintenance 19
B. RESPONSIBILITIES 19
1. Inspections and Right to Entry 19
2. Duty to Provide Information 19
3. Transfer of Ownership or Control 19
4. Modification, Suspension, or Revocation of Permit By Division 20
5. Permit Violations 21
6. Legal Responsibilities 21
7. Severability 21
8. Renewal Application 21
9. Confidentiality 21
10. Fees 21
11. Requiring an Individual CDPS Permit 22
-2b-
PART I
A. COVERAGE UNDER THIS PERMIT
1. Authority to Discharge
PART I
Permit - Page 3
Permit No. COR -030000
Under this permit, facilities are granted authorization to discharge stormwater associated with construction activities into
waters of the state of Colorado. This permit also authorizes the discharge of specific allowable non-stormwater discharges,
in accordance with Part I.D.3 of the permit, which includes discharges to the ground. This includes stormwater discharges
from areas that are dedicated to producing earthen materials, such as soils, sand and gravel, for use at a single construction
site (i.e., borrow or fill areas). This permit also authorizes stormwater discharges from dedicated asphalt batch plants and
dedicated concrete batch plants. (Coverage under the construction site permit is not required for batch plants if they have
alternate CDPS permit coverage.) This permit does not authorize the discharge of mine water or process water from such
areas.
a) Applicable Sections: In accordance with Part I.A.3 of this permit, some parts of this permit do not apply to sites
covered under a Qualifying Local Program, as defined in I.A.2.d. For sites not covered by a Qualifying Local
Program, all parts of the permit apply except Part I.A.3. The permittee will be responsible for determining and then
complying with the applicable sections.
b) Oil and Gas Construction: Stormwater discharges associated with construction activities directly related to oil and
gas exploration, production, processing, and treatment operations or transmission facilities are regulated under the
Colorado Discharge Permit System Regulations (5CCR 1002-61), and require coverage under this permit in
accordance with that regulation. However, references in this permit to specific authority under the Federal Clean
Water Act (CWA) do not apply to stormwater discharges associated with these oil and gas related construction
activities, to the extent that the references are limited by the federal Energy Policy Act of 2005.
2. Definitions
a) Stormwater: Stormwater is precipitation -induced surface runoff.
b) Construction activity: Construction activity refers to ground surface disturbing activities, which include, but are
not limited to, clearing, grading, excavation, demolition, installation of new or improved haul roads and access
roads, staging areas, stockpiling of fill materials, and borrow areas. Construction does not include routine
maintenance to maintain original line and grade, hydraulic capacity, or original purpose of the facility.
c) Small construction activity: Stormwater discharge associated with small construction activity means the discharge
of stormwater from construction activities that result in land disturbance of equal to or greater than one acre and less
than five acres. Small construction activity also includes the disturbance of less than one acre of total land area that
is part of a larger common plan of development or sale, if the larger common plan will ultimately disturb equal to or
greater than one and less than five acres.
d) Qualifying Local Program: This permit includes conditions that incorporate qualifying local erosion and sediment
control program (Qualifying Local Program) requirements by reference. A Qualifying Local Program is a municipal
stormwater program for stormwater discharges associated with small construction activity that has been formally
approved by the Division.
Other Definitions: Definitions of additional terms can be found in Part I.E. of this permit.
3. Permit Coverage Without Application — for small construction activities under a Qualifying Local Program only
If a small construction site is within the jurisdiction of a Qualifying Local Program, the operator of the construction
activity is authorized to discharge stormwater associated with small construction activity under this general permit without
the submittal of an application to the Division.
a) Applicable Sections: For sites covered by a Qualifying Local Program, only Parts 1.A.1, 1.A.2, 1.A.3, I.D.1, I.D.2,
I.D.3, I.D.4, I.D.7, I.D.8, I.D.11, I.E and Part II of this permit, with the exception of Parts II.A.1, II.B.3, II.B.8, and
II.B10, apply.
PART I
Permit - Page 4
Permit No. COR -030000
A. COVERAGE UNDER THIS PERMIT (cont.)
b) Local Agency Authority: This permit does not pre-empt or supersede the authority of local agencies to prohibit,
restrict, or control discharges of stormwater to storm drain systems or other water courses within their jurisdiction.
c) Permit Coverage Termination: When a site under a Qualifying Local Program has been finally stabilized,
coverage under this permit is automatically terminated.
d) Compliance with Qualifying Local Program: A construction site operator that has authorization to discharge
under this permit under Part I.A.3 shall comply with the requirements of the Qualifying Local Program with
jurisdiction over the site.
e) Full Permit Applicability: The Division may require any operator within the jurisdiction of a Qualifying Local
Program covered under this permit to apply for and obtain coverage under the full requirements of this permit. The
operator must be notified in writing that an application for full coverage is required. When a permit certification
under this permit is issued to an operator that would otherwise be covered under Part I.A.3 of this permit, the full
requirements of this permit replace the requirements as per Part I.A.3 of this permit, upon the effective date of the
permit certification. A site brought under the full requirements of this permit must still comply with local
stormwater management requirements, policies or guidelines as required by Part I.D.1.g of this permit.
4. Application, Due Dates
a) Application Due Dates: At least ten calendar days prior to the commencement of construction activities, the
applicant shall submit an application form as provided by the Division, with a certification that the Stormwater
Management Plan (SWMP) is complete.
One original completed discharge permit application shall be submitted, by mail or hand delivery, to:
Colorado Department of Public Health and Environment
Water Quality Control Division
WQCD-Permits-B2
4300 Cherry Creek Drive South
Denver, Colorado 80246-1530
b) Summary of Application: The application requires, at a minimum, the following:
1) The applicant's company name; address; telephone number; and email address (if available); whether the
applicant is the owner, developer, or contractor; and local contact information;
2) Project name, address, county and location of the construction site, including the latitude and longitude to the
nearest 15 seconds of the approximate center of the construction activity;
3) Legal description or map of the construction site;
4) Estimates of: the total area of the site, the area of the site that is expected to be disturbed, and the total area of
the larger common plan of development or sale to undergo disturbance;
5) The nature of the construction activity;
6) The anticipated start date and final stabilization date for the project;
7) The name of the receiving water(s), or the municipal separate storm sewer system and the ultimate (i.e., named)
receiving water(s);
8) Certification that the SWMP for the construction site is complete (see Part I.C. below); and
9) The signature of the applicant, signed in accordance with Part I.F.1 of this permit.
5. Permit Certification Procedures
If this general permit is appropriate for the applicant's operation, then a certification will be developed and the applicant
will be authorized to discharge stormwater under this general permit.
a) Request for Additional Information: The Division shall have up to ten calendar days after receipt of the above
information to request additional data and/or deny the authorization for any particular discharge. Upon receipt of
additional information, the Division shall have an additional ten calendar days to issue or deny authorization for
the particular discharge. (Notification of denial shall be by letter, in cases where coverage under an alternate general
permit or an individual permit is required, instead of coverage under this permit.)
PART I
Permit - Page 5
Permit No. COR -030000
A. COVERAGE UNDER THIS PERMIT (cont.)
b) Automatic Coverage: If the applicant does not receive a request for additional information or a notification of
denial from the Division dated within ten calendar days of receipt of the application by the Division, authorization to
discharge in accordance with the conditions of this permit shall be deemed granted.
c) Individual Permit Required: If, after evaluation of the application (or additional information, such as the SWMP),
it is found that this general permit is not appropriate for the operation, then the application will be processed as one
for an individual permit. The applicant will be notified of the Division's decision to deny certification under this
general permit. For an individual permit, additional information may be requested, and 180 days may be required to
process the application and issue the permit. At the Division's discretion, temporary coverage under this general
permit may be allowed until the individual permit goes into effect.
d) General vs. Individual Permit Coverage: Any permittee authorized by this permit may request to be excluded
from the coverage of this permit by applying for an individual CDPS permit. The permittee shall submit an
individual application, with reasons supporting the request, to the Division at least 180 days prior to any discharge.
e) Local Agency Authority: This permit does not pre-empt or supersede the authority of local agencies to prohibit,
restrict, or control discharges of stormwater to storm drain systems or other water courses within their jurisdiction.
6. Inactivation Notice
When a site has been finally stabilized in accordance with the SWMP, the permittee must submit an Inactivation Notice
form that is signed in accordance with Part I.F.1. of this permit. The Inactivation Notice form is available from the
Division and includes:
a) Permit certification number;
b) The permittee's name, address, telephone number;
c) Name, location, and county for the construction site for which the inactivation notice is being submitted; and
d) Certification that the site has been finally stabilized, and a description of the final stabilization method(s).
7. Transfer of Permit
When responsibility for stormwater discharges at a construction site changes from one entity to another, the permittee shall
submit a completed Notice of Transfer and Acceptance of Terms form that is signed in accordance with Part I.F.1. of
this permit. The Notice of Transfer form is available from the Division and includes:
a) Permit certification number;
b) Name, location, and county for the construction site for which the Notice of Transfer is being submitted;
c) Identifying information for the new permittee;
d) Identifying information for the current permittee; and
e) Effective date of transfer.
If the new responsible party will not complete the transfer form, the permit may be inactivated upon written request to the
Division and completion of the Inactivation Notice if the permittee has no legal responsibility, through ownership or
contract, for the construction activities at the site. In this case, the new owner or operator would be required to obtain
permit coverage separately.
8. Reassignment of Permit
When a permittee no longer has control of a specific portion of a permitted site, and wishes to transfer coverage of that
portion of the site to a second party, the permittee shall submit a completed Notice of Reassignment of Permit Coverage
form that is signed in accordance with Part I.F.1. of this permit. The Notice of Reassignment of Permit Coverage form is
available from the Division and includes:
a) Current permit certification number;
b) Identifying information and certification as required by Part I.A.4.b for the new permittee;
c) Identifying information for the current permittee, revised site information and certification for reassignment; and
d) Effective date of reassignment.
PART I
Permit - Page 6
Permit No. COR -030000
A. COVERAGE UNDER THIS PERMIT (cont.)
If the new responsible party will not complete the reassignment form, the applicable portion of the permitted site may be
removed from permit coverage upon written request to the Division if the permittee has no legal responsibility, through
ownership or contract, for the construction activities at the portion of the site. In this case, the new owner or operator
would be required to obtain permit coverage separately.
9. Sale of Residence to Homeowners
For residential construction only, when a residential lot has been conveyed to a homeowner and all criteria in paragraphs
a through e, below, are met, coverage under this permit is no longer required and the conveyed lot may be removed from
coverage under the permittee's certification. At such time, the permittee is no longer responsible for meeting the terms and
conditions of this permit for the conveyed lot, including the requirement to transfer or reassign permit coverage. The
permittee remains responsible for inactivation of the original certification.
a) The lot has been sold to the homeowner(s) for private residential use;
b) the lot is less than one acre of disturbed area;
c) all construction activity conducted by the permittee on the lot is completed;
d) a certificate of occupancy (or equivalent) has been awarded to the home owner; and
e) the SWMP has been amended to indicate the lot is no longer covered by permit.
Lots not meeting all of the above criteria require continued permit coverage. However, this permit coverage may be
transferred (Part I.A.7, above) or reassigned (Part I.A.8, above) to a new owner or operator.
10. Permit Expiration Date
Authorization to discharge under this general permit shall expire on June 30, 2012. The Division must evaluate and
reissue this general permit at least once every five years and must recertify the permittee's authority to discharge under the
general permit at such time. Therefore, a permittee desiring continued coverage under the general permit must reapply by
March 31, 2012. The Division will initiate the renewal process; however, it is ultimately the permittee's responsibility to
ensure that the renewal is submitted. The Division will determine if the permittee may continue to operate under the terms
of the general permit. An individual permit may be required for any facility not reauthorized to discharge under the
reissued general permit.
11. Individual Permit Criteria
Various criteria can be used in evaluating whether or not an individual (or alternate general) permit is required instead of
this general permit. This information may come from the application, SWMP, or additional information as requested by
the Division, and includes, but is not limited to, the following:
a) the quality of the receiving waters (i.e., the presence of downstream drinking water intakes or a high quality fishery,
or for preservation of high quality water);
b) the size of the construction site;
c) evidence of noncompliance under a previous permit for the operation;
d) the use of chemicals within the stormwater system; or
e) discharges of pollutants of concern to waters for which there is an established Total Maximum Daily Load (TMDL).
In addition, an individual permit may be required when the Division has shown or has reason to suspect that the
stormwater discharge may contribute to a violation of a water quality standard.
B. STORMWATER MANAGEMENT PLAN (SWMP) — GENERAL REQUIREMENTS
1. A SWMP shall be developed for each facility covered by this permit. The SWMP shall be prepared in accordance with
good engineering, hydrologic and pollution control practices. (The SWMP need not be prepared by a registered engineer.)
PART I
Permit - Page 7
Permit No. COR -030000
B. STORMWATER MANAGEMENT PLAN (SWMP) — GENERAL REQUIREMENTS (cont.)
2. The SWMP shall:
a) Identify all potential sources of pollution which may reasonably be expected to affect the quality of stormwater
discharges associated with construction activity from the facility;
b) Describe the practices to be used to reduce the pollutants in stormwater discharges associated with construction
activity at the facility; and ensure the practices are selected and described in accordance with good engineering
practices, including the installation, implementation and maintenance requirements; and
c) Be properly prepared, and updated in accordance with Part I.D.5.c, to ensure compliance with the terms and
conditions of this permit.
3. Facilities must implement the provisions of the SWMP as written and updated, from commencement of construction activity
until final stabilization is complete, as a condition of this permit. The Division reserves the right to review the SWMP, and
to require the permittee to develop and implement additional measures to prevent and control pollution as needed.
4. The SWMP may reflect requirements for Spill Prevention Control and Countermeasure (SPCC) plans under section 311 of
the CWA, or Best Management Practices (BMPs) Programs otherwise required by a separate CDPS permit, and may
incorporate any part of such plans into the SWMP by reference, provided that the relevant sections of such plans are
available as part of the SWMP consistent with Part I.D.5.b.
5. For any sites with permit coverage before June 30, 2007, the permittee's SMWP must meet the new SWMP requirements as
summarized in Section II.I of the rationale. Any needed changes must be made by October 1, 2007.
C. STORMWATER MANAGEMENT PLAN (SWMP) — CONTENTS
The SWMP shall include the following items, at a minimum.
1. Site Description. The SWMP shall clearly describe the construction activity, to include:
a) The nature of the construction activity at the site.
b) The proposed sequence for major activities.
c) Estimates of the total area of the site, and the area and location expected to be disturbed by clearing, excavation,
grading, or other construction activities.
d) A summary of any existing data used in the development of the site construction plans or SWMP that describe the
soil or existing potential for soil erosion.
e) A description of the existing vegetation at the site and an estimate of the percent vegetative ground cover.
f) The location and description of all potential pollution sources, including ground surface disturbing activities (see
Part I.A.2.b), vehicle fueling, storage of fertilizers or chemicals, etc.
g) The location and description of any anticipated allowable sources of non-stormwater discharge at the site, e.g.,
uncontaminated springs, landscape irrigation return flow, construction dewatering, and concrete washout.
h) The name of the receiving water(s) and the size, type and location of any outfall(s). If the stormwater discharge is to
a municipal separate storm sewer system, the name of that system, the location of the storm sewer discharge, and the
ultimate receiving water(s).
2. Site Map. The SWMP shall include a legible site map(s), showing the entire site, identifying:
a) construction site boundaries;
b) all areas of ground surface disturbance;
c) areas of cut and fill;
d) areas used for storage of building materials, equipment, soil, or waste;
e) locations of dedicated asphalt or concrete batch plants;
f) locations of all structural BMPs;
g) locations of non-structural BMPs as applicable; and
h) locations of springs, streams, wetlands and other surface waters.
PART I
Permit - Page 8
Permit No. COR -030000
C. STORMWATER MANAGEMENT PLAN (SWMP) — CONTENTS (cont.)
3. Stormwater Management Controls.
The SWMP must include a description of all stormwater management controls that will be implemented as part of the
construction activity to control pollutants in stormwater discharges. The appropriateness and priorities of stormwater
management controls in the SWMP shall reflect the potential pollutant sources identified at the facility.
The description of stormwater management controls shall address the following components, at a minimum.
a) SWMP Administrator - The SWMP shall identify a specific individual(s), position or title who is responsible for
developing, implementing, maintaining, and revising the SWMP. The activities and responsibilities of the
administrator shall address all aspects of the facility's SWMP.
b) Identification of Potential Pollutant Sources - All potential pollutant sources, including materials and activities, at
a site must be evaluated for the potential to contribute pollutants to stormwater discharges. The SWMP shall
identify and describe those sources determined to have the potential to contribute pollutants to stormwater
discharges, and the sources must be controlled through BMP selection and implementation, as required in paragraph
(c), below.
At a minimum, each of the following sources and activities shall be evaluated for the potential to contribute
pollutants to stormwater discharges, and identified in the SWMP if found to have such potential:
1) all disturbed and stored soils;
2) vehicle tracking of sediments;
3) management of contaminated soils;
4) loading and unloading operations;
5) outdoor storage activities (building materials, fertilizers, chemicals, etc.);
6) vehicle and equipment maintenance and fueling;
7) significant dust or particulate generating processes;
8) routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, etc.;
9) on-site waste management practices (waste piles, liquid wastes, dumpsters, etc.);
10) concrete truck/equipment washing, including the concrete truck chute and associated fixtures and equipment;
11) dedicated asphalt and concrete batch plants;
12) non -industrial waste sources such as worker trash and portable toilets; and
13) other areas or procedures where potential spills can occur.
c) Best Management Practices (BMPs) for Stormwater Pollution Prevention - The SWMP shall identify and
describe appropriate BMPs, including, but not limited to, those required by paragraphs 1 through 8 below, that will
be implemented at the facility to reduce the potential of the sources identified in Part I.C.3.b to contribute pollutants
to stormwater discharges. The SWMP shall clearly describe the installation and implementation specifications for
each BMP identified in the SWMP to ensure proper implementation, operation and maintenance of the BMP.
1) Structural Practices for Erosion and Sediment Control. The SWMP shall clearly describe and locate all
structural practices implemented at the site to minimize erosion and sediment transport. Practices may include,
but are not limited to: straw bales, wattles/sediment control logs, silt fences, earth dikes, drainage swales,
sediment traps, subsurface drains, pipe slope drains, inlet protection, outlet protection, gabions, and temporary
or permanent sediment basins.
2) Non -Structural Practices for Erosion and Sediment Control. The SWMP shall clearly describe and locate, as
applicable, all non-structural practices implemented at the site to minimize erosion and sediment transport.
Description must include interim and permanent stabilization practices, and site-specific scheduling for
implementation of the practices. The SWMP should include practices to ensure that existing vegetation is
preserved where possible. Non-structural practices may include, but are not limited to: temporary vegetation,
permanent vegetation, mulching, geotextiles, sod stabilization, slope roughening, vegetative buffer strips,
protection of trees, and preservation of mature vegetation.
PART I
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Permit No. COR -030000
C. STORMWATER MANAGEMENT PLAN (SWMP) — CONTENTS (cont.)
3) Phased BMP Implementation. The SWMP shall clearly describe the relationship between the phases of
construction, and the implementation and maintenance of both structural and non-structural stormwater
management controls. The SWMP must identify the stormwater management controls to be implemented
during the project phases, which can include, but are not limited to, clearing and grubbing; road construction;
utility and infrastructure installation; vertical construction; final grading; and final stabilization.
4) Materials Handling and Spill Prevention. The SWMP shall clearly describe and locate all practices
implemented at the site to minimize impacts from procedures or significant materials (see definitions at Part
I.E.) that could contribute pollutants to runoff. Such procedures or significant materials could include: exposed
storage of building materials; paints and solvents; fertilizers or chemicals; waste material; and equipment
maintenance or fueling procedures.
Areas or procedures where potential spills can occur must have spill prevention and response procedures
identified in the SWMP.
5) Dedicated Concrete or Asphalt Batch Plants. The SWMP shall clearly describe and locate all practices
implemented at the site to control stormwater pollution from dedicated concrete batch plants or dedicated
asphalt batch plants covered by this certification.
6) Vehicle Tracking Control. The SWMP shall clearly describe and locate all practices implemented at the site to
control potential sediment discharges from vehicle tracking. Practices must be implemented for all areas of
potential vehicle tracking, and can include: minimizing site access; street sweeping or scraping; tracking pads;
graveled parking areas; requiring that vehicles stay on paved areas on-site; wash racks; contractor education;
and/or sediment control BMPs, etc.
7) Waste Management and Disposal, Including Concrete Washout.
i) The SWMP shall clearly describe and locate the practices implemented at the site to control stormwater
pollution from all construction site wastes (liquid and solid), including concrete washout activities.
ii) The practices used for concrete washout must ensure that these activities do not result in the contribution
of pollutants associated with the washing activity to stormwater runoff.
iii) Part I.D.3.c of the permit authorizes the conditional discharge of concrete washout water to the ground.
The SWMP shall clearly describe and locate the practices to be used that will ensure that no washout
water from concrete washout activities is discharged from the site as surface runoff or to surface waters.
8) Groundwater and Stormwater Dewatering.
i) The SWMP shall clearly describe and locate the practices implemented at the site to control stormwater
pollution from the dewatering of groundwater or stormwater from excavations, wells, etc.
ii) Part I.D.3.d of the permit authorizes the conditional discharge of construction dewatering to the ground.
For any construction dewatering of groundwater not authorized under a separate CDPS discharge permit,
the SWMP shall clearly describe and locate the practices to be used that will ensure that no groundwater
from construction dewatering is discharged from the site as surface runoff or to surface waters.
4. Final Stabilization and Long-term Stormwater Management
a) The SWMP shall clearly describe the practices used to achieve final stabilization of all disturbed areas at the site,
and any planned practices to control pollutants in stormwater discharges that will occur after construction operations
have been completed at the site.
b) Final stabilization practices for obtaining a vegetative cover should include, as appropriate: seed mix selection and
application methods; soil preparation and amendments; soil stabilization practices (e.g., crimped straw, hydro mulch
or rolled erosion control products); and appropriate sediment control BMPs as needed until final stabilization is
achieved; etc.
PART I
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Permit No. COR -030000
C. STORMWATER MANAGEMENT PLAN (SWMP) — CONTENTS (cont.)
c) Final stabilization is reached when all ground surface disturbing activities at the site have been completed, and
uniform vegetative cover has been established with an individual plant density of at least 70 percent of pre -
disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed.
The Division may, after consultation with the permittee and upon good cause, amend the final stabilization criteria in this
section for specific operations.
5. Inspection and Maintenance
Part I.D.6 of the permit includes requirements for site inspections. Part I.D.7 of the permit includes requirements for BMP
maintenance. The SWMP shall clearly describe the inspection and maintenance procedures implemented at the site to
maintain all erosion and sediment control practices and other protective practices identified in the SWMP, in good and
effective operating condition.
D. TERMS AND CONDITIONS
1. General Limitations
The following limitations shall apply to all discharges covered by this permit:
a) Stormwater discharges from construction activities shall not cause, have the reasonable potential to cause, or
measurably contribute to an exceedance of any water quality standard, including narrative standards for water
quality.
b) Concrete washout water shall not be discharged to state surface waters or to storm sewer systems. On-site
permanent disposal of concrete washout waste is not authorized by this permit. Discharge to the ground of concrete
washout waste that will subsequently be disposed of off-site is authorized by this permit. See Part I.D.3.c of the
permit.
c) Bulk storage structures for petroleum products and any other chemicals shall have secondary containment or
equivalent adequate protection so as to contain all spills and prevent any spilled material from entering State waters.
d) No chemicals are to be added to the discharge unless permission for the use of a specific chemical is granted by the
Division. In granting the use of such chemicals, special conditions and monitoring may be addressed by separate
correspondence.
e) The Division reserves the right to require sampling and testing, on a case-by-case basis, in the event that there is
reason to suspect that compliance with the SWMP is a problem, or to measure the effectiveness of the BMPs in
removing pollutants in the effluent. Such monitoring may include Whole Effluent Toxicity testing.
f) All site wastes must be properly managed to prevent potential pollution of State waters. This permit does not
authorize on-site waste disposal.
g)
All dischargers must comply with the lawful requirements of federal agencies, municipalities, counties, drainage
districts and other local agencies regarding any discharges of stormwater to storm drain systems or other water
courses under their jurisdiction, including applicable requirements in municipal stormwater management programs
developed to comply with CDPS permits. Dischargers must comply with local stormwater management
requirements, policies or guidelines including erosion and sediment control.
2. BMP Implementation and Design Standards
Facilities must select, install, implement, and maintain appropriate BMPs, following good engineering, hydrologic and
pollution control practices. BMPs implemented at the site must be adequately designed to provide control for all potential
pollutant sources associated with construction activity to prevent pollution or degradation of State waters.
PART I
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Permit No. COR -030000
D. TERMS AND CONDITIONS (cont.)
3. Prohibition of Non-Stormwater Discharges
a) Except as provided in paragraphs b, c, and d below, all discharges covered by this permit shall be composed
entirely of stormwater associated with construction activity. Discharges of material other than stormwater must
be addressed in a separate CDPS permit issued for that discharge.
b) Discharges from the following sources that are combined with stormwater discharges associated with construction
activity may be authorized by this permit, provided that the non-stormwater component of the discharge is identified
in the SWMP (see Part I.C.1.g of this permit):
- emergency fire fighting activities - landscape irrigation return flow
- uncontaminated springs
c) Discharges to the ground of concrete washout water from washing of tools and concrete mixer chutes may be
authorized by this permit, provided that:
1) the source is identified in the SWMP;
2) BMPs are included in the SWMP in accordance with Part I.C.3(c)(7) and to prevent pollution of groundwater in
violation of Part I.D.1.a; and
3) these discharges do not leave the site as surface runoff or to surface waters
d) Discharges to the ground of water from construction dewatering activities may be authorized by this permit,
provided that:
1) the source is groundwater and/or groundwater combined with stormwater that does not contain pollutants in
concentrations exceeding the State groundwater standards in Regulations 5 CCR 1002-41 and 42;
2) the source is identified in the SWMP;
3) BMPs are included in the SWMP, as required by Part I.C.3(c)(8); and
4) these discharges do not leave the site as surface runoff or to surface waters.
Discharges to the ground from construction dewatering activities that do not meet the above criteria must be covered
under a separate CDPS discharge permit. Contaminated groundwater requiring coverage under a separate CDPS
discharge permit may include groundwater contaminated with pollutants from a landfill, mining activity, industrial
pollutant plume, underground storage tank, or other source.
4. Releases in Excess of Reportable Quantities
This permit does not relieve the permittee of the reporting requirements of 40 CFR 110, 40 CFR 117 or 40 CFR 302. Any
discharge of hazardous material must be handled in accordance with the Division's Noncompliance Notification
Requirements (see Part II.A.3 of the permit).
5. SWMP Requirements
a) SWMP Preparation and Implementation: The SWMP shall be prepared prior to applying for coverage under the
general permit, and certification of its completion submitted with the application. The SWMP shall be implemented
prior to commencement of construction activities. The plan shall be updated as appropriate (see paragraph c,
below), below). SWMP provisions shall be implemented until expiration or inactivation of permit coverage.
b) SWMP Retention Requirements: A copy of the SWMP must be retained on site unless another location, specified
by the permittee, is approved by the Division.
c) SWMP Review/Changes: The permittee shall amend the SWMP:
1) when there is a change in design, construction, operation, or maintenance of the site, which would require the
implementation of new or revised BMPs; or
2) if the SWMP proves to be ineffective in achieving the general objectives of controlling pollutants in stormwater
discharges associated with construction activity; or
PART I
Permit - Page 12
Permit No. COR -030000
D. TERMS AND CONDITIONS (cont.)
3) when BMPs are no longer necessary and are removed.
SWMP changes shall be made prior to changes in the site conditions, except as allowed for in paragraph d, below.
SWMP revisions may include, but are not limited to: potential pollutant source identification; selection of
appropriate BMPs for site conditions; BMP maintenance procedures; and interim and final stabilization practices.
The SWMP changes may include a schedule for further BMP design and implementation, provided that, if any
interim BMPs are needed to comply with the permit, they are also included in the SWMP and implemented during
the interim period.
d) Responsive SWMP Changes: SWMP changes addressing BMP installation and/or implementation are often
required to be made in response to changing conditions, or when current BMPs are determined ineffective. The
majority of SWMP revisions to address these changes can be made immediately with quick in -the -field revisions to
the SWMP. In the less common scenario where more complex development of materials to modify the SWMP is
necessary, SWMP revisions shall be made in accordance with the following requirements:
1) the SWMP shall be revised as soon as practicable, but in no case more than 72 hours after the change(s) in
BMP installation and/or implementation occur at the site, and
2) a notation must be included in the SWMP prior to the site change(s) that includes the time and date of the
change(s) in the field, an identification of the BMP(s) removed or added, and the location(s) of those BMP(s).
6. Inspections
Site inspections must be conducted in accordance with the following requirements and minimum schedules. The required
minimum inspection schedules do not reduce or eliminate the permittee's responsibility to implement and maintain BMPs
in good and effective operational condition, and in accordance with the SWMP, which could require more frequent
inspections.
a) Minimum Inspection Schedule: The permittee shall, at a minimum, make a thorough inspection, in accordance
with the requirements in I.D.6.b below, at least once every 14 calendar days. Also, post -storm event inspections
must be conducted within 24 hours after the end of any precipitation or snowmelt event that causes surface erosion.
Provided the timing is appropriate, the post -storm inspections may be used to fulfill the 14 -day routine inspection
requirement. A more frequent inspection schedule than the minimum inspections described may be necessary, to
ensure that BMPs continue to operate as needed to comply with the permit. The following conditional modifications
to this Minimum Inspection Schedule are allowed:
1) Post -Storm Event Inspections at Temporarily Idle Sites — If no construction activities will occur following a
storm event, post -storm event inspections shall be conducted prior to re -commencing construction activities,
but no later than 72 hours following the storm event. The occurrence of any such delayed inspection must be
documented in the inspection record. Routine inspections still must be conducted at least every 14 calendar
days.
2) Inspections at Completed Sites/Areas — For sites or portions of sites that meet the following criteria, but final
stabilization has not been achieved due to a vegetative cover that has not become established, the permittee
shall make a thorough inspection of their stormwater management system at least once every month, and post -
storm event inspections are not required. This reduced inspection schedule is only allowed if:
i) all construction activities that will result in surface ground disturbance are completed;
ii) all activities required for final stabilization, in accordance with the SWMP, have been completed, with
the exception of the application of seed that has not occurred due to seasonal conditions or the necessity
for additional seed application to augment previous efforts; and
iii) the SWMP has been amended to indicate those areas that will be inspected in accordance with the
reduced schedule allowed for in this paragraph.
PART I
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Permit No. COR -030000
D. TERMS AND CONDITIONS (cont.)
3) Winter Conditions Inspections Exclusion — Inspections are not required at sites where construction activities
are temporarily halted, snow cover exists over the entire site for an extended period, and melting conditions
posing a risk of surface erosion do not exist. This exception is applicable only during the period where melting
conditions do not exist, and applies to the routine 14 -day and monthly inspections, as well as the post -storm -
event inspections. The following information must be documented in the inspection record for use of this
exclusion: dates when snow cover occurred, date when construction activities ceased, and date melting
conditions began. Inspections, as described above, are required at all other times.
When site conditions make the schedule required in this section impractical, the permittee may petition the Division
to grant an alternate inspection schedule.
b) Inspection Requirements
1) Inspection Scope - The construction site perimeter, all disturbed areas, material and/or waste storage areas that
are exposed to precipitation, discharge locations, and locations where vehicles access the site shall be inspected
for evidence of, or the potential for, pollutants leaving the construction site boundaries, entering the stormwater
drainage system, or discharging to state waters. All erosion and sediment control practices identified in the
SWMP shall be evaluated to ensure that they are maintained and operating correctly.
2) Inspection Report/Records - The permittee shall keep a record of inspections. Inspection reports must
identify any incidents of non-compliance with the terms and conditions of this permit. Inspection records must
be retained for three years from expiration or inactivation of permit coverage. At a minimum, the inspection
report must include:
i) The inspection date;
ii) Name(s) and title(s) of personnel making the inspection;
iii) Location(s) of discharges of sediment or other pollutants from the site;
iv) Location(s) of BMPs that need to be maintained;
v) Location(s) of BMPs that failed to operate as designed or proved inadequate for a particular location;
vi) Location(s) where additional BMPs are needed that were not in place at the time of inspection;
vii) Deviations from the minimum inspection schedule as provided in Part I.D.6.a above;
vii) Description of corrective action for items iii, iv, v, and vi, above, dates corrective action(s) taken, and
measures taken to prevent future violations, including requisite changes to the SWMP, as necessary; and
viii) After adequate corrective action(s) has been taken, or where a report does not identify any incidents
requiring corrective action, the report shall contain a signed statement indicating the site is in compliance
with the permit to the best of the signer's knowledge and belief.
c) Required Actions Following Site Inspections — Where site inspections note the need for BMP maintenance
activities, BMPs must be maintained in accordance with the SWMP and Part I.D.7 of the permit. Repair,
replacement, or installation of new BMPs determined necessary during site inspections to address ineffective or
inadequate BMPs must be conducted in accordance with Part I.D.8 of the permit. SWMP updates required as a
result of deficiencies in the SWMP noted during site inspections shall be made in accordance with Part I.D.5.c of the
permit.
7. BMP Maintenance
All erosion and sediment control practices and other protective measures identified in the SWMP must be maintained in
effective operating condition. Proper selection and installation of BMPs and implementation of comprehensive Inspection
and Maintenance procedures, in accordance with the SWMP, should be adequate to meet this condition. BMPs that are not
adequately maintained in accordance with good engineering, hydrologic and pollution control practices, including removal
of collected sediment outside the acceptable tolerances of the BMPs, are considered to be no longer operating effectively
and must be addressed in accordance with Part I.D.8, below. A specific timeline for implementing maintenance
procedures is not included in this permit because BMP maintenance is expected to be proactive, not responsive.
Observations resulting in BMP maintenance activities can be made during a site inspection, or during general observations
of site conditions.
PART I
Permit - Page 14
Permit No. COR -030000
D. TERMS AND CONDITIONS (cont.)
8. Replacement and Failed BMPs
Adequate site assessment must be performed as part of comprehensive Inspection and Maintenance procedures, to assess
the adequacy of BMPs at the site, and the necessity of changes to those BMPs to ensure continued effective performance.
Where site assessment results in the determination that new or replacement BMPs are necessary, the BMPs must be
installed to ensure on-going implementation of BMPs as per Part I.D.2.
Where BMPs have failed, resulting in noncompliance with Part I.D.2, they must be addressed as soon as possible,
immediately in most cases, to minimize the discharge of pollutants.
When new BMPs are installed or BMPs are replaced, the SWMP must be updated in accordance with Part I.D.5(c).
9. Reporting
No scheduled reporting requirements are included in this permit; however, the Division reserves the right to request that a
copy of the inspection reports be submitted.
10. SWMP Availability
A copy of the SWMP shall be provided upon request to the Division, EPA, or any local agency in charge of approving
sediment and erosion plans, grading plans or stormwater management plans, and within the time frame specified in the
request. If the SWMP is required to be submitted to any of these entities, it must include a signed certification in
accordance with Part I.F.1 of the permit, certifying that the SWMP is complete and meets all permit requirements.
All SWMPs required under this permit are considered reports that shall be available to the public under Section 308(b) of
the CWA and Section 61.5(4) of the Colorado Discharge Permit System Regulations. The permittee shall make plans
available to members of the public upon request. However, the permittee may claim any portion of a SWMP as
confidential in accordance with 40 CFR Part 2.
11. Total Maximum Daily Load (TMDL)
If a TMDL has been approved for any waterbody into which the permittee discharges, and stormwater discharges
associated with construction activity have been assigned a pollutant -specific Wasteload Allocation (WLA) under the
TMDL, the Division will either:
a) Ensure that the WLA is being implemented properly through alternative local requirements, such as by a municipal
stormwater permit; or
b) Notify the permittee of the WLA, and amend the permittee's certification to add specific BMPs and/or other
requirements, as appropriate. The permittee may be required to do the following:
1) Under the permittee's SWMP, implement specific management practices based on requirements of the WLA,
and evaluate whether the requirements are being met through implementation of existing stormwater BMPs or
if additional BMPs are necessary. Document the calculations or other evidence that show that the requirements
are expected to be met; and
2) If the evaluation shows that additional or modified BMPs are necessary, describe the type and schedule for the
BMP additions/revisions.
Discharge monitoring may also be required. The permittee may maintain coverage under the general permit provided they
comply with the applicable requirements outlined above. The Division reserves the right to require individual or alternate
general permit coverage.
PART I
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Permit No. COR -030000
E. ADDITIONAL DEFINITIONS
For the purposes of this permit:
1. Best Management Practices (BMPs): schedules of activities, prohibitions of practices, maintenance procedures, and
other management practices to prevent or reduce the pollution of waters of the State. BMPs also include treatment
requirements, operating procedures, pollution prevention, and practices to control site runoff, spillage or leaks, waste
disposal, or drainage from material storage.
2. Dedicated asphalt plants and concrete plants: portable asphalt plants and concrete plants that are located on or adjacent
to a construction site and that provide materials only to that specific construction site.
3. Final stabilization: when all ground surface disturbing activities at the site have been completed, and uniform vegetative
cover has been established with an individual plant density of at least 70 percent of pre -disturbance levels, or equivalent
permanent, physical erosion reduction methods have been employed. For purposes of this permit, establishment of a
vegetative cover capable of providing erosion control equivalent to pre-existing conditions at the site will be considered
final stabilization.
4. Municipal separate storm sewer system: a conveyance or system of conveyances (including: roads with drainage
systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains), owned or operated
by a State, city, town, county, district, or other public body (created by state law), having jurisdiction over disposal of
sewage, industrial waste, stormwater, or other wastes; designed or used for collecting or conveying stormwater.
5. Operator: the entity that has day-to-day supervision and control of activities occurring at the construction site. This can
be the owner, the developer, the general contractor or the agent of one of these parties, in some circumstances. It is
anticipated that at different phases of a construction project, different types of parties may satisfy the definition of
'operator' and that the permit may be transferred as the roles change.
6. Outfall: a point source at the point where stormwater leaves the construction site and discharges to a receiving water or a
stormwater collection system.
7. Part of a larger common plan of development or sale: a contiguous area where multiple separate and distinct
construction activities may be taking place at different times on different schedules.
8. Point source: any discernible, confined and discrete conveyance from which pollutants are or may be discharged. Point
source discharges of stormwater result from structures which increase the imperviousness of the ground which acts to
collect runoff, with runoff being conveyed along the resulting drainage or grading pattern.
9. Pollutant: dredged spoil, dirt, slurry, solid waste, incinerator residue, sewage, sewage sludge, garbage, trash, chemical
waste, biological nutrient, biological material, radioactive material, heat, wrecked or discarded equipment, rock, sand, or
any industrial, municipal or agricultural waste.
10. Process water: any water which, during manufacturing or processing, comes into contact with or results from the
production of any raw material, intermediate product, finished product, by product or waste product. This definition
includes mine drainage.
11. Receiving Water: any classified stream segment (including tributaries) in the State of Colorado into which stormwater
related to construction activities discharges. This definition includes all water courses, even if they are usually dry, such as
borrow ditches, arroyos, and other unnamed waterways.
12. Significant Materials include, but are not limited to: raw materials; fuels; materials such as solvents, detergents, and
plastic pellets; finished materials such as metallic products; raw materials used in food processing or production; hazardous
substances designated under section 101(14) of CERCLA; any chemical the facility is required to report pursuant to
section 313 of title III of SARA; fertilizers; pesticides; and waste products such as ashes, slag and sludge that have the
potential to be released with stormwater discharge.
13. Stormwater: precipitation -induced surface runoff.
PART I
Permit - Page 16
Permit No. COR -030000
F. GENERAL REQUIREMENTS
1. Signatory Requirements
a) All reports required for submittal shall be signed and certified for accuracy by the permittee in accordance with the
following criteria:
1) In the case of corporations, by a principal executive officer of at least the level of vice-president or his or her
duly authorized representative, if such representative is responsible for the overall operation of the facility from
which the discharge described in the form originates;
2) In the case of a partnership, by a general partner;
3) In the case of a sole proprietorship, by the proprietor;
4) In the case of a municipal, state, or other public facility, by either a principal executive officer, ranking elected
official, or other duly authorized employee, if such representative is responsible for the overall operation of the
facility from which the discharge described in the form originates.
b) Changes to authorization. If an authorization under paragraph a) of this section is no longer accurate because a
different individual or position has responsibility for the overall operation of the facility, a new authorization
satisfying the requirements of paragraph a) of this section must be submitted to the Division, prior to or together
with any reports, information, or applications to be signed by an authorized representative.
c) Certification. Any person signing a document under paragraph a) of this section shall make the following
certification:
"I certify under penalty of law that this document and all attachments were prepared under my direction or
supervision in accordance with a system designed to assure that qualified personnel properly gather and
evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or
those persons directly responsible for gathering the information, the information submitted is, to the best of my
knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for
submitting false information, including the possibility of fine and imprisonment for knowing violations."
2. Retention of Records
a) The permittee shall retain copies of the SWMP and all reports required by this permit and records of all data used to
complete the application to be covered by this permit, for three years after expiration or inactivation of permit
coverage.
b) The permittee shall retain a copy of the SWMP required by this permit at the construction site from the date of
project initiation to the date of expiration or inactivation of permit coverage, unless another location, specified by
the permittee, is approved by the Division.
3. Monitoring
The Division reserves the right to require sampling and testing, on a case-by-case basis (see Part I.D.1.e), for example to
implement the provisions of a TMDL (see Part I.D.11 of the permit). Reporting procedures for any monitoring data
collected will be included in the notification by the Division of monitoring requirements.
If monitoring is required, the following definitions apply:
a) The thirty (30) day average shall be determined by the arithmetic mean of all samples collected during a thirty (30)
consecutive -day period.
b) A grab sample, for monitoring requirements, is a single "dip and take" sample.
PART II
A. MANAGEMENT REQUIREMENTS
1. Amending a Permit Certification
PART II
Permit - Page 17
Permit No. COR -030000
The permittee shall inform the Division (Permits Section) in writing of changes to the information provided in the permit
application, including the legal contact, the project legal description or map originally submitted with the application, or
the planned total disturbed acreage. The permittee shall furnish the Division with any plans and specifications which the
Division deems reasonably necessary to evaluate the effect on the discharge and receiving stream. If applicable, this
notification may be accomplished through submittal of an application for a CDPS process water permit authorizing the
discharge. The SWMP shall be updated and implemented prior to the changes (see Part I.D.5.c).
Any discharge to the waters of the State from a point source other than specifically authorized by this permit or a different
CDPS permit is prohibited.
2. Special Notifications - Definitions
a) Spill: An unintentional release of solid or liquid material which may cause pollution of state waters.
b) Upset: An exceptional incident in which there is unintentional and temporary noncompliance with permit discharge
limitations because of factors beyond the reasonable control of the permittee. An upset does not include
noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate
treatment facilities, lack of preventative maintenance, or careless or improper operation.
3. Noncompliance Notification
a) The permittee shall report the following instances of noncompliance:
1) Any noncompliance which may endanger health or the environment;
2) Any spill or discharge of hazardous substances or oil which may cause pollution of the waters of the state.
3) Any discharge of stormwater which may cause an exceedance of a water quality standard.
b) For all instances of noncompliance based on environmental hazards and chemical spills and releases, all needed
information must be provided orally to the Colorado Department of Public Health and Environment spill reporting
line (24-hour number for environmental hazards and chemical spills and releases: 1-877-518-5608) within 24 hours
from the time the permittee becomes aware of the circumstances.
For all other instances of noncompliance as defined in this section, all needed information must be provided orally to
the Water Quality Control Division within 24 hours from the time the permittee becomes aware of the
circumstances.
For all instances of noncompliance identified here, a written submission shall also be provided within 5 calendar
days of the time the permittee becomes aware of the circumstances. The written submission shall contain a
description of:
1) The noncompliance and its cause;
2) The period of noncompliance, including exact dates and times, and if the noncompliance has not been
corrected, the anticipated time it is expected to continue;
3) Steps taken or planned to reduce, eliminate, and prevent reoccurrence of the noncompliance.
PART II
Permit - Page 18
Permit No. COR -030000
A. MANAGEMENT REQUIREMENTS (cont.)
4. Submission of Incorrect or Incomplete Information
Where the permittee failed to submit any relevant facts in a permit application, or submitted incorrect information in a
permit application or report to the Division, or relevant new information becomes available, the permittee shall promptly
submit the relevant application information which was not submitted or any additional information needed to correct any
erroneous information previously submitted.
5. Bypass
a) A bypass, which causes effluent limitations (i.e., requirements to implement BMPs in accordance with Parts I.B.3
and I.D.2 of the permit) to be exceeded is prohibited, and the Division may take enforcement action against a
permittee for such a bypass, unless:
1) Bypass was unavoidable to prevent loss of life, personal injury, or severe property damage;
2) There were no feasible alternatives to the bypass, such as the use of auxiliary treatment facilities (e.g.,
alternative BMPs), retention of untreated wastes, or maintenance during normal periods of equipment
downtime. This condition is not satisfied if the permittee could have installed adequate backup equipment (e.g.,
implemented additional BMPs) to prevent a bypass which occurred during normal periods of equipment
downtime or preventative maintenance; and
3) The permittee submitted notices as required in "Non -Compliance Notification," Part II.A.3.
6. Upsets
a) Effect of an Upset: An upset constitutes an affirmative defense to an action brought for noncompliance with permit
limitations and requirements if the requirements of paragraph b of this section are met. (No determination made
during administrative review of claims that noncompliance was caused by upset, and before an action for
noncompliance, is final administrative action subject to judicial review.)
b) Conditions Necessary for a Demonstration of Upset: A permittee who wishes to establish the affirmative defense
of upset shall demonstrate through properly signed contemporaneous operating logs, or other relevant evidence that:
1) An upset occurred and that the permittee can identify the specific cause(s) of the upset;
2) The permitted facility was at the time being properly operated;
3) The permittee submitted notice of the upset as required in Part ILA.3. of this permit (24-hour notice); and
4) The permittee complied with any remedial measures required under 40 CFR Section 122.41(d) of the federal
regulations or Section 61.8(3)(h) of the Colorado Discharge Permit System Regulations.
c) Burden of Proof: In any enforcement proceeding the permittee seeking to establish the occurrence of an upset has
the burden of proof.
7. Removed Substances
Solids, sludges, or other pollutants removed in the course of treatment or control of discharges shall be properly disposed
of in a manner such as to prevent any pollutant from such materials from entering waters of the State.
8. Minimization of Adverse Impact
The permittee shall take all reasonable steps to minimize any adverse impact to waters of the State resulting from
noncompliance with any terms and conditions specified in this permit, including such accelerated or additional monitoring
as necessary to determine the nature and impact of the noncomplying discharge.
PART II
Permit - Page 19
Permit No. COR -030000
A. MANAGEMENT REQUIREMENTS (cont.)
9. Reduction, Loss, or Failure of Stormwater Controls
The permittee has the duty to halt or reduce any activity if necessary to maintain compliance with the permit requirements.
Upon reduction, loss, or failure of any stormwater controls, the permittee shall, to the extent necessary to maintain
compliance with its permit, control production, or remove all pollutant sources from exposure to stormwater, or both, until
the stormwater controls are restored or an alternative method of treatment/control is provided.
It shall not be a defense for a permittee in an enforcement action that it would be necessary to halt or reduce the permitted
activity in order to maintain compliance with the conditions of this permit.
10. Proper Operation and Maintenance
The permittee shall at all times properly operate and maintain all facilities and systems of treatment and control (and
related appurtenances) which are installed or used by the permittee to achieve compliance with the conditions of this
permit. Proper operation and maintenance includes effective performance, adequate funding, adequate operator staffing
and training, and adequate laboratory and process controls, including appropriate quality assurance procedures. This
provision requires the operation of back-up or auxiliary facilities or similar systems only when necessary to achieve
compliance with the conditions of the permit.
B. RESPONSIBILITIES
1. Inspections and Right to Entry
The permittee shall allow the Director of the State Water Quality Control Division, the EPA Regional Administrator,
and/or their authorized representative(s), upon the presentation of credentials:
a) To enter upon the permittee's premises where a regulated facility or activity is located or in which any records are
required to be kept under the terms and conditions of this permit;
b) At reasonable times to have access to and copy any records required to be kept under the terms and conditions of
this permit and to inspect any monitoring equipment or monitoring method required in the permit; and
c) To enter upon the permittee's premises to investigate, within reason, any actual, suspected, or potential source of
water pollution, or any violation of the Colorado Water Quality Control Act. The investigation may include, but is
not limited to, the following: sampling of any discharge and/or process waters, the taking of photographs,
interviewing permittee staff on alleged violations and other matters related to the permit, and access to any and all
facilities or areas within the permittee's premises that may have any effect on the discharge, permit, or any alleged
violation.
2. Duty to Provide Information
The permittee shall furnish to the Division, within the time frame specified by the Division, any information which the
Division may request to determine whether cause exists for modifying, revoking and reissuing, or inactivating coverage
under this permit, or to determine compliance with this permit. The permittee shall also furnish to the Division, upon
request, copies of records required to be kept by this permit.
3. Transfer of Ownership or Control
Certification under this permit may be transferred to a new permittee if:
a) The current permittee notifies the Division in writing when the transfer is desired as outlined in Part I.A.7; and
b) The notice includes a written agreement between the existing and new permittees containing a specific date for
transfer of permit responsibility, coverage and liability between them; and
c) The current permittee has met all fee requirements of the Colorado Discharge Permit System Regulations, Section
61.15.
PART II
Permit - Page 20
Permit No. COR -030000
B. RESPONSIBILITIES (cont.)
4. Modification, Suspension, or Revocation of Permit By Division
All permit modification, inactivation or revocation and reissuance actions shall be subject to the requirements of the
Colorado Discharge Permit System Regulations, Sections 61.5(2), 61.5(3), 61.7 and 61.15, 5 C.C.R. 1002-61, except for
minor modifications.
a) This permit, and/or certification under this permit, may be modified, suspended, or revoked in whole or in part
during its term for reasons determined by the Division including, but not limited to, the following:
1) Violation of any terms or conditions of the permit;
2) Obtaining a permit by misrepresentation or failing to disclose any fact which is material to the granting or
denial of a permit or to the establishment of terms or conditions of the permit;
3) Materially false or inaccurate statements or information in the application for the permit;
4) Promulgation of toxic effluent standards or prohibitions (including any schedule of compliance specified in
such effluent standard or prohibition) which are established under Section 307 of the Clean Water Act, where
such a toxic pollutant is present in the discharge and such standard or prohibition is more stringent than any
limitation for such pollutant in this permit.
b) This permit, and/or certification under this permit, may be modified in whole or in part due to a change in any
condition that requires either a temporary or permanent reduction or elimination of the permitted discharge, such as:
1) Promulgation of Water Quality Standards applicable to waters affected by the permitted discharge; or
2) Effluent limitations or other requirements applicable pursuant to the State Act or federal requirements; or
3) Control regulations promulgated; or
4) Other available information indicates a potential for violation of adopted Water Quality Standards or stream
classifications.
c) This permit, or certification under this permit, may be modified in whole or in part to include new effluent
limitations and other appropriate permit conditions where data submitted pursuant to Part I indicate that such
effluent limitations and permit conditions are necessary to ensure compliance with applicable water quality
standards and protection of classified uses.
d) At the request of the permittee, the Division may modify or inactivate certification under this permit if the following
conditions are met:
1) In the case of inactivation, the permittee notifies the Division of its intent to inactivate the certification, and
certifies that the site has been finally stabilized;
2) In the case of inactivation, the permittee has ceased any and all discharges to state waters and demonstrates to
the Division there is no probability of further uncontrolled discharge(s) which may affect waters of the State.
3) The Division finds that the permittee has shown reasonable grounds consistent with the Federal and State
statutes and regulations for such modification, amendment or inactivation;
4) Fee requirements of Section 61.15 of the Colorado Discharge Permit System Regulations have been met; and
5) Applicable requirements of public notice have been met.
For small construction sites covered by a Qualifying Local Program, coverage under this permit is automatically
terminated when a site has been finally stabilized.
PART II
Permit - Page 21
Permit No. COR -030000
B. RESPONSIBILITIES (cont.)
5. Permit Violations
Failure to comply with any terms and/or conditions of this permit shall be a violation of this permit.
Dischargers of stormwater associated with industrial activity, as defined in the EPA Stormwater Regulation (40 CFR
122.26(b)(14) and Section 61.3(2) of the Colorado Discharge Permit System Regulations, which do not obtain coverage
under this or other Colorado general permits, or under an individual CDPS permit regulating industrial stormwater, will be
in violation of the federal Clean Water Act and the Colorado Water Quality Control Act, 25-8-101, as amended. Failure to
comply with CDPS permit requirements will also constitute a violation.
6. Legal Responsibilities
The issuance of this permit does not convey any property or water rights in either real or personal property, or stream
flows, or any exclusive privileges, nor does it authorize any injury to private property or any invasion of personal rights,
nor any infringement of Federal, State or local laws or regulations.
Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any
responsibilities, liabilities, or penalties established pursuant to any applicable State law or regulation under authority
granted by Section 510 of the Clean Water Act.
7. Severability
The provisions of this permit are severable. If any provisions of this permit, or the application of any provision of this
permit to any circumstance, are held invalid, the application of such provision to other circumstances and the application of
the remainder of this permit shall not be affected.
8. Renewal Application
If the permittee desires to continue to discharge, a permit renewal application shall be submitted at least ninety (90) days
before this permit expires. If the permittee anticipates that there will be no discharge after the expiration date of this
permit, the Division should be promptly notified so that it can inactivate the certification in accordance with Part II.B.4.d.
9. Confidentiality
Except for data determined to be confidential under Section 308 of the Federal Clean Water Act and Colorado Discharge
Permit System Regulations, Section 61.5(4), all reports prepared in accordance with the terms of this permit shall be
available for public inspection at the offices of the Division. The permittee must state what is confidential at the time of
submittal.
Any information relating to any secret process, method of manufacture or production, or sales or marketing data which has
been declared confidential by the permittee, and which may be acquired, ascertained, or discovered, whether in any
sampling investigation, emergency investigation, or otherwise, shall not be publicly disclosed by any member, officer, or
employee of the Commission or the Division, but shall be kept confidential. Any person seeking to invoke the protection
of this section shall bear the burden of proving its applicability. This section shall never be interpreted as preventing full
disclosure of effluent data.
10. Fees
The permittee is required to submit payment of an annual fee as set forth in the Water Quality Control Act. Failure to
submit the required fee when due and payable is a violation of the permit and will result in enforcement action pursuant to
Section 25-8-601 et. seq., C.R.S. 1973 as amended.
PART II
Permit - Page 22
Permit No. COR -030000
B. RESPONSIBILITIES (cont.)
11. Requiring an Individual CDPS Permit
The Director may require the permittee to apply for and obtain an individual or alternate general CDPS permit if:
a) The discharger is not in compliance with the conditions of this general permit;
b) Conditions or standards have changed so that the discharge no longer qualifies for a general permit; or
c) Data/information become available which indicate water quality standards may be violated.
The permittee must be notified in writing that an application for an individual or alternate general CDPS permit is required.
When an individual or alternate general CDPS permit is issued to an operator otherwise covered under this general permit,
the applicability of this general permit to that operator is automatically inactivated upon the effective date of the individual
or alternate general CDPS permit.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
Water Quality Control Division
WQCD-P-B2
4300 Cherry Creek Drive South
Denver, Colorado 80246-1530
RATIONALE
STORMWATER DISCHARGES ASSOCIATED WITH
CONSTRUCTION ACTIVITY
GENERAL PERMIT IN COLORADO
THIRD RENEWAL
COLORADO DISCHARGE PERMIT NUMBER COR -030000
CONTENTS PAGE
I. Introduction 1
II. Changes in this General Permit 1
III. Background 8
IV. Stormwater Discharges Associated with
Construction Activity 9
V. Coverage Under this Permit 10
VI. Application and Certification 10
VII. Qualifying Local Programs 11
VIII. Terms and Conditions of Permit 11
IX. Public Notice —12/22/06 15
X. Public Notice — 3/23/07 15
I. INTRODUCTION
This permit is for the regulation of stormwater runoff from construction activities, and specific allowable non-
stormwater discharges in accordance with Part I.D.3 of the permit. The term "construction activity" includes
ground surface disturbing activities, including, but not limited to, clearing, grading, excavation, demolition,
installation of new or improved haul and access roads, staging areas, stockpiling of fill materials, and borrow
areas. "Stormwater" is precipitation -induced surface runoff. This rationale will explain the background of the
Stormwater program, activities which are covered under this permit, how to apply for coverage under this permit,
and the requirements of this permit.
The forms discussed in the rationale and permit are available on the Water Quality Control Division's website
at: www.cdphe.state.co.us/wePermitsUnit
IL CHANGES IN THIS GENERAL PERMIT
Several notable changes from the previous General Permit for Construction Activities have been incorporated into
this permit. Significant changes are listed below. Numerous other minor changes were made for clarification
purposes only.
A. Authority to Discharge
This section has been restructured to list all of the types of activities covered by this permit, and to be
consistent with the definition of "construction activity." The definition of construction activity has been
expanded to provide clarification. See Part I.A.1 of the permit.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 2. Permit No. COR -030000
IL CHANGES IN THIS GENERAL PERMIT (cont.)
B. Authority to Discharge — Oil and Gas Construction
This section has been added, to take into account a regulatory change. The federal Energy Policy Act of 2005
exempts nearly all oil and gas construction activities from federal requirements under the Clean Water Act's
NPDES stormwater discharge permit program. In January 2006, the Colorado Water Quality Control
Commission held a hearing to determine what effects, if any, the change in federal law would have upon
Colorado's stormwater regulations. The Commission determined that oil and gas construction sites in
Colorado that disturb one or more acres are still required to be covered under Colorado's stormwater
permitting regulations (Colorado Discharge Permit System (CDPS) regulations (5CCR 1002-61)). In practice,
oil and gas construction sites have the same requirements under this permit as do other types of construction.
However, this permit contains some references to the federal Clean Water Act; generally these references are
not applicable to oil and gas construction sites to the extent that the references are limited by the federal
Energy Policy Act of 2005. See Part I.A.1(b) of the permit.
C. Application Requirements
The permit application requirements have changed slightly, including the addition of an email address, if
available. See Part I.A.4(b).
The applicant must be either the owner and/or operator of the construction site. An operator at a construction
site that is not covered by a certification held by an appropriate entity may be held liable for operating without
the necessary permit coverage.
D. Temporary Coverage
Part I.A.5(d) of the previous permit (effective July 1, 2002) dealt with temporarily covering a facility under the
general permit even if an individual permit is more appropriate. This permit section essentially duplicated the
previous section (see Part I.A.5(c)), and so it has been deleted.
E. Reassignment of Permit Coverage
Procedures have been added to clarify the requirements for the transfer of coverage of specific portions of a
permitted site to a second party. See Section VIII.I.3 of the rationale and Part I.A.8 of the permit.
F. Individual Permit Criteria
This section has been modified to include situations involving a Total Maximum Daily Load (TMDL). See Part
I.A. 11 of the permit.
G. Stormwater Management Plan (SWMP)
The Stormwater Management Plan section has been divided into two parts: Stormwater Management Plan
(SWMP) — General Requirements, which provides the basic framework and general requirements for the
SWMP, and Stormwater Management Plan (SWMP) — Contents, which specifically identifies each item that
must be addressed in the SWMP. See Parts I.B and I. C of the permit.
H. Stormwater Management Plan (SWMP) — General Requirements
The SWMP General Requirements section has been modified to require that the SWMP be updated in
accordance with Parts I.D.5(c) and I.D.5(d) of the permit (SWMP Review/Changes). This additional
requirement ensures that the SWMP provisions reflect current site conditions. See Part I.B.2(c) of the permit.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 3. Permit No. COR -030000
IL CHANGES IN THIS GENERAL PERMIT (cont.)
I. Stormwater Management Plan (SWMP) — Contents
The SWMP Contents section has been modified. Some of the changes are limited to organization of
information, which does not require modification of an existing permittee's current SWMP. Most of the SWMP
changes involve either clarifications, reformatting, or taking recommendations from the Division's SWMP
guide and making them permit requirements (e.g., vehicle tracking controls, BMP installation specifications).
If an existing permittee (Le., those with permit coverage before June 30, 2007) followed the recommendations
in the SWMP guide (Appendix A of the permit application), then their SWMP will presumably meet the new
requirements. However, for any existing permittees who did not follow the applicable SWMP guide
recommendations, their SMWP must be amended to include the new required items:
- SWMP Administrator
-Identification of potential pollutant sources
- Best Management Practices descriptions and installation specifications, including dedicated concrete or
asphalt batch plants; vehicle tracking control; and waste management and disposal (including concrete
washout activities).
For existing permittees, any SWMP changes based on the change in permit requirements must be completed by
October 1, 2007. The plan is not to be submitted to the Division unless requested, but must be available on site
as outlined in Part I.D.5(b) of the permit.
The BMP requirement clarifications included in this renewed permit in no way imply that adequate BMPs to
address all pollutant sources at a permitted site were not required in previous permits. The revised
requirements are intended only to better clarify SWMP content requirements and provide improved direction to
permittees.
The SWMP changes are listed below. All new applicants (after June 30, 2007) for permit coverage for their
sites must fully comply with the new SWMP organization, plan requirements, and implementation.
1. Site Description: The requirement to provide an estimate of the run-off coefficient has been removed.
The run-off coefficient as currently utilized in the SWMP may not contribute sufficiently to permit
compliance to justify the effort in determining accurate values. See Part I. C.1 of the permit. However,
the Division still encourages use of the coefficient as needed to adequately evaluate site-specific BMP
selection and design criteria (e.g., pond capacities, BMP location, etc.) See Section C.2 of the SWMP
guidance (Appendix A of the permit application).
2. Site Map: The requirement to identify boundaries of the 100 year flood plain has been removed. The
boundaries as currently utilized in the SWMP may not contribute sufficiently to permit compliance to
justify the effort in determining their location. See Part I. C.2 of the permit.
3. Stormwater Management Controls: This section has been modified to require identification of a SWMP
Administrator and all potential pollutants sources in the SWMP. See Part I. C.3 of the permit.
a) The SWMP Administrator is a specific individual(s), position or title who is responsible for the
process of developing, implementing, maintaining, and revising the SWMP. This individual
serves as the comprehensive point of contact for all aspects of the facility's SWMP. This
requirement may necessitate changes to existing permittees' SWMPs.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 4. Permit No. COR -030000
IL CHANGES IN THIS GENERAL PERMIT (cont.)
b) The requirement to identify Potential Pollutant Sources has been expanded to include more
details for the evaluation of such sources. This evaluation allows for the appropriate selection of
BMPs for implementation at a facility or site. Additionally, this section was added to be
consistent with the SWMP guide. This requirement may necessitate changes to existing
permittees' SWMPs.
c) Best Management Practices (BMPs) for Stormwater Pollution Prevention: This section was
modified to require the following items to be addressed in the SWMP. These requirements may
necessitate changes to existing permittees' SWMPs. This section also requires that the SWMP
provide installation and implementation specifications for each BMP identified in the SWMP.
For structural BMPs, in most cases, this must include a technical drawing to provide adequate
installation specifications. See Part I. C.3(c).
i) Dedicated concrete or asphalt batch plants. This section requires that the practices used to
reduce the pollutants in stormwater discharges associated with dedicated concrete or asphalt
batch plants be identified in the SWMP. (Coverage under the construction site SWMP and
permit is not required for batch plants if they have alternate CDPS permit coverage.)
ii) Vehicle tracking control. This section requires that practices be implemented to control
sediment from vehicle tracking, and that all such practices implemented at the site be clearly
described in the SWMP.
iii) Waste management and disposal. This section requires that the practices implemented at the
site to control stormwater pollution from construction site waste, including concrete washout
activities, be clearly described in the SWMP. It also requires that concrete washout activities
be conducted in a manner that does not contribute pollutants to surface waters or stormwater
runoff
iv) Concrete Washout Water. Part I.D.3(c) of the permit has been revised to conditionally
authorize discharges to the ground of concrete wash water from washing of tools and
concrete mixer chutes when appropriate BMPs are implemented. The permit prohibits the
discharge of concrete washout water to surface waters and to storm sewer systems. Part
I. C.3(c)(7) of the permit requires that BMPs be in place to prevent surface discharges of
concrete washout water from the site.
The use of unlined pits to contain concrete washout water is a common practice in Colorado.
The Division has further evaluated the need for a permit for discharge of concrete washout
water to the ground. The Division has determined that the use of appropriate BMPs for on-
site washing of tools and concrete mixer chutes would prevent any significant discharge to
groundwater. BMPs to protect groundwater are required by Part 1.C.3(c)(7) of the permit.
Because pH is a pollutant of concern for washout activities, the soil must have adequate
buffering capacity to result in protection of the groundwater standard, or a liner/containment
must be used. The following management practices are recommended to prevent an impact
from unlined pits to groundwater:
(1) the use of the washout site should be temporary (less than 1 year), and
(2) the washout site should be not be located in an area where shallow groundwater may be
present, such as near natural drainages, springs, or wetlands.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 5. Permit No. COR -030000
IL CHANGES IN THIS GENERAL PERMIT (cont.)
Where adequate management practices are not followed to protect groundwater quality, the
Department may require discharges to unlined pits to cease, or require the entity to obtain
alternate regulatory approval through notice from either the Water Quality Control Division
or the Hazardous Materials and Waste Management Division.
In addition, Part I.D. 1(b) of the permit has been revised to clearly state that the permit does
not authorize on-site permanent disposal of concrete washout waste, only temporary
containment of concrete washout water from washing of tools and concrete mixer chutes.
Upon termination of use of the washout site, accumulated solid waste, including concrete
waste and any contaminated soils, must be removed from the site to prevent on-site disposal
of solid waste.
v) Construction Dewatering. Part I.D.3(d) of the permit has been revised to conditionally
authorize discharges to the ground of water from construction dewatering activities when
appropriate BMPs are implemented. The permit does not authorize the discharge of
groundwater from construction dewatering to surface waters or to storm sewer systems. Part
I.C. 3 (c)(8) of the permit requires that BMPs be in place to prevent surface discharges. The
permittee may apply for coverage under a separate CDPS discharge permit, such as the
Construction Dewatering general permit, if there is a potential for discharges to surface
waters.
The Division has determined that potential pollutant sources introduced into groundwater
from construction dewatering operations do not have a reasonable potential to result in
exceedance of groundwater standards when the discharge is to the ground. The primary
pollutant of concern in uncontaminated groundwater is sediment. Although technology-based
standards for sediment do exist in 5 CCR 1002-41, the discharge of sediment to the ground as
part of construction dewatering does not have the reasonable potential to result in transport
of sediment to the groundwater table so as to result in an exceedance of those standards.
For a discharge of water contaminated with other pollutants that are present in
concentrations that may cause an exceedance of groundwater standards, separate CDPS
discharge permit coverage is required. Contaminated groundwater may include that
contaminated with pollutants from a landfill, mining activity, industrial pollutant plume,
underground storage tank, or other source of human -induced groundwater pollution and
exceeding the State groundwater standards in Regulations 5 CCR 1002-41 and 42.
J. Terms and Conditions, General Limitations and Design Standards
This section reiterates the requirement that facilities select, install, implement, and maintain appropriate
BMPs, following good engineering, hydrologic and pollution control practices. In addition, requirements for
protection of water quality standards (see Part I.D.1. (a) of the permit) and requirements to adequately design
BMPs to prevent pollution or degradation of State waters (see Part I.D.2 of the permit) have been revised and
are fully discussed in Part III.B of the rationale, below. Additional language was also added to Section III.B
of the rationale further clarifying the expectations for compliance with this permit.
1. Management of Site Waste
This section has been modified to clarify that on-site waste must be properly managed to prevent
potential pollution of State waters, and that this permit does not authorize on-site waste disposal. Solid
waste disposal is regulated by the Hazardous Materials and Waste Management Division.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 6. Permit No. COR -030000
IL CHANGES IN THIS GENERAL PERMIT (cont.)
K. Terms and Conditions, SWMP Requirements
1. SWMP Review/Changes: This section now requires that when changes are made to site conditions, the
SWMP must be revised immediately, except for some BMP description changes which conditionally may
occur within 72 hours. This requirement is included to both ensure that the SWMP be kept accurate and
up-to-date, and to clarify that stormwater management at a site typically should be proactive instead of
responsive, and be integrated into site management to ensure it is calibrated with those changes. The
section was also clarified to state that only changes in site conditions that do not require new or
modified BMPs do not need to be addressed in the SWMP. See Part ID. 5(c) of the permit.
2. SWMP Certification: The previous permit was unclear on a requirement that the copy of SWMP that
remains at the facility had to be signed in accordance with permit signatory requirements. This
requirement has been deleted. The signatory requirement of Part I.F.1 only applies to the SWMP if it is
to be submitted to the Division or to EPA. See Part I.F.1 of the permit.
L. Terms and Conditions, Post -Storm Inspections
The previous permit required post -storm inspections, but did not specify the timing of inspections. This section
now requires that post -storm event inspections generally be conducted within 24 hours of the event. An
alternative timeline has been allowed, only for sites where there are no construction activities occurring
following a storm event. For this condition, post -storm event inspections shall instead be conducted prior to
commencing construction activities, but no later than 72 hours following the storm event, and the delay noted
in the inspection report.
Any exception from the minimum inspection schedule is temporary, and does not eliminate the requirement to
perform routine maintenance due to the effects of a storm event, including maintaining vehicle tracking
controls and removing sediment from impervious areas. In many cases, maintenance needs will require a
more frequent inspection schedule than the minimum inspections required in the permit, to ensure that BMPs
continue to operate as needed to comply with the permit. See Part I.D.6(a) of the permit.
M Terms and Conditions, Inspections
1. The Winter Conditions Inspection Exclusion section has been modified to include documentation
requirements for this exclusion. See Part I.D.6(a) of the permit. The Inspection Scope has been modified
to include the requirement to inspect waste storage areas during inspections conducted in accordance
with the permit. See Part ID.6(b) of the permit.
2. The requirements for sites to qualify for reduced inspection frequencies for completed sites have been
slightly modified (see Part I.D.6(a)(2) of the permit,). The requirement now is that only construction
activities that disturb the ground surface must be completed. Construction activities that can be
conducted without disturbance of the ground surface; for example, interior building construction, and
some oil well activities, would not prohibit a site from otherwise qualifying for the reduced inspection
frequency. In addition, the requirement for the site to be prepared for final stabilization has been
slightly modified to allow for sites that have not yet been seeded to qualify, as long as the site has
otherwise been prepared for final stabilization, including completion of appropriate soil preparation,
amendments and stabilization practice. This will allow for sites with seasonal seeding limitations or
where additional seed application may be needed in the future to still qualify.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 7. Permit No. COR -030000
IL CHANGES IN THIS GENERAL PERMIT (cont.)
3. The Inspection Report/Records section (Part ID.6(b)(2)) was added to clarify requirements for
inspection reports generated during an inspection conducted in accordance with Part I.D. 6 of the
permit. Inspection reports must be signed by the inspector, or the individual verifying the corrective
action indicated in the inspection report, on behalf of the permittee. Inspection reports are not typically
required to be submitted to the Division, and therefore, are not required to be signed and certified for
accuracy in accordance with Part I.F.1 of the permit. However, any inspection reports that are
submitted to the Division must follow the signatory requirements contained in that section.
N. Terms and Conditions, Maintenance, Repair, and Replacement of Control Practices
These sections have been added to clarify requirements for maintaining the BMPs identified in the SWMP and
for addressing ineffective or failed BMPs. BMP maintenance and site assessment to determine the overall
adequacy of stormwater quality management at the site must occur proactively, in order to ensure adequate
control of pollutant sources at the site. In most cases, if BMPs are already not operating effectively, or have
failed, the issue must be addressed immediately, to prevent discharge of pollutants. See Parts I.D. 7 and I.D.8
of the permit.
0. Total Maximum Daily Load (TMDL)
A section on TMDLs has been added. This section gives a general outline of the additional requirements that
may be imposed by the Division if the facility discharges to a waterbody for which a stormwater-related TMDL
is in place. See Section VIII. C of the rationale and Part I.D.11 of the permit.
P. Additional Definitions
Q.
Part I.E of the permit has been modified to remove the definition of runoff coefficient, as it is no longer a
permit requirement. The definition for state waters has also been deleted, but can be found in Regulation 61.
Changes in Discharge
The section on the types of discharge or facility changes that necessitate Division notification has been
clarified. See Part II.A.1 of the permit.
R. Non -Compliance Notification
The section on notification to the Division regarding instances of non-compliance has been amended to clarify
which types of noncompliance require notification. See Part II.A.3 of the permit.
S. Short Term Certifications
The previous permit allowed small short-term construction activities to be authorized for a predetermined
period from 3 to 12 months, and then automatically expire (an inactivation request did not need to be
submitted). The issuance of these certifications has led to significant confusion and incidents of
noncompliance resulting from permittees unintentionally letting their certifications expire prior to final
stabilization, as well as issues regarding billing. Therefore, the provisions for short-term certifications have
been deleted.
T. Bypass
The Division has revised the Bypass conditions in Part II.A.5 of the permit to be consistent with the
requirements of Regulation 61.8(3)(i). The revised language addresses under what rare occurrences BMPs
may be bypassed at a site.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 8. Permit No. COR -030000
III. BACKGROUND
As required under the Clean Water Act amendments of 1987, the Environmental Protection Agency (EPA) has
established a framework for regulating municipal and industrial stormwater discharges. This framework is under
the National Pollutant Discharge Elimination System (NPDES) program (Note: The Colorado program is referred
to as the Colorado Discharge Permit System, or CDPS, instead of NPDES.) The Water Quality Control Division
("the Division') has stormwater regulations (5CCR 1002-61) in place. These regulations require specific types of
industrial facilities that discharge stormwater associated with industrial activity (industrial stormwater), to obtain a
CDPS permit for such discharge. The regulations specifically include construction activities that disturb one acre of
land or more as industrial facilities. Construction activities that are part of a larger common plan of development
which disturb one acre or more over a period of time are also included.
A. General Permits
The Division has determined that the use of general permits is the appropriate procedure for handling most of
the thousands of industrial stormwater applications within the State.
B. Permit Requirements
This permit does not impose numeric effluent limits or require submission of effluent monitoring data in the
permit application or in the permit itself. The permit instead imposes practice -based effluent limitations for
stormwater discharges through the requirement to develop and implement a Stormwater Management Plan
(SWMP). The narrative permit requirements include prohibitions against discharges of non-stormwater (e.g.,
process water). See Part I.D.3 of the permit.
The permit conditions for the SWMP include the requirement for dischargers to select, implement and maintain
Best Management Practices (BMPs) at a permitted construction site that adequately minimize pollutants in the
discharges to assure compliance with the terms and conditions of the permit. Part I.D.2 of the permit includes
basic design standards for BMPs implemented at the site. Facilities must select, install, implement, and
maintain appropriate BMPs, following good engineering, hydrologic and pollution control practices. BMPs
implemented at the site must be adequately designed to control all potential pollutant sources associated with
construction activity to prevent pollution or degradation of State waters. Pollution is defined in CDPS
regulations (5CCR 1002-61) as man-made or man -induced, or natural alteration of the physical, chemical,
biological, and radiological integrity of water. Utilizing industry -accepted standards for BMP selection that
are appropriate for the conditions and pollutant sources present will typically be adequate to meet these
criteria, since construction BMPs are intended to prevent the discharge of all but minimal amounts of sediment
or other pollutants that would not result in actual pollution of State waters, as defined above. However, site-
specific design, including ongoing assessment of BMPs and pollutant sources, is necessary to ensure that
BMPs operate as intended.
The permit further requires that stormwater discharges from construction activities shall not cause, have the
reasonable potential to cause, or measurably contribute to an excursion above any water quality standard,
including narrative standards for water quality. This condition is the basis for all CDPS Discharge permits,
and addresses the need to ensure that waters of the State maintain adequate water quality, in accordance with
water quality standards, to continue to meet their designated uses. It is believed that, in most cases, BMPs can
be adequate to meet applicable water quality standards. If water quality impacts are noted, or the Division
otherwise determines that additional permit requirements are necessary, they are typically imposed as follows:
1) at the renewal of this general permit or through a general permit specific to an industrial sector (if the issue
is sector -based); 2) through direction from the Division based on the implementation of a TMDL (if the issue is
watershed -based); or 3) if the issue is site-specific, through a revision to the certification from the Division
based on an inspection or SWMP review, or through an individual permit.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 9. Permit No. COR -030000
III. BACKGROUND (cont.)
Some construction sites may be required to comply with a Qualing Local Program in place of meeting
several of the specific requirements in this permit. Sites covered by a Qualifying Local Program may not be
required to submit an application for coverage or a notice of inactivation and may not be required to pay the
Division's annual fee. See Section VII of the rationale.
C. Violations/Penalties
Dischargers of stormwater associated with industrial activity, as defined in the CDPS regulations (5CCR
1002-61), that do not obtain coverage under this or other Colorado general permits, or under an individual
CDPS permit regulating industrial stormwater, will be in violation of the Federal Clean Water Act and the
Colorado Water Quality Control Act, 25-8-101. For facilities covered under a CDPS permit, failure to comply
with any CDPS permit requirement constitutes a violation. As of the time of permit issuance, civil penalties for
violations of the Act or CDPS permit requirements may be up to $10,000 per day, and criminal pollution of
state waters is punishable by fines of up to $25,000 per day.
IV. STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY
The stormwater regulations (CDPS regulations (5CCR 1002-61)), require that stormwater discharges associated
with certain industrial activities be covered under the permit program. Construction activity that disturbs one acre
or more during the life of the project is specifically included in the listed industrial activities. This permit is intended
to cover most stormwater discharges from construction facilities required by State regulation to obtain a permit.
A. Construction Activity
Construction activity includes ground surface disturbing activities including, but not limited to, clearing,
grading, excavation, demolition, installation of new or improved haul and access roads, staging areas,
stockpiling of fill materials, and dedicated borrow/fill areas. Construction does not include routine
maintenance to maintain original line and grade, hydraulic capacity, or original purpose of the facility. (The
maintenance exclusion is intended for projects such as road resurfacing, and where there will be less than one
acre of additional ground disturbed. Improvements or upgrades to existing facilities or roads, where at least
one acre is disturbed, would not qualify as "routine maintenance. ')
Definitions of additional terms can be found in Part I.E of the permit.
Stormwater discharges from all construction activity require permit coverage, except for operations that result
in the disturbance of less than one acre of total land area and which are not part of a larger common plan of
development or sale. A "larger common plan of development or sale" is a contiguous area where multiple
separate and distinct construction activities may be taking place at different times on different schedules.
B. Types of Discharges/Activities Covered
1. Stormwater: This permit is intended to cover most new or existing discharges composed entirely of
stormwater from construction activities that are required by State regulation to obtain a permit. This
includes stormwater discharges associated with areas that are dedicated to producing earthen materials,
such as soils, sand, and gravel, for use at a single construction site. These areas may be located at the
construction site or at some other location. This permit does not authorize the discharge of mine water
or process water from borrow areas. This permit may also cover stormwater discharges associated with
dedicated asphalt plants and concrete plants located at a specific construction site.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 10. Permit No. COR -030000
IV. STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY (cont.)
2. Process water: Under certain restrictions, discharges to the ground from construction dewatering, and
from concrete washout activities, are also covered (see Parts 1.C.3(c)(7),1.C.3(c)(8), I.D.3(c) and
I.D.3(d) of the permit).
C. Types of Activities NOT Covered
1. Stormwater: Aside from the sources listed in subparagraph B.1, above, this permit does not cover
stormwater discharged from construction sites that is mixed with stormwater from other types of
industrial activities, or process water of any kind. Other types of industrial activities that require
stormwater discharge permits pursuant to different sections of the regulations (Regulation 5 CCR 1002-
61, Section 61.2(e)(iii)(A-I, K)], are not covered by this permit.
2. Process water: This permit also does not cover any discharge of process water to surface waters. If the
construction activity encounters groundwater, in order to discharge this groundwater to surface waters,
a Construction Dewatering Discharge Permit (permit number COG -070000) must also be obtained. An
application for this permit can be obtained from the Division at the address listed in Part I.A.4(a) of the
permit, or at the website in Section I of the rationale.
V. COVERAGE UNDER THIS GENERAL PERMIT
Under this general permit, owners or operators of stormwater discharges associated with construction activity may
be granted authorization to discharge stormwater into waters of the State of Colorado. This includes stormwater
discharges associated with industrial activity from areas that are dedicated to producing earthen materials, such as
soils, sand and gravel, for use at a single construction site, and dedicated asphalt plants and dedicated concrete
plants.
This permit does not pre-empt or supersede the authority of other local, state or federal agencies to prohibit, restrict
or control discharges of stormwater to storm drain systems or other water courses within their jurisdiction.
Authorization to discharge under the permit requires submittal of a completed application form and a certification
that the SWMP is complete, unless the site is covered by a Qualifying Local Program. Upon receipt of all required
information, the Division may allow or disallow coverage under the general permit.
VI. APPLICATION AND CERTIFICATION
At least ten days prior to the commencement of construction activities, the owner or operator of the construction site
shall submit an original completed application which includes the signed certification that the SWMP is complete.
Original signatures are required for the application to be considered complete. For small construction sites only, if
the site is covered by a Qualifying Local Program (see below), submittal of an application is not required.
For the purposes of this permit, the "operator" is the person who has day-to-day control over the project. This can
be the owner, the developer, the general contractor or the agent of one of these parties, in some circumstances. At
different times during a construction project, different types of parties may satisfy the definition of "operator" and
the certification may be transferred as roles change.
(Note - Under the Federal regulations, this application process is referred to as a Notice of Intent, or NOI. For
internal consistency with its current program, the Division will continue to use the term "application. ') A summary
of the permit application requirements is found in the permit at Part I.A.4(b).
If coverage under this general permit is appropriate, then a certification will be developed and the applicant will be
certified under this general permit.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 11. Permit No. COR -030000
VII. QUALIFYING LOCAL PROGRAMS
For stormwater discharges associated with small construction activity (i. e., one to five acre disturbed area sites), the
permit includes conditions that incorporate approved qualifying local erosion and sediment control program
(Qualifying Local Program) requirements by reference. A Qualifying Local Program is a municipal stormwater
program for stormwater discharges associated with small construction activity that has been formally approved by
the Division. The requirements for Qualifying Local Programs are outlined in Part 61.8(12) of the Colorado
Discharger Permit System Regulations (also see the Division's "Qualing Local Programs for Small Construction
Sites - Application Guidance'). Such programs must impose requirements to protect water quality that are at least
as stringent as those required in this permit.
A. Approval Termination
A Qualifying Local Program may be terminated by either the Division or the municipality. Upon termination of
Division approval of a Qualifying Local Program, any small construction activity required to obtain permit
coverage under Section 61.3(2)(h) of the CDPS regulations (5CCR 1002-61), shall submit an application form
as provided by the Division, with a certification that the Stormwater Management Plan (SWMP) is complete as
required by Part I.A.3 of the permit, within 30 days of Division notification.
B. Approval Expiration
Division approval of a Qualifying Local Program will expire with this general permit on June 30, 2012. Any
municipality desiring to continue Division approval of their program must reapply by March 31, 2012. The
Division will determine if the program may continue as a approved Qualifying Local Program.
VIII. TERMS AND CONDITIONS OF PERMIT
A. Coverage under a Qualifying Local Program — For Small Construction Sites Only
For small construction sites (disturbing less than 5 acres) covered under a Qualifying Local Program (see
Section VII, above), only certain permit requirements apply, as outlined below. The local program must have
been formally designated by the Division to qualify. Most municipalities have some type of local program and
may require permits and fees. However, simply having a program in place does not necessarily mean that it is
a qualifying program and that a State permit is not required. The local municipality is responsible for
notifying operators and/or owners that they are covered by a Qualifying Local Program. As of May 31, 2007,
the only approved Qualifying Local Programs within the state are for Golden, Durango and Lakewood. An
updated list of municipalities with Qualifying Local Programs, including contact information, is available on
the Division's website at: http://www.cdphe.state.co.us/wq/Permits Unit/stormwater/construction.html.
The Division reserves the right to require any construction owner or operator within the jurisdiction of a
Qualifying Local Program covered under this permit to apply for and obtain coverage under the full
requirements of this permit.
1. Permit Coverage: If a construction site is within the jurisdiction of a Qualing Local Program, the
owner or operator of the construction activity is authorized to discharge stormwater associated with
small construction activity under this general permit without the submittal of an application to the
Division. The permittee also is not required to submit an inactivation notice or payment of an annual
fee to the Division.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 12. Permit No. COR -030000
VIII. TERMS AND CONDITIONS OF PERMIT (cont.)
2. Permit Terms and Conditions: The permittee covered by a Qualiing Local Program must comply
with the requirements of that Qualifying Local Program. In addition, the following permit sections are
applicable:
a) Parts 1.A.1, 1.A.2, and 1.A.3: Authorization to discharge and discussion of coverage under the
permit.
b) Part I.D.1: General limitations that must be met in addition to local requirements.
c) Parts I.D.2, I.D.3, I.D.4: BMP implementation, prohibition of non-stormwater discharges unless
addressed in a separate CDPS permit, and requirements related to releases of reportable
quantities.
d) Part I.D.11: Potential coverage under a Total Maximum Daily Load (TMDL).
e) Part I.E: Additional definitions.
f Part II (except for Parts II.A.1, II.B.3, II.B.8, and II.B.10): Specifically includes, but is not
limited to, provisions applicable in the case of noncompliance with permit requirements, and
requirements to provide information and access.
B. Stormwater Management Plans (SWMPs)
Prior to commencement of construction, a stormwater management plan (SWMP) shall be developed and
implemented for each facility covered by this permit. A certification that the SWMP is complete must be
submitted with the permit application. The SWMP shall identify potential sources of pollution (including
sediment) which may reasonably be expected to affect the quality of stormwater discharges associated with
construction activity from the facility. In addition, the plan shall describe the Best Management Practices
(BMPs) which will be used to reduce the pollutants in stormwater discharges from the construction site. (Note
that permanent stormwater controls, such as ponds, that are used as temporary construction BMPs must be
adequately covered in the SWMP.) Facilities must implement the provisions of their SWMP as a condition of
this permit. The SWMP shall include the following items:
1. Site Description
2. Site Map
3. Stormwater Management Controls
4. Long-term Stormwater Management
5. Inspection and Maintenance
(See Parts I.B. and IC of the permit for a more detailed description of SWMP requirements.) The Division has
a guidance document available on preparing a SWMP. The document is included as Appendix A of the permit
application, and is available on the Division's website at www.cdphe.state.co.us/wq/PermitsUnit.
Some changes have been made to the SWMP requirements. See Section II.I of the rationale for a discussion on
permittee responsibilities regarding those changes.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 13. Permit No. COR -030000
VIII. TERMS AND CONDITIONS OF PERMIT (cont.)
Master SWMP
Often, a large construction project will involve multiple smaller construction sites that are within a common
plan of development, or multiple well pads under construction within an oil and gas well field. Pollutant
sources and the types of BMPs used can be relatively consistent in such cases. A permittee could significantly
streamline the SWMP development process through the use of a master SWMP. SWMP information must be
developed and maintained for all construction activities that exceed one acre (or are part of a common plan of
development exceeding one acre) conducted within the permitted area. By developing a single master plan, the
permittee can eliminate the need to develop repetitive information in separate plans. Such a plan could include
two sections, one containing a reference section with information applicable to all sites (e.g., installation
details and maintenance requirements for many standard BMPs, such as silt fence and erosion blankets), and
the second containing all of the information specific to each site (e.g., site BMP map, drainage plans, details
for BMPs requiring site specific design, such as retention ponds).
As new activities begin, information required in the SWMP is added to the plan, and as areas become finally
stabilized, the related information is removed. Records of information related to areas that have been finally
stabilized that are removed from the active plan must be maintained for a period of at least three years from
the date that the associated site is finally stabilized.
C. Total Maximum Daily Load (TMDL)
If the designated use of a stream or water body has been impaired by the presence of a pollutant(s),
development of a Total Maximum Daily Load (TMDL) may be required. A TMDL is an estimate of allowable
loading in the waterbody for the pollutant in question. Types of discharges that are or have the potential to be
a significant source of the pollutant are also identified. If a TMDL has been approved for any waterbody into
which the permittee discharges, and stormwater discharges associated with construction activity have been
assigned a pollutant -specific Wasteload Allocation (WLA) under the TMDL, the Division will either:
1. Notify the permittee of the TMDL, and amend the permittee's certification to add specific BMPs and/or
other requirements, as appropriate; or
2. Ensure that the TMDL is being implemented properly through alternative local requirements, such as by
a municipal stormwater permit. (The only current example of this is the Cherry Creek Reservoir Control
Regulation (72.0), which mandates that municipalities within the basin require specific BMPs for
construction sites.)
See Part ID. 11 of the permit for further information.
D. Monitoring
Sampling and testing of stormwater for specific parameters is not required on a routine basis under this
permit. However, the Division reserves the right to require sampling and testing on a case-by-case basis, in
the event that there is reason to suspect that compliance with the SWMP is a problem, or to measure the
effectiveness of the BMPs in removing pollutants in the effluent. See Part I.D. 1(e) of the permit.
E. Facility Inspections
Construction sites typically must inspect their stormwater management controls at least every 14 days and
within 24 hours after the end of any precipitation or snowmelt event that causes surface erosion. At sites or
portions of sites where ground -disturbing construction has been completed but a vegetative cover has not been
established, these inspections must occur at least once per month. (At sites where persistent snow cover
conditions exist, inspections are not required during the period that melting conditions do not exist. These
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 14. Permit No. COR -030000
VIII TERMS AND CONDITIONS OF PERMIT (cont.)
conditions are only expected to occur at high elevations within the Colorado mountains.) For all of these
inspections, records must be kept on file. Exceptions to the inspection requirements are detailed in Part I.D.6
of the permit.
F. SWMP Revisions
The permittee shall amend the SWMP whenever there is a change in design, construction, operation, or
maintenance of the site, which would require the implementation of new or revised BMPs. The SWMP shall
also be amended if it proves to be ineffective in achieving the general objectives of controlling pollutants in
stormwater discharges associated with construction activity. The timing for completion of SWMP changes is
detailed in Parts I.D.5(c) and I.D.5(d) of the permit.
SWMP revisions shall be made prior to change in the field, or in accordance with Part I.D.5(d) of the permit.
G. Reporting
The inspection record shall be made available to the Division upon request. Regular submittal of an annual
report is not required in this permit. See Part I.D.9 of the permit.
H. Annual Fee
The permittee is required to submit payment of an annual fee as set forth in the Water Quality Control Act.
Permittees will be billed for the initial permit fee within a few weeks of permit issuance and then annually,
based on a July 1 through June 30 billing cycle.
I Responsibility for Permit
The permit certification for a site may be inactivated, once coverage is no longer needed. The certification
may be transferred, if another party is assuming responsibility for the entire area covered by the certification.
In addition, permit responsibility for part of the area covered by the certification may be reassigned to another
party. These actions are summarized below. The Stormwater Program construction fact sheet explains these
actions in further detail under the section on Multiple Owner/Developer Sites, and is available on the Division
website at http://www.cdphe.state.co.us/wq/PermitsUnit/stormwater/ConstFactSheet.PDF, Section F.
1. Inactivation Notice: When a site has been finally stabilized in accordance with the SWMP, the
permittee shall submit an Inactivation Notice that is signed in accordance with Part I.F.1 of the permit.
A summary of the Inactivation Notice content is described in Part I.A. 6 of the permit. A copy of the
Inactivation Notice form will be mailed to the permittee along with the permit certification. Additional
copies are available from the Division.
For sites where all areas have been removed from permit coverage, the permittee may submit an
inactivation notice and terminate permit coverage. In such cases the permittee would no longer have
any land covered under their permit certification, and therefore there would be no areas remaining to
finally stabilize. Areas may be removed from permit coverage by:
- reassignment of permit coverage (Part I.A.8 of the permit);
- sale to homeowner(s) (Part I.A.9 of the permit); or
- amendment by the permittee, in accordance with Division guidance for areas where permit coverage
has been obtained by a new operator or returned to agricultural use.
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 15. Permit No. COR -030000
VIII. TERMS AND CONDITIONS OF PERMIT (cont.)
2. Transfer of Permit: When responsibility for stormwater discharges for an entire construction site
changes from one individual to another, the permit shall be transferred in accordance with Part I.A.7 of
the permit. The permittee shall submit a completed Notice of Transfer form, which is available from
the Division, and at www.cdphe.state.co.us/wq/PermitsUnit. If the new responsible party will not
complete the transfer form, the permit may be inactivated if the permittee has no legal responsibility,
through ownership or contract, for the construction activities at the site. In this case, the new owner or
operator would be required to obtain permit coverage separately.
3. Reassignment of Permit: When a permittee no longer has control of a specific portion of a permitted
site, and wishes to transfer coverage of that portion of the site to a second party, the permittee shall
submit a completed Notice of Reassignment of Permit Coverage form, which is available from the
Division, and at www.cdphe.state.co.us/wq/PermitsUnit. The form requires that both the existing
permittee and new permittee complete their respective sections. See Part I.A.8 of the permit.
J. Duration of Permit
The general permit will expire on June 30, 2012. The permittee's authority to discharge under this permit is
approved until the expiration date of the general permit. Any permittee desiring continued coverage under the
general permit past the expiration date must apply for recertification under the general permit at least 90 days
prior to its expiration date.
Kathleen Rosow
December 18, 2006
IX PUBLIC NOTICE —12/22/06
The permit was sent to public notice on December 22, 2006. A public meeting was requested, and was held on
February 2, 2007. Numerous comments were received on the draft permit. Responses to those comments, and a
summary of changes made to the draft permit, are in a separate document entitled "Division Response To Public
Comments." The permit will be sent to a second public notice on March 23, 2007. Any changes resulting from the
second public notice will be summarized in the rationale.
Kathleen Rosow
March 22, 2007
X. PUBLIC NOTICE — 3/23/07
The permit was sent to public notice for a second time on March 23, 2007. Numerous comments were received on the
second draft permit. Responses to those comments, and a summary of the additional changes made to the draft
permit, are contained in a separate document entitled `Division Response To Public Comments Part II". This
document is part of the rationale. Any changes based on the Division response are incorporated into the rationale and
permit. The response document is available online at
http://www.cdphe.state.co.us/wq/Permits Unit/stormwater/construction.html, or by emailing
cdphe.wqstorm@state.co.us, or by calling the Division at 303-692-3517.
Kathleen Rosow
May 31, 2007
Appendix D
Installation Details for Structural Best Management Practices
Williams..
Storm Water and 404 Manual of
Best Management Practices (BMPs)
January 2006
W
Storm Water and 404 Manual of
Best Management Practices
(BMPs)
Williams
Parachute, CO
Prepared by:
The RETEC Group, Inc.
1726 Cole Boulevard, Building 22, Suite 150
Golden, CO 80401-3213
RETEC Project Number: WPRO2-19093-501
Prepared for:
Williams
1058 County Road 215
P.O. Box 370
Parachute, CO 81635
January 26, 2006
Storm Water and 404 Manual of
Best Management Practices
(BMPs)
Williams
Parachute, CO
Prepared by:
The RETEC Group, Inc.
1726 Cole Boulevard, Building 22, Suite 150
Golden, CO 80401-3213
RETEC Project Number: WPRO2-19093-501
Prepared for:
Williams
1058 County Road 215
P.O. Box 370
Parachute, CO 81635
Prepared by:
Emily Schneider, Engineer
Reviewed by:
Thomas M. Kreutz, P.E., Senior Project Manager
January 26, 2006
G:\Projects\Williams E&P\2009 SWMP\HMI SWMP Updates\BMP Manual (Appendix D)\Storm Water Management Manual.doc
Table of Contents
1 Introduction 1
2 Determination of BMP Applicability 2
3 BMP Selection 4
Step 1 — Area of Construction 4
Step 2 — Stage of Construction 4
Step 3 — Type of control 4
Step 4 — BMP selection 5
4 BMP Implementation 6
5 Inspection and Maintenance 7
6 References 8
Figure la 10
Figure lb 11
Figure lc 12
Figure 2 13
i
1 Introduction
The primary purpose of this Storm Water and 404 Manual of BMPs is to
provide Williams' personnel, contractors, and subcontractors with information
on the proper selection, design, installation, and management of Best
Management Practices (BMPs) to manage oil and gas (O&G) related storm
water and to meet federal and state Storm Water Management Plan (SWMP)
implementation requirements. The BMPs found in this manual are operating
practices used to control erosion, runoff, and sedimentation associated with
storm water runoff from areas disturbed by clearing, grading, and excavating
activities related to site preparation and construction of oil and gas production
facilities. The BMPs were derived from both common industry practices and
from practical field experience.
Personnel responsible for storm water management, whether it be design,
construction, maintenance, or environmental compliance, should have a
thorough knowledge of the applicable erosion and sediment control measures
and the related specifications.
The main objectives of this manual are to:
1. Serve as an easy-to-use guide for selecting, designing,
constructing, and maintaining BMPs.
2. Function as a reference for construction plans and specifications.
3. Ultimately lead to the avoidance of any net increase in off-site
erosion and sedimentation of waters of the U.S. (see below).
4. Provide a basis for field handbooks and training.
In the preparation of this document, emphasis was placed on the selection and
practical application of BMPs, given a variety of basic physical
circumstances. This document is provided as a tool to quickly evaluate which
BMPs may be useful at a given construction site, whether new or existing.
This document anticipates that the user will be prudent and exercise good
judgment in evaluating site conditions and deciding which BMP or
combination of BMPs is to be used at a specific site. If the BMPs selected are
not effective to prevent discharges of potentially undesirable quantities of
sediment to a regulated water body, different or additional BMPs should be
employed.
Rev: 0
Date: 1/26/06
Page 1 Storm Water and 404 Manual of BMPs
2 Determination of BMP Applicability
There are several physical conditions that can determine whether BMPs are
applicable and if so, which BMPs will be effective at a given construction site.
Two primary factors are the proximity to waters of the U.S. (regulated water
body) and the amount of vegetative cover between the construction site and
the regulated water body. Other physical considerations include the slope of
the terrain, rainfall, and soil erodibility.
A regulated water body is any body of water that is subject to the U.S.
Environmental Protection Agency's (EPA's) jurisdiction under the Clean
Water Act. EPA's jurisdiction extends over "waters of the U.S." as defined in
33 CFR 328.
The U.S. Army Corps of Engineers regulates the discharge of dredge and fill
material into waters of the U.S. through a permit program under Section 404
of the Clean Water Act. The Corps jurisdiction over waters of the U.S.
includes major rivers, streams, and creeks such as the Colorado River,
Parachute Creek and Piceance Creek. Drainages and wetlands that are
tributary or adjacent to waters of the U.S. such as Wheeler Gulch, Riley
Gulch, Starkey Gulch, and Cottonwood Gulch are also typically considered by
the Corps to be waters of the U.S. and within their jurisdiction.
Williams' O&G operations are primarily located north and east of Parachute,
CO. Lower elevations at the site are categorized as deserts while higher
elevations (containing the majority of O&G sites) are categorized as xeric
mountains. Common characteristics of deserts include slopes from 0 to 40%,
shallow rocky or sandy soils with low erodibility, low vegetation cover, and
low annual precipitation. Common characteristics of xeric mountains include
slopes exceeding 10%, variable vegetation cover, shallow rocky soils with low
to moderate erodibility, and low to moderate annual precipitation.
In April 2004 Horizon Environmental Services, Inc. developed a Guidance
Document of Reasonable and Prudent Practices for Stabilization (RAPPS) of
Oil and Gas Construction Sites. For each region (deserts and xeric
mountains) the RAPPS document suggests minimum distances from a site to a
regulated body of water within which BMPs should be considered. For oil
and gas construction sites in desert locations, BMPs will be considered if the
site is located within 75 feet of a regulated water body. For roads, well pads,
and pipelines in excess of 75 feet, it is assumed that sediment transported from
these areas will not reach the stream channel. For oil and gas construction
sites in the xeric mountains, BMPs will be considered if the site is located
within 150 feet from a regulated water body. For roads, well pads, and
pipelines in excess of 150 feet, it is assumed that sediment transported from
these areas will not reach the stream channel.
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Page 2 Storm Water and 404 Manual of BMPs
For consideration of BMPs, this manual will be useful in determining which
BMPs would be effective for the given circumstances. The above identified
minimum distances were determined using the assumed general physical
characteristics for either deserts or xeric mountains. If local conditions in the
immediate area do not meet those for deserts or xeric mountains the user
should use good judgment in the determination of BMP applicability and
selection.
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3 BMP Selection
If it has been determined that BMPs are applicable to the construction site, the
following steps should be followed in order to select the most appropriate
BMP:
Step 1 — Area of Construction
In what area of construction is the BMP required? Choose one of the
following:
• Access roads
• Well pads (including any aerial disturbance such as compressors,
plants, etc.)
• Pipelines
Step 2 — Stage of Construction
In what stage of construction will the BMP be installed? Choose one of the
following:
• Pre -construction - Refers to all BMPs that could be implemented
prior to commencement of construction on well pads, pipelines,
and/or roads.
• Construction - Refers to all BMPs that could be implemented
during/as part of the construction of well pads, pipelines, and/or
roads.
• Interim (Temporary) Reclamation - Refers to all BMPs that could be
implemented on completion of construction for temporary
reclamation of well pads.
• Final (Permanent) Reclamation - Refers to all BMPs that could be
implemented on completion of construction OR on completion of
any interim time period for permanent reclamation of well pads,
pipelines, and/or roads.
Step 3 — Type of control
What is the primary purpose of the BMP and what will the BMP control?
Choose from one of the following three main types of storm water control
measures:
• Erosion Control (EC) — any source control practice that protects the
soil surface and/or strengthens the subsurface in order to prevent
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soil particles from being detached by rain or wind, thus controlling
raindrop, sheet, and/or rill erosion.
• Runoff Control (RC) — any practice that reduces or eliminates gully,
channel, and stream erosion by minimizing, diverting, or
conveying runoff.
• Sediment Control (SC) — any practice that traps the soil particles
after they have been detached and moved by wind or water.
Sediment control measures are usually passive systems that rely on
filtering or settling the particles out of the water or wind that is
transporting them prior to leaving the site boundary.
Step 4 — BMP selection
Which BMP will be used? Once the area of construction, stage of
construction, and type of control are determined (steps 1 through 3), use the
BMP Matrix (Figures 1A, 1B, and 1C, below) to find suggested BMP
alternatives. Each BMP is also numbered, which corresponds to a fact sheet.
A fact sheet is a short document that gives all the information about a
particular BMP. Typically, each fact sheet contains the following
information:
• Description
• Applicability
• Limitations
• Design Criteria
• Construction Specifications
• Maintenance Considerations
• Removal
• References
The applicability section in each fact sheet contains information on specific
site characteristics (such as slope and drainage area) where that BMP may be
used. Determination of which BMP or combination of BMPs to install should
ultimately be decided after reviewing the BMP applicability section.
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4 BMP Implementation
Once this manual has been used to choose specific BMPs, each control should
be incorporated into a site-specific plan drawing. Each BMP has a symbol
that should be used on plan drawings to represent that BMP at the desired
location of installation. Each symbol is listed in Figure 2, below, for
convenience. All symbols include a letter or combination of letters to identify
the BMP, such as SBB to indicate a straw bale barrier. There are three main
types of symbols. BMPs that cover an area, such as surface roughening,
mulching and seeding, will consist of a hatch over the entire area of
implementation with the letter identifier circled within the hatched area. If a
single area is to be temporarily seeded and mulched, the area will be hatched
and include both circled identifiers (VEGT and MLCH). BMPs that will be
installed linearly, such as silt fencing or a swale, will consist of a line broken
periodically with the circled identifier. BMPs that will be installed at a spot
location, such as a sediment basin or a level spreader, will consist only of the
circled identifier.
The design criteria section in each BMP fact sheet should be used to properly
locate and size each control (some controls may not require a formal design).
The construction requirements and installation figures should then be used in
the field to properly install the control with the appropriate materials and
methods of construction and at the location indicated on the site-specific plan
drawings.
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5 Inspection and Maintenance
All BMPs must be properly inspected and maintained throughout the life of
the entire operation according to the "Maintenance Considerations" section in
each BMP fact sheet. In general, the maintenance program should provide for
inspection of BMPs on a regular basis. Inspection of BMPs should also occur
as soon as possible after major rainfall events, particularly at sensitive areas in
proximity to a perennial drainage. The inspection should include repair of the
BMPs, where needed, to ensure effective and efficient operation.
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6 References
California Stormwater Quality Association, Stormwater Best Management
Practice (BMP) Handbook — Construction. January, 2003.
<http://www.cabmphandbooks.com/Construction.asp>
City of Knoxville, Stormwater Engineering, Knoxville BMP Manual - Best
Management Practices. July 2003.
<http://www.ci.knoxville.tn.us/engineering>
Colorado Department of Transportation (CDOT), Erosion Control and
Stormwater Quality Guide. 2002.
<http : //www. dot. state. c o . us/environmental/env W aterQual/wgms4. asp>
Environmental Protection Agency (EPA), National Pollutant Discharge
Elimination System (NPDES). Construction Site Storm Water Runoff
Control. Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and
Prudent Practices for Stabilization (RAPPS) of Oil and Gas
Construction Sites. April 2004.
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of
Agriculture (USDA), Forest Service, US Agency of International
Development (USAID), 2005.
<http://www.blm.gov/bmp/field%20guide.htm>
Maine Department of Conservation, Best Management Practices for Forestry:
Protecting Maine's Water Quality. Maine Forest Service, Forest
Policy and Management Division. Augusta, Maine. 2004.
<http ://www. state. me.us/doc/mfs/pubs/pdf/bmp_manual/bmp_manual.pdf5
New York State Department of Environmental Conservation, New York
Guidelines for Urban Erosion and Sediment Control. New York.
Fourth Edition, 1997.
<http://www.dec . state.ny.us/website/dow/toolbox/escstandards>
United States Army Corps of Engineers (USACE), Engineering and Design -
Handbook for the Preparation of Storm Water Pollution Prevention
Plans for Construction Activities. February 1997.
<http://www.usace.army.mil/inet/usace-docs/eng-pamphlets/ep 1110-1-16/>
United States Department of Agriculture (USDA), Natural Resources
Conservation Service (NRCS), Field Office Technical Guide. 2002.
<www.nrcs.usda.gov/technical/efotg>
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Page 8 Storm Water and 404 Manual of BMPs
United States Department of the Interior, Bureau of Land Management
(BLM), United States Department of Agriculture (USDA), Forest
Service, Surface Operating Standards for Oil and Gas Exploration
and Development "Gold Book". Fourth Edition, 2005.
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Page 9 Storm Water and 404 Manual of BMPs
Figure 1A - BMP Matrix - Erosion Control
WELL PADS
PIPELINES
ROADS
Pre -Construction
Construction
Interim (Short -Term) Restoration
Final (Long -Term) Reclamation
Pre -Construction
Construction
Final Restoration
Pre -Construction
Construction
Final Restoration
Erosion Control (EC
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Page 10 Figure 1A
Protect Surface/Stabilize Soil
EC -1
Land Grading - Wellpads & Pipelines
X
X
X
X
X
EC -2
Land Grading - Roads
X
X
EC -3
Road Gravel
X
EC -4
Surface Roughening
X
X
X
X
EC -5
Temporary Vegetation
X
EC -6
Permanent Vegetation
X
X
X
EC -7
Mulching
X
X
X
X
EC -8
Wattles
X
X
X
X
X
X
EC -9
Erosion Control Blanket
X
X
X
X
EC -10
Low Water Crossing
X
EC -11
Brush Matting
X
X
X
X
X
X
X
EC -12
Terracing
X
X
X
X
EC -13
Preserve Existing Vegetation
X
X
X
X
EC -15
Slope Drain
X
X
EC -16
Brush Layering
X
X
X
X
EC -17
Gabions
X
X
EC -18
Level Spreader
X
X
X
EC -19
Retaining Wall
X
X
X
EC -20
Chemical Stabilization
X
X
Strengthen Subsurface
EC -5
Temporary Vegetation
X
EC -6
Permanent Vegetation
X
X
X
EC -14
Vegetated Buffer
X
X
X
EC -16
Brush Layering
X
X
X
X
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Page 10 Figure 1A
Figure 1B - BMP Matrix - Runoff Control
WELL PADS
PIPELINES
ROADS
Pre -Construction
Construction
Interim (Short -Term) Restoration
Final (Long -Term) Reclamation
Pre -Construction
Construction
Final Restoration
Pre -Construction
Construction
Final Restoration
Runoff Control (RC
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Page 11 Figure 1B
Convey Runoff
RC -1
Roadside & Turnout Ditches
X
X
X
RC -2
Culvert Cross -Drain
X
RC -10
Temporary Swale
X
X
X
RC -11
Temporary Diversion
X
X
X
RC -12
Permanent Diversion
X
X
X
EC -15
Slope Drain
X
X
Divert Runoff
RC -1
Roadside & Turnout Ditches
X
X
X
RC -6
Road Slope
X
RC -7
Drainage Dip
X
RC -8
Temporary Berm
X
X
X
RC -11
Temporary Diversion
X
X
X
RC -13
Water Bar
X
Reduce Velocity
RC -4
Riprap
X
X
X
RC -9
Culvert Inlet Protection
X
RC -3
Culvert Outlet Protection
X
RC -5
Check Dam
X
X
X
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Page 11 Figure 1B
Figure 1C — BMP Matrix — Sediment Control
WELL PADS
PIPELINES
ROADS
Pre -Construction
Construction
Interim (Short -Term) Restoration
Final (Long -Term) Reclamation
Pre -Construction
Construction
Final Restoration
Pre -Construction
Construction
Final Restoration
Sediment Control (SC)
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Page 12 Figure 10
Filter Sediment
SC -1
Straw Bale Barrier
X
X
X
SC -2
Silt Fence
X
X
X
SC -5
Brush Barrier
X
X
X
X
X
X
SC -7
Filter Berm
X
X
X
SC -9
Wind Fence
X
X
X
EC -8
Wattles
X
X
X
X
X
X
RC -5
Check Dam
X
X
X
Trap Sediment
SC -3
Sediment Basin
X
X
X
SC -6
Sediment Trap
X
X
X
SC -8
Rock Dam
X
X
X
RC -5
Check Dam
X
X
X
Control Mud/Dust
SC -4
Stabilized Construction Entrance
X
X
X
EC -3
Road Gravel
X
EC -10
Low Water Crossing
X
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Page 12 Figure 10
Figure 2 - BMP Symbols
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Page 13 Figure 2
EC -1 Land Grading — Well Pads and
Pipelines
Description
Land grading involves reshaping the ground surface to planned grades as determined
by an engineering survey, evaluation, and layout. Land grading provides more
suitable topography for well pads and pipelines and helps to control surface runoff,
soil erosion, and sedimentation during and after construction in these areas.
Applicability
Land grading is applicable to sites with uneven or steep topography or easily erodible
soils, because it stabilizes slopes and decreases runoff velocity. All land grading for
well pads and pipelines, including stockpiles, borrow areas, and spoil, shall be subject
to the provisions of this standard.
Limitations
• Improper grading practices that disrupt natural storm water patterns might
lead to poor drainage, high runoff velocities, and increased peak flows
during storm events.
• Clearing and grading of the entire site without vegetated buffers or other
controls promotes off-site transport of sediments and other pollutants.
• The grading plan must be designed with erosion and sediment control and
storm water management goals in mind
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EC -1 Land Grading
Page 1 of 4 Well Pads and Pipelines
Design Criteria
Grading Plan
A grading plan should be prepared that establishes which areas of the site will be
graded, how drainage patterns will be directed, and how runoff velocities will affect
receiving waters. The grading plan also includes information regarding when
earthwork will start and stop, establishes the degree and length of finished slopes, and
dictates where and how excess material will be disposed of (or where borrow
materials will be obtained if needed). Practices must be developed for erosion
control, slope stabilization, and safe disposal of runoff water and drainage, such as
waterways, lined ditches, reverse slope benches (include grade and cross section),
grade stabilization structures, retaining walls, and surface drains. Berms, diversions,
and other storm water practices that require excavation and filling also should be
incorporated into the grading plan.
Land grading should be based upon well pad and pipeline layouts that fit and utilize
existing topography and desirable natural surroundings to avoid extreme grade
modifications. Clearing and grading should only occur at those areas necessary for
well pad activities and equipment traffic. Maintaining undisturbed temporary or
permanent buffer zones in the grading operation provides a low-cost sediment control
measure that will help reduce runoff and off-site sedimentation.
Construction Specifications
1. All applicable erosion and sediment control practices and measures shall
be constructed prior to any land grading activities, and maintained in
accordance with this BMP manual. Control practices should remain in
place until all graded or disturbed areas, including slopes, are adequately
stabilized.
2. Cut and fill slopes that are to be stabilized with grasses shall not be steeper
than 2:1. When slopes exceed 2:1, special design and stabilization
consideration are required.
3. Areas to be filled shall be cleared, grubbed, and stripped of topsoil to
remove trees, vegetation, roots, or other objectionable material.
4. Except for nonstructural fills, fill material shall be free of brush, logs,
stumps, roots, or other objectionable materials that would interfere with,
or prevent, construction of satisfactory fills. Frozen material shall not be
placed in the fill nor shall the fill material be placed on a frozen
foundation.
5. All fills shall be compacted as required to reduce erosion, slippage,
settlement, subsidence, or other related problems. Fill intended to support
buildings, structures, and conduits, etc., shall be placed in layers not to
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EC -1 Land Grading
Page 2 of 4 Well Pads and Pipelines
exceed nine inches and compacted in accordance with local requirements
or codes.
6. Cut slopes occurring in ripable rock shall be serrated as shown in
Figure EC -1-1. The serrations shall be made with conventional equipment
as the excavation is made. Each step or serration shall be constructed on
the contour and will have steps cut at nominal two -foot intervals with
nominal three-foot horizontal shelves. These steps will vary depending on
the slope ratio or the cut slope. The nominal slope line is 1 '/2: 1. These
steps will weather and act to hold moisture, lime, fertilizer, and seed thus
producing a much quicker and lasting vegetative cover and better slope
stabilization. Overland flow shall be diverted from the top of all serrated
cut slopes and carried to a suitable outlet.
7. Topsoil required for the establishment of vegetation shall be stockpiled in
the amount necessary to complete finished grading of all exposed areas.
8. Areas that are to be topsoiled shall be scarified to a minimum depth of
four inches prior to placement of topsoil.
9. Reverse slope benches (terraces) shall be provided whenever the vertical
interval (height) of any 2:1 slope exceeds 20 feet; for 3:1 slope it shall be
increased to 30 feet and for 4:1 to 40 feet. Benches shall be designed
according to EC -12 Terracing.
10. To ensure that surface runoff will not damage slopes or other graded areas,
diversions or slope drains will be used to safely direct surface runoff to
storm drains, protected outlets, or to stable water courses, except where:
a. The face of the slope is or shall be stabilized and the face of all graded
slopes shall be protected from surface runoff until they are stabilized.
b. The face of the slope shall not be subject to any concentrated flows of
surface water such as from natural drainage ways, graded swales,
downspouts, etc.
c. The face of the slope will be protected by special erosion control
materials, gravel, riprap, or other stabilization method.
11. All graded areas shall be permanently stabilized, either structurally or
vegetatively, immediately following finished grading.
Maintenance Considerations
All graded areas and supporting erosion and sediment control practices should be
periodically checked, especially following heavy rainfalls. All sediment should be
removed from diversions or other storm water conveyances promptly. If washouts
or breaks occur, they should be repaired immediately. Prompt maintenance of
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EC -1 Land Grading
Page 3 of 4 Well Pads and Pipelines
small-scale eroded areas is essential to prevent these areas from becoming significant
gullies.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control. Washington,
D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Figure EC -1-1
Typical Section of Serrated Cut Slope
/\/
\�\\ mayA:\ \
NOT TO SCALE
• r
or steeper 1-5
\/ /\// \
/\ \/\%,.//\//,i\\/ /\/
i\.
,/j\/ \�\ jam/��// \/,
Diversion
//////// /
�ce<�\���INTCH
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EC -1 Land Grading
Page 4 of 4 Well Pads and Pipelines
EC -2 Land Grading - Roads
Description
Land grading of roads involves reshaping the ground surface to planned grades as
determined by an engineering survey, evaluation, and layout. The objectives of
routine road cuts and fills are:
• To create space for the road template and driving surface
• To balance material between the cut and fill
• To remain stable over time
• To not be a source of sediment
Applicability
Land grading of roads is applicable to sites with uneven or steep topography or easily
erodible soils, because it stabilizes slopes and decreases runoff velocity. Land
grading should be based upon road layouts that fit and utilize existing topography and
desirable natural surroundings to avoid extreme grade modifications.
Limitations
• Improper grading practices that disrupt natural storm water patterns might
lead to poor drainage, high runoff velocities, and increased peak flows
during storm events.
• The grading plan must be designed with erosion and sediment control and
storm water management goals in mind
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Page 1 of 6 EC -2 Land Grading - Roads
Design Criteria
Grading Plan
A grading plan should be prepared that establishes the extent to which the road will
be graded, how drainage patterns will be directed, and how runoff velocities will
affect receiving waters. The grading plan also includes information regarding when
earthwork will start and stop, establishes the degree and length of finished slopes, and
dictates where and how excess material will be disposed of (or where borrow
materials will be obtained if needed). Practices must be developed for erosion
control, slope stabilization, and safe disposal of runoff water and drainage, such as
ditches and culverts, grade stabilization structures, retaining walls, and surface drains.
Berms, diversions, and other storm water practices that require excavation and filling
also should be incorporated into the grading plan.
Slope Failures
Landslides and failed road cuts and fills can be a major source of sediment, they can
close the road or require major repairs, and they can greatly increase road
maintenance costs. Slope failures, or landslides, typically occur where a slope is
over -steep, where fill material is not compacted, or where cuts in natural soils
encounter groundwater or zones of weak material. Good road location can often
avoid landslide areas and reduce slope failures. When failures do occur, the slide area
should be stabilized by removing the slide material, flattening the slope, adding
drainage, or using structures, as discussed below. Designs are typically site specific
and may require input from geotechnical engineers and engineering geologists.
Failures that occur typically impact road operations and can be costly to repair.
Failures near streams and channel crossings have an added risk of impact to water
quality.
Construction Specifications
1. All applicable erosion and sediment control practices and measures shall
be constructed prior to any road grading activities, and maintained in
accordance with this BMP manual. Control practices should remain in
place until all graded or disturbed areas, including slopes, are adequately
stabilized.
2. Areas to be filled shall be cleared, grubbed, and stripped of topsoil to
remove trees, vegetation, roots, or other objectionable material.
3. Fill material shall be free of brush, logs, stumps, roots, or other
objectionable materials that would interfere with, or prevent, construction
of satisfactory fills. Frozen material shall not be placed in the fill nor shall
the fill material be placed on a frozen foundation.
4. Table EC -2-1 presents a range of commonly used cut and fill slope ratios
appropriate for the soil and rock types described. Figures EC -2-1 and
EC -2-2 present typical fill slope and cut slope design options for varying
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Page 2 of 6 EC -2 Land Grading - Roads
slope and site conditions. Vertical cut slopes should not be used unless the
cut is in rock or very well cemented soil. Ideally, both cut and fill slopes
should be constructed with a 2:1 or flatter slope to promote growth of
vegetation, but cut slopes in dense, sterile soils or rocky material are often
difficult to vegetate.
5. All fills shall be compacted as required to reduce erosion, slippage,
settlement, subsidence, or other related problems. Fill intended to support
buildings, structures, and conduits, etc., shall be placed in layers not to
exceed nine inches and compacted in accordance with local requirements
or codes.
6. Topsoil required for the establishment of vegetation shall be stockpiled in
the amount necessary to complete finished grading of all exposed areas.
7. Areas that are to be topsoiled shall be scarified to a minimum depth of
four inches prior to placement of topsoil.
8. Reverse slope benches (terraces) shall be provided whenever the vertical
interval (height) of any 2:1 slope exceeds 20 feet; for 3:1 slope it shall be
increased to 30 feet and for 4:1 to 40 feet. Benches shall be designed
according to EC -12 Terracing.
9. To ensure that surface runoff will not damage slopes or other graded areas,
diversions or slope drains will be used to safely conduct surface runoff to
storm drains, protected outlets, or to stable water courses, except where:
a. The face of the slope is or shall be stabilized and the face of all graded
slopes shall be protected from surface runoff until they are stabilized.
b. The face of the slope shall not be subject to any concentrated flows of
surface water such as from natural drainage ways, graded swales,
downspouts, etc.
c. The face of the slope will be protected by special erosion control
materials, gravel, riprap, or other stabilization method.
10. All graded areas shall be permanently stabilized, either structurally or
vegetatively, immediately following finished grading. The following list
are some common slope stabilization options appropriate for roads:
a. Vegetate the slope (EC -6 Permanent Vegetation)
b. Use an erosion control blanket (EC -9 Erosion Control Blanket)
c. Cover the slope with riprap (RC -4 Riprap)
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Page 3 of 6 EC -2 Land Grading - Roads
d. Design and construct gabions (EC -17 Gabions) or retaining walls
(EC -19 Retaining Wall)
Maintenance Considerations
All graded areas and supporting erosion and sediment control practices should be
periodically checked, especially after heavy rainfalls. All sediment should be
removed from diversions or other storm water conveyances promptly. If washouts or
breaks occur, they should be repaired immediately. Prompt maintenance of
small-scale eroded areas is essential to prevent these areas from becoming significant
gullies.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa. gov/npdes/stormwater/menuofbmps/con_site.cfm>
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Table EC -2-1
Stable Slope Ratios for Various Conditions
Soil/Rock Condition
Slope Ratio
(Hor:Vert)
Most rock
%:1 to 1/2:1
Very well cemented soils
%:1 to 1/2:1
Most in-place soils
3/4:1 to 1:1
Very fractured rock
1:1 to 1 1/2: 1
Loose coarse granular soils
1 %: 1
Heavy clay soils
2:1 to 3:1
Soft clay rich zones or wet
seepage areas
2;1 to 3:1
Fills of most soils
1 %2:1 to 2:1
Fills of hard, angular rock
1 1/3 :1
Low cuts and fills
(<10 ft high)
2:1 or flatter
(for revegetation)
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Page 4 of 6 EC -2 Land Grading - Roads
Figure EC -2-1
Fill Slope Design Options
a. Typical Fill
Note: Side -cast till material only
on gentle slopes, away from streams
Fs
L Benched Slope Fill
with Layer Placement
On ground where slopes exceed
40-45%, construct benches ± 10
ft. wide or wide enough for
excavation and compaction
equipment.
c. Reinforced Fill
Reinforced fills are used on steep
ground as an altemative to retaining
structures. The 1:1 (oversteep) face
usually requires stabilization -
d. Through Fill
NOT TO SCALE
Long fill
slope 2:1
Brush or Other Sediment
Control (typ.)
Nifr
Road
Road
Scarify and remove
organic material
Short fill
slope 3:1
Drain
Ground Surface
0-40% Ground Slopes
Ground Surface
Road
40.60% Ground Slopes
Fill material placed in layer. Use
lifts of 6 to 12 in. thick. Compact
to specified density or wheel roll
each layer -
Ground Surface
Road
Typically
gp%+ Ground Slopes
Geognd orgeotexhte
reinforcement layers
Ground Surface
0-40% Ground Slopes
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Page 5 of 6 EC -2 Land Grading - Roads
Figure EC -2-2
Cut Slope Design Options
a. Balanced Cut and Fill b. Full Bench Cut
Ground Surface
Use a Balanced Cut and fill
Section for Moet Conshuction
on Hill slopes
Typical Cut slopes in
Most Soils o:1 to 1:1
Road Cut Typical Cut slopes in Typical rock
— Fill
Brush or Ther Sediment Control
0.60% Ground Slopes
c. Through Cut
.7
Road
Ground Surface
Low Cut Can be Steep or Flatter
0.60% Ground Slopes
Most Soils ;:1 to 1:1 Cut Slopes
,:1 to z:1
High Cut Typically
Sleeper Where Stable
Road
Use Full Bench Guts When the
Ground slopes Exceed ± 60%
60%+ Ground Slopes
NOT TO SCALE
Rev.: 0
Date: 1/26/06
Page 6 of 6 EC -2 Land Grading - Roads
EC -3 Road Gravel (RG)
Description
Road gravel is used to stabilize soft road sections, prevent erosion (particularly on
steep slopes), limit dust from passing vehicles, and reduce the amount of mud that
may develop during wet weather.
Applicability
Road gravel should be used for "soft" road sections, steep grades, highly erosive
soils, or where all-weather access is needed. Road gravel may be used as "fill"
material in ruts or as a full structural section over the entire road.
Limitations
• Rutting and washboarding may develop if the surface gravel is too thin,
has poor gradation, has little or no binding characteristic, or has a low
percentage of fractured stone.
• Flat-blading to maintain the roadway must be done properly to avoid
changes in gravel thickness, road slope, and road grade.
Design Criteria
No formal design is required.
Construction Specifications
1. Maintain a 3-5% road cross -slope with insloping, outsloping, or a crown
to rapidly move water off the road surface (see RC -6 Road Slope).
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Date: 1/26/06
Page 1 of 3 EC -3 Road Gravel
2. Gradation of gravel should be according to Figure EC -3-1. This figure
shows the typical gradation ranges of aggregates used in road
construction, how the materials, ranging from coarse to fine, best perform
for a road, and the approximate limitations to the desirable gradation
ranges. Ideally, aggregate surfacing material is (1) hard, durable, and
crushed or screened to a minus 2 inch size; (2) well graded to achieve
maximum density; (3) contains 5-15% clayey binder to prevent raveling;
and (4) has a Plasticity Index of 2 to 10.
3. Gravel should be placed to a thickness of at least twice the diameter of the
largest stone with a minimum thickness of four inches. Over very weak
soils gravel thickness can be reduced with the use of geotextile or geogrid
subgrade reinforcement. Also, geotextile layers are useful over soft soils
to separate the gravel from the soil, keep it uncontaminated, and extend
the useful life of the gravel.
4. Compact the aggregate during construction and maintenance to achieve a
dense, smooth road surface and thus reduce the amount of water that can
soak into the road.
5. "Spot" stabilize local wet areas and soft areas with four to six inches of
coarse rocky material. Add more rock as needed.
6. Stabilize the road surface in sensitive areas near streams and at drainage
crossings to minimize road surface erosion.
7. Control excessive road dust.
8. Blend coarse aggregate and fine clay -rich soil (when available) to produce
a desirable composite roadway material that is coarse yet well -graded with
5-15 % fines for binder.
Maintenance Considerations
The gravel applied to the road must be maintainable in order to prevent and control
rutting and erosion. The road surface and shoulders should be periodically smoothed
and reshaped with a grader blade (flat-blading). This should be done when the gravel
is moist. Maintain the proper road slope and grade while flat-blading. Also be sure
to avoid plugging roadside ditches or altering adjacent drainage structures, as this
may cause them to not function properly. Flat-blading may also cause road gravel to
be pushed off the main roadway and onto the shoulders. To avoid this, blade toward
the center of the road.
Rev: 0
Date: 1/26/06
Page 2 of 3 EC -3 Road Gravel
References
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. http://www.blm.gov/bmp/field%20guide.htm
z
ccF�.
x
Figure EC -3-1
Gradation and Performance of
Roadway Surfacing Materials
SIEVE ANALYSIS
Size of opening' Ir+ Inches
Noomoor of Mesh - U.S. Standard
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W
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NOTE: (�radatio�u Ranges Shown Are Approximate.
1 J MA@ UattIVOINW.103d
Rev: 0
Date: 1/26/06
Page 3 of 3 EC -3 Road Gravel
EC -4 Surface Roughening (SR)
Tracking
Grooving
Stair Stepping
Description
Surface (soil) roughening is a temporary erosion control practice often used in
conjunction with grading (EC -1 Land Grading — Well pads and Pipelines, EC -2 Land
Grading - Roads). Soil roughening involves increasing the relief of a bare soil
surface with horizontal grooves, stair -stepping (running parallel to the contour of the
land), or tracking using construction equipment. Slopes that are not fine graded and
that are left in a roughened condition can also reduce erosion. Soil roughening
reduces runoff velocity, increases infiltration, reduces erosion, traps sediment, and
prepares the soil for seeding and planting by giving seed an opportunity to take hold
and grow.
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Page 1 of 4 EC -4 Surface Roughening
Applicability
Soil roughening is most effective on areas on one acre or less, and works well for the
following applications:
• To aid the establishment of vegetative cover from seed
• To reduce runoff velocity and increase infiltration
• To reduce erosion and provide for trapping of sediment
• Any slope, but particularly slopes greater than 3:1
• Areas with highly erodible soils
• Soils that are frequently disturbed
Limitations
• Soil roughening is not appropriate for rocky slopes.
• Soil compaction might occur when roughening with tracked machinery.
• Soil roughening is of limited effectiveness in anything more than a gentle
or shallow depth rain.
• If roughening is washed away in a heavy storm, the surface will have to be
re -roughened and new seed laid.
Design Criteria
There are many different methods to achieve a roughened soil surface on a slope. No
formal design required. However, the selection of the appropriate method depends on
the type of slope. Methods include tracking, grooving, and stair -stepping. Steepness,
mowing requirements, and/or a cut or fill slope operation are all factors considered in
choosing a roughening method.
Tracking
Tracking should be used primarily in sandy soils to avoid undue compaction of the
soil surface. Tracking is generally not as effective as the other roughening methods
described. (It has been used as a method to track down mulch.) Operate tracked
machinery up and down the slope to leave horizontal depressions in the soil. Do not
back -blade during the final grading operation.
Grooving
Grooving (Figure EC -4-1) uses machinery to create a series of ridges and depressions
that run across the slope on the contour. Groove using any appropriate implement
that can be safely operated on the slope, such as disks, tillers, spring harrows, or the
teeth of a front-end loader bucket. Do not make the grooves less than 3 inches deep
or more than 15 inches apart.
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Page 2 of 4 EC -4 Surface Roughening
Stair -stepping
Stair -stepping (Figure EC -4-2) should be used on any erodible material that is soft
enough to be ripped with a bulldozer. Slopes consisting of soft rock with some
subsoil are particularly suited to stair -step grading. The vertical cut distance should
be less than the horizontal distance, and the horizontal portion of the step should be
slightly sloped toward the vertical wall.
Construction Specifications
To slow erosion, roughening should be done as soon as possible after grading
activities have ceased (temporarily or permanently) in an area. Excessive compacting
of the soil surface should be avoided during roughening, and areas should be seeded
as quickly as possible after roughening is complete.
1. Roughening for a Cut Slope:
a. Stair -step grade (Figure EC -4-2) or groove cut (Figure EC -4-1) slopes
with a gradient steeper than 3.1
b. Use stair -step grading on any erodible material soft enough to be
ripped with a bulldozer. Slopes of soft rock with some soil are
particularly suited to stair -step grading.
c. Make the vertical cut distance less than the horizontal distance, and
slightly slope the horizontal position of the step to the vertical wall.
d. Do not make vertical cuts more than two feet in soft materials or
three feet in rocky materials.
2. Roughening for a Fill Slope:
a. Place fill to create slopes with a gradient steeper than 3:1 in lifts
nine inches or less and properly compacted. Ensure the face of the
slope consists of loose, uncompacted fill four to six inches deep. Use
grooving (Figure EC -4-1) as described above to roughen the slope, if
necessary.
b. Do not blade or scrape the final slope face.
Maintenance Considerations
Areas need to be inspected as soon as possible after storms, since roughening might
need to be repeated. Regular inspection of roughened slopes will indicate where
additional erosion and sediment control measures are needed. If rills appear, they
should be filled, graded again, and reseeded immediately. Proper dust control
methods should be used.
Rev: 0
Date: 1/26/06
Page 3 of 4 EC -4 Surface Roughening
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Figure EC -4-1
Grooving
•-•.� 15" max.
3' Max.
GROOVE BY CUTTING FURROWS ALONG
THE CONTOUR. IRREGULARITIES IN THE
SOIL SURFACE CATCH RAINWATER AND
RETAIN LIME, FERTILIZER AND SEED,
NOT TO SCALE
i
CUT STEPS WITH DRAINAGE TO
THE BACK. AVOID LOW SPOTS.
NOT TO SCALE
Figure EC -4-2
Stair Stepping
\ ;a
DEBRIS FROM
SLOPE ABOVE IS
CAUGHT BY STEPS
2' MAX. IN
SOFT MATERIALS,
3' MAX. IN
ROCKY MATERIALS
GREATER THAN
VERTICAL
Rev: 0
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Page 4 of 4 EC -4 Surface Roughening
EC -5 Temporary Vegetation (VEGT)
Description
Temporary vegetation involves the establishment of a temporary vegetative cover on
disturbed areas by seeding with appropriate rapidly growing annual plants. Annual
plants which sprout rapidly and survive for only one growing season are suitable for
establishing temporary vegetative cover.
Temporary vegetation reduces erosion and sedimentation by stabilizing disturbed
areas that will not be brought to final grade for a period of more than 30 days.
Temporary vegetation also reduces damage from sediment and runoff to downstream
or off-site areas, and provides protection to bare soils exposed during construction
until permanent vegetation or other erosion control measures can be established.
Applicability
Temporary vegetation is most effective on slopes no steeper than 2.1 and may be used
in areas where exposed soil surfaces are not to be regraded for periods longer than
30 days. Such areas include denuded areas, soil stockpiles, dikes, dams, sides of
sediment basins, temporary road banks, etc. A permanent vegetative cover (see
EC -6 Permanent Vegetation) shall be applied to areas that will be left dormant for a
period of more than one year.
Limitations
• The effectiveness of seeding can be limited due to high erosion potential
during establishment and the need for stable soil temperature and soil
moisture content during germination and early growth.
• Proper seedbed preparation and the use of quality seed are important in
this practice just as in permanent seeding. Failure to carefully follow
sound agronomic recommendations will often result in an inadequate
stand of vegetation that provides little or no erosion control.
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Page 1 of 3 EC -5 Temporary Vegetation
Design Criteria
Successful plant establishment can be maximized with proper planning; consideration
of soil characteristics; selection of plant materials that are suitable for the site;
adequate seedbed preparation, liming, and fertilization; timely planting; and regular
maintenance.
When to Seed
Areas to be stabilized with temporary vegetation must be seeded or planted one to
four months after grading unless temporary stabilization measures are in place.
Seed Selection
Select plants appropriate to the season and site conditions from the following table.
Note that this table presents plants which can be used without extensive evaluation of
site conditions.
Planting Dates
Species
Rate
(Lbs/acre)
Sept. 1 — Feb. 15
50/50 Mix of Annual Ryegrass (Lolium
multi-florum) & Cereal (Winter) Rye
(Secale cereale)
50 - 100
Feb. 16 — Apr. 30
Annual Ryegrass (Lolium multi-florum)
60 - 100
May 1 — Aug. 31
German Millet (Setaria italica)
50
Amendments
An evaluation should be conducted to determine if lime is necessary for temporary
seeding. In most soils, it takes up to six months for a pH adjustment to occur
following the application of lime. Therefore, it may be difficult to justify the cost of
liming a temporary site, especially when the soil will later be moved and regraded.
Construction Specifications
1. Seeding does not immediately stabilize soils. Prior to seeding, install
necessary erosion and sediment control practices such as diversions, straw
bales, and basins until vegetation is established.
2. To control erosion on bare soil surfaces, plants must be able to germinate
and grow. Seedbed preparation is essential.
a. Fertilizer may be applied as 600 lbs/acre of 10-20-10 or equivalent
nutrients. Lime and fertilizer may be incorporated into the top two to
four inches of the soil if possible. The following table includes
suggested lime application rates:
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Page 2 of 3 EC -5 Temporary Vegetation
pH Test
Recommended Application
of Agricultural Limestone
below 4.2
3 tons per acre
4.2 to 5.2
2 tons per acre
5.2 to 6.0
1 tons per acre
b. Surface Roughening: If the area has been recently loosened or
disturbed, no further roughening is required. When the area is
compacted, crusted, or hardened, the soil surface shall be loosened by
disking, raking, harrowing, or other acceptable means (see
EC -4 Surface Roughening).
3. The appropriate seed shall be evenly applied with a broadcast seeder, drill,
cultipacker seeder or hydroseeder. Small grains shall be planted no more
than 1.5 inches deep. Small seeds, such as Kentucky Bluegrass, should be
planted no more than 0.25 inches deep. Other Grasses and Legumes
should be planted from 0.25 inch to 0.5 inches deep.
4. Seedings made in fall for winter cover and during hot and dry summer
months shall be mulched according to EC -7 Mulching and using straw
mulch. Temporary seedings made under favorable soil and site conditions
during optimum spring and fall seeding dates may not require mulch.
Maintenance Considerations
Inspect seeded areas periodically. Areas which fail to establish vegetative cover
adequate to prevent rill erosion will be reseeded as soon as such areas are identified.
References
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
United States Army Corps of Engineers (USACE), Engineering and Design -
Handbook for the Preparation of Storm Water Pollution Prevention Plans for
Construction Activities. February 1997.
<http://www.usace.army.mil/inet/usace-docs/eng-pamphlets/ep 1110-1-16/>
Rev: 0
Date: 1/26/06
Page 3 of 3 EC -5 Temporary Vegetation
EC -6 Permanent Vegetation (VEGP)
Description
Permanent vegetation involves the establishment of perennial vegetative cover on
disturbed areas by planting seed. Permanent vegetation reduces erosion, decreases
sediment yield from disturbed areas, and permanently stabilizes disturbed areas in a
manner that is economical, adaptable to site conditions, and allows selection of the
most appropriate plant materials. Vegetation also improves wildlife habitat, and
enhances natural beauty.
Applicability
Permanent vegetation is well-suited in areas where permanent, long-lived vegetative
cover is needed to stabilize the soil. Permanent vegetation is most effective on slopes
no steeper than 2.1 and may be used for final reclamation or on roughly graded areas
that will not be brought to final grade for a year or more.
Limitations
The effectiveness of vegetation can be limited due to the following:
• High erosion potential during establishment.
• The need to reseed areas that fail to establish.
• Limited seeding times depending on the season.
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Page 1 of 5 EC -6 Permanent Vegetation
• The need for stable soil temperature and soil moisture content during
germination and early growth.
Design Criteria
Successful plant establishment can be maximized with proper planning; consideration
of soil characteristics; selection of plant materials that are suitable for the site;
adequate seedbed preparation, liming, and fertilization; timely planting; and regular
maintenance.
When to Seed
Areas to be stabilized with vegetation must be seeded or planted one to four months
after the final grade is achieved unless temporary stabilization measures are in place.
Appropriate dates for seeding are as follows:
Zone
Spring Seeding
Fall Seeding
Below 6000'
Spring thaw to June 1st
September 1st until
consistent ground freeze
6000' to 7000'
Spring thaw to June 15th
August 15th until consistent
ground freeze
7000' to 8000'
Spring thaw to July 1st
August 1st until consistent
ground freeze
Above 8000'
Spring thaw to consistent
ground freeze
Spring thaw to consistent
ground freeze
Seed Mix
Climate, soils, and topography are major factors that dictate the suitability of plants
for a particular site. Vegetation that is adapted to the site, has strong roots, and
provides good ground cover should be used. Although a native seed mix is best,
some grasses, such as Vetiver, have been used extensively worldwide because of their
strong, deep roots, adaptability, and non-invasive properties. The recommended seed
mix to be used on all disturbed areas during appropriate planting seasons will be
determined by the White River Field Office and may include the following:
1. Western wheatgrass
2. Indian ricegrass
3. Bluebunch wheatgrass
4. Thickspike wheatgrass
5. Needle and thread grass
6. Basin wildrye
7. Fourwing saltbrush
8. Slender wheatgrass
9. Big bluegrass
10. Canby bluegrass
11. Mountain broome
Rev: 0
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Page 2 of 5 EC -6 Permanent Vegetation
Construction Specifications
1. Seeding does not immediately stabilize soils. Temporary erosion and
sediment control measures should be in place to prevent off-site transport
of sediments from disturbed areas until vegetation is established.
2. Vegetation should not be established on slopes that are unsuitable due to
inappropriate soil texture, poor internal structure or internal drainage,
volume of overland flow, or excessive steepness, until measures have been
taken to correct these problems.
3. If the area has been recently loosened or disturbed, no further roughening
is required. When the area is compacted, crusted, or hardened, the soil
surface shall be loosened by disking, raking, harrowing, or other
acceptable means to ensure good water infiltration and root penetration
(see EC -4 Surface Roughening).
4. The soil on a disturbed site may need to be modified to provide an
optimum environment for seed germination and seedling growth. To
maintain a good stand of vegetation, the soil must meet certain minimum
requirements as a growth medium. If any of the below criteria cannot be
met then topsoil shall be applied. The existing soil must have these
characteristics:
a. Enough fine-grained material to maintain adequate moisture and
nutrient supply.
b. Sufficient depth of soil to provide an adequate root zone. The depth to
rock or impermeable layers such as hardpans shall be 12 inches or
more, except on slopes steeper than 2:1 where the addition of soil is
not feasible.
c. A favorable pH range for plant growth. If the soil is so acidic that a
pH range of 6.0-7.0 cannot be attained by addition of ph -modifying
materials, then the soil is considered an unsuitable environment for
plant roots and further soil modification would be required.
d. Freedom from toxic amounts of materials harmful to plant growth.
e. Freedom from excessive quantities of roots, branches, large stones,
large clods of earth, or trash of any kind. Clods and stones may be left
on slopes steeper than 3:1 if they do not significantly impede good
seed soil contact.
5. Add fertilizer and/or lime, if necessary. The addition of lime is equally as
important as applying fertilizer. Lime will modify the pH and supply
calcium and magnesium. Its effect on pH makes other nutrients more
available to the plant.
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Page 3 of 5 EC -6 Permanent Vegetation
6. Apply seed uniformly with a broadcast seeder, drill, culti-packer seeder, or
hydro seeder on a firm, friable seedbed. Seeding depth should be 1/4 to
1/2 inch.
7. If necessary, apply mulch according to EC -7 Mulching. The mulch will
hold moisture and modify temperature extremes, and prevent erosion
while seedlings are growing.
Maintenance Considerations
New seeded areas should be supplied with adequate moisture. Supply water as
needed, especially late in the season, in abnormally hot or dry weather, or on adverse
sites. Water application rates should be controlled to prevent excessive runoff.
Inadequate amounts of water may be more harmful than no water.
Grasses should emerge within 4-28 days and legumes 5-28 days after seeding, with
legumes following grasses. A successful stand should exhibit the following:
• Vigorous dark green or bluish green seedlings, not yellow
• Uniform density, with nurse plants, legumes, and grasses well intermixed
• Green leaves—perennials should remain green throughout the summer, at
least at the plant bases
Vegetation is considered established when a density of at least 70 percent of pre -
disturbance levels has been reached. Seeded areas should be inspected for failure and
any necessary repairs and re-seedings should be made within the same season, if
possible.
• If vegetative cover is inadequate to prevent rill erosion, over -seed and
fertilize in accordance with soil test results.
• If timing is bad, Ryegrass or German Millet can be overseeded to thicken
the stand until a suitable time for seeding perennials.
• If a stand has less than 40% cover (see Figure EC -6-1, below), re-evaluate
choice of plant materials and quantities of lime and fertilizer. The soil
must be tested to determine if acidity or nutrient imbalances are
responsible. Reestablish the stand following seedbed preparation and
seeding recommendations.
In general, a stand of vegetation cannot be determined to be fully established until it
has been maintained for one full year after planting. On a typical disturbed site, full
plant establishment usually requires refertilization in the second growing season. Soil
tests can be used to determine if more fertilizer needs to be added. Do not fertilize
cool season grasses in late May through July. Grass that looks yellow may be
Rev: 0
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Page 4 of 5 EC -6 Permanent Vegetation
nitrogen deficient. Do not use nitrogen fertilizer if the stand contains more than
20 percent legumes.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control. Washington,
D.C., February, 2003.
<http : //cfpub. epa. gov/npdes/stormwater/menuofbmps/con_site. cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
4 4-
15% COVER
Figure EC -6-1
Percent Vegetation Cover
4-
4 4-- 44 4
50% COVER
85% COVER
Rev: 0
Date: 1/26/06
Page 5 of 5 EC -6 Permanent Vegetation
EC -7 Mulching (MLCH)
Loose Mulch
Mulch with Netting
Description
Mulching is a temporary erosion control practice in which materials such as grass,
hay, wood chips, wood fibers, straw, or gravel are placed on exposed or recently
planted soil surfaces. Mulching stabilizes soils by minimizing rainfall impact and
reducing storm water runoff velocity. When used in combination with seeding or
planting, mulching can aid plant growth by holding seeds, fertilizers, and topsoil in
place, preventing birds from eating seeds, retaining moisture, and insulating plant
roots against extreme temperatures.
Mulch mattings are materials such as jute or other wood fibers that are formed into
sheets and are more stable than loose mulch. Jute and other wood fibers, plastic,
paper, or cotton can be used individually or combined into mats to hold mulch to the
ground. Netting can be used to stabilize soils while plants are growing, although
netting does not retain moisture or insulate against extreme temperatures. Mulch
binders consist of asphalt or synthetic materials that are sometimes used instead of
netting to bind loose mulches.
Applicability
Mulching is often used in areas where temporary seeding cannot be used because of
environmental constraints. On steep slopes and critical areas such as waterways,
mulch matting is used with netting or anchoring to hold it in place. Mulches can be
used on seeded and planted areas where slopes are steeper than 2:1 or where sensitive
seedlings require insulation from extreme temperatures or moisture retention. Mulch
is most effective when used on an area less than two acres in size and can last for one
to two years.
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Page 1 of 5 EC -7 Mulching
Limitations
• Mulching, matting, and netting might delay seed germination because the
cover changes soil surface temperatures.
• The mulches themselves are subject to erosion and may be washed away
in a large storm.
• Maintenance is necessary to ensure that mulches provide effective erosion
control.
Design Criteria
No formal design is required.
Construction Specifications
1. Site Preparation
a. Prior to mulching, install the necessary temporary or permanent
erosion control practices and drainage systems within or adjacent to
the area to be mulched.
b. Slope, grade and smooth the site to fit needs of selected mulch
products.
c. Remove all undesirable stones and other debris to meet the needs of
the anticipated land use and maintenance required.
2. Mulching & Anchoring
a. Select the appropriate mulch and application rate that will best meet
the need and availability of material. When possible, organic mulches
should be used for erosion control and plant material establishment.
See Table EC -7-1 for suggested materials. Other materials include
hydraulic mulch products with 100 -percent post -consumer paper
content and yard trimming composts. Pea gravel or crushed granite
can be used in unvegetated areas. All materials should be free of
seed.
b. Apply mulch after soil amendments and planting is accomplished or
simultaneously if hydroseeding is used. See Table EC -7-1 for
installation guidelines.
c. Loose hay or straw should be anchored using one of the methods
described in Table EC -7-2. Materials that are heavy enough to stay in
place (for example, gravel or bark or wood chips on flat slopes) do not
need anchoring. Mulches may or may not require a binder, netting, or
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Page 2 of 5 EC -7 Mulching
tacking. Effective use of netting and matting material requires firm,
continuous contact between the materials and the soil.
Maintenance Considerations
Mulched areas should be inspected frequently to identify areas where mulch has
loosened or been removed, especially after rainstorms. Such areas should be reseeded
(if necessary) and the mulch cover replaced immediately. Mulch binders should be
applied at rates recommended by the manufacturer. If washout, breakage, or erosion
occurs, surfaces should be repaired, reseeded, and remulched, and new netting should
be installed. Inspections should be continued until vegetation is firmly established.
Removal
Anchor netting and any other artificial mulch material should be removed when
protection is no longer needed and disposed of in a landfill.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa. gov/npdes/stormwater/menuofbmps/con_site.cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
United States Department of Agriculture (USDA), Natural Resources Conservation
Service (NRCS), Field Office Technical Guide. 2002.
<www.nrcs.usda.gov/technical/efotg>
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Page 3 of 5 EC -7 Mulching
Table EC -7-1
Typical Mulching Materials and Application Rates
Material
Rate per
Acre
Requirements
Notes
Organic Mulches
Straw
1 - 2 tons
Dry, unchopped,
unweathered; avoid
weeds.
Spread by hand or
machine; must be tacked
or tied down.
Wood fiber or
wood cellulose
1/2 - 1 ton
Use with hydroseeder;
may be used to tack
straw. Do not use in hot,
dry weather.
Wood chips
5 - 6 tons
Air dry. Add fertilizer N,
12 Ib/ton.
Apply with blower, chip
handler, or by hand. Not
for fine turf areas.
Bark
35 yd3
Air dry, shredded, or
hammermilled, or chips
Apply with mulch blower,
chip handler, or by hand.
Do not use asphalt tack.
Nets and Mats
Jute net
Cover area
Heavy, uniform; woven
of single jute yarn. Used
with organic mulch.
Withstands water flow.
Excelsior (wood
fiber) mat
Cover area
Fiberglass roving
1/2 - 1 ton
Continuous fibers of
drawn glass bound
together with a non-toxic
agent.
Apply with compressed
air ejector. Tack with
emulsified asphalt at a
rate of 25 - 35 gal./1000
ft.2
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Page 4 of 5 EC -7 Mulching
Table EC -7-2
Mulch Anchoring Guide
Anchoring Method
or Material
Kind of Mulch
to be Anchored
How to Apply
1. Peg and Twine
Hay or straw
After mulching, divide areas into blocks
approximately 1 sq. yd. in size. Drive 4-6 pegs
per block to within 2" to 3" of soil surface.
Secure mulch to surface by stretching twine
between pegs in criss-cross pattern on each
block. Secure twine around each peg with two
or more tight turns. Drive pegs flush with soil.
Driving stakes into ground tightens twine.
2. Mulch netting
Hay or straw
Staple the light -weight paper, jute, wood fiber,
or plastic nettings to soil surface according to
manufacturer's recommendations. Should be
biodegradable. Most products are not suitable
for foot traffic.
3. Wood cellulose
fiber
Hay or straw
Apply hydroseeder immediately after mulching.
Use 500 lbs. Wood fiber per acre. Some
products contain an adhesive material,
possibly advantageous.
4. Mulch anchoring
tool
Hay or straw
Apply mulch and pull a mulch anchoring tool
(blunt, straight discs) over mulch as near to the
contour as possible. Mulch material should be
"tucked" into soil surface about 3".
5. Chemical
Hay or straw
Apply Terra Tack AR 120 lbs./ac. In 480 gal. of
water (#156/ac.) or Aerospray 70 (60 gal/ac.)
according to manufacturer's instructions.
Avoid application during rain. A 24-hour curing
period and a soil temperature higher than 45
deg. Fahrenheit are required.
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Page 5 of 5 EC -7 Mulching
EC -8 Wattles (W)
Description
A wattle (also called a fiber roll) consists of straw, flax, or other similar materials
bound into a tight tubular roll. When wattles are placed at the toe and on the face of
slopes, they intercept runoff, reduce its flow velocity, release the runoff as sheet flow,
and provide removal of sediment from the runoff. By interrupting the length of a
slope, fiber rolls can also reduce erosion.
Applicability
Wattles may be suitable:
• Along the toe, top, face, and at grade breaks of exposed and erodible
slopes to shorten slope length and spread runoff as sheet flow
• At the end of a downward slope where it transitions to a steeper slope
• Along the perimeter of a project
• As check dams in unlined ditches
• Down-slope of exposed soil areas
• Around temporary stockpiles
Limitations
• Wattles are not effective unless trenched.
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Page 1 of 3 EC -8 Wattles
• Wattles at the toe of slopes greater than 5:1 (H:V) should be a minimum of
20 in. diameter or installations achieving the same protection (i.e. stacked
smaller diameter wattles, etc.).
• Difficult to move once saturated.
• If not properly staked and trenched in, wattles could be transported by
high flows.
• Wattles have a very limited sediment capture zone.
• Wattles should not be used on slopes subject to creep, slumping, or
landslide.
Design Criteria
No formal design is required.
Construction Specifications
Wattles should be either prefabricated rolls or rolled tubes of erosion control blanket.
(If using an erosion control blanket roll the length of erosion control blanket into a
tube of minimum 8 in. diameter and bind roll at each end and every 4 ft along length
of roll with jute -type twine.)
See Figure EC -8-1.
1. Locate wattles on level contours spaced as follows:
a. Slope inclination of 4:1 (H:V) or flatter: Fiber rolls should be placed at
a maximum interval of 20 ft.
b. Slope inclination between 4:1 and 2:1 (H:V): Fiber Rolls should be
placed at a maximum interval of 15 ft. (a closer spacing is more
effective).
c. Slope inclination 2:1 (H:V) or greater: Fiber Rolls should be placed at
a maximum interval of 10 ft. (a closer spacing is more effective).
2. Turn the ends of the wattles up slope to prevent runoff from going around
the roll.
3. Stake wattles into a 2 to 4 in. deep trench with a width equal to the
diameter of the wattle. Drive stakes at the end of each wattle and spaced
4 ft maximum on center.
4. If more than one wattle is placed in a row, the rolls should be overlapped,
not abutted.
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Page 2 of 3 EC -8 Wattles
Maintenance Considerations
Inspect wattles periodically and after rain events. Repair or replace split, torn,
unraveling, or slumping rolls. If the wattle is used as a sediment capture device, or as
an erosion control device to maintain sheet flows, sediment that accumulates must be
periodically removed in order to maintain wattle effectiveness. Sediment should be
removed when sediment accumulation reaches one-half the designated sediment
storage depth, usually one-half the distance between the top of the wattle and the
adjacent ground surface.
Removal
Wattles are typically left in place. If wattles are removed, collect and dispose of
sediment accumulation, and fill and compact holes, trenches, depressions or any other
ground disturbance to blend with adjacent ground.
References
California Stormwater Quality Association, Stormwater Best Management
Practice(BMP) Handbook — Construction. January, 2003.
<http://www.cabmphandbooks.com/Construction.asp>
Figure EC -8-1
Wattle Installation
• 4' max.
Wattle
4' max
Install wattle near
slope where it
transitions into
steeper slope
M
2' min. //
4' max. \
12" min.' ;
• \i//\
Vertical spacing measured along the face
of the slope vanes between 10' and 20'
Wattle 8" min.
/ 111 max slope
- 2" x 2" wood stakes
Note: Install wattle along a level contour.
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Page 3 of 3 EC -8 Wattles
EC -9 Erosion Control Blanket (ECB)
Description
Erosion control blankets are porous fabrics and are manufactured by weaving or
bonding fibers made from organic or synthetic materials. Erosion control blankets
are installed on steep slopes or in channels to prevent erosion until final vegetation is
established. However, blankets can also be used as separators or to aid in plant
growth by holding seeds, fertilizers, and topsoil in place.
Applicability
Erosion control blankets may be used in the following applications:
• To control erosion on steep slopes and to promote the establishment of
vegetation.
• To stabilize channels against erosion from concentrated flows.
• To protect exposed soils immediately and temporarily, such as when
active piles of soil are left overnight.
• As a separator between riprap and soil to prevent soil from being eroded
from beneath the riprap and to maintain the riprap's base.
• May be used on slopes as steep as 1:1.
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Page 1 of 4 EC -9 Erosion Control Blanket
Limitations
• Blankets used on slopes should be biodegradable, or photodegradable,
non-toxic to vegetation or germination of seed, and non-toxic or injurious
to humans.
• Should not be used on slopes where vegetation is already established.
• Some blankets might promote increased runoff and might blow away if
not firmly anchored.
• If the fabric is not properly selected, designed, or installed, the
effectiveness may be reduced drastically.
Design Criteria
There are many types of erosion control blankets available. Therefore, the selected
fabric should match its purpose. Effective netting and matting require firm,
continuous contact between the materials and the soil. If there is no contact, the
material will not hold the soil, and erosion will occur underneath the material.
Table EC -9-1 indicates some recommended criteria for the selection of erosion
control blankets.
Construction Specifications
1. Smooth soil prior to installation and apply seed prior to fabric installation
for final stabilization of construction sites.
2. Select the appropriate fabric type using the guidelines from Table EC -9-1.
3. Installation of the blankets shall be in accordance with the manufacturer's
recommendations and according to Figure EC -9-1. Fabric needs to be in
continuous contact with exposed soil.
4. Pins or staples shall be made of wire 0.162 inch or larger in diameter. "U"
shaped staples shall have legs 8" long, and a 1" crown. "T" shaped pins
shall have a minimum length of 8". The bar of the "T" shall be at least
4" long. Triangular survey stakes can also be used.
Maintenance Considerations
Regular inspections should be made to determine if cracks, tears, or breaches have
formed in the fabric; if so, it should be repaired or replaced immediately. Re -anchor
loosened matting and replace missing matting and staples as required. It is necessary
to maintain contact between the ground and the blanket at all times. Trapped
sediment should be removed after each storm event.
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Page 2 of 4 EC -9 Erosion Control Blanket
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http : //cfpub. epa. gov/npdes/stormwater/menuof bmps/con_site. cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
Table EC -9-1
Suggested Blanket Types
Condition
Blanket Type
Slopes 2:1 or Steeper
Straw Blanket
Straw/coconut blanket
Synthetic Blanket
Wood Fiber Blanket (excelsior)
Erosive soil (sand) or slopes
receiving sheet flow from
roadway surface runoff
Straw Blanket
Straw/coconut blanket
Synthetic Blanket
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Page 3 of 4 EC -9 Erosion Control Blanket
Flow
Figure EC -9-1
Erosion Control Blanket Installation
Bury upsIope end of blanket in
trench 6" deep by 6" wide
Use a 4' min. overlay wherever two
2 widths of blanket are applied side
by side.
Staple pattern: Minimum 3 per
square yard.
Flow
Blanket Fabric
anchored in trench
Blanket fabric
anchored in trench
Use a 6" overlap wherever one roll
3 of blanket ends and another begins.
Check slots should be made every 18'. Insert a fold of the blanket
4 into a trench 6" wide by 6' deep and tamp firmly. Lay the blanket
smoothly or the surface 0f the soil. Do not stretch the blanket, and
do not allow wrinkles. Install staple 26" on center in trench.
Flow
Nor
18' Max.
fi
Place blanket seam
perbendicular to the
direction of flow. Do not join
ships in the center of ditch.
Use check slots as required.
Flow
Blanket fabric
anchored in trends
Blanket fabric
anchored in french
Place blanket parallel to the
direction of flow and anchor
securely. Bring blanket to a
level area before terminating
the installation.
NOT TO SCALE
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Page 4 of 4 EC -9 Erosion Control Blanket
EC -10 Low Water Crossing (LWC)
Vented Aggregate Ford
Bridge
Description
A low water crossing is a temporary structure erected to provide a safe and stable way
for construction vehicle traffic to cross waterways. The primary purpose of such a
structure is to provide streambank stabilization, reduce the risk of damaging the
streambed or channel, and reduce the risk of sediment loading from construction
traffic. A low water crossing may be a bridge, a culvert, or a ford surfaced with
gravel, rip -rap, or concrete.
Applicability
Low water crossings may be used for the following applications:
• Wherever heavy construction equipment must be moved from one side of
a stream channel to the other, or where lighter construction vehicles will
cross the stream a number of times during the construction period.
• Bridges are ideal to pass the year-round flows associated with perennial
drainages.
• Vented fords can be used to pass drainages with low flows and keep
vehicles out of the water, avoiding water quality degradation.
• Fords can be designed as a broadcrested weir in order to pass larger flow.
• Fords can be "forgiving" and accommodate uncertainties in the design
flow and thus are ideal for ephemeral and intermittent drainages with
unknown or variable flow characteristics.
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Page 1 of 7 EC -10 Low Water Crossing
Limitations
• Low-water crossings that are not surfaced should not be used in wet
conditions.
• Bridges can be a safety hazard if not properly designed and constructed.
Bridges might also prove to be more costly in terms of repair costs and
lost construction time if they are washed out or collapse.
• The construction and removal of culverts are usually very disturbing to the
surrounding area, and erosion and downstream movement of soils is often
great.
• The approaches to fords often have high erosion potential. In addition,
excavation of the streambed and approach to lay riprap or other
stabilization material causes major stream disturbance. Mud and other
debris are transported directly into the stream unless the crossing is used
only during periods of low flow.
• Ford -type structures may imply some periodic or occasional traffic delays
during periods of high flow.
Design Criteria
Site location
Locate the crossing where there will be the least disturbance to the soils of the
existing waterway banks. When possible, locate the crossing at a point receiving
minimal surface runoff.
Elimination of Fish Migration Barriers
Bridges pose the least potential for creating barriers to aquatic migration. The
construction of any specific crossing method shall not cause a significant water level
difference between the upstream and downstream water surface elevations.
Crossing Alignment
Where possible, the low water crossing shall be at right angles to the stream.
Road Approaches
The centerline of both roadway approaches shall coincide with the crossing alignment
centerline for a minimum distance of 50 feet from each bank of the waterway being
crossed. If physical or right-of-way restraints preclude the 50 feet minimum, a
shorter distance may be provided. All fill materials associated with the roadway
approach shall be limited to a maximum height of two feet above the existing flood
plain elevation.
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Page 2 of 7 EC -10 Low Water Crossing
Bridges
Over -stream bridges are generally the preferred low water crossing structure. The
expected load and frequency of the stream crossing, however, will govern the
selection of a bridge as the correct choice for a temporary stream crossing. Bridges
usually cause minimal disturbance to a stream's banks and cause the least obstruction
to stream flow and fish migration. They should be constructed only under the
supervision and approval of a qualified engineer.
Culverts
Temporary culverts are used where a) the channel is too wide for normal bridge
construction, b) anticipated loading may prove unsafe for single span bridges, or
c) access is not needed from bank to bank. Bridges are normally preferred over a ford
type of crossing, since disturbance to the waterway is only during construction and
removal of the culvert.
Fords
Fords are appropriate in steep areas subject to flash flooding, where normal flow is
shallow or intermittent across a wide channel Fords should be used for crossing
seasonally dry streambeds (ephemeral or intermittent drainages) or streams with low
flows during most periods of road use. Use fords in place of culverts when there is a
high possibility of plugging by debris or vegetation. Use improved (vented) fords
with pipes or concrete box culverts to pass low water flows and keep vehicles out of
the water.
Construction Specifications
Bridges
See Figure EC -10-1.
1. Clearing and excavation of the stream shores and bed should be kept to a
minimum.
2. A temporary bridge structure shall be constructed at or above bank
elevation to prevent the entrapment of floating materials and debris.
3. Abutments should be parallel to the stream and on stable banks.
4. If the crossing is to extend across a channel wider than 8 feet (as measured
from top of bank to top of bank), the bridge should be designed with one
in -water support for each 8 feet of stream width. No footing, pier, or
bridge support will be permitted within the channel for waterways less
than 8 feet wide.
5. Stringers shall either be logs, saw timber, pre -stressed concrete beams,
metal beams, or other approved materials.
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Page 3 of 7 EC -10 Low Water Crossing
6. Decking shall be of sufficient strength to support the anticipated load. All
decking members shall be placed perpendicular to the stringers, butted
tightly, and securely fastened to the stringers. Decking materials must be
butted tightly to prevent any soil material tracked onto the bridge from
falling into the waterway below.
7. Run planking (optional) shall be securely fastened to the length of the
span. One run plank shall be provided for each track of the equipment
wheels. Although run planks are optional, they may be necessary to
properly distribute loads.
8. Curbs or fenders may be installed along the outer sides of the deck. Curbs
or fenders are an option, which will provide additional safety.
9. Bridges shall be securely anchored at only one end using steel cable or
chain. Anchoring at only one end will prevent channel obstruction in the
event that floodwaters float the bridge. Acceptable anchors are large trees,
large boulders, or driven steel anchors. Anchoring shall be sufficient to
prevent the bridge from floating downstream and possibly causing an
obstruction to the flow.
10. All areas disturbed during installation shall be stabilized within
14 calendar days of that disturbance in accordance with EC -4 Temporary
Seeding or EC -5 Permanent Seeding.
Culverts
See RC -2 Culvert Cross -Drain.
Fords
See Figure EC -10-2.
1. Locate fords where stream banks are low and where the channel is well
confined.
2. Clearing and excavation of the stream shores and bed should be kept to a
minimum.
3. Excavate streambed as necessary and place a 18" thick layer of 4" to
8" riprap. Cover this layer of riprap with a 6" thick layer of 2" to
4" crushed aggregate. The total thickness of riprap/aggregate should be a
minimum of 24 inches thick. This type of simple low water crossing is
ideal for ephemeral drainages.
4. For all approach roads the cut banks shall be no steeper than 5:1. The road
approach shall be a minimum distance of 50 feet from each bank. Spoil
material from the banks shall be stored out of the floodplain and
stabilized.
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Page 4 of 7 EC -10 Low Water Crossing
5. Use an adequately long aggregate surface to protect the "wetted
perimeter" of the natural flow channel. Add protection above the expected
level of the high flow. Allow for some freeboard, typically a minimum of
12 inches in elevation, between the top of the reinforced driving surface
and the expected high water level.
6. The downstream edge of a ford is a particularly critical location for scour
and may need energy dissipators or riprap protection.
7. Use well placed, sturdy depth markers at fords to advise traffic of
dangerous water depths.
8. All areas disturbed during ford installation shall be stabilized within
14 calendar days of that disturbance in accordance with EC -5 Temporary
Vegetation or EC -6 Permanent Vegetation.
Maintenance Considerations
Bridges
Periodic inspection shall be performed to ensure that the bridge, streambed, and
streambanks are maintained and not damaged. If any structural damage is reported,
construction traffic should stop use of the structure until appropriate repairs are made.
Evidence of streambank erosion should be repaired immediately. Any trapped
sediment or debris shall be removed and disposal of outside of the floodplain and
stabilized.
Culverts
Periodic inspection shall be performed to ensure that the culverts, streambed, and
streambanks are not damaged, and that sediment is not entering the stream or
blocking fish passage or migration. Evidence of structural or streambank erosion
should be repaired immediately. Any trapped sediment or debris shall be removed
and disposal of outside of the floodplain and stabilized.
Fords
Fords should be inspected periodically and after storm events to ensure that
stabilization material (aggregate) remains in place. If the material has moved
downstream during periods of peak flow, the lost material should be replaced
immediately.
Removal
All low water crossings shall be removed within 14 calendar days after the structure
is no longer needed.
Rev: 0
Date: 1/26/06
Page 5 of 7 EC -10 Low Water Crossing
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
United States Department of the Interior, Bureau of Land Management (BLM),
United States Department of Agriculture (USDA), Forest Service, Surface
Operating Standards for Oil and Gas Exploration and Development "Gold
Book". Fourth Edition, 2005.
Figure EC -10-1
Bridge Installation
Abw,ments
- Decking
7
Curbs
•
Stringers
NOT TO SCALE
Abutments
\/\
r.d
Abu tnen[son
Stabilized Banks
Rev: 0
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Page 6 of 7 EC -10 Low Water Crossing
:1
50 rnin. Road Approach
Freeboard
12" min.
Figure EC -10-2
Ford Installation
Traffic Flow
Width of stream bed
Sf]'
rnin. Road Approach
Maximum expected
high water level
1$"
24'1,
a.
):!:,, rs?y.•?y.•arsaxc• x�.. "•�r: rs`%y�.� i��#i:�.�'s!}�Y'"I
Crushed r ate (2'-4"dia. j��/jam /!!////j� \ //,
NOT TO SCALE Aggregate (4" - 8" dia.)
Rev: 0
Date: 1/26/06
Page7of7
EC -10 Low Water Crossing
EC -11 Brush Matting (BM)
Description
Brush matting consists of a mattress of brush laid on a slope and fastened down with
stakes and wire. The brush mat protects the soil surface on slopes from erosive forces
through the generation of a dense stand of woody vegetation.
Applicability
Brush mattresses are used primarily on streambanks where the velocity is less than
six feet per second and excessive runoff from stream flow has created erosive
conditions. The maximum slope shall be 1.5:1.
Limitations
This practice can resist temporary inundation, but not scour or undercutting.
Design Criteria
No formal design required.
Construction Specifications
See Figure EC -11-1.
1. Prepare slope surface by grading to a uniform, smooth surface, clear of
obstruction. Slopes should be graded before the brush mattress is installed.
2. Lay brush (willow or dogwood) a minimum of three inches thick
beginning at the downstream end of the work.
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Page 1 of 3 EC -11 Brush Matting
3. The butt end of the brush will be placed upstream and plant materials
inclined approximately 30 degrees.
4. The upstream edge of the mattress will be keyed into the slope two feet.
Stakes will be driven throughout the mattress on 3 -foot centers each way
beginning along the toe of the mattress.
5. No. 9 wire will be attached to the stakes and tightened to secure the
mattress.
6. Place large rock over the end of the mattress to hold in place.
7. Sloped areas above the mattress will be shaped and seeded.
Maintenance
Scheduled inspections the first year are necessary to make sure the anchoring system
is sound. Broken wire or missing stakes should be replaced immediately. Any
missing toe material should be replaced.
Removal
Brush matting may remain in place to decompose or be removed after the area has
been fully stabilized.
References
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Rev: 0
Date: 1/26/06
Page 2 of 3 EC -11 Brush Matting
Figure EC -11-1
Brush Matting Installation
Large rock
rip rap
Water
A minimum of 50 branches, 1" or less in
diameter, per 3 feet evenly distributed
for full width of mattress
Wooden Stakes
9 gauge galvanized
wire secured to stakes
Cut end of branches facing down slope
Large rock
rip rap
9 gauge galvanized
wire secured to slakes
\\
V Water 1$P -
Wooden Slakes
12 to 1 max.
f slope
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Date: 1/26/06
Page 3 of 3 EC -11 Brush Matting
EC -12 Terracing (T)
Description
Gradient terraces (also called reverse slope benches) are made of either earthen
embankments or ridge and channel systems that are properly spaced and are
constructed with an adequate grade. They reduce damage from erosion by collecting
and redistributing surface runoff to stable outlets at slower speeds and by increasing
the distance of overland runoff flow. They also surpass smooth slopes in holding
moisture and help to minimize sediment loading of surface runoff.
Applicability
Gradient terraces most effective for areas less than 10 acres in size and, are suitable
for the following applications:
• Areas with an existing or expected water erosion problem and no
vegetation.
• Slopes no steeper than 2:1 and greater than five feet in height, which are
not part of a trench or excavation.
• Graded areas with smooth hard surfaces or any cleared area prior to
permanent seeding.
• Where the length of slopes need to be shortened by terracing.
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Page 1 of 3 EC -12 Terracing
Limitations
• Gradient terraces are not appropriate for use on sandy, steep, or shallow
soils.
• If too much water permeates the soil in a terrace system, sloughing could
occur, and cut and fill costs could increase substantially.
Design Criteria
The design of terraces should be determined by a civil engineer based upon actual site
conditions.
Construction Specifications
Terraces should be constructed according to Figure EC -12-1.
1. Construct diversion ditches at the top of the slope if necessary to prevent
or reduce surface water from running down the slope face.
2. The upper step should begin immediately below the top of the cut or fill.
Continue constructing terraces or benches down to the toe of the slope.
3. Remove the loose material that collects at the end of terraces or benches
and blend the ends of each terrace or bench into the natural ground
surface.
4. Terraces must drain to a stabilized outlet, such as a grassed waterway,
vegetated area, or other suitable outlet. Slope drains (EC -15 Slope Drain)
may be needed to convey surface runoff from the terraces or benches to
the toe of the slope without causing erosion. Analysis of the local site
conditions should determine the needed outlets.
5. Stabilize or revegetate the slope with methods applicable to the particular
site.
Maintenance Considerations
Regular inspections should occur after any major storms and at least once a year to
ensure that the terraces are structurally sound and have not been subject to erosion.
Maintain terrace ridge height and outlet elevations. Remove sediment that has
accumulated in the terrace to maintain capacity, a positive channel grade, and to
maintain capacity where soil infiltration serves as the outlet. If excessive seepage or
surface runoff is a problem, control the seepage/runoff with appropriate drainage
facilities. Take prompt action as needed to ensure proper drainage and slope stability.
Repair rills and reseed damaged areas as they develop. Substantial maintenance of
the newly planted or seeded vegetation may be required.
Rev: 0
Date: 1/26/06
Page 2 of 3 EC -12 Terracing
References
City of Knoxville, Stormwater Engineering, Knoxville BMP Manual - Best
Management Practices. July 2003. http://www.ci.knoxville.tn.us/engineering
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
United States Department of Agriculture (USDA), Natural Resources Conservation
Service (NRCS), Field Office Technical Guide. 2002.
<www.nrcs.usda.gov/technical/efotg>
Figure EC -12-1
Terracing
Diversion channel
or herrn
Maximum
slope heighl jam.
See able y�\
1' min.
Slope Maximum
Slope Height
2:1 20'
31 30'
41 40'
NOT TO SCALE
— 8' min. —
Maximum ��!
slope height . "�" ` \
See table . ./•/22
Normal slope line
2:1 (H:V) or flatter
Ditch to catch
loose material
1. Terraces shall slope between 2% and 3% to a stabilized outlet.
2. Flow length along a terrace shall not exceed 800 feet.
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Page 3 of 3 EC -12 Terracing
EC -13 Preserve Existing Vegetation
(PEV)
Description
The principal advantage of preserving existing vegetation is the protection of
desirable trees, vines, bushes, and grasses from damage during project development.
Vegetation provides erosion control, storm water detention, biofiltration, and
aesthetic values to a site during and after construction activities. Other benefits of
preserving natural areas are because natural vegetation:
• Can process higher quantities of storm water runoff than newly seeded
areas
• Does not require time to establish
• Has a higher filtering capacity than newly planted vegetation because
aboveground and root structures are typically denser
• Reduces storm water runoff by intercepting rainfall, promoting infiltration,
and lowering the water table through transpiration
• Provides buffers and screens against noise and visual disturbance
• Provides a fully developed habitat for wildlife
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Page 1 of 3 EC -13 Preserve Existing Vegetation
Applicability
Preservation of existing vegetation is applicable to stream banks, steep slopes, and
other areas where erosion controls would be difficult to establish, install, or maintain.
Only land needed for drilling operations and vehicle traffic needs to be cleared.
Limitations
• It requires planning to preserve and maintain the existing vegetation.
• Equipment must have enough room to maneuver; in some cases preserved
vegetation might block equipment traffic and may constrict the area
available for construction activities.
• Preconstruction drainage patterns should be maintained. Improper grading
of a site might result in the alteration of hydrology and lead to die -off of
preserved vegetation because their environmental requirements are no
longer met.
Design Criteria
Site Map
A site map should be prepared with the locations of trees and boundaries of
environmentally sensitive areas and buffer zones to be preserved. The location of
roads, well pads and pipelines can be planned to avoid these areas. Preservation
requires careful site management to minimize the impact of construction activities on
existing vegetation. Large trees located near construction zones should be protected
because damage during construction activities may result in reduced vigor or death
after construction has ceased. The boundaries around contiguous natural areas should
be extended and marked to protect the root zone from damage. Although direct
contact by equipment is an obvious means of damage to trees and other vegetation,
compaction, filling, or excavation of land too close to the vegetation also can cause
severe damage.
Selection
When selecting trees for preservation, the following factors should be considered:
• Tree vigor. Preserving healthy trees that will be less susceptible to
damage, disease, and insects. Indicators of poor vigor include dead tips of
branches, stunted leaf growth, sparse foliage, and pale foliage color.
Hollow, rotten, split, cracked, or leaning trees also have less chance of
survival.
• Tree age. Older trees are more aesthetically pleasing as long as they are
healthy.
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Page 2 of 3 EC -13 Preserve Existing Vegetation
• Wildlife benefits. Trees that are preferred by wildlife for food, cover, and
nesting should be chosen.
Construction Specifications
1. Vegetation should be marked for preservation before clearing activities
begin.
2. Barriers should be used to prevent the approach of equipment within
protected areas.
3. Equipment, construction materials, topsoil, and fill dirt should not be
placed within the limit of preserved areas.
Maintenance Considerations
Even if precautions are taken, some damage to protected areas may occur. In such
cases, damaged vegetation should be repaired or replaced immediately to maintain the
integrity of the natural system. Continued maintenance is needed to ensure that
protected areas are not adversely impacted by new construction.
Removal
During final site cleanup, barriers around preserved areas and trees should be
removed.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http : //cfpub. epa. gov/npdes/stormwater/menuof bmps/con_site. cfm>
Rev: 0
Date: 1/26/06
Page 3 of 3 EC -13 Preserve Existing Vegetation
EC -14 Vegetated Buffer (VB)
Description
Vegetated buffers are areas of either natural or established vegetation that are
maintained to protect the water quality of neighboring areas. Buffer zones reduce the
velocity of storm water runoff, provide an area for the runoff to permeate the soil,
contribute to ground water recharge, and act as filters to catch sediment. The
reduction in velocity also helps to prevent soil erosion.
Applicability
Vegetated buffers can be used in any area that is able to support vegetation but they
are most effective and beneficial on floodplains, near wetlands, along streambanks,
and on steep, unstable slopes. They are also effective in separating land use areas that
are not compatible and in protecting wetlands or water bodies by displacing activities
that might be potential sources of non -point source pollution.
Limitations
• Vegetated buffers require plant growth before they can be effective, and
land on which to plant the vegetation must be available.
• If the cost of the land is very high, buffer zones might not be
cost-effective.
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Page 1 of 2 EC -14 Vegetated Buffer
• Although vegetated buffers help to protect water quality, they usually do
not effectively counteract concentrated storm water flows to neighboring
or downstream wetlands.
Design Criteria
No formal design is required.
Construction Specifications
1. Buffer widths should be determined after careful consideration of slope,
vegetation, soils, depth to impermeable layers, runoff sediment
characteristics, type and quantity of storm water pollutants, and annual
rainfall. Buffer widths should increase as slope increases.
2. Zones of vegetation (native vegetation in particular), including grasses,
deciduous and evergreen shrubs, and understory and overstory trees,
should be intermixed.
3. Fertilizing seeded or planted ground may enhance growth (and improve its
effectiveness as a buffer).
4. Direct sediment -laden water onto the naturally vegetated or stabilized
planted ground.
5. Do not place any equipment, construction debris, or extra soil in the buffer
area.
Maintenance Considerations
Keeping vegetation healthy in vegetated buffers requires routine maintenance, which
(depending on species, soil types, and climatic conditions) can include weed and pest
control, mowing, fertilizing, liming, irrigating, and pruning. Inspection and
maintenance are most important when buffer areas are first installed. Once
established, vegetated buffers do not require much maintenance beyond the routine
procedures listed earlier and periodic inspections of the areas, especially after any
heavy rainfall and at least once a year. Inspections should focus on encroachment,
gully erosion, density of vegetation, evidence of concentrated flows through the areas,
and any damage from foot or vehicular traffic. If there is more than six inches of
sediment in one place, it should be removed.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuof bmps/con_site.cfm>
Rev: 0
Date: 1/26/06
Page 2 of 2 EC -14 Vegetated Buffer
EC -15 Slope Drain (SD)
Description
A slope drain is a flexible conduit extending the length of a disturbed slope and
serving as a temporary outlet for a diversion. Slope drains convey runoff without
causing erosion on or at the bottom of the slope. This practice is a temporary
measure used during grading operations until permanent drainage structures are
installed and until slopes are permanently stabilized. They are typically used for less
than two years.
Applicability
Slope drains can be used on most disturbed slopes to eliminate gully erosion
problems resulting from concentrated flows discharged at a diversion outlet.
Recently graded slopes that do not have permanent drainage measures installed
should have a slope drain and a temporary diversion installed. A slope drain used in
conjunction with a diversion conveys storm water flows and reduces erosion until
permanent drainage structures are installed.
Limitations
The area drained by a temporary slope drain should not exceed five acres. Physical
obstructions substantially reduce the effectiveness of the drain. Other concerns are
failures from overtopping because of inadequate pipe inlet capacity, and reduced
diversion channel capacity and ridge height.
Design Criteria
No formal design is required.
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Page 1 of 3 EC -15 Slope Drain
Construction Specifications
See Figure EC -15-1 for installation details.
1. The slope drain shall have a slope of 3 percent or steeper.
2. The top of the diversion berm over the inlet pipe, and those diversions
carrying water to the pipe, shall be at least six inches higher at all points
than the top of the inlet pipe.
3. A flared end section of corrugated metal shall be attached to the inlet end
of the pipe with a watertight connection. The corrugated metal pipe
should have watertight joints at the ends.
4. The drain should consist of heavy-duty material manufactured for the
purpose and have grommets for anchoring at a spacing of 10 feet or less.
The pipe is typically corrugated plastic or flexible tubing, although for
flatter, shorter slopes, a polyethylene -lined channel is sometimes used.
Where flexible tubing is used, it shall be the same diameter as the inlet
pipe and shall be constructed of a durable material.
5. The soil around and under the pipe and end section shall be hand tamped
in 4 in. lifts to the top of the diversion berm.
6. The slope drain shall outlet into a sediment trapping device when the
drainage area is disturbed. A riprap apron shall be installed below the pipe
outlet where water is being discharged into a stabilized area.
7. A riprap apron shall be used below the pipe outlet where clean water is
being discharged into a stabilized area.
Maintenance Considerations
The slope drain should be inspected after each rainfall to determine if capacity was
exceeded or if blockages occurred. Repairs should be made promptly. Construction
equipment and vehicular traffic must be rerouted around slope drains
Removal
Remove slope drain on completion of construction and stabilization activities.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http : //cfpub. epa. gov/npdes/stormwater/menuof bmps/con_site. cfm>
Rev: 0
Date: 1/26/06
Page 2 of 3 EC -15 Slope Drain
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Anchor !oh!! slope
Provide outlet
protection
Flared end
Section
Figure EC -15-1
Slope Drain Installation
Earthen Berm or diversion (compacted)
Corrugated metal extension collar
Waterproof seal
Rigid or flexable pipe
Flared end
section
10' min. ,..� .z c , c.\4hzac :, :r -' ^\ �.. ,
ij/\%%� /
\\\ \'\\\//\ \\\\\/\A
Well compacted stable
Till slope
Drainage Pipeftubing
Area Diameter (in.)
(acres) ❑
<05 12
18
21
24
30
<1.5
<25
<3.5
<5
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Page 3 of 3 EC -15 Slope Drain
EC -16 Brush Layering (BL)
I.
Description
A brush layer is a horizontal row of live branch cuttings placed in soil with other
similar rows, spaced a specific vertical distance apart. A brush layer helps to stabilize
sloped areas by reinforcing the soil with un -rooted branch stems, trap debris on
slopes, dries excessively wet sites, and redirects adverse slope seepage by acting as a
horizontal drain.
Applicability
Generally applicable to stabilize slope areas above the flow line of streambanks as
well as cut -and -fill slopes. Brush layers can be used on slopes up to 2:1 in steepness
and 20 feet in height.
Limitations
Brush layering works better on fill than cut slopes because branches with much
longer stems can be used in fill.
Design Criteria
No formal design is required.
Construction Specifications
1. Care shall be taken not to severely damage the live branch cuttings during
installation. Damaged cuttings will be replaced prior to backfilling.
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Page 1 of 3 EC -16 Brush Layering
2. Starting at the toe of the slope, excavate benches along the contour of the
slope. The benches shall range from 2' to 3' wide and the surface of the
bench shall be angled so the front edge is higher than the back of the
bench (See Figure EC -16-1). The benches shall be spaced according to the
following table:
Slope (H:V)
Wet Slope
Dry Slope
Max. Slope Length
2 to 2.5
3'
3'
15'
2.5 to 3.5
3'
4'
15'
3.5 to 4.0
4'
5'
25'
3. Live branch cuttings (%2" to 2" in diameter) shall be placed on the bench in
a crisscross or overlapping configuration in layers 3" - 4" thick. No leaf
buds shall have initiated growth beyond 1/4" and the cambium layer shall
be moist, green, and healthy. The cuttings shall be long enough to contact
the back of the bench with the growing tips protruding out of the slope
face. Backfill shall be placed on top of the live branch cuttings and
tamped in 6" lifts. Small plate compactors may be used to settle the soil.
Areas between the rows of brush layers shall be stabilized by seeding or
other appropriate erosion control method.
Maintenance Considerations
Due to the susceptibility of plant materials to the physical constraints of the site,
climate conditions, and animal populations, it is necessary to inspect installations
frequently. This is especially important during the first year or two of establishment.
Plant materials missing or damaged should be replaced as soon as possible. Sloughs
or breaks in drainage pattern should be reestablished for the site as quickly as possible
to maintain stability.
References
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Rev: 0
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Page 2 of 3 EC -16 Brush Layering
Figure EC -16-1
Brush Layer Installation
Live branch cuttings
2' to 2" in diameter
Seed or other erosion control
material between rows
Backfill
Excavated bench
Branch cuttings installed
to contact back of bench
Front of
Trench
NOT TO SCALE
2' to 3'
3" to 4" thick
layer of branches
Back of
trench
\k�, Branch cuttings installed
to contact back of bench
//Branch culling arranged
, in crisscross fashion, 3"
i to 4" thick
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Page 3 of 3 EC -16 Brush Layering
EC -17 Gabions (G)
Description
Gabions are rectangular, rock -filled wire baskets that are pervious, semi -flexible
building blocks which can be used to armor the bed and/or banks of channels or to
divert flow away from eroding channel sections.
Applicability
Gabions may be used for the following applications:
• As retaining walls to mechanically stabilize steep slopes.
• Along a streambank or drainage channel, as a stable lining that resists
erosion.
• Around culvert outlets and inlets to prevent scour and undercutting.
Limitations
• Materials costs and professional design requirements may make use of
gabions impractical.
• Gabions may alter stream dynamics or adversely affect wildlife habitat.
• When used in channels with high sediment loads, the galvanizing wire on
the cages quickly wears off, causing rusting and the premature failure of
the cages.
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Page 1 of 4 EC -17 Gabions
• Gabions are a structural element that must be professionally designed.
Design Criteria
Gabions
Gabions should be designed and installed in accordance with manufacturer's
standards and specifications and must be able to handle expected storm and flood
conditions (see Figure EC -17-1 for details). At a minimum, they should be
constructed of a hexagonal triple twist mesh of heavily galvanized steel wire
(galvanized wire may also receive a polyvinyl chloride coating). The maximum
linear dimension of the mesh opening shall not exceed 4 %2 inches and the area of the
mesh opening shall not exceed 10 square inches.
Design Velocity
The design water velocity for channels utilizing gabions should not exceed those
listed as follows:
Gabion Thickness
(feet)
Maximum Velocity
(feet per second)
0.5
6
0.75
11
1.0
14
Construction Specifications
1. Gabions shall be fabricated in such a manner that the sides, ends, and lid
can be assembled at the construction site into a rectangular basket of the
specified sizes. Gabions shall be of single unit construction and shall be
installed according manufacturer's recommendations. General
specifications are listed below.
2. Clear and grade the area of trees, brush, vegetation and unsuitable soils.
Compact subgrade firmly to prevent slumping or undercutting.
3. Install a filter fabric or granular filter according to RC -4 Riprap to
maintain separation of rock material with the underlying soil.
4. Place empty gabion baskets. Each row, tier, or layer of baskets should be
reasonably straight and should conform to the specified line and grade (see
Figure EC -17-1 for details). The empty gabion baskets should be fastened
to the adjacent baskets along the top and vertical edges. Each layer should
be fastened to the underlying layer along the front, back and ends.
Fastening should be performed in the same manner as provided for
assembling the gabion units.
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Page 2 of 4 EC -17 Gabions
5. Unless otherwise indicated on the plans, the vertical joints between basket
units of adjacent tiers or layers, along the length of the structure, should be
staggered by at least one cell.
6. Before filling each gabion with rock, all kinks and folds in the wire mesh
should be removed and all baskets should be properly aligned. A standard
fence stretcher, chain fall or steel rod may be used to stretch the wire
baskets and hold alignment.
7. The gabion cells should be carefully filled with four to eight inch rock
placed by hand/machine in such a manner that the alignment of the
structure will be maintained and so as to avoid bulges and to minimize
voids. Rock should be sound, durable, and well graded. All exposed rock
surface should have a reasonably smooth and neat appearance. No sharp
rock edges should project through the wire mesh.
8. The gabion cells in any row or layer should be filled in stages so that local
deformations may be avoided.
9. At no time should any cell be filled to a depth exceeding 12 inches more
than any adjacent cell.
10. The layer of rock should completely fill the gabion basket so that the lid
will bear on the rock when it is secured. The lid should be joined to the
sides, ends, and diaphragms in the same manner as specified for joining
the vertical edges. The gabion basket lid should be secured so that no
more than one inch gap remains at any connection.
11. Gabion rows or layers not completed at the end of each shift should have
the last gabion filled with rock tied internally as an end gabion.
12. The area behind the gabion structure should be backfilled with granular
material. Geotextile, if required, should be spread uniformly over the back
of the gabion structure. Joining edges of the geotextile should be
overlapped a minimum of 12 inches and should be anchored in position
with approved anchoring devices. The Contractor should place the
backfill material in a manner that will not tear, puncture, or shift the
geotextile.
Maintenance Considerations
Inspect regularly and after each major storm. Check for signs of undercutting or
other instability. Repair damaged areas immediately to restore designed effectiveness
and to prevent damage or erosion of the slope or streambank. Check wire of cages
for rusting and wear. Repair where possible or replace.
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Page 3 of 4 EC -17 Gabions
References
City of Knoxville, Stormwater Engineering, Knoxville BMP Manual - Best
Management Practices. July 2003.
<http://www.ci.knoxville.tn.us/engineering>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Figure EC -17-1
Gabion Design
Flat Beddill (smooth fare)
1
Note: Loading conditions are for silty
sand to sand and gravel backfill. For
fines or clay rich soils. earth pressure
on the wall will increase and the wall
base widlh (B] will have to increase for
each height. Backfill weight = 110 pcf.
- Safe against overturning for soils
with a minimum bearing capacity of
2 TonsItt2
-For flat or sloping backfills, either a
flat or stepped face may be used.
NOT TO SCALE
No. of
levels
2
3
4
5
5
H
B
No. of
gabions
(per
width)
3'-3"
8-6"
8'- 9"
13'-1"
16-"
19'-7"
3'-3"
4'-3"
5'-3"
6'•6•
3.2"
9%9"
1
12
2
2
2z
3
Fill at 1 #:1 (race with steps) 1.5
■I
■ ■ "/
E1.
R
■■■ /
MNIffii :.'"
No. 0
levels
B
H
8
No. of
gebions
(per
width)
1 3-3"
2 6-6"
3 9'- 9"
4 13'-1"
5 16'-4
6 19'-7"
4'-11"
6-5"
6'-2"
11'-5"
1
1
2
2Z
3
33
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Page 4 of 4 EC -17 Gabions
EC -18 Level Spreader (LS)
Description
A level spreader is a device used to prevent erosion and to improve infiltration by
spreading concentrated storm water runoff evenly over the ground as shallow flow
instead of through channels. It usually involves a depression in the soil surface that
disperses flow onto a flatter area across a slight slope and then releases the flow onto
level vegetated areas. This reduces flow speed and increases infiltration.
Applicability
A level spreader is most effective for areas less than five acres in size and on slopes
no steeper than 2:1. Level spreaders may be used where:
• Sediment -free storm runoff can be released in sheet flow down a stabilized
slope without causing erosion.
• A level lip can be constructed without filling.
• The area below the level lip is uniform with a slope of 10% or less and the
runoff will not re -concentrate after release.
• No traffic will be allowed over the spreader.
Limitations
This practice applies only in those situations where the spreader can be constructed
on undisturbed soil and the area below the level lip is uniform with a slope of 10% or
less and is stabilized by natural vegetation. The runoff water should not be allowed to
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Page 1 of 4 EC -18 Level Spreader
reconcentrate after release unless it occurs during interception by another measure
(such as a detention basin) located below the level spreader.
Design Criteria
Capacity
The design capacity shall be determined by estimating the peak flow from the 10 -year
storm. The drainage area shall be restricted to limit the maximum flows into the
spreader to 30 cfs.
Construction Specifications
See Figure EC -18-1 for details.
1. A transition section will be constructed from the diversion channel to the
spreader to smoothly blend the different dimension and grades.
2. The level lip will be constructed in undisturbed soil to a uniform height
and zero grade over the length of the spreader. For design flows less than
5 cfs, a vegetated level lip may be constructed with an erosion -resistant
material, such as jute or excelsior blankets, to inhibit erosion and allow
vegetation to become established. The matting should be a minimum of
4 ft. wide extending 6 inches over the lip and buried 6 inches deep in a
vertical trench on the lower edge.
3. For design flows higher than 5 cfs and permanent installations, a rigid
level lip of non -erodible material, such as pressure -treated timbers or
concrete curbing, should be used.
4. The runoff discharge will be outleted onto a stabilized and generally
smooth vegetated slope not exceeding 10%.
5. Seed and mulch the disturbed area immediately after construction.
6. Heavy equipment and traffic should not be allowed on the level spreader,
as they can cause compaction of soil and disturbance of the slope grade.
Maintenance Considerations
The spreader should be inspected after every rainfall. The spreader should be
regraded if ponding or erosion channels develop. Dense vegetation should be
sustained and damaged areas reseeded when necessary.
Removal
Level spreaders may be left in place or removed upon final site reclamation.
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Date: 1/26/06
Page 2 of 4 EC -18 Level Spreader
References
City of Knoxville, Stormwater Engineering, Knoxville BMP Manual - Best
Management Practices. July 2003. http://www.ci.knoxville.tn.us/engineering
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
United States Army Corps of Engineers (USACE), Engineering and Design -
Handbook for the Preparation of Storm Water Pollution Prevention Plans for
Construction Activities. February 1997.
<http://www.usace.army.mil/inet/usace-docs/eng-pamphlets/ep 1110-1-16/>
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Date: 1/26/06
Page 3 of 4 EC -18 Level Spreader
Figure EC -18-1
Level Spreader Installation
Notes:
1) Vegetated lip for level
spreader should not be
constructed from fill material -
Transition section Do not allow any traffic onto
See note 2 vegetated lip.
2) The last 20' of approach
. - - - channel should be a transition
Flow section and have a grads less
than 1%.
Level lip for spreader
See note 1
Vegetated Lip
Transition section
See note 2
Flow
Rigid lip material
(typ. landscape timber)
Coarse aggregate in
galvanized wire
basket or gabion
4'rebers at regular
intervals to
anchor rigid lip
Secure wire basket
or gabion to ground
with stakes
Rigid Lip
NOT TO SCALE
10'
Secure wire mesh
- or gabion to rigid lip
material
1p' (typ)
t
. 6" min.
6' min.
Jute net or excelsior mat
stapled In place and
anchored 6" into ground
-' 10'to 30' length 10' min.
a
-
ope 2' (lyi7.)
6" min-
.
6' min.
Geotextile fitter cloth
r�•
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Page 4 of 4 EC -18 Level Spreader
EC -19 Retaining Wall (RW)
Rock Retaining Wall
Timber Retaining Wall
Description
Retaining walls are structures that are used to stabilize and hold soil in place, gain
space on roadways or well pads, or to keep soil contained within a site boundary.
Several different retaining wall types are:
1. Rigid Gravity and Semi -Gravity Walls. These walls may be constructed of
reinforced concrete, un -reinforced concrete, or stone masonry. The rigid
gravity and semi -gravity walls develop their capacity from their dead
weights and structural resistance, and are generally used for permanent
applications.
2. Non -gravity Cantilevered Walls. These walls develop lateral resistance
through the embedment of vertical wall elements and support retained soil
with wall facing elements. Vertical wall elements are normally extended
deep in the ground to provide lateral and vertical support. The vertical
wall elements can be piles, drilled shafts, steel sheet piles, etc. Wall faces
can be reinforced concrete, metal, or timber. Cantilevered walls are
generally limited to a maximum height of about 15 feet.
3. Anchored Walls. These walls typically consist of the same elements as the
non -gravity cantilevered walls but derive additional lateral resistance from
one or more tiers of anchors. The anchored walls are typically used in the
cut situation, in which the construction proceeds from the top to the base
of the wall.
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Page 1 of 4 EC -19 Retaining Wall
4. Mechanically Stabilized Earth (MSE). These walls normally include a facing
element and a reinforcement element embedded in the backfill behind the
facing. The facing element can be concrete or steel wire mesh. The
reinforcement element can be either metallic (strip, grid, wire mesh) or
polymeric (sheet, grid, or strip type). MSE walls are well suited when
used to support fills and when substantial total and differential settlement
are anticipated. These wall systems are normally used in a fill situation.
5. Geosynthetic retaining wall. These flexible retaining walls are constructed
of geosynthetics, often a geotextile. A geosynthetic wall is constructed by
placing successive layers of fill material, each on a geosynthetic layer with
the geosynthetic folded over and covering the face of the wall. The weight
of the next layer of fill material then holds the folded geosynthetic from
the previous layer in place.
Applicability
Retaining walls are often used near the toe of a cut or fill slope so that a flatter slope
can be constructed to prevent or minimize slope erosion or failure. They can also be
used to keep a toe of a slope from encroaching into a stream and thus prevent
potential undercutting of the toe by flowing water. Retaining walls should be used
when sites have very steep slopes or loose, highly erodible soils that cause other
methods, such as chemical or vegetative stabilization or regrading, to be ineffective.
The preconstruction drainage pattern should be maintained to the extent possible.
Limitations
• To be effective, retaining walls must be designed to handle expected
loads. Non -engineered walls should not be used where traffic is expected
near the top of the wall.
• They must be properly installed and maintained to avoid failure.
• Some types of retaining walls must be placed on a good foundation, such
as bedrock or firm, in-place soil.
• Some MSE walls have height restrictions. Backfill must meet specific
material property requirements.
Design Criteria
Most retaining walls require a site-specific design. Wall heights, requirements for
drainage, and suitable materials must be determined through on-site investigation.
MSE walls are normally designed by the manufacturers. An engineered retaining
structure is a designed structure that is supported by plans and specifications signed
and sealed by a Professional Engineer. Non -engineered retaining structures may be
Rev: 0
Date: 1/26/06
Page 2 of 4 EC -19 Retaining Wall
designed by an engineer; however, if the design is not supported by the seal and
signature, the retaining structure is not considered engineered.
Construction Specifications
Rock retaining wall guidelines
1. See Figure EC -19-1.
2. Excavate a footing trench at the location of the proposed wall.
3. Place the largest rocks in the footing trench with their longitudinal axis
normal to the wall face. Arrange subsequent rock layers so that each rock
above the foundation course has a firm seating on the underlying rocks.
4. The batter of the wall face shall be between 1/2H:1 V and vertical,
depending upon the height of the wall, the height of the slope, the width of
the right-of-way, or other limitations on space.
5. Place fill material behind the rock wall. Slope above the wall should be
maintained at 2H:1 V or flatter. Backfill the footing trench with excavated
material. If a roadway is located at the toe of the wall, pave the roadway
up to the base of the rock wall and provide roadway curb for water
transport. If a roadway is not located at the toe of the retaining wall, slope
the backfilled material away from the wall.
6. Revegetate the stabilized slope with a method applicable to the particular
site.
Timber retaining wall guidelines
1. Prepare the site by rough grading the ground surface. Set the bottom
course of timbers onto a rigid base foundation material, and secure with
pinning or metal collars.
2. Place fill material behind the wall.
3. Place next layer of timbers and fasten it to the lower layer.
4. Place backfill and compact.
5. Proceed in a similar fashion to the desired height.
6. Revegetate the backfill behind the walls according to procedures
applicable to the specific site.
All other walls should be constructed as designed by a Professional Engineer.
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Page 3 of 4 EC -19 Retaining Wall
Maintenance Considerations
Retaining walls should be inspected periodically, particularly after rainstorms, to
check for structural failure, erosion, damage, or other signs of deterioration. In
stream bank installations, inspect for signs of undercutting and other instability.
Make all repairs promptly, as needed.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Figure EC -19-1
Construction of Retaining Structures
Height
15' Max.
2
ear 4
UMW
isrimrrmi
as
Y.
4.
irli
Rock
7 min.
mil
,� Aggrepate
itaysFill
Height 2
8' ' To Vertical
1' min.
Width • 0.7 Height
woo
2:-A os
,.
•
isTr4
eit
1' min.
Width = 0.5 Height
NOT TO SCALE
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Page 4 of 4 EC -19 Retaining Wall
EC -20 Chemical Stabilization (CS)
Description
Chemical stabilizers, also known as soil binders or soil palliatives, provide temporary
soil stabilization. Materials made of vinyl, asphalt, or rubber are sprayed onto the
surface of exposed soils to hold the soil in place and protect against erosion from
runoff and wind. Chemicals used for stabilization are easily applied to the surface of
the soil, can be effective in stabilizing areas where vegetative practices cannot be
established, and provide immediate protection.
Applicability
Chemical stabilization can be used in areas where other methods of stabilization such
as temporary seeding or permanent vegetation are not effective because of
environmental constraints. They can also be used in combination with vegetative or
perimeter practices to enhance erosion and sediment control.
Limitations
• Chemical stabilization can create impervious surfaces where water cannot
infiltrate and which might increase storm water runoff.
• Overuse of chemical stabilizers might adversely affect water quality,
although the chemicals' impacts on wildlife are still unknown.
• Chemical stabilization is usually more expensive than vegetative practices.
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Page 1 of 2 EC -20 Chemical Stabilization
Design Criteria
No formal design is required.
Construction Specifications
The application rates and procedures recommended by the manufacturer of a
chemical stabilization product should be followed as closely as possible to prevent the
products from forming ponds and to avoid creating impervious areas where storm
water cannot infiltrate.
Maintenance Considerations
Chemically stabilized areas should be regularly inspected for signs of erosion.
Stabilizers should be reapplied if necessary.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa. gov/npdes/stormwater/menuofbmps/con_site.cfm>
Rev: 0
Date: 1/26/06
Page 2 of 2 EC -20 Chemical Stabilization
RC -1 Roadside (RSD) and Turnout (TO)
Ditches
Riprap Lined Channel
Concrete Lined Channel
Turnout/Wing Ditch
Description
Roadside ditches are channels constructed parallel to roads. The ditches convey
concentrated runoff of surface water from roads and surrounding areas to a stabilized
outlet. Turnouts (wing ditches) are extensions of road -side ditches. Turnouts
effectively remove run-off water from the roadside ditch into well -stabilized areas
before it reaches a waterway.
Applicability
• Roadside ditches should be used for all roads built on a slope with either
an insloped or a crowned design.
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RC -1 Roadside and
Page 1 of 4 Turnout Ditches
• Ditch turnouts should be used as much as possible but their best use may
be on slopes longer than 150 ft or greater than 5%, as conditions allow.
Limitations
• If these structures are not installed correctly they may become a source of
erosion.
• Road -side ditches do not necessarily filter sediment from runoff.
• Turnouts should be on gradual slopes only.
• Turnouts require vegetative cover or other filter at the discharge point.
• Turnouts only work well if small volumes of runoff drain into the turnout.
Turnouts should only receive runoff from the road and ditch surface, not
from large, uphill watersheds.
Design Criteria
No formal design is required.
Construction Specifications
See Figure RC -1-1 for details.
Roadside Ditches
1. Roadside ditches should be constructed according to RC -10 Temporary
Swale or RC -11 Temporary Diversion with no projections of roots,
stumps, rocks, or similar debris.
2. Excavate channel along roadside to a width and depth that can handle
expected flows.
3. Slope channels so that water velocities do not cause excessive erosion, but
no less than 0.5%.
4. Vegetate or line channel with material to prevent erosion.
Turnouts
1. Turnouts should be constructed on undisturbed soil whenever possible.
2. Slope turnout gradually down from bottom of road -side ditch.
3. Angle turnout at approximately 30 degrees to the road -side ditch.
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RC -1 Roadside and
Page 2 of 4 Turnout Ditches
4. Discharge turnout into well -vegetated area or install secondary control
such as rock filter or straw bales. As a good Rule of Thumb, the buffer
area should be a minimum of one half the size of the total drainage area
draining into it.
5. Space turnouts according to slope.
Maintenance Considerations
Road ditches and turnouts should be inspected after construction and storm events for
any signs of channelization, and repaired immediately. Structures will fail if water
exits in channelized flow. Also inspect for sediment buildup at the outlet and remove
if necessary.
References
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
United States Department of the Interior, Bureau of Land Management (BLM),
United States Department of Agriculture (USDA), Forest Service, Surface
Operating Standards for Oil and Gas Exploration and Development "Gold
Book". Fourth Edition, 2005.
Rev: 0
Date: 1/26/06
RC -1 Roadside and
Page 3 of 4 Turnout Ditches
Figure RC -1-1
Roadside Ditch and Turnout Layout
Well vegetated area (or other Well vegetated area (or other
erosion control measure) erosion control measure)
O. 1 ► 4
_3O' RP.)
i __ _ ► Road Slope Turnout
Drainage Ditch 0.5% min. — Spacing X
» Spacing X <2% <500 ft.
Access Road
2-5% 200 ft.
5-10% 100 ft.
Drainage Ditch 0.5% min. >10% 75 ft
■
Well vegetated area (or other Well vegetated area (or other
erosion control measure) erosion control measure)
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RC -1 Roadside and
Page 4 of 4 Turnout Ditches
RC -2 Culvert Cross -Drain (CCD)
Description
Culvert cross -drains are typically concrete, steel, aluminum, or plastic pipe used to
move ditch water under the road or to direct stream flow under the road or
construction area.
Applicability
Culvert cross -drains are ideal on road grades less than 15%. For grades over 15%, it
is difficult to slow down the water or remove it from the road surface rapidly. On
such steep grades, it is best to use frequently spaced cross -drain culverts, with
armored ditches (see RC -4 Riprap). Culverts may be used in the following
applications:
• As drainage crossing culverts in streams and gullies to allow normal
drainage to flow under the traveled way.
• As ditch relief culverts to periodically relieve the inside ditch line flow by
piping water to the opposite side of the road where the flow can be
dispersed away from the roadway. Culverts placed in natural drainages
may be utilized for ditch relief.
Limitations
• If undersized, culverts are susceptible to plugging and require cleaning.
• Culverts will not filter sediment.
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Page 1 of 7 RC -2 Culvert Cross -Drain
Design Criteria
Capacity
All culverts should be designed for a minimum 25 -year -frequency storm with an
allowable head that does not overlap the roadway. However, the minimum
acceptable size culvert diameter to prevent failure from debris blockage is 18 inches
for intermittent stream crossings and 36 inches for perennial stream crossings. Pipe
size can be determined using general design criteria, such as in Table RC -2-1, but is
ideally based upon site-specific hydrologic analysis.
Depth
The depth of culvert burial must be sufficient to ensure protection of the culvert barrel
for the design life of the culvert. This requires anticipating the amount of material
that may be lost due to road use and erosion.
Headwalls
Use headwalls on culvert pipes as often as possible (see EC -19 Retaining Wall). The
advantages of headwalls include: preventing large pipes from floating out of the
ground when they plug; reducing the length of the pipe; increasing pipe capacity;
helping to funnel debris through the pipe; retaining the backfill material; and reducing
the chances of culvert failure if it is overtopped.
Construction Specifications
Drainage crossing culverts
1. Make road crossings of natural drainages perpendicular to the drainage to
minimize pipe length and area of disturbance (Figure RC -2-1).
2. Use single large pipes versus multiple smaller diameter pipes to minimize
plugging potential in most channels (unless roadway elevation is critical).
In very broad channels, multiple pipes are desirable to maintain the natural
flow spread across the channel. All culverts should be concrete,
corrugated metal pipe (CMP) made of steel or aluminum, or properly
bedded and backfilled corrugated plastic pipe.
3. Align culverts in the bottom and middle of the natural channel so that
installation causes no change in the stream channel alignment or stream
bottom elevation. Culverts should not cause damming or pooling or
increase stream velocities significantly
4. Extend the outlet of the culvert at least one foot beyond the toe of the
slope to prevent erosion of the fill material. Alternatively, use retaining
walls (headwalls) to hold back the fill slope.
5. It may be necessary to install rip -rap or other energy dissipater devices at
the outlet end of the culvert to prevent soil erosion or to trap sediment (see
RC -3 Culvert Outlet Protection).
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Page 2 of 7 RC -2 Culvert Cross -Drain
6. Install an overflow/drainage dip off the side of the culvert in drainage
channels with a large fill that could be overtopped (see RC -7 Drainage
Dip). Also use overflow dips on long sustained road grades where a
plugged culvert could divert water down the road, plugging subsequent
culverts and causing extensive off-site damage (Figure RC -2-1).
Ditch relief culverts
1. See Figure RC -2-2 for installation details.
2. Ditch relief culverts can provide better flow when skewed 0 to 30 degrees
perpendicular to the road.
3. The culvert gradient should be at least 2% greater than the approach ditch
gradient. This improves the flow hydraulics and reduces siltation and
debris from plugging the culvert inlet.
4. Discharge culvert at natural ground level (see Figure RC -2-3 — Type A),
on firm, non-erosive soil or in rocky or brushy areas. If discharged on the
fill slopes, armor outlets with riprap or logging slash (see Figure RC -2-3 —
Type B), or use down -drain structures (see Figure RC -2-3 — Type C and
EC -15 Slope Drain).
5. Extend the outlet of the culvert at least one foot beyond the toe of the
slope to prevent erosion of the fill material.
6. It may be necessary to install rip -rap or other energy dissipater devices at
the outlet end of the culvert to prevent soil erosion or to trap sediment
(see RC -3 Culvert Outlet Protection).
7. Spacing of culverts is dependent on the road gradient, soil types, and
runoff characteristics according to the following table:
Soil Type
Road Grade
a
2-4 /0
5-8%9-12%
Highly corrosive
granitic or sandy
240'
180'
140'
Intermediate erosive
clay or load
310'
260'
200'
Low erosive shale or
gravel
400'
325'
250'
Backfill and Compaction
1. See Figure RC -2-4.
2. Firmly compact well -graded fill material (soil or road base) around
culverts, particularly around the bottom half, using placement in layers to
achieve a uniform density. Use slightly plastic sandy gravel with fines.
Avoid the use of fine sand and silt rich soils for bedding material because
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Page 3 of 7 RC -2 Culvert Cross -Drain
of their susceptibility to piping. Pay particular attention to culvert bedding
and compaction around the haunches of the pipe. Do not allow the
compaction to move or raise the pipe. In large fills, allow for settlement.
3. Cover the top of metal and plastic culvert pipes with fill to a depth of at
least 1 foot to prevent pipe crushing by heavy trucks. Use a minimum
cover of 2 feet of fill over concrete pipe. For maximum allowable fill
height, follow the manufacturer's recommendations.
Maintenance Considerations
Each culvert should be inspected annually and after major storms. If any damage to
culvert or inlet/outlet protection is noted or if there is any evidence of scour, repairs
should be made immediately. Any debris that may be blocking the culvert inlet or
outlet should be removed.
References
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
United States Department of the Interior, Bureau of Land Management (BLM),
United States Department of Agriculture (USDA), Forest Service, Surface
Operating Standards for Oil and Gas Exploration and Development "Gold
Book". Fourth Edition, 2005.
Rev: 0
Date: 1/26/06
Page 4 of 7 RC -2 Culvert Cross -Drain
Table RC -2-1
Culvert Sizing
Drainage Area
(acres)
Size of Drainage Structure (diameter and area)
Steep Slopes
(Light Vegetation)
C=0.7
Gentle Slopes
(Heavy Vegetation)
C=0.2
Round Pipe (in)
Area (sq. ft)
Round Pipe
(in)
Area (sq. ft)
0 —10
30"
4.9
18"
1.8
10 - 20
42"
9.6
24"
3.1
20 - 35
48"
12.6
30"
4.9
35 - 75
72"
28.3
42"
9.6
75 - 125
84"
38.5
48"
12.6
125 - 200
96"
50.3
60"
19.6
Notes: If pipe size is not available, use the next larger pipe size for the given drainage area. For intermediate
terrain, interpolate between pipe sizes. Pipe size is based upon the Rational Formula and Culvert Capacity curves.
Assumes a rainfall intensity of 3 to 4 in/hr. Values of "C" are the Runoff Coefficients for the terrain.
Figure RC -2-1
Drainage Crossing Culvert Alignment & Overflow Dip
Note: Make road crossing perpendicular to
the drainage to minimize pipe length
and area of disturbance.
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Page 5 of 7 RC -2 Culvert Cross -Drain
Figure RC -2-2
Ditch Relief Culvert Installation
Inlet protection as needed
Spacing 140-400'
- Culvert between culverts
0-30'
Inlet protection as needed
Place outlet pipe at natural ground -
level or riprap armor the fill malarial -
NOT TO SCALE
//\\/�/�:
/.
Figure RC -2-3
Culvert Installation Options
Culvert
cross -drain
TYPE A
Natural ground surface
Roadbed
Inslope 3.5% Compacted
..................... Fill
Culvert -
TYPE C
Roactped
Ins1ope 536 J Compacted Fill
\/ ' Anchor the Slope drain pipe to the fill slope
_Y
%\�\ wish slakes, cable anchor Clocks, etc-
\ , 1
TYPE B
Roadbed Compacted Fill
Inslope 3.5%
Culvert \ //\\/\\ j
Outlet protection
with rock riprap
4\,<\\T\
Add riprap or other
slope protection
Outlet protection
with rock riprap
Outlet protection
with rock riprap
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Page 6 of 7 RC -2 Culvert Cross -Drain
Figure RC -2-4
Culvert Backfill and Compaction
At least 111. of cover for CMP or
one third of diameter for large
culverts. Use 2 ft. cover for
concrete pipe.
Roadbed
1 •I
Bass and sidewall fill material
should be compacted. Compact
the 511 a minium of each culvert
diameter on each side of the
culverL
NOT TO SCALE
Culvert
/j, Tamp backfill material at
regualar intervals (lifts) of 13-13"
Level of natural streambed
Gravel or soil culvert bed
(no rock larger than 3")
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Page 7 of 7 RC -2 Culvert Cross -Drain
RC -3 Culvert Outlet Protection (COP)
Description
Culvert outlet protection involves placing structurally lined aprons or other
appropriate energy -dissipating devices, such as a plunge pool, at the outlets of pipes
to reduce the velocity of storm water flows and thereby prevent scouring at storm
water outlets, protect the outlet structure, and minimize potential for erosion
downstream.
Applicability
This practice applies where discharge velocities and energies at the outlets of culverts
or channels are sufficient to erode the next downstream reach.
Limitations
For pipe outlets at the top of cuts or on slopes steeper than 10 percent cannot be
protected by rock aprons or riprap sections due to re -concentration of flows and high
velocities encountered after the flow leaves the apron.
Design Criteria
Tailwater Depth
The depth of tailwater immediately below the pipe outlet must be determined for the
design capacity of the pipe. If the tailwater depth is less than half the diameter of the
outlet pipe, and the receiving stream is wide enough to accept divergence of the flow,
it shall be classified as a Minimum Tailwater Condition. If the tailwater depth is
greater than half the pipe diameter and the receiving stream will continue to confine
the flow, it shall be classified as a Maximum Tailwater Condition. Pipes which outlet
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Date: 1/26/06
Page 1 of 5 RC -3 Culvert Outlet Protection
onto flat areas with no defined channel may be assumed to have a Minimum
Tailwater Condition.
Apron Size & D50
The apron length (LA) and the D50 of the riprap shall be determined from
Table RC -3-1 according to the design flow and whether there is a minimum or
maximum tailwater condition. The apron width (W) shall then be determined as:
W=d+0.4LA
where d is the diameter of the culvert. If the pipe discharges directly into a well
defined channel, the apron shall extend across the channel bottom and up the channel
banks to an elevation one foot above the maximum tailwater depth or to the top of the
bank, whichever is less. The upstream end of the apron, adjacent to the pipe, shall
have a width two (2) times the diameter of the outlet pipe, or conform to pipe end
section if used.
Materials
The outlet protection may be done using rock riprap, grouted riprap, or gabions
according to EC -17 Gabions. Riprap shall be composed of a well -graded mixture of
stone size so that 50 percent of the pieces, by weight, shall be larger than the D50 size
determined from Table RC -3-1. A well -graded mixture, as used herein, is defined as
a mixture composed primarily of larger stone sizes, but with a sufficient mixture of
other sizes to fill the smaller voids between the stones. The diameter of the largest
stone size in such a mixture shall be 1.5 times the D50 size. All grout for grouted
riprap must be one part Portland cement for every 3 parts sand, mixed thoroughly
with water.
Filter
A filter of cloth or gravel shall be designed according to RC -4 Riprap.
Thickness
The minimum thickness of the riprap layer shall be 1.5 times the maximum stone
diameter for D50 of 15 inches or less; and 1.2 times the maximum stone size for D50
greater than 15 inches.
Stone Quality
Stone for riprap shall consist of field stone or rough unhewn quarry stone. The stone
shall be hard and angular and of a quality that will not disintegrate on exposure to
water or weathering. The specific gravity of the individual stones shall be at least 2.5.
Recycled concrete equivalent may be used provided it has a density of at least
150 pounds per cubic foot, and does not have any exposed steel or reinforcing bars.
Rev: 0
Date: 1/26/06
Page 2 of 5 RC -3 Culvert Outlet Protection
Construction Specifications
See Figure RC -3-1.
1. Prepare the subgrade for the riprap filter, riprap, or gabion to the required
lines and grades. Any fill required in the subgrade shall be compacted to a
density of approximately that of the surrounding undisturbed material.
2. If a pipe discharges into a well-defined channel, the channel's side slopes
may not be steeper than 2:1.
3. Construct apron to the design length and width with no slope
(Figure RC -3-1). The invert elevations must be equal at the receiving
channel and the apron's downstream end. No overfall at the end of the
apron is allowed. The elevation of the downstream end of the apron shall
be equal to the elevation of the receiving channel or adjacent ground. The
outlet protection apron shall be located so that there are no bends in the
horizontal alignment.
4. Line the apron with riprap, grouted riprap, concrete, or gabion baskets.
Riprap should be the appropriate size and thickness as designed.
See RC -4 Riprap for the placement of riprap and see EC -17 Gabions for
the sizing and placement of gabions.
5. If grouted riprap is to be used, the spaces between the stones are to be
filled with grout to a minimum depth of six inches, with the deeper
portions choked with fine material.
6. If a paved channel is to be used, the end of the paved channel outlet must
be smoothly joined with the receiving channel section, with no overfall at
the end of the paved section.
Maintenance Considerations
Once culvert outlet protection has been installed, the maintenance needs are very low.
It should be inspected after high flows for evidence of scour beneath riprap or for
dislodged stones. Repairs should be made immediately.
References
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Rev: 0
Date: 1/26/06
Page 3 of 5 RC -3 Culvert Outlet Protection
Table RC -3-1
Outlet Protection Design
Riprap Aprons for Low Tailwater
(downstream flow depth c 0.5 x pipe diameter)
Culvert
Diameter
La.r.+est value
Intermediate values to interpolate from
Highest
value
0
L.,.
DT
0
LA
Dti
Q
LA
Da,
0
LA
Dya
i)
LA
D-0
Cfs
Ft
In
Cfs
Ft
In
Cfs
Ft
11
Cfs
Ft
In
Cfs
Ft
In
12"
4
7
2.5
6
10
3.5
9
131
6
'12
16
7
14
17
8.5
15"
6.5
8
3
10
12
6
15
16
7
20
18
10
25
20
12
18"
10
9
3.5
15
14
5.5
20
17
7
30
22
11=:J
25
14
21"
15
11
4
25
18
7
35
22
'10
45
26
13
6i1
29
18
24"
21
13
5
35
20
8.5
50
26
'12
65
30
16
&3
33
19
27"
27
'14
5.5
50
24
9.5
70
29
'14
90
34
18
110
37
22
30"
36
'16
6
60
25
9.5
90
33
'15.5
'120
38
20
140
41
24
36"
56
20
7
100
32
13
140
40
18
'180
45
23
220
50
28
42"
82
22
8.5
120
32
12
160
39
17
200
45
20
260
52
26
48"
120
26
10
170
37
14
220
46
19
270
54
23
320
64
37
Riprap Aprons for High Tailwater
(downstream flow depth > 0.5 x pipe diameter)
Culvert
Diameter
Lowest value
I n:ermediate values to interpolate from
Hioh st ...a 1. e
Q
L,
D50
Q
LA
Dip
0
L,
DED
0
LA
lam
0
LA
Dr-,
Cfs
Ft
In
Cfs
9
In
Cfs
Ft
Im
Cfs
Ft
In
Cts
Ft
In
12"
4
8
2
6
18
2.5
9
28
4.5
'12
36
7
14
40
8
15"
7
8
2
10
20
2.5
15
34
5
20
42
7.5
25
50
10
18"
'10
8
2
15
22
3
20
34
5
30
50
9
40
60
1'1
21"
'15
8
2
25
32
4.5
35
48
7
45
58
11
60
72
14
24"
20
8
2
35
36
5
50
55
8.5
65
68
12
80
80
15
27"
27
10
2
50
41
6
70
58
10
90
70
14
110
82
17
30"
36
11
2
60
42
n
90
64
11
120
80
15
140
90
18
36"
56
13
2.5
100
60
7
140
85
'13
180
'104
18
220
120
23
42"
82
15
2.5
120
50
6
160
75
•0
200
96
14
260
120
19
48"
120
20
2.5
170
58
7
220
85
2
270
105
16
320
120
20
Rev: 0
Date: 1/26/06
Page 4 of 5 RC -3 Culvert Outlet Protection
Figure RC -3-1
Typical Outlet Protection Installation
201,
•
A
1.5x0„
or 12 x ❑r,a,
2
w = d+O 4 La
—d12—
Graded aggregate
filter or filter cloth
Graded aggregate
filter or filler Goth La
}
NOT TO SCALE
Rev: 0
Date: 1/26/06
Page 5 of 5 RC -3 Culvert Outlet Protection
RC -4 Riprap (RIP)
Roadside Ditch Protection
Slope Stabilization
Description
Riprap is a permanent, erosion -resistant layer made of stones. It is intended to
stabilize areas subject to erosion and protect against scour of the soil caused by
concentrated, high velocity flows.
Applicability
Riprap can be used for areas subject to erosion or weathering, particularly where
conditions prohibit the establishment of vegetation or where flow velocities exceed
5 ft/sec. Riprap may be used in the following applications:
• Cut -and -fill slopes
• Channel side slopes and/or bottoms
• Inlets and outlets to culverts or slope drains
• Roadside ditches
Limitations
Riprap is limited by steepness of slope, because slopes greater than 1.5:1 have
potential riprap loss due to erosion and sliding. When working within flowing
streams, measures should be taken to prevent excessive turbidity and erosion during
construction. Bypassing base flows or temporarily blocking base flows are two
possible methods.
Design Criteria
Gradation
A well -graded mixture of rock sizes should be used instead of one uniform size.
50% by weight should be larger than the specified design size. The diameter of the
largest stone size in such a mixture should be 1.5 times the d50 size with smaller sizes
graded down to one inch.
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Date: 1/26/06
Page 1 of 6 RC -4 Riprap
Quality
Riprap must be durable so that freeze/thaw cycles do not decompose it in a short time.
They should be angular and not subject to breaking down when exposed to water or
weathering. The specific gravity should be at least 2.5.
Size
The sizes of stones used for riprap protection are determined by purpose and specific
site conditions:
1. Slope Stabilization. Riprap stone for slope stabilization not subject to
flowing water should be sized for the proposed grade. The gradient of the
slope to be stabilized should be less than the natural angle of repose of the
stone selected. Angles of repose of riprap stones may be estimated from
Figure RC -4-1. Riprap used for surface stabilization of slopes does not
add significant resistance to sliding or slope failure and should not be
considered a retaining wall. Slopes approaching 1.5:1 may require special
stability analysis. The inherent stability of the soil must be satisfactory
before riprap is used for surface stabilization.
2. Outlet Protection. Design criteria for sizing stone and determining
dimensions of riprap aprons are presented in RC -3 Culvert Outlet
Protection.
3. Streambank Protection. If the shear stress is estimated, riprap stone for
streambank protection can be selected from the gradations in
Table RC -4-1, below. The riprap should extend two feet below the
channel bottom and be keyed into the bank both at the upstream end and
downstream end of the proposed work or reach.
Filter material
Filter material is usually required between riprap and the underlying soil surface to
prevent soil from moving through the riprap. Filter cloth material or a layer of sand
and/or gravel is usually used for the filter.
The design of a sand/gravel filter blanket is based on the ratio of particle size in the
overlying filer material to that of the base material in accordance with the criteria
below. Multiple layers (each a minimum of 6 inches thick) may be designed to affect
a proper filter if necessary. A sand/gravel filter blanket should have the following
relationship for a stable design:
d15 filter
d85 base < 5
d15 filter
5 < d50 base < 40
d50 filter
d50 base < 40
Rev: 0
Date: 1/26/06
Page 2 of 6 RC -4 Riprap
The design of a synthetic filter fabric, which may be used with or in place of gravel
filters, is based upon the following particle size relationships:
1. Filter fabric covering a base containing 50% or less by weight of fine
particles (#200 sieve size):
a. d85 base (mm)
EOS*filter fabric (mm) > 1
b. total open area of filter fabric should not exceed 36%
2. Filter fabric covering other soils:
a. EOS is no larger than 0.21 mm (#70 sieve size)
b. total open area of filter fabric should not exceed 10%
*EOS - Equivalent opening size compared to a U.S. standard sieve size
No filter fabric should have less than 4% open area or an EOS less than U.S. Standard
Sieve #100 (0.15 mm). The permeability of the fabric must be greater than that of the
soil. The fabric may be made of woven or non -woven monofilament yarns and
should meet the following minimum requirements:
Thickness 20-60 mils
Grab strength 90-120 lbs
Conform to ASTM D-1682 or ASTM D-177
Construction Specifications
See Figure RC -4-2.
1. Subgrade Preparation. Prepare the subgrade for riprap and filter to the
required lines and grades shown on the plans. Compact any fill required
in the subgrade to a density approximating that of the undisturbed material
or overfill depressions with riprap. Remove brush, trees, stumps, and
other objectionable material. Cut the subgrade sufficiently deep so that
the finished grade of the riprap will be at the elevation of the surrounding
area. Channels should be excavated sufficiently to allow placement of the
riprap in a manner such that the finished inside dimensions and grade of
the riprap meet design specifications.
2. Sand/gravel filter blanket. If using a granular filter, spread filter stone in a
uniform layer to the specified depth. Where more than one layer of filter
material is used, spread the layers with minimal mixing.
3. Synthetic filter fabric. If using a filter fabric, place the cloth directly on the
prepared foundation according to EC -9 Erosion Control Blanket. Where
large stones are to be placed, a 4 -inch layer of fine sand or gravel is
Rev: 0
Date: 1/26/06
Page 3 of 6 RC -4 Riprap
recommended to protect the filter cloth. Filter fabric is not recommended
as a filter on slopes steeper than 2 horizontal to 1 vertical.
4. Stone placement. Placement of the riprap should follow immediately after
placement of the filter. Place riprap so that it forms dense, well -graded
mass of stone with a minimum of voids. The desired distribution of stones
throughout the mass may be obtained by selective loading at the quarry
and controlled dumping during final placement. Place riprap to its full
thickness in one operation. Do not place riprap by dumping through
chutes or other methods that cause segregation of stone sizes. Be careful
not to dislodge the underlying base filter or damage the filter cloth when
placing the stones. If damage occurs, remove the riprap and repair filter.
5. The toe of the riprap should be keyed into a stable foundation at its base as
shown in Figure RC -4-2. The finished slope should be free of pockets of
small stone or clusters of large stones. Hand placing may be necessary to
achieve proper distribution of stone sizes to produce a relatively smooth,
uniform surface. The finished grade of the riprap should blend with the
surrounding area.
Maintenance Considerations
Riprap should be inspected annually and after major storms. If riprap has been
damaged, repairs should be made promptly to prevent a progressive failure. If repairs
are needed repeatedly at one location, the site should be evaluated to determine if the
original design conditions have changed. Channel obstructions such as trees and
sediment bars can change flow patterns and cause erosive forces that may damage
riprap. Control of weed and brush growth may be needed in some locations.
Removal
Riprap is generally not removed.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Rev: 0
Date: 1/26/06
Page 4 of 6 RC -4 Riprap
Table RC -4-1
Riprap Gradations
Unit shear stress
(Ib/ft2)
D50
dmax
Minimum blanket
thickness (inches)
0.67
2
4
6
2
6
9
14
3
9
14
20
4
12
18
27
5
15
22
32
6
18
27
32
7.8
21
32
38
8
24
36
43
Unit shear stress calculated as T=y*d*s where:
T = shear stress in Ib/ft2
y = unit weight of water, 62.4 Ib/ft2
d = flow depth in ft
s = channel gradient in ft/ft
45'
40'
Angle of V
Repose
35'
30'
Figure RC -4-1
Angles of Repose of Riprap Stones
C'ruslied Rock
Anraular Rock
Rounded Stones
1"
2,. 4„ I]5p 10„
20"
40"
1:1
Slope (H:V)
1.5 : 1
Rev: 0
Date: 1/26/06
Page 5 of 6 RC -4 Riprap
Figure RC -4-2
Typical Riprap Slope Protection Detail
r 1.5x0,vx.(min.]
3' min.
NOT TO SCALE
Gravel oilier
or filter fabric ‘\�\/
�2' mina/
Rev: 0
Date: 1/26/06
Page 6 of 6 RC -4 Riprap
RC -5 Check Dam (CD)
Rock Check Dam
Straw Bale Check Dam
Sand Bag Check Dam
Description
Check dams are small, temporary dams constructed across a swale or channel Check
dams can be constructed using gravel, rock, sandbags, logs, or straw bales and are
used to slow the velocity of concentrated flow in a channel and thus reduce erosion.
As a secondary function, check dams can also be used to catch sediment from the
channel itself or from the contributing drainage area as storm water runoff flows
through the structure.
Applicability
Check dams are most often used in small, open channels with a contributing drainage
area of 2 to 10 acres, and side slopes of less than 2:1. Check dams may be used in the
following applications:
Rev: 0
Date: 1/26/06
Page 1 of 4 RC -5 Check Dam
• In swales or channels that will be used for a short period of time where it
is not practical to line the channel or implement other flow control
practices.
• Where temporary seeding has been recently implemented but has not had
time to take root and fully develop.
• As a series of check dams in a channel, spaced at appropriate intervals.
Limitations
• Check dams should not be used in live, flowing streams unless approved
by an appropriate regulatory agency.
• Because the primary function of check dams is to slow runoff in a channel,
they should not be used as a stand-alone substitute for other sediment -
trapping devices.
• Leaves have been shown to be a significant problem by clogging check
dams in the fall. Therefore, they might necessitate increased inspection
and maintenance.
Design Criteria
No formal design is required.
Construction Specifications
1. Dams should be installed with careful placement of the construction
material. Mere dumping of the dam material into a channel is not
appropriate and will reduce overall effectiveness.
2. Check dams can be constructed from a number of different materials.
Most commonly, they are made of rock, logs, sandbags, or straw bales.
When using rock or stone, the material diameter should be 2 to 15 inches.
Logs should have a diameter of 6 to 8 inches.
3. All check dams should have a maximum height of three feet. The center
of the dam should be at least six inches lower than the edges. This design
creates a weir effect that helps to channel flows away from the banks and
prevent further erosion.
4. Additional stability can be achieved by implanting the dam material
approximately 6 inches into the sides and bottom of the channel.
5. If dams are used in a series, they should be spaced such that the base of
the upstream dam is at the same elevation as the top of the next
downstream dam.
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Date: 1/26/06
Page 2 of 4 RC -5 Check Dam
6. When installing more than one check dam in a channel, outlet stabilization
measures should be installed below the final dam in the series. Because
this area is likely to be vulnerable to further erosion, riprap, geotextile
lining, or some other stabilization measure is highly recommended.
7. Install straw bale and rock check dams according to Figures RC -5-1 &
RC -5-2, respectively.
Maintenance Considerations
Check dams should be inspected after each storm event to ensure continued
effectiveness. During inspection, large debris, trash, and leaves should be removed.
The center of a check dam should always be lower than its edges. If erosion or heavy
flows cause the edges of a dam to fall to a height equal to or below the height of the
center, repairs should be made immediately. Accumulated sediment should be
removed from the upstream side of a check dam when the sediment has reached a
height of approximately one-half the original height of the dam (measured at the
center).
Removal
All accumulated sediment should be removed prior to removing a check dam.
Removal of a check dam should be completed only after the contributing drainage
area has been completely stabilized. Permanent vegetation should replace areas from
which gravel, stone, logs, or other material has been removed.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
Rev: 0
Date: 1/26/06
Page 3 of 4 RC -5 Check Dam
Figure RC -5-1
Straw Bale Check Dam Installation
FLOW
_ 1 B" x 18"x36"
Typical Strew Bales
Stake
*Point A
/ 1411"11F, 4419111411111W417 \/
\/`�/\ p I// //
Trench
6" into
Swale
- Point A *
Point B *
NOTTO SCALE
* Point A must be higher that Point B
Toof swa
SECTION VIEW
Boltom of Swale
PROFILE VIEW
Flow
> >
Embed
Geotextlle 1'
B' min.
Slake
FLOW srr
1
18" x 18"x 38"
Typical Straw Bales
Point C
L
Remove accumulate sediment
when it reaches one half of
exposed bale height
L = Distance such that Points C and D
are equal elevation
Figure RC -5-2
Rock Check Dam Installation
Trench 6" into Swale
Top of Swale
Geotextile (extend to 2" beyond
crest of check dam)
Point D
//\ fj /.
24"
Top of Swale
Bolton]of Swale Flow
ice\ -. ..y\
/
NOT TO SCALE
Polnt C —
24"
L = Distance such that Points C and D
are equal elevation
Point 0
,/ \\ <//�i\moi\%\\/ 'r
i./®/,/i /
Rev: 0
Date: 1/26/06
Page 4 of 4 RC -5 Check Dam
RC -6 Road Slope
Description
Roads using sloping provide good drainage of water from the surface of the road into
stabilized ditches or vegetation, and help keep the traveled way dry and passable
during wet weather. The three most common types of roadway sloping are outsloped,
insloped, or crowned as shown in Figure RC -6-1.
Outsloped Roads
Outsloped roads minimize the concentration of water and minimize road width by
avoiding the need for an inside ditch, but may require roadway surface and fill slope
stabilization. Outsloped roads with clay rich, slippery road surface materials often
require rock surface stabilization (see EC -7 Road Gravel) or limited use during rainy
periods to assure traffic safety. On road grades over 10 to 12 percent and on steep hill
slope areas, outsloped roads are difficult to drain and can feel unsafe.
Insloped Roads
Insloped roads are the best method to control surface water. However, insloped roads
also concentrate water and require a system of ditches and turnouts or cross -drains.
Crowned Roads
Crowned roads are appropriate for higher standard, two lane roads on gentle grades.
They also require a system of inside ditches and turnouts or cross -drains. It is
difficult to create and maintain a crown on a narrow road, so generally insloped or
outsloped road drainage is more effective.
Rev: 0
Date: 1/26/06
Page 1 of 3 RC -6 Road Slope
Applicability
Road sloping is applicable for the construction of any road.
Limitations
• Only sheds runoff collected from the surface of the road.
• May cause concentrated flows from sheet flow.
• Requires vegetative ditches, turnouts, and/or cross -drains.
Design Criteria
No formal design is required.
Construction Specifications
1. Compact soil or road base material to direct runoff
2. If crowning a road, runoff is directed to both sides of the road requiring
two road -side ditches.
3. If using an inslope design, runoff is directed toward the hillside and
requires a road -side ditch and turnout or cross -drain installation.
4. If using an outslope design, ensure a moderate road slope with dense
vegetative cover.
Maintenance Considerations
Maintain crowns and outslopes and repair any problems as soon as possible.
References
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
United States Department of the Interior, Bureau of Land Management (BLM),
United States Department of Agriculture (USDA), Forest Service, Surface
Operating Standards for Oil and Gas Exploration and Development "Gold
Book". Fourth Edition, 2005.
Rev: 0
Date: 1/26/06
Page 2 of 3 RC -6 Road Slope
Figure RC -6-1
Typical Road Surface Drainage Options
Crown Section
2
1 I—
a
Outslope Section
7I1
4//
BRUSH 1 \ \\/\ / /// //\ // \�\//\:ye �/
Inslope with Ditch Section
2
1
NOT TO SCALE
&996
ARMORED DITCH1 <\
/\/
1
\/\ \•\\ \ \��/\\/\`7\/ \//\1\;/`\\//::/://\)/
\% /\\// /:/\/
Rev: 0
Date: 1/26/06
Page 3 of 3
RC -6 Road Slope
RC -7 Drainage Dip (DD)
Description
Drainage dips intercept and remove surface water from the road and shoulders before
the combination of water volume and velocity begins to erode the surface materials.
Drainage dips are constructed diagonally across and as part of the road surface, and
will pass slow traffic while dispersing surface water.
Applicability
Drainage dips may be used in the following applications:
• To move water off the road surface efficiently and economically.
• In place of a culvert, which is costly and susceptible to plugging or failure.
• On low volume, low to moderate speed roads (10-35 mph) with grades
less than 12%.
Limitations
• Size limited by the safe passage of trucks and equipment
• May cause concentrated flows from sheet flows
• Require vegetative cover or other filter at discharge point
Design Criteria
No formal design required.
Rev: 0
Date: 1/26/06
Page 1 of 3 RC -7 Drainage Dip
Construction Specifications
See Figure RC -7-1.
1. Construct rolling dips deep enough to provide adequate drainage, angled
0-25 degrees from perpendicular to the road, with a 3-5% outslope, and
long enough (50 to 200 feet) to pass vehicles and equipment.
2. In soft soils, armor the mound and dip with gravel or rock, as well as the
outlet of the dip.
3. Spacing of drainage dips depends upon local conditions such as soil
material, grade, and topography. See Table RC -7-1 for recommended
maximum distances between drainage dips.
Maintenance Considerations
Inspect discharge point for erosion after major rain events.
References
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
Maine Department of Conservation, Best Management Practices for Forestry:
Protecting Maine's Water Quality. Maine Forest Service, Forest Policy and
Management Division. Augusta, Maine. 2004.
<http://www. state.me.us/doc/mfs/pubs/pdf/bmp_manual/bmp_manual.pdf>
United States Department of the Interior, Bureau of Land Management (BLM),
United States Department of Agriculture (USDA), Forest Service, Surface
Operating Standards for Oil and Gas Exploration and Development "Gold
Book". Fourth Edition, 2005.
Rev: 0
Date: 1/26/06
Page 2 of 3 RC -7 Drainage Dip
Table RC -7-1
Maximum Distance between Drainage Dips
Road Grade, %
Low to
Non -Erosive Soils (1)
Erosive Soils (2)
0 - 3
400'
200'
4 - 6
300'
160'
7 - 9
250'
130'
10 - 12
200'
110'
12+
160'
100'
(1) Low Erosion Soils = Coarse Rocky Soils, Gravel, and Some Clay
(2) High Erosion Soils = Fine, Friable Soils, Silt, Fine Sands
Figure RC -7-1
Typical Drainage Dip
Dip Mound
Road Grade
a r b
d
h
2%
10' 10'
0.6'
0.4'
4%
14' 14'
1.0'
0.8'
6%
16' 18'
1.2'
14'
8%
22 24'
2.0'
2.2'
Mound
100-4001G
NOT TO SCALE
Rev: 0
Date: 1/26/06
Page 3 of 3 RC -7 Drainage Dip
RC -8 Temporary Berm (TB)
Description
A temporary berm is a ridge of compacted soil located at the top or base of a sloping
disturbed area. The purpose of a temporary diversion berm is to control the velocity,
divert onsite surface runoff to a sediment trapping device, and/or divert clean water
away from disturbed areas.
Applicability
Temporary berms are applicable where it is desirable to divert flows away from
disturbed areas such as cut or fill slopes and to divert runoff to a stabilized outlet.
Temporary berms are usually appropriate for drainage basins smaller than five acres,
but with modifications they can be capable of servicing areas as large as ten acres.
With regular maintenance, earthen berms have a useful life span of approximately
18 months.
Limitations
• To alleviate erosion capability, berms must be directed into a stabilized
outlet or well -vegetated area or to sediment trapping devices, where
erosion sediment can settle out of the runoff before being discharged to
surface waters.
• If a berm crosses a vehicle roadway or entrance, its effectiveness can be
reduced. Wherever possible, berms should be designed to avoid crossing
vehicle pathways.
Rev: 0
Date: 1/26/06
Page 1 of 4 RC -8 Temporary Berm
Design Criteria
No formal design is required.
Construction Specifications
1. Prior to excavation or mound building, remove all trees, brush, stumps and
other objects in the path of the berm and till the base of the berm before
laying the fill.
2. Construct the berm according to Figure RC -8-1 for the appropriate
drainage area. For points where vehicles will cross the berm, the slope
should be no steeper than 3:1 and the mound should be constructed of
gravel rather than soil. This will prolong the life of the berm and increase
effectiveness at the point of vehicle crossing.
3. All berms shall have positive drainage to an outlet. Field location should
be adjusted as needed to utilize a stabilized safe outlet.
4. For points where vehicles will cross the berm, the slope should be no
steeper than 3:1 and the mound should be constructed of gravel rather than
soil.
5. Route the berm outlet into a well -vegetated area or install a sediment
trapping or filter control at the outlet, such as straw bales.
6. If the expected life span of the temporary berm is greater than 15 days, it
is strongly recommended that both the berm be seeded with vegetation
immediately after construction.
7. Stabilization shall be in accordance with EC -5 Temporary Vegetation or
EC -7 Mulching if not in seeding season. Also see Table RC -8-1 for
stabilization specifics for berms on various slopes.
8. Berms should be constructed and fully stabilized prior to commencement
of major land disturbance. This will maximize the effectiveness of the
structure as an erosion and sediment control device.
Maintenance Considerations
Temporary berms should be inspected periodically for evidence of erosion or
deterioration and after each rainfall to ensure continued effectiveness. The berm
should be maintained at the original height, and any decrease in height due to settling
or erosion should be repaired immediately. To remain effective, berms should be
compacted at all times.
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Date: 1/26/06
Page 2 of 4 RC -8 Temporary Berm
Removal
Temporary berms should remain in place and in good condition until the disturbed
areas are permanently stabilized. There is no need to formally remove the berm on
completion of stabilization.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Table RC -8-1
Temporary Berm Stabilization
Type of
Treatment
Channel Grade'
A (<5 Ac.)
B (5-10 Ac)
1
0.5-3.0%
Seed & Straw Mulch
Seed & Straw Mulch
2
3.1-5.0%
Seed & Straw Mulch
Seed and cover with
Jute or Excelsior,
Sod,
or lined with 2 in.
stone
3
5.1-8.0%
Seed and cover with
Jute, Excelsior, Sod,
or line with 2 in. stone
Line with 4-8 in. or
stone or Recycled
Concrete Equivalent2
4
8.1-20%
Line with 4-8 in. or
stone or Recycled
Concrete Equivalent2
Engineering Design
In highly erodible soils, as defined by the local approving agency, refer to the next higher slope grade for type of
stabilization.
2Recycled Concrete Equivalent shall be concrete broken into the required size, and shall contain no steel
reinforcement.
Rev: 0
Date: 1/26/06
Page 3 of 4 RC -8 Temporary Berm
Figure RC -8-1
Temporary Berm Installation
B
/ \ \' \� \�\� \/ \\/\
Slabilizabon as required (see table).• /\��\\ \�\/\ \\\�\ \
On steep slopes excavate to provide /\/�v��//\\/v•\/%��%��jv���\\\i\\%/�/v
required flow width al flow depth.
CUT OR FILL SLOPE
Natural ground surface
Note: Slope ditch 0.5% to 20% b
stabilized outlet.
BERMA BERM B1
(c5 acre) (5-10 acre]
A- BERM HEIGHT 18 in. 36 in.
B - BERM WIDTH 24 in. i 36 in.
C - FLOW WIDTH 48 in. I 60 In.
D - FLOW DEPTH 8 in. 1 15 in.
Rev: 0
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Page 4 of 4
RC -8 Temporary Berm
RC -9 Culvert Inlet Protection (CIP)
Description
Culvert inlet protection involves placing riprap, trash racks, and/or any other
protection at the inlets of pipes. Riprap, or other energy -dissipating devices, will
reduce the velocity of storm water flows and thereby prevent erosion and help protect
the inlet structure. Trash racks may be constructed with logs, pipe, rebar, angle iron,
railroad rail, H -Piles, and so on. The trash racks will trap debris, thus preventing the
plugging of the culvert.
Applicability
Riprap inlet protection should be used where velocities and energies at the inlets of
culverts are sufficient to erode around the inlet structure. Riprap may also be used to
help channel the storm water to the inlet of the culvert. Trash racks should be used at
the invert of culverts where a lot of debris is found in the channel
Limitations
• Trash racks require regular maintenance and cleaning.
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Date: 1/26/06
Page 1 of 3 RC -9 Culvert Inlet Protection
• Trash racks are undesirable if other alternatives, such as installing a larger
pipe, are available.
Design Criteria
No formal design is required.
Construction Specifications
1. For riprap installation see RC -4 Riprap.
2. After installation of a culvert, examine the stream channel for the amount
of debris, logs, and brushy vegetation present. In channels with large
amounts of debris, consider using oversized pipes or trash racks.
3. Trash rack may be located either at the pipe or upstream of the pipe
depending on site conditions and access for cleaning and maintenance
(see Figure RC -9-1).
Maintenance Considerations
Riprap should be inspected annually and after major storms. If riprap has been
damaged or dislodged, repairs should be made immediately. Trash racks should be
inspected regularly and after major storm events and high flows. All debris should be
removed from the rack and any necessary repairs or cleaning should be made
immediately.
References
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
Rev: 0
Date: 1/26/06
Page 2 of 3 RC -9 Culvert Inlet Protection
Figure RC -9-1
Trash Rack Inlet Protection
Located at the Pipe Inlet
Located Upstream of Pipe Inlet
Rev: 0
Date: 1/26/06
Page 3 of 3 RC -9 Culvert Inlet Protection
RC -10 Temporary Swale (TS)
Description
A temporary swale is an excavated drainageway used to prevent runoff from entering
disturbed areas by intercepting and diverting it to a stabilized outlet or to intercept
sediment laden water and divert it to a sediment trapping device.
Applicability
Temporary swales are usually appropriate for drainage basins smaller than five acres,
but with modifications they can be capable of servicing areas as large as ten acres.
For drainage areas larger than ten acres, refer to RC -12 Permanent Diversion.
Temporary swales may be used in the following applications:
• To divert flows from entering a disturbed area.
• Intermittently across disturbed areas to shorten overland flow distances.
• To direct sediment laden water along the base of slopes to a trapping
device.
Design Criteria
No formal design is required.
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Date: 1/26/06
Page 1 of 3 RC -10 Temporary Swale
Construction Specifications
See Figure RC -10-1 for details.
1. All trees, brush, stumps, obstructions, and other objectionable material
shall be removed and disposed of so as not to interfere with the proper
functioning of the swale.
2. The appropriate size and design of temporary swales depends on the size
of the contributing drainage area according to Figure RC -10-1.
3. The swale shall be free of bank projections or other irregularities which
will impede normal flow.
4. All temporary swales shall have uninterrupted positive grade to an outlet.
5. Diverted runoff from a disturbed area shall be conveyed to a sediment
trapping device.
6. Diverted runoff from an undisturbed area shall outlet directly into an
undisturbed, well vegetated and stabilized area at non-erosive velocity.
7. Fills shall be compacted by earth moving equipment.
8. All earth removed and not needed for construction shall be placed so that
it will not interfere with the functioning of the swale.
9. Stabilization shall be as per Table RC -10-1.
Maintenance Considerations
Periodic inspections and maintenance should be provided after each rain event.
Removal
Swales collecting runoff from disturbed areas shall remain in place until the disturbed
areas are permanently stabilized.
References
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Rev: 0
Date: 1/26/06
Page 2 of 3 RC -10 Temporary Swale
Table RC -10-1
Temporary Swale Stabilization
'In highly erodible soils, as defined by the local approving agency, refer to the next higher slope grade
for type of stabilization.
2Recycled Concrete Equivalent shall be concrete broken into the required size, and shall contain no
steel reinforcement.
Figure RC -10-1
Temporary Swale Installation
^ J f_ ^ --------
Storage Area
Max.'
/4\7' ��\�„ /\\/\\//,0 ����\% Stabilization malenal
A (5 acra or less)
C-1fl.
❑-4fl.
6(5-10acre)
C-1ft.
❑-5ft.
Note: Slope ditch 0.5% to 20% to stabilized outlet
Flow
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Page 3 of 3 RC -10 Temporary Swale
Stabilization Material
Type of
Treatment
Channel
Grader
A (<5 Ac.)
B (5-10 Ac)
1
0.5-3.0%
Seed & Straw Mulch
Seed & Straw Mulch
2
3.1-5.0%
Seed & Straw Mulch
Seed and cover with
Jute or Excelsior, Sod,
or lined with 2 in. stone
3
5.1-8.0%
Seed and cover with
Jute, Excelsior, Sod, or
line with 2 in. stone
Line with 4-8 in. or
stone or Recycled
Concrete Equivalent2
4
8.1-20%
Line with 4-8 in. or
stone or Recycled
Concrete Equivalent2
Engineering Design
'In highly erodible soils, as defined by the local approving agency, refer to the next higher slope grade
for type of stabilization.
2Recycled Concrete Equivalent shall be concrete broken into the required size, and shall contain no
steel reinforcement.
Figure RC -10-1
Temporary Swale Installation
^ J f_ ^ --------
Storage Area
Max.'
/4\7' ��\�„ /\\/\\//,0 ����\% Stabilization malenal
A (5 acra or less)
C-1fl.
❑-4fl.
6(5-10acre)
C-1ft.
❑-5ft.
Note: Slope ditch 0.5% to 20% to stabilized outlet
Flow
Rev: 0
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Page 3 of 3 RC -10 Temporary Swale
RC -11 Temporary Diversion (TD)
Definition
A temporary and uncompacted berm of soil excavated from an adjoining swale. The
purpose of a temporary diversion is to prevent off site storm runoff from entering a
disturbed area, to prevent sediment laden storm runoff from leaving the construction
site or disturbed area, to prevent flows from eroding slopes, and to direct sediment
laden flows to a trapping device.
Applicability
A temporary diversion may be located along roads, along the perimeter of a site or
disturbed area, or along the top or base of slopes. The maximum drainage area is
two acres. For drainage areas larger than two acres but less than ten acres, see
RC -10 Temporary Swale or RC -8 Temporary Berm. For drainage areas larger than
ten acres, see RC -12 Permanent Diversion.
Limitations
• To alleviate erosion capability, berms must be directed into a stabilized
outlet or well -vegetated area or to sediment trapping devices, where
erosion sediment can settle out of the runoff before being discharged to
surface waters.
• Temporary diversions should be designed to avoid crossing vehicle
pathways.
Design Criteria
No formal design is required.
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Page 1 of 3 RC -11 Temporary Diversion
Construction Specifications
See Figure RC -11-1.
1. All temporary diversions shall have uninterrupted positive grade to an
outlet.
2. Diverted runoff from a disturbed area shall be conveyed to a sediment
trapping device.
3. Diverted runoff from an undisturbed area shall outlet into an undisturbed
stabilized area at non-erosive velocities.
4. The ditch shall be excavated or shaped to line grade, and cross section as
required to meet the specified criteria. The diversion does not need to be
compacted.
5. Stabilization of the area disturbed by the diversion shall be done in
accordance with EC -5 Temporary Vegetation or EC -7 Mulching and shall
be done within 10 days.
Maintenance Considerations
Periodic inspection and required maintenance should be provided after each rain
event.
Removal
The temporary diversion shall remain in place until the disturbed areas are
permanently stabilized.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http : //cfpub. ep a. gov/npdes/stormwater/menuofbmps/con_site. cfm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Rev: 0
Date: 1/26/06
Page 2 of 3 RC -11 Temporary Diversion
Figure RC -11-1
Temporary Diversion Installation
24" min.
Flaw
Diversion shall slop® between 9.5%
and 8% to a stabilized outlet
NOT TO SCALE
Rev: 0
Date: 1/26/06
Page 3 of 3 RC -11 Temporary Diversion
RC -12 Permanent Diversion (PD)
Definition
A permanent diversion is a drainage way of parabolic or trapezoidal cross-section
with a supporting ridge on the lower side that is constructed across the slope. The
purpose of a diversion is to intercept and convey storm water runoff away from
developing areas and to stable outlets at non-erosive velocities.
Applicability
Diversions are used where:
• Runoff from higher areas has potential for causing erosion or interfering
with, or preventing the establishment of, vegetation on lower areas.
• Surface flow is damaging sloping areas.
• The length of slopes needs to be reduced so that soil loss will be kept to a
minimum.
Diversions are only applicable below stabilized or protected areas. Avoid
establishment on slopes greater than fifteen percent. Diversions should be used with
caution on soils subject to slippage. Construction of diversions shall be in
compliance with state drainage and water laws.
Limitations
The area around the channel that is disturbed by its construction must be stabilized so
that it is not subject to similar erosion as the steep slope the channel is built to protect.
Design Criteria
Location
Diversion location shall be determined by considering outlet conditions, topography,
land use, soil type, length of slope, and the development layout.
Rev: 0
Date: 1/26/06
Page 1 of 4 RC -12 Permanent Diversion
Capacity
Peak rates of runoff values used in determining the capacity requirements shall be as
outlined by TR -55, Urban Hydrology for Small Watersheds. The constructed
diversion shall have capacity to carry, as a minimum, the peak discharge from a ten-
year frequency rainfall event with freeboard of not less than 0.3 feet.
Cross Section
See Figure RC -12-1 for details. The diversion channel shall be parabolic or
trapezoidal in shape. The diversion shall be designed to have stable side slopes. The
side slopes shall not be steeper than 2.1 and shall be flat enough to ensure ease of
maintenance of the diversion and its protective vegetative cover. The ridge shall have
a minimum width of four feet at the design water elevation; a minimum of 0.3 feet
freeboard and a reasonable settlement factor (10%) shall be provided.
Velocity and Grade
The permissible velocity for the specific soil type will determine the maximum
grade. The maximum permissible velocity for sand and silt vegetated channels is
3 ft/sec, and 5 ft/sec for clay vegetated channels. Diversions are not usually
applicable below high sediment producing areas unless structural measures, designed
to prevent damaging accumulations of sediment in the channels, are installed with, or
before, the diversions.
Construction Specifications
1. All trees, brush, stumps, obstructions, and other objectionable material
shall be removed and disposed of so as not to interfere with the proper
functioning of the diversion.
2. The diversion shall be excavated or shaped to line, grade, and cross
section as required to meet the criteria specified herein, and be free of
bank projections or other irregularities which will impede normal flow.
3. Parabolic and triangular-shaped, grass -lined channels should not have a
top width of more than 30 feet. Trapezoidal, grass -lined channels may not
have a bottom width of more than 15 feet unless there are multiple or
divided waterways, they have a riprap center, or other methods of
controlling the meandering of low flows are provided.
4. If grass -lined channels have a base flow, a stone center or subsurface drain
or another method for managing the base flow must be provided.
5. Fills shall be compacted as needed to prevent unequal settlement that
would cause damage in the complete diversion.
6. All earth removed and not needed in construction shall be spread or
disposed of so that it will not interfere with the functioning of the
diversion.
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Page 2 of 4 RC -12 Permanent Diversion
7. Each diversion must have an adequate outlet. The outlet may be a grassed
waterway or a well -vegetated area. In either case, the outlet must convey
runoff to a point where outflow will not cause damage. Vegetated outlets
shall be installed before diversion construction, if needed, to ensure
establishment of vegetative cover in the outlet channel.
8 Immediately after the ridge and channel are constructed, they must be
seeded and mulched according to EC -6 Permanent Vegetation and
EC -7 Mulching along with any disturbed areas that drain into the
diversion.
a. For design velocities less than 3 5 ft/sec, seeding and mulching may be
used for establishment of the vegetation. It is recommended that,
when conditions permit, temporary diversions or other means should
be used to prevent water from entering the diversion during the
establishment of the vegetation.
b. For design velocities or more than 3.5 ft/sec, the diversion shall be
stabilized with seeding protected by Jute or Excelsior matting, or with
seeding and mulching including temporary diversion of the water until
the vegetation is established.
Maintenance Considerations
Diversions should be inspected periodically and after every rainfall before final
stabilization. Channels should be cleared of sediment, repairs made when necessary,
and seeded areas reseeded if a vegetative cover is not established. Maintain diversion
capacity, ridge height, and outlet elevations especially if high sediment yielding areas
are in the drainage area above the diversion. Establish necessary cleanout
requirements. Redistribute sediment as necessary to maintain the capacity of the
diversion.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
United States Department of Agriculture (USDA), Natural Resources Conservation
Service (NRCS), Field Office Technical Guide. 2002.
<www.nrcs.usda.gov/technical/efotg>
Rev: 0
Date: 1/26/06
Page 3 of 4 RC -12 Permanent Diversion
FLOW
Figure RC -12-1
Diversion Installation
1O" Set!lement
1 Max.
2
NOT TO SCALE
Fill Material
Rev: 0
Date: 1/26/06
Page 4 of 4 RC -12 Permanent Diversion
RC -13 Water Bar (WB)
Description
A water bar is a ridge, or ridge and channel, constructed diagonally across a sloping
road or trail that is subject to erosion. Water bars are normally used for drainage and
erosion protection of closed, blocked, or infrequently used roads to limit the
accumulation of erosive volumes of water by diverting surface runoff at pre -designed
intervals.
Applicability
Water bars are applicable where runoff protection is needed to prevent erosion on
sloping access right-of-ways or either long, narrow sloping areas generally less than
100 feet in width. This is a practice that can be used on limited -use roads, trails and
firebreaks. It is an excellent method of retiring roads and trails as well as abandoned
roads where surface water runoff may cause erosion of exposed mineral soil.
Limitations
• Not for use on concentrated flows
• May cause concentrated flows from sheet flow
• Requires vegetative cover or other filter at discharge point
Design Criteria
No formal design is required.
Rev: 0
Date: 1/26/06
Page 1 of 3 RC -13 Water Bar
Construction Specifications
See Figure RC -13-1.
1. Clear the base for the ridge before placing Ell.
2. Track the ridge to compact it to the design cross section.
3. Install the water bar according to Figure RC -13-1 as soon as the right of
way is cleared and graded. The positive grade shall not exceed 2%.
4. Extend the water bar inlet and outlet 1 foot or more beyond the trail to
keep the diverted water from re-entering the trail.
5. Space the water bars according to Table RC -13-1.
6. Locate the outlet on an undisturbed area. Field spacing shall be adjusted
to use the most stable outlet areas. Outlet protection will be provided
when natural areas are not adequate.
7. Vehicle crossing shall be stabilized with gravel. Exposed areas shall be
immediately seeded and mulched.
Maintenance Considerations
Periodically inspect water bars for erosion damage and sediment. Check outlet areas
and make repairs as needed to restore operation.
Removal
If water bars are used on a closed or blocked road, they should be removed prior to
re -opening of the road. Water bars on infrequently used roads may remain in place as
long as necessary.
References
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
Rev: 0
Date: 1/26/06
Page 2 of 3 RC -13 Water Bar
Maine Department of Conservation, Best Management Practices for Forestry:
Protecting Maine's Water Quality. Maine Forest Service, Forest Policy and
Management Division. Augusta, Maine. 2004.
<http://www. state.me.us/doc/mfs/pubs/pdf/bmp_manual/bmp_manual.pdf>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Table RC -13-1
Water Bar Spacing
Road/Trail Grade (%)
r Low to Non -Erosive Soils (1)
Erosive Soils (2)
0 - 5
245'
130'
6 — 10
200'
100'
11 - 15
150'
65'
16 - 20
115'
50'
21 - 30
100'
40'
31+
50'
30'
'Low Erosion Soils = Coarse Rocky Soils, Gravel, and Some Clay
2High Erosion Soils = Fine, Friable Soils, Silt, Fine Sands
SILT FENCE OR
STRAW BAILS
AS NEEDED
Figure RC -13-1
Water Bar Installation
5' min,
18- MIN.
\f\,/ • :: 1��"Z'�s �i GRAVEL
\\\
\j
/
,OUTLET
��/
STABILIZED AREAINTO
7A811TEDANTO \//\\/ y EDGE OF R.O.W.
(WELL VEGETATED
/• Note: Side slopes shall be 4:1 where
vehicles cross.
EDGE OF R.O.W.
NOT TO SCALE
Rev: 0
Date: 1/26/06
Page 3 of 3 RC -13 Water Bar
SC -1 Straw Bale Barrier (SBB)
Streambank Stabilization
Perimeter Protection
Description
A straw bale barrier is a series of entrenched and staked straw bales placed on a level
contour to intercept sheet flows. The barrier reduces runoff velocity and filters
sediment laden runoff from small drainage areas of disturbed soil. The barrier may
also be used to protect against erosion. Straw bale barriers have an estimated design
life of three (3) months.
Applicability
Straw bale barriers may be used below disturbed areas subject to sheet and rill erosion
where the length of slope above the straw bale barrier does not exceed the following
limits
Constructed Slope
Percent Slope
Slope Length (ft)
2:1
50%
25'
3:1
33%
50'
4:1
25%
75'
Straw bales may be used in the following applications:
• Below the toe of erodible slopes or other small cleared areas
• At the top of slopes to divert runoff away from disturbed slopes
• As sediment traps at outlets to culverts, ditches, turnouts, etc.
• Along the perimeter of a site
• Around temporary stockpiles and spoil areas
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Page 1 of 4 SC -1 Straw Bale Barrier
• Along streams and channels for both erosion and sediment control
• As check dams across mildly sloped swales or construction roads (See
RC -5 Check Dam)
Limitations
• For short-term use only
• For use below small drainage areas less than 2 acres
• Decomposes over time
• May be consumed by livestock
• Straw bales must be certified weed free to avoid invasive weeds that may
develop and should not be used in areas where weeds are a concern.
• Removal of anchor stakes will be necessary after stabilization is complete
• Not recommended for concentrated flow, live streams, or swales where
there is the possibility of a washout
Design Criteria
No formal design is required.
Construction Specifications
See Figure SC -1-1 for installation details.
1. Bales shall be placed in a single row on a level contour with ends of
adjacent bales tightly abutting one another. Bales shall be certified weed
free.
2. Allow sufficient space up slope from the barrier to allow ponding, and to
provide room for sediment storage.
3. All bales shall be either wire -bound or string -tied. Straw bales shall be
installed so that bindings are oriented around the sides rather than along
the tops and bottoms of the bales in order to prevent deterioration of the
bindings.
4. A trench shall be excavated the width of a bale and the length of the
proposed barrier to a minimum depth of 4 inches. Stake the bales with
minimum 2" x 2" x 36" wood stakes or standard "T" or "U" steel posts
(minimum weight of 1.33 pounds per linear foot).
Rev: 0
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Page 2 of 4 SC -1 Straw Bale Barrier
5. After the bales are staked and chinked (gaps filled by wedging), the
excavated soil shall be backfilled against the barrier. Backfill soil shall
conform to the ground level on the downhill side and shall be built up to
4 inches against the uphill side of the barrier.
6. Each bale shall be securely anchored by at least two stakes driven through
the bale. The first stake or steel post in each bale shall be driven toward
the previously laid bale to force the bales together. Stakes or steel pickets
shall be driven a minimum 18 inches deep into the ground to securely
anchor the bales.
Maintenance Considerations
Straw bale barriers should be inspected after each significant rainfall and more often
during prolonged rainfall. Close attention should be paid to the repair of damaged or
rotting bales, end runs and undercutting beneath bales. Necessary repairs to barriers
or replacement of bales should be accomplished promptly. Sediment deposits should
be removed when the level of deposition reaches approximately one-half the height of
the barrier.
Removal
Straw bale barriers may be removed when they have served their usefulness or may
remain in place to decompose over time. Straw bales should not be removed,
however, until the upslope areas have been permanently stabilized. Any sediment
deposits remaining in place after the straw bale barrier is no longer required should be
dressed to conform to the existing grade, prepared and seeded.
References
Colorado Department of Transportation (CDOT), Erosion Control and Stormwater
Quality Guide. 2002.
<http : //www. dot. state. c o . us/environmental/env W aterQual/wgms4. asp>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Rev: 0
Date: 1/26/06
Page 3 of 4 SC -1 Straw Bale Barrier
Figure SC -1-1
Straw Bale Installation
Bales must be tightly
abutting with no gaps
Stake (installed to at
least 12" below grade)
NOT TO SCALE
Bale Width �.
18" x 18" x 38"
Typical Straw Bales
Backfill Matenal (compact sail
to prevent piping)
Rev: 0
Date: 1/26/06
Page 4 of 4 SC -1 Straw Bale Barrier
SC -2 Silt Fence (SF)
Silt Fence at Outlet where concentrated
flow is not expected.
Silt Fence at Site Perimeter
Description
Silt fences are used as temporary perimeter controls around sites where there will be
soil disturbance due to construction activities. They consist of a length of filter fabric
stretched between anchoring posts spaced at regular intervals along the site perimeter.
Applicability
Silt fences are generally applicable to construction sites with relatively small drainage
areas. They are appropriate in areas where runoff will be occurring as low-level
shallow flow, not exceeding 0.5 cfs. The drainage area for silt fences generally
should not exceed 0.25 acre per 100 -foot fence length. Slope length above the fence
should not exceed 100 feet.
Limitations
• Silt fences should not be installed along areas where rocks or other hard
surfaces will prevent uniform anchoring of fence posts and entrenching of
the filter fabric. This will greatly reduce the effectiveness of silt fencing
and can create runoff channels leading off site.
• Silt fences are not suitable for areas where large amounts of concentrated
runoff are likely.
• Open areas where wind velocity is high may present a maintenance
challenge, as high winds may accelerate deterioration of the filter fabric.
• Silt fences should not be installed across streams, ditches, or waterways.
Rev: 0
Date: 1/26/06
Page 1 of 4 SC -2 Silt Fence
• When the pores of the fence fabric become clogged with sediment, pools
of water are likely to form on the uphill side of fence. Siting and design of
the silt fence should account for this and care should be taken to avoid
unnecessary diversion of storm water from these pools that might cause
further erosion damage.
Design Criteria
The fence should be designed to withstand the runoff from a 10 -year peak storm
event.
Construction Specifications
1. Erect silt fence according to Figure SC -2-1.
2. If standard strength fabric is used in combination with wire mesh, the
support posts should be spaced no more than 10 feet apart. If extra -
strength fabric is used without wire mesh reinforcement, the support posts
should be spaced no more than 6 feet apart.
3. Stakes used to anchor the filter fabric should be either wooden or metal.
Wooden stakes should be at least three feet long and have a minimum
diameter of two inches if a hardwood such as oak is used. Softer woods
such as pine should be at least four inches in diameter. When using metal
post in place of wooden stakes, they should have a minimum weight of
1.00 to 1.33 lb/linear foot. If metal posts are used, attachment points are
needed for fastening the filter fabric using wire ties. The height of the
fence posts should be between 16 and 34 inches above the original ground
surface.
4. Material for silt fences should be a pervious sheet of synthetic fabric such
as polypropylene, nylon, polyester, or polyethylene yarn, chosen based on
minimum synthetic fabric requirements, as shown in the following table:
Physical Property
Requirements
Filtering Efficiency
75 — 85% (minimum): highly
dependent on local conditions
Tensile Strength at 20%
(maximum) Elongation
Standard Strength: 30 lbs/linear inch
(minimum)
Extra Strength: 50 lbs/linear inch
(minimum)
Ultraviolet Radiation
90% (minimum)
Slurry Flow Rate
0.3 gal/ft2/min (minimum)
5. Use a continuous roll of fabric to eliminate unwanted gaps in the fence. If
a continuous roll of fabric is not available, the fabric should overlap from
both directions only at stakes or posts with a minimum overlap of
six inches.
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Page 2 of 4 SC -2 Silt Fence
6. Extend silt fence across grade and upslope for a short distance.
7. Compact backfill at base of fabric.
8. A trench should be excavated to bury the bottom of the fabric fence at
least 6 inches below the ground surface. This will help prevent gaps from
forming near the ground surface that would render the fencing useless as a
sediment barrier.
Maintenance Considerations
Silt fences should be inspected regularly and frequently as well as after each rainfall
event to ensure that they are intact and that there are no gaps at the fence -ground
interface or tears along the length of the fence. If gaps or tears are found, they should
be repaired or the fabric should be replaced immediately. Accumulated sediments
should be removed from the fence base when the sediment reaches one-third to one-
half the height of the fence. Sediment removal should occur more frequently if
accumulated sediment is creating noticeable strain on the fabric and there is the
possibility of the fence failing from a sudden storm event.
Removal
Remove silt fences and all accumulated sediment after uphill drainage areas are
stabilized by vegetation or other means.
References
Colorado Department of Transportation (CDOT), Erosion Control and Stormwater
Quality Guide. 2002.
<http: //www. dot. state. co.us/environmental/envW aterQual/wgms4. asp>
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best
Management Practices Field Guide. United States Department of Agriculture
(USDA), Forest Service, US Agency of International Development (USAID),
2005. <http://www.blm.gov/bmp/field%20guide.htm>
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Page 3 of 4 SC -2 Silt Fence
Silt fence fabric
anchored in
trench and
attached to post
Compacted
51l
Figure SC -2-1
Silt Fence Installation
Post (2"x2" Nominal)
10' max.
6"x6" Trench
NOT TO SCALE
20"
min.
Flow
Post (2"x7 Nominal)
Silt fence fabric
anchored in
trench and
attached to post
Flow
t
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Page 4 of 4 SC -2 Silt Fence
SC -3 Sediment Basin (SEDB)
Description
A sediment basin is an earthen embankment used to retain sediment on the
construction site and prevent sedimentation in off site water bodies. The structure
allows a shallow pool to form in an excavated or natural depression where sediment
from storm water runoff can settle. Basin dewatering is achieved through a single
riser and drainage hole leading to a suitable outlet on the downstream side of the
embankment. Water is released at a substantially slower rate than would be possible
without the control.
Applicability
• Sediment basins can be temporary or permanent structures. Generally,
sediment basins designed to be used for up to three years are described as
temporary, while those designed for longer service are said to be
permanent. Temporary sediment basins can be converted into permanent
storm water runoff management ponds, but they must meet all regulatory
requirements for wet ponds.
• Sediment basins are applicable in drainage areas where it is anticipated
that other erosion controls, such as sediment traps, will not be sufficient to
prevent off-site transport of sediment.
• Sediment basins are appropriate where failure of the dam will not result in
substantial damage or loss of property or life.
• If properly constructed, sediment basins can handle storm water runoff
from drainage basins as large as 100 acres.
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Page 1 of 5 SC -3 Sediment Basin
Limitations
• A sediment basin with an earthen embankment should not be used in areas
of continuously running water (live streams).
• The use of sediment basins is not intended for areas where failure of the
earthen or rock dam will result in loss of life, or damage to homes or other
buildings.
• Sediment basins should not be used in areas where failure will prevent the
use of public roads or utilities.
Design Criteria
The potential sites for sediment basins should be investigated during the initial site
evaluation. Basins should be constructed before any grading takes place within the
drainage area. For structures that will be permanent, the design of the basin should be
completed by a qualified engineer experienced in the design of dams.
Sediment basins should be outfitted with a dewatering pipe and riser set just above
the sediment removal cutoff level. The riser pipe should be located at the deepest
point of the basin and extend no farther than 1 foot below the level of the earthen
dam. A water -permeable cover should be placed over the primary dewatering riser
pipe to prevent trash and debris from entering and clogging the spillway. To provide
an additional path for water to enter the primary spillway, secondary dewatering holes
can be drilled near the base of the riser pipe, provided the holes are protected with
gravel to prevent sediment from entering the spillway piping.
To ensure adequate drainage, the following equation can be used to approximate the
total area of dewatering holes for a particular basin:
Ao = (Asx (2h) / (T x Cd x 20,428)
where:
Ao = total surface area of dewatering holes, ft2;
As = surface area of the basin, ft2;
h = head of water above the hole, ft;
Cd = coefficient of contraction for an orifice, approximately 0.6; and
T = detention time or time needed to dewater the basin, hours.
In all cases, such structures should be designed by an appropriate professional based
on local hydrologic, hydraulic, topographic, and sediment conditions.
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Page 2 of 5 SC -3 Sediment Basin
Construction Specifications
See Figure SC -3-1.
1. Site Preparation. Areas under the embankment shall be cleared, grubbed,
and stripped of topsoil to remove trees, vegetation, roots, or other
objectionable material. In order to facilitate cleanout and restoration, the
pool area (measured at the top of the pipe spillway) will be cleared of all
brush, trees, and other objectionable materials.
2. Cutoff -Trench. A cutoff trench shall be excavated along the centerline of
earth fill embankments. The minimum depth shall be two feet. The cutoff
trench shall extend up both abutments to the riser crest elevation. The
minimum bottom width shall be four feet, but wide enough to permit
operation of excavation and compaction equipment. The side slopes shall
be no steeper than 1:1. Compaction requirements shall be the same as
those for embankment. The trench shall be dewatered during the
backfilling/compaction operations.
3. Embankment. The fill material shall be taken from approved areas shown
on the plans. It shall be clean soil free of roots, woody vegetation,
oversized stones, rocks, or other objectionable material. Relatively
pervious materials such as sand or gravel (Unified Soil Classes GW, GP,
SW & SP) shall not be placed in the embankment. Areas on which fill is
to be placed shall be scarified prior to placement of fill. The fill material
shall contain sufficient moisture so that it can be formed by hand into a
ball without crumbling. If water can be squeezed out of a ball, it is too
wet for proper compaction. Fill material shall be placed in six to eight
inch thick continuous layers over the entire length of the fill. Compaction
shall be obtained by routing and hauling the construction equipment over
the fill so that the entire surface of each layer of the fill is traversed by at
least one wheel or tread track of the equipment or by the use of a
compactor. The embankment shall be constructed to an elevation
10 percent higher than the design height to allow for settlement.
4. Pipe Spillway. The riser shall be securely attached to the barrel or barrel
stub by welding the full circumference making a watertight structural
connection. The barrel stub must be attached to the riser at the same
percent (angle) of grade as the outlet conduit. The connection between the
riser and the riser base shall be watertight. All connections between barrel
sections must be achieved by approved watertight bank assemblies. The
barrel and riser shall be placed on a firm, smooth foundation of
impervious soil. Pervious materials such as sand, gravel, or crushed stone
shall not be used as backfill around the pipe or anti -seep collars. The fill
material around the pipe spillway shall be placed in four inch layers and
compacted under and around the pipe to at least the same density as the
adjacent embankment. A minimum depth of two feet of hand compacted
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Page 3 of 5 SC -3 Sediment Basin
backfill shall be placed over the pipe spillway before crossing it with
construction equipment. Steel base plates on risers shall have at least
2 1/2 feet of compacted earth, stone, or gravel placed over it to prevent
flotation.
5. Emergency Spillway. The emergency spillway shall be installed in
undisturbed ground. The achievement of planned elevations, grades,
design width, entrance and exit channel slopes are critical to the successful
operation of the emergency spillway and must be constructed within a
tolerance of +/- 0.2 feet.
6. Vegetative Treatment. Stabilize the embankment and emergency spillway
in accordance with the appropriate vegetative standard and specification
immediately following construction. In no case shall the embankment
remain unstabilized for more than seven (7) days.
Maintenance Considerations
Routine inspection and maintenance of sediment basins is essential to their continued
effectiveness. Basins should be inspected after each storm event to ensure proper
drainage from the collection pool and to determine the need for structural repairs.
Erosion from the earthen embankment or stones moved from rock dams should be
replaced immediately. Sediment basins must be located in an area that is easily
accessible to maintenance crews for removal of accumulated sediment. Sediment
should be removed from the basin when its storage capacity has reached
approximately 50 percent. Trash and debris from around dewatering devices should
be removed promptly after rainfall events.
Removal
When temporary structures have served their intended purpose and the contributing
drainage area has been properly stabilized, the embankment and resulting sediment
deposits are to be leveled or otherwise disposed of in accordance with the approved
sediment control plan. Water contained within the storage areas shall be removed
from the basin by pumping, cutting the top of the riser, or other appropriate method
prior to removing or breaching the embankment. Sediment shall not be allowed to
flush into a stream or drainage way.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
Rev: 0
Date: 1/26/06
Page 4 of 5 SC -3 Sediment Basin
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
United States Department of Agriculture (USDA), Natural Resources Conservation
Service (NRCS), Field Office Technical Guide. 2002.
<www.nrcs.usda.gov/technical/efotg>
\`\///\%\�/
Figure SC -3-1
Sediment Basin Installation
Top of Embankment
Crest of Emergency Spillway
Primary Outlet
Secondary Dewatering Outlet
ma<��%`�/may/\�/
i / /`\/\/ "Wet' Storage
NOT TO SCALE
Dry Storage
V min.
Embankment
jN/j `'j\\j/�
/\\,•\/ Outlet Pipe
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Page 5 of 5 SC -3 Sediment Basin
SC -4 Stabilized Construction Entrance
(SCE)
Description
A stabilized construction entrance is a pad of gravel over filter cloth where
construction traffic leaves a site. The purpose of a stabilized entrance to a site is to
minimize the amount of tracked mud and dust that leaves a site. As a vehicle drives
over the gravel pad, mud and sediment are removed from the vehicle's wheels and
offsite transport of soil is reduced. The gravel pad also reduces erosion and rutting on
the soil beneath the stabilization structure. The filter fabric separates the gravel from
the soil below, preventing the gravel from being ground into the soil. The fabric also
reduces the amount of rutting caused by vehicle tires by spreading the vehicle's
weight over a larger soil area than just the tire width.
Applicability
Typically, stabilized construction entrances are installed at locations where
construction traffic leaves or enters an existing paved road. However, the
applicability of site entrance stabilization should be extended to any roadway or
entrance where vehicles will access or leave the site.
Limitations
Although stabilizing a construction entrance is a good way to help reduce the amount
of sediment leaving a site, some soil may still be deposited from vehicle tires onto
paved surfaces. To further reduce the chance of these sediments polluting storm
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SC -4 Stabilized
Page 1 of 3 Construction Entrance
water runoff, sweeping of the paved area adjacent to the stabilized site entrance is
recommended.
Design Criteria
No formal design is required.
Construction Specifications
See Figure SC -4-1 for installation details.
1. Place woven or nonwoven fabric filter cloth over the entire area prior to
placing the stone. Piping of surface water under entrance shall be
provided as required.
2. Place a matrix of 1" and 2" stone gravel, or reclaimed or recycled concrete
equivalent, to a minimum thickness of six (6) inches, a minimum width of
12 feet and a minimum length of 50 feet.
3. All surface water flowing or diverted toward construction entrance shall
be piped across the entrance. If piping is impractical, a mountable berm
with 5:1 slopes will be permitted.
Maintenance Considerations
Stabilization of site entrances should be maintained until the remainder of the
construction site has been fully stabilized. Stone and gravel might need to be
periodically added to each stabilized construction site entrance to keep the entrance
effective. Soil that is tracked offsite should be swept up immediately for proper
disposal.
References
Colorado Department of Transportation (CDOT), Erosion Control and Stormwater
Quality Guide. 2002.
<http: //www. dot. state. co.us/environmental/envW aterQual/wgms4. asp>
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http : //cfpub. epa. gov/npdes/stormwater/menuofbmps/con_site. cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Rev: 0
Date: 1/26/06
SC -4 Stabilized
Page 2 of 3 Construction Entrance
Figure SC -4-1
Stabilized Construction Entrance Installation
Existing Ground
Filter Cloth
Existing Ground
NOT TO SCALE
50' min.
1'-2" gravel •
r Existing Pavement
6" min. -
Mountable berm (optional) •
50' min.
V-2" gravel
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SC -4 Stabilized
Page 3 of 3 Construction Entrance
SC -5 Brush Barrier (BB)
Brush Barrier (with no Filter Cloth)
Description
Brush barriers are perimeter sediment control structures used to prevent soil in storm
water runoff from leaving a construction site. Brush barriers are constructed of
material such as small tree branches, root mats, stone, or other debris naturally
available or left over from site clearing and grubbing. In some configurations, brush
barriers are covered with a filter cloth to stabilize the structure and improve barrier
efficiency.
Applicability
Brush barriers are applicable to sites where there is enough material from clearing
and grubbing to form a sufficient mound of debris along the perimeter of an area.
The drainage area for brush barriers must be no greater than 0.25 acre per 100 feet of
barrier length. In addition, the drainage slope leading down to a brush barrier must be
no greater than 2:1 and no longer than 100 feet. Brush barriers have limited
usefulness because they are constructed of materials that decompose.
Limitations
• Brush barriers are not appropriate for high -velocity flow areas.
• A large amount of material is needed to construct a useful brush barrier.
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Page 1 of 3 SC -5 Brush Barrier
• Although brush barriers provide temporary storage for large amounts of
cleared material from a site, this material may ultimately need to be
removed from the site after construction activities have ceased and the
area reaches final stabilization.
Design Criteria
No formal design is required.
Construction Specifications
1. Place material cleared from the site across the slope or swale. Material
with a diameter larger than six inches should not be used.
2. Cut up brush if necessary and compact to avoid large voids within the
barrier.
3. The barrier mound should be at least three feet high and five feet wide at
its base.
4. It is recommended that the mound be covered with a filter fabric barrier to
hold the material in place and increase sediment barrier efficiency. If
using a filter fabric cover, bury the edge in a trench four inches deep and
six inches wide on the drainage side of the barrier. This is done to secure
the fabric and create a barrier to sediment while allowing storm water to
pass through the water -permeable filter fabric. The filter fabric should be
extended just over the peak of the brush mound and secured on the down-
slope edge of the fabric by fastening it to twine or small -diameter rope that
is staked securely.
Maintenance Considerations
Brush barriers should be inspected after each significant rainfall event to ensure
continued effectiveness. If channels form through void spaces in the barrier, the
barrier should be reconstructed to eliminate the channels. Accumulated sediment
should be removed from the uphill side of the barrier when sediment height reaches
between 1/3 and 1/2 the height of the barrier.
Removal
When the entire site has reached final stabilization, the brush barrier may need to be
removed and disposed of properly.
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Page 2 of 3 SC -5 Brush Barrier
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http : //cfpub. epa. gov/npdes/stormwater/menuof bmps/con_site. cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Rev: 0
Date: 1/26/06
Page 3 of 3 SC -5 Brush Barrier
SC -6 Sediment Trap (ST)
Description
Sediment traps are small ponding areas that allow sediment to settle out of runoff
water. They are usually installed in a drainage way or other point of discharge from a
disturbed area. Temporary diversions can be used to direct runoff to the sediment
trap.
Sediment traps are formed by excavating below grade and/or by constructing an
earthen embankment with a hard -lined spillway to slow the release of runoff.
Applicability
Sediment traps are generally temporary control measures used at the outlets of storm
water diversion structures, channels, slope drains, construction site entrance wash
racks, or any other runoff conveyance that discharges waters containing erosion
sediment and debris. Sediment traps should be used for drainage areas less than
five acres. The effective life span of these temporary structures is usually limited to
24 months.
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Page 1 of 4 SC -6 Sediment Trap
Limitations
• Although sediment traps allow for settling of eroded soils, because of their
short detention periods for storm water they typically do not remove fine
particles such as silts and clays.
• Water will remain in trap for extended periods.
• Use only for treatment of onsite runoff.
• Never construct a sediment trap on a flowing stream or in wetlands.
Design Criteria
Location
Traps should be located at points of discharge from disturbed areas. The location will
be determined by the natural terrain, drainage pattern of the runoff, and the
accessibility for maintenance. Sediment traps should not be located in areas where
their failure due to storm water runoff excess can lead to further erosive damage of
the landscape. Alternative diversion pathways should be designed to accommodate
these potential overflows.
Storage Capacity
A sediment trap should be designed to maximize surface area for infiltration and
sediment settling. This will increase the effectiveness of the trap and decrease the
likelihood of backup during and after periods of high runoff intensity. The
approximate storage capacity of each trap should be 3,600 ft3 per acre of contributing
drainage area. Half of this volume shall be in the form of wet storage or a permanent
pool. The other half shall be in the form of dry storage. When possible, the wet
storage volume should be contained within the excavated portion of the trap. The
volume of a natural sedimentation trap can be approximated by the following
equation:
Volume (ft3) = 0.4 x surface area (ft2) x maximum pool depth (ft)
Construction Specifications
See Figure SC -6-1 for installation details.
1. Sediment traps, along with other perimeter controls, shall be installed
before any land disturbance takes place in the drainage area.
2. Area under embankment shall be cleared, grubbed and stripped of any
vegetation and root mat. The pool area shall be cleared.
3. The fill material for the embankment shall be free of roots and other
woody vegetation as well as over -sized stones, rocks, organic material or
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Page 2 of 4 SC -6 Sediment Trap
other objectionable material. The embankment shall be compacted by
traversing with equipment while it is being constructed.
4. The spillway shall consist of a stone section in the embankment formed by
a combination coarse aggregate/riprap to provide for filtering/detention
capability. Riprap shall be 4- to 8 -inch rock, while the coarse aggregate
shall be 1/2 to 3/4 inches.
5. A geotextile should be placed at the stone -soil interface to act as a
separator.
Maintenance Considerations
The primary maintenance consideration for temporary sediment traps is the removal
of accumulated sediment from the basin. This must be done periodically to ensure
the continued effectiveness of the sediment trap. Sediments should be removed when
the basin reaches approximately 50 percent sediment capacity. A sediment trap
should be inspected after each rainfall event to ensure that the trap is draining
properly. Inspectors should also check the structure for damage from erosion. The
depth of the spillway should be checked and maintained at a minimum of 1.5 feet
below the low point of the trap embankment.
Removal
The structure shall be removed and the area stabilized when the drainage area has
been properly stabilized.
References
Colorado Department of Transportation (CDOT), Erosion Control and Stormwater
Quality Guide. 2002.
<http: //www. dot. state. co.us/environmental/envW aterQual/wgms4. asp>
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Rev: 0
Date: 1/26/06
Page 3 of 4 SC -6 Sediment Trap
Figure SC -6-1
Sediment Trap Installation
Varies
•
Length of crest =
1.5 x drainage area (ac)
Ste
Fr' "NAAOA
Coarse Aggregate
4' min.
-- Small Riprap
Geotexlile
Weir Crest
- Embankment
Coarse Aggregate
d' min -
1800 ft'lac dry storage
5' max. 1
— Z typ.
— Geotextile
NOT TO SCALE >
1800 ftlac dry storage
Embankment
Wel r Crest
Small Riprap
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Page 4 of 4 SC -6 Sediment Trap
SC -7 Filter Berm (FB)
Description
A filter berm is a temporary ridge made up of loose gravel, stone, or crushed rock that
slows, filters, and diverts flow from an open traffic area and acts as an efficient form
of sediment control.
Applicability
Gravel or stone filter berms are most suitable in areas where vehicular traffic needs to
be rerouted because roads are under construction, or in traffic areas within a
construction site. The following are suitable applications:
• Below the toe of slopes.
• Along the site perimeter.
• Along streams and channels, or adjacent to roadways.
• Around temporary spoil areas or other small cleared areas.
Limitations
• Intended to be used only in gently sloping areas.
• Filter berms do not last very long.
• Maintenance is required due to clogging from mud and soil on vehicle tires.
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Page 1 of 3 SC -7 Filter Berm
• Availability of rock.
• May be difficult to remove after construction.
Design Criteria
No formal design is required.
Construction Specifications
See Figure SC -7-1 for installation details.
1. Place filter berm along a level contour. Use well -graded gravel or crushed
rock of medium to large diameter with larger rocks on the bottom.
2. Cover with geotextiles fabric or wire screen if concentrated flows are
expected to help keep berm in tack. Anchor fabric or wire by placing
under the berm or use stakes.
3. Trenching is not required.
4. Berms should be spaced according to the steepness of the slope, with
berms spaced closer together as the slope increases.
Maintenance Considerations
The berm should be inspected after every rainfall to ensure that sediment has not built
up and that no damage has been done by vehicles. Regular inspection should indicate
the frequency of sediment removal needed. Sediment that builds up should be
removed and disposed of and the filter material and/or fabric should be replaced if
necessary. It is important that repairs be performed at the first sign of deterioration to
ensure that the berm is functioning properly.
Removal
Remove filter berms after uphill drainage areas are stabilized. Rock may be left in
place if it does not cause any landscaping problems. Remove all manmade materials
(wire, fabric and/or stakes).
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http : //cfpub. ep a. gov/npdes/stormwater/menuofbmps/con_site. cfm>
Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
April 2004.
Rev: 0
Date: 1/26/06
Page 2 of 3 SC -7 Filter Berm
Figure SC -7-1
Filter Berm Installation
Gravel or Crushed Rock
24" min,
Flow
max.
NOT TO SCALE
Note: Place berm along level contour.
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Page 3 of 3 SC -7 Filter Berm
SC -8 Rock Dam (RD)
Description
A rock dam is a rock embankment used to retain sediment on the construction site
and prevent sedimentation in off site water bodies. Basin dewatering is achieved
gradually through the gravel of the rock dam.
Applicability
This standard applies to the installation of temporary rock dams on sites where:
• It is difficult to construct a stable, earthen embankment for a sediment
basin and rock materials are readily available.
• Failure of the structure would not result in loss of life, damage to homes or
buildings, or interruption of use or service of public roads or utilities.
• The drainage area does not exceed 50 acres.
• The dam is to be removed within 36 months after the beginning of
construction.
For structures that will be permanent, the design of the dam should be completed by a
qualified professional engineer experienced in the design of dams.
Limitations
• A rock dam should not be used in areas of continuously running water
(live streams).
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Page 1 of 4 SC -8 Rock Dam
• The use of rock dams is not intended for areas where failure of the dam
will result in loss of life, or damage to homes or other buildings.
• Rock dams should not be used in areas where failure will prevent the use
of public roads or utilities.
Design Criteria
This rock dam should not be located in a live stream. The top of the dam will serve
as the overflow outlet. The inside of the dam will be faced with smaller stone to
reduce the rate of seepage so a sediment pool forms during runoff events.
Drainage Area
The drainage area for this off stream structure is limited to 50 acres.
Location
The location of the dam should:
• provide a large area to trap sediment
• intercept runoff from disturbed areas
• be accessible to remove sediment
• not interfere with construction activities
Storage Volume
The storage volume behind the dam should be at least 3,600 cubic feet based on the
amount of disturbed area draining to the dam. This volume is measured one foot
below the top of dam.
Length of Crest
The crest length should be designed to carry the 10 yr. peak runoff with a flow depth
of one foot and one foot of freeboard.
Trapping Efficiency
To obtain maximum trapping efficiency, design for a long detention period. Usually
a minimum of eight (8) hours before the basin is completely drained. Maximize the
length of travel of sediment laden water from the inlet to the drain. Achieve a surface
area equal to 0.01 acres per cfs (inflow) based on the 10 -year storm.
Construction Specifications
See Figure SC -8-1 for installation details.
1. The potential need for rock dams should be investigated during the initial
site evaluation, and dams should be constructed before any grading takes
place within the drainage area.
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Page 2 of 4 SC -8 Rock Dam
2. The area under the rock dam shall be cleared and stripped of roots and
other objectionable material. The reservoir shall be cleared as needed to
facilitate sediment removal.
3. The dimensions, as shown on Figure SC -8-1, are minimum. A key trench
shall be excavated from abutment to abutment on the dam centerline.
Geotextile filter fabric shall be placed from the upstream edge of the key
trench to the downstream edge of the apron. Joints will lap a minimum of
1 ft. with upstream strip on top.
4. The rock fill should be well graded, hard, erosion resistant stone with a
minimum d50 size of 9 inches. The upstream face of the dam should be
covered with a fine gravel a minimum 3 feet thick to reduce the drainage
rate. Rock abutments shall be maintained 2 ft. above the crest.
5. The rock dam shall be constructed prior to clearing the basin area.
Stabilize all disturbed areas, except the basin area, with temporary seeding
(EC -5 Temporary Vegetation).
6. Fences and warning signs should be placed as appropriate.
Maintenance Considerations
Check the basin area after each rainfall event. Remove sediment and restore original
volume when sediment accumulates to one-half the design volume. Check the
structure for erosion, piping, and rock displacement after each significant event and
replace immediately.
Removal
Remove the structure and any sediment immediately after the construction area has
been permanently stabilized. All water should be removed from the basin prior to the
removal of the rock dam. Sediment should be placed in designated disposal areas and
not allowed to flow into streams or drainage ways during structure removal.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http ://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm>
New York State Department of Environmental Conservation, New York Guidelines
for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997.
<http://www.dec.state.ny.us/website/dow/toolbox/escstandards>
Rev: 0
Date: 1/26/06
Page 3 of 4 SC -8 Rock Dam
Fine Gravel —
Z > Flow
1'
Figure SC -8-1
Rock Dam Installation
Flow
Crest
. •
.01404
s�`ss�%ry s : Am�ii
.1-'412E4o Ili e*.
"'zitSk
Abutment
Weir Crest
Abutment
Small Riprap
3
1.5'
Key trench 7 L
Rock Size = c1,0=9' 1
2'
NOT TO SCALE
Filter Fabric
8' max. [La=11]
Rev: 0
Date: 1/26/06
Page 4 of 4 SC -8 Rock Dam
SC -9 Wind Fence (WF)
Description
Wind fences are barriers of small, evenly spaced wooden slats or fabric erected to reduce
wind velocity and to trap blowing sand. They can be used effectively as perimeter
controls around open construction sites to reduce the off-site movement of fine sediments
transported by wind. They also prevent off-site damage to roads, streams, and adjacent
properties. The spaces between fence slats allow wind and sediment to pass through but
reduces the wind velocity, which causes sediment deposition along the fence.
Applicability
Wind fences are applicable to areas with a preponderance of loose, fine -textured soils that
can be transported off-site by high winds. They are especially advantageous for
construction sites with large areas of cleared land or in arid regions where blowing sand
and dust are especially problematic.
Limitations
• A wind fence does not control sediment carried in storm water runoff.
• Wind fences should be installed in conjunction with other sediment and
erosion control measures that capture sediment from runoff.
Design Criteria
No formal design is required.
Rev: 0
Date: 1/26/06
Page 1 of 2 SC -9 Wind Fence
Construction Specifications
1. Erect the fence perpendicular, or as close to perpendicular as possible, to the
prevailing wind.
2. Erect multiple fences to increase sediment -trapping efficiency, depending on the
degree of protection desired. Linear rows of fence two to four feet high and
spaced 20 to 40 feet apart may be installed.
Maintenance Considerations
Wind fences require periodic inspection to ensure that there are no breaks or gaps.
Repairs should be made immediately. Sand and sediment should be cleaned from the
fence area periodically to prevent their mobilization by storm water runoff.
Removal
Remove fence after construction activities are complete and site is stabilized.
References
Environmental Protection Agency (EPA), National Pollutant Discharge Elimination
System (NPDES). Construction Site Storm Water Runoff Control.
Washington, D.C., February, 2003.
<http : //cfpub. epa. gov/npdes/stormwater/menuofbmps/con_site. cfm>
Rev: 0
Date: 1/26/06
Page 2 of 2 SC -9 Wind Fence
Erosion Control (EC)
EC -1 Land Grading — Well Pads and Pipelines
EC -2 Land Grading — Roads
EC -3 Road Gravel (RG)
EC -4 Surface Roughening (SR)
EC -5 Temporary Vegetation (VEGT)
EC -6 Permanent Vegetation (VEGP)
EC -7 Mulching (MLCH)
EC -8 Wattles (W)
EC -9 Erosion Control Blanket (ECB)
EC -10 Low Water Crossing (LWC)
EC -11 Brush Matting (BM)
EC -12 Terracing (T)
EC -13 Preserve Existing Vegetation (PEV)
EC -14 Vegetated Buffer (VB)
EC -15 Slope Drain (SD)
EC -16 Brush Layering (BL)
EC -17 Gabions (G)
EC -18 Level Spreader (LS)
EC -19 Retaining Wall (RW)
EC -20 Chemical Stabilization (CS)
Runoff Control (RC)
RC -1 Roadside (RSD) & Turnout (TO) Ditches
RC -2 Culvert Cross -Drain (CCD)
RC -3 Culvert Outlet Protection (COP)
RC -4 Riprap (RIP)
RC -5 Check Dam (CD)
RC -6 Road Slope
RC -7 Drainage Dip (DD)
RC -8 Temporary Berm (TB)
RC -9 Culvert Inlet Protection (CIP)
RC -10 Temporary Swale (TS)
RC -11 Temporary Diversion (TD)
RC -12 Permanent Diversion (PD)
RC -13 Water Bar (WB)
Sediment Control (SC)
SC -1 Straw Bale Barrier (SBB)
SC -2 Silt Fence (SF)
SC -3 Sediment Basin (SEDB)
SC -4 Stabilized Construction Entrance (SCE)
SC -5 Brush Barrier (BB)
SC -6 Sediment Trap (ST)
SC -7 Filter Berm (FB)
SC -8 Rock Dam (RD)
SC -9 Wind Fence (WF)
Appendix E
Non -Structural Best Management Practices
Scheduling of Activities
Non -Structural Control Number Description
NS1
Neither road grading nor pipeline installation will be initiated in heavy rains or
periods of runoff. Perimeter BMP installation for the well pad construction will
not be initiated during heavy rains. If BMP installation is necessary to protect
already disturbed soils, it will be completed as soon as possible.
NS2 Structural controls will be installed in increments, along the road shoulders as
soon as practicable after road grading and/or pipe installation.
NS3 Pipeline installation will be completed in smaller increments to coordinate
excavation, installation, and backfilling to limit the time that disturbed soils are
exposed to the elements. Pipelines may be installed along access roads
minimizing the width of the road and utilize the same structural BMPs used for
the access road. Should the pipeline alignment fall outside the area of the access
road, separate BMPs may be required in the pipeline right-of-way (ROW).
Disturbed Area Exposure Control
Non -Structural Control Number Description
NS4
NS5
NS6
NS7
NS8
The most effective management practice that will be used throughout the project
will involve limiting the area of vegetation disturbance and time of soil exposure
during structural BMP installation and construction activities.
During road grading, existing trees, shrubs, or vegetative ground cover will be
removed or disturbed only where necessary. Grading outside of access roads and
pipelines will be done only when necessary for the safe operation of equipment,
to allow for equipment turn -around, and for fire protection. When possible,
vegetation will be cut off near ground level leaving the root system intact or
trimmed rather than disturbed to facilitate clearing and grading. Trees, shrubs,
and ground cover outside the site construction area will not be disturbed, but
when necessary, will have overhanging limbs removed by cutting.
Cuts made in steep, rolling terrain during construction may be regraded and
contoured to blend into the adjoining landscape and to reestablish natural
drainage patterns to the extent possible.
Temporary stabilization of slopes may be used including mulch with a tackifier
and hydro seeding. The mulch is typically certified weed free straw or hay, and
may be applied by disking or hydro mulching, and may include a tackifier.
Erosion control blankets are used to prevent erosion, protect against rill
formation and encourage vegetation growth along slopes and channels. Erosion
control blankets can be composed of synthetic or organic materials and may be
installed on slopes and erosion prone areas.
NS9
Grubbing, grading, or trenching for perimeter controls installed for site
excavation will be completed efficiently to limit the amount of time that
disturbed soil is exposed to wind, precipitation, and snow melt. Permanent or
temporary controls such as silt fencing, brush barriers, Jersey barriers, or straw
wattles may be used as perimeter controls for site installation. These controls
may be placed on the down slope sides of the construction area at the toe of fill
slopes.
NS 10 Soil exposed during construction of the site (stripping, grading, etc.) will be
maintained in a roughened condition by ripping or disking along land contours.
NS 11 After permanent or temporary perimeter controls are installed, the site will be
constructed. The final site will be level to help to reduce runoff velocities and
ponding from precipitation and snowmelt.
NS 12 Seeding of exposed disturbed soils may be used on pipeline ROWs, slopes
adjacent to access roads, on slopes of sites, and stockpiles. Seeding can provide
temporary or permanent cover, decreased soil erosion, and improve wildlife
habitat and site appearance. The appropriate seed mix and seeding application
rate will be used and dictated by individual site conditions, see the BLM menu -
based seed mixes and application rates (Section Error! Reference source not
found.).
NS 13 When an area is no longer needed for production, the land will be re-contoured as
close as possible to its natural grade and seeded. This effective BMP minimizes
erosion and runoff and will allow a reduction of inspection frequencies of these
reclaimed areas.
Training and Inspection Procedures
Non -Structural Control Number Description
NS 14 Personnel involved in exploration and production activities, inspectors, and
contractors involved in BMP maintenance/implementation will be familiar with
the SWMP and the accompanying permit requirements. Additionally, Williams
personnel who work in the Rulison Field receive annual SWMP training.
NS 15 Site inspections are conducted in accordance with permit requirements. Please
refer to section 6.0 for a description of the inspection procedures.
Good Housekeeping Practices
Non -Structural Control Number Description
NS 16 Debris and waste materials such as well completion and drilling mud materials,
drill pipe, and other equipment no longer needed for well installation may be
removed.
NS 17 When necessary, water sprinkling will be implemented for control of airborne
dust along the construction ROWs, on unpaved haul roads, and other graded,
unpaved traffic routes.
NS 18 Regular disposal for garbage, rubbish, construction wastes, and sanitary waste
will be maintained during operations.
NS 19 If a measurable quantity of sediment is discharged from the site as a result of
structural failure or lack of designed capacity of temporary erosion control
measures, the sediment will be cleaned up as soon as practical and replaced or
properly disposed of in a manner approved by the general permit.
Appendix F
Reclamation Seed Mixes
MENU -BASED SEED MIXES BY HABITAT TYPE
FOR USE IN INTERIM AND FINAL RECLAMATION
Table 1-1. Low -Elevation Salt -Desert Scrub/Basin Bi Sagebrush
Common Name
Scientific Names
Variety
Season
Form
PLS
lbs/acre*
Plant Both of the Following (5% Each, 10% Total)
Fourwing Saltbush
Atriplex canescens
Shrub
1.9
Shadscale
Atriplex confertifolia
Shrub
1.5
and Both of the Following (20% Each, 40% Total)
Galleta
Pleuraphis [Hilaria] jamesii
Viva florets
Warm
Bunch
2.5
Alkali Sacaton
Sporobolus airoides
Salado
Warm
Bunch
0.2
and One of the Following (20% Total)
Streambank Wheatgrass
Elymus lanceolatus ssp. psammophilus,
Agropyron riparium
Sodar
Cool
Sod -forming
2.5
Western Wheatgrass
Pascopyrum [Agropyron] smithii
Arriba
Cool
Sod -forming
3.6
and Two of the Following (15% Each, 30% Total)
Indian Ricegrass
Achnatherum [Oryzopsis] hymenoides
Nezpar, Paloma,
Rimrock
Cool
Bunch
7
2.1
Bottlebrush Squirreltail
Elymus elymoides, Sitanion hystrix
Cool
Bunch
1.5
Slender Wheatgrass
Elymus trachycaulus, Agropyron trachycaulum
San Luis, Pryor
Cool
Bunch
1.8
Sandberg Bluegrass
Poa sandbergii (Poa secunda)
Cool
Bunch
0.3
*Based on 45 pure live seeds (PLS) per square foot, drill -seeded. Double this rate (90 PLS per square foot) if broadcast or hydroseeded.
Tablell-2. Pinyon -Juniper Woodland and/or Mountain/Wvoming Bi Sagebrush Shrubland
Common Name
Scientific Names
Variety
Season
Form
PLS
lbs/acre*
Plant the Following (10% Total)
Indian Ricegrass
Achnatherum [Oryzopsisj hymenoides
Nezpar, Paloma,
Rimrock
Cool
Bunch
1.9
and Both of the Following (15% Each, 30% Total)
Galleta
Pleuraphis [Hilaria] jamesii
Viva florets
Warm
Bunch
2.5
Bluebunch Wheatgrass
Pseudoroegneria spicata, Agropyron spicatum
Secar, P-7,
Anatone
Cool
Bunch
2.8
and One of the Following (20% Total)
Thickspike Wheatgrass
Elymus lanceolatus ssp. lanceolatus, Agropyron
dasystachyum
Critana,
Schwendimar
Cool
Sod -forming
3.4
Slender Wheatgrass
Elymus trachycaulus, Agropyron trachycaulum
San Luis
Cool
Bunch
3.3
and Two of the Following (40% Total)
Muttongrass
Poa fendleriana
Cool
Bunch
0.6
Sandberg Bluegrass
Poa sandbergii, Poa secunda
Cool
Bunch
0.6
Bottlebrush Squirreltail
Elymus elymoides, Sitanion hystrix
Cool
Bunch
2.7
*Based on 60 pure live seeds (PLS) per square foot, drill -seeded. Double this rate (120 PLS per square foot) if broadcast or hydroseeded.
Table 1-3. Mixed Mountain Shrubland, Including Oakbrush
Common Name
Scientific Names
Variety
Season
Form
PLS
lbs/acre*
Plant Both of the Following (20% Each, 40% Total)
Thickspike Wheatgrass
Elymus lanceolatus ssp. lanceolatus, Agropyron
dasystachyum
Critana,
Schwendimar
Cool
Sod -forming
3.4
Bluebunch Wheatgrass
Pseudoroegneria spicata, Agropyron spicatum
Secar, P-7,
Anatone
Cool
Bunch
3.7
and One of the Following (20% Total)
Bottlebrush Squirreltail
Elymus elymoides, Sitanion hystrix
Cool
Bunch
2.7
Slender Wheatgrass
Elymus trachycaulus, Agropyron trachycaulum
San Luis
Cool
Bunch
3.3
and One of the Following (20% Total)
Canby Bluegrass
Poa canbyi, P. secunda
Canbar
Cool
Bunch
0.6
Mutton Bluegrass
Poa fendleriana
Cool
Bunch
0.6
and One of the Following (10% Total)
Letterman Needlegrass
Achnatherum [Stipa] lettermanii
Cool
Bunch
1.7
Columbia Needlegrass
Achnatherum [Stipa] nelsonii, Stipa columbiana
Cool
Bunch
1.7
and One of the Following (10% Total)
Indian Ricegrass
Achnatherum [Oryzopsis] hymenoides
Nezpar, Paloma,
Rimrock
Cool
Bunch
1.9
Junegrass
Koeleria macrantha, K cristata
Cool
Bunch
0.1
*Based on 60 pure live seeds (PLS) per square foot, drill -seeded. Double this rate (120 PLS per square foot) if broadcast or hydroseeded
Appendix G
Example Inspection Report
Williams Storm Water Inspection Checklist
Project Name
Project ID
Unique ID
Field Name
RPW 22-23-596
Description
14 day
Red Point
Site Type
Permit Name
Permit Date
Priority
Well Pad
Description
14 day
N/A
Recommended
Contractor
Work
Completed
Since Last
Inspection
William's
Supervisor
Range
Section
Description
14 day
Muddy melting snow
conditions. Pit has been
reclaimed. Work over rig on
site.
Sediment
Trap SC -6
No
The sediment trap at the toe of the fill slope
is in good condition.
Inspection Date
Inspector
Inspection Type
Comments
02-21-2007
Kay Lambert
14 day
Muddy melting snow
conditions. Pit has been
reclaimed. Work over rig on
site.
Acres Disturbed
Acres Subject to Interim
Reclamation
Acres Restored
Distance to
Receiving Water
Name of Receiving
Water
Type
Estimated Runoff
Coefficient
200
Parachute Creek
Perennial
The temporary berm at the pad's edge
above the road is in good condition.
Best Management Practices
Type
Maintenance
Required
Date
Maintenance
Completed
Comment
Temporary
Berm RC-
8
No
The temporary berm at the pad's edge
above the road is in good condition.
Sediment
Trap SC -6
No
The sediment trap at the toe of the fill slope
is in good condition.
Temporary
Diversion
RC -11
No
The temporary diversion above the pad will
be effective at preventing run-on water
form entering the site.
Processing Eauioment
# of
Tanks
# of
Separators
Freeboard in
Secondary
Containment
Storm Water
in Secondary
Containment
Comment
3
1
> 2 feet
No
Secondary Wells On Site
Other Eauioment
Type of Equipment
Comment
Reserve pit
Reserve pit has been reclaimed.
Work over rig
Housekeeping/Site Trash
No issues
Materials Handling
No issues
Spills or Leaks
None observed
Vegetation
Seed Mix
Date
Planted
70%
Revegetated
Comment
Files
Type of File
Location
Site Complies With Storm Water Standards (Yes or No)
Y
Authorization to Complete Work
Operations Manager
❑ Work is authorized. Charge No:
❑ Work is not authorized.
Authorizing Manager
Assigned to:
Responsible Person
Notes/Comments
❑ Williams
❑ Contractor
Date work completed:
Legend
Parachute Field Boundary
Figure 1
Parachute Field Boundaries
Willgams. ahadatitizo ll�lR 11
O:\Projects\PIC\ MultiProspect\09\0617 Valley Pipeline BMP\Parachute Field Area General.mxd mreynold 7/21/2009 10:14:57AM
0 1 2
4
Miles
Williams.
Williams.
‘,0 --
Construction Field Wide
Stormwater Management Plan
Parachute Field
Garfield County, Colorado
July 16, 2009
Rev No: 2
Prepared By:
Habitat Management, Inc.
TABLE OF CONTENTS
INTRODUCTION 1
1) NARRATIVE CONSTRUCTION SITE DESCRIPTION 3
a) Construction Activity Site Description 3
b) Sequence of Construction Activities 3
c) Site Area 3
d) Site Characteristics 4
e) Predominant Vegetation 4
f) Potential Pollution Sources 4
g) Allowable Sources of Non-Stormwater Discharge 5
h) Receiving Waters of the Parachute Field 5
2) SITE MAPS 6
3) STORMWATER MANAGEMENT CONTROLS 7
a) SWMP Administrator 7
b) Potential Stormwater Contaminants 7
c) Best Management Practices for Stormwater Pollution Prevention 8
i) Structural Best Management Practices for Erosion and Sediment Control 8
ii) Non -Structural Best Management Practices for Erosion and Sediment Control 8
iii) Phased BMP Implementation 9
iv) Materials Handling and Spill Prevention 9
(1) Fuels and Chemicals Management 9
(a) Petroleum Products 9
(b) Other Chemicals 10
(2) Spill Prevention 10
v) Dedicated Asphalt or Concrete Batch Plants 10
vi) Offsite Vehicle Tracking Control 11
vii) Waste Management & Disposal 11
(1) Construction Site Housekeeping 11
viii) Groundwater and Stormwater Dewatering 12
4) FINAL STABILIZATION AND LONG-TERM STOMRWATER MANAGEMENT 13
a) Final Stabilization 13
i) Interim Reclamation 13
ii) Final Reclamation 13
b) Establishment of Vegetative Cover and Seeding Guidelines 13
c) Final Stabilization and Permit Termination 14
5) INSPECTION AND MAINTENANCE 15
a) Minimum Inspection Schedule 15
i) Post -Storm Event Inspections at Temporarily Idle Sites 15
ii) Inspections at Completed Sites 15
iii) Winter Conditions 15
b) Inspection Requirements 15
c) Maintenance 16
6) REFERENCES 17
7) CERTIFICATIONS 18
i
FIGURES
Figure 1 Parachute Field Map
APPENDICIES
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Appendix G
Appendix H
Documentation of Amendments to the SWMP
Permit Requirements & Guidance Documents
CDPS Permit Certification & Rationale
Installation Details for Structural Best Management Practices-Stormwater Manual
Non-structural Best Management Practices
Reclamation Seed Mixes
Example Inspection Report
Site Specific Stormwater Management Plans
INTRODUCTION
This Stormwater Management Plan (SWMP) was developed in compliance with Colorado Department of
Public Health and Environment's (CDPHE) Colorado Discharge Permit System (CDPS) stormwater
discharge permit for general construction activity associated with oil and gas development. The purpose
of this SWMP is to identify possible pollutant sources that may contribute pollutants to stormwater, and
identify Best Management Practices (BMPs) that, when implemented, will reduce or eliminate any
possible water quality impacts. This SWMP will be implemented at the time the project breaks ground,
and revised as construction proceeds, to accurately reflect the conditions and practices at the site. This
SWMP has been prepared in accordance with good engineering, hydrologic, and pollution control
practices.
The stormwater discharge permit was issued to Williams Production Company RMT for the Parachute
Field on July 1, 2007. As a condition of the permit, the provisions of this SWMP, as written and updated,
will be implemented from commencement of construction activity until final stabilization is complete.
This Field Wide SWMP provides Williams with the framework for reducing soil erosion and minimizing
pollutants in stormwater during construction activities in the Parachute Field. This Field Wide SWMP
will achieve the following:
• Identify all potential sources of pollution which may reasonably be expected to affect the quality
of stormwater discharges associated with construction activity;
• Describe the practices to be used to reduce the pollutants in stormwater discharges associated
with construction activity;
• Ensure the practices are selected and described in accordance with good engineering practices,
including the installation, implementation and maintenance requirements;
• Describe the pollution control measures that may be used to prevent non-stormwater
contamination of State Waters;
• Create an implementation schedule so that the practices described in this SWMP are effective;
• Describe the final stabilization methods to minimize erosion and prevent stormwater impacts after
well pad/site, road, pipeline, and related installations are complete.
It is Williams' priority to ensure compliance with all federal, state, and local regulations regarding
stormwater management. However in certain instances, Williams receives directives from various
regulatory agencies that are at odds with the stormwater regulations put for the by the CDPHE. In these
instances, Williams will use a common sense approach to resolve the specific issue at hand.
This plan also contains the following information:
• Appendix B contains the CDPS General Permit Application, SWMP guidance document and the
Stormwater Fact Sheet, Construction Permitting for Oil and Gas Facilities;
• The CDPS Permit Certification received by Williams from the State of Colorado is found in
Appendix C;
• Appendix D, Appendix G, and Appendix G provide Best Management Practices (BMPs)
installation details, an example inspection report as required by the CDPHE, and information
specific to individual sites or construction projects;
• The approximate area of each site and area to undergo clearing and grading, existing vegetation,
and percent ground cover are included in the Site specific Plans included in Appendix H;
1
• Non-stormwater components of discharge and the name of the receiving waters are included in
the Site specific Plans included in Appendix H;
• A map of each site indicating the locations of major BMP structures is included in Appendix H.
The site map and accompanying figures may include the following information: construction site
boundaries, areas of soil disturbance, cuts and fills, areas for storage of materials, and surface
waters.
This Field Wide SWMP describes the means by which pollution control measures will be implemented.
This SWMP will be periodically updated as needed to address planned developments, new disturbances,
and other changes needed to manage stormwater and protect surface water quality. The updates may
include:
• Revision of existing BMPs for erosion control and sediment control;
• Revisions and updates to the site maps to indicate the locations of BMPs, soil disturbance areas,
construction material and waste storage areas, etc;
• Deletion of BMPs and reduction in monitoring frequency for individual facility locations where
interim and long-term vegetation has been successfully established;
• Addition of new site specific plans as new pads are scheduled for construction.
2
1) NARRATIVE CONSTRUCTION SITE DESCRIPTION
a) Construction Activity Site Description
Projects include, but are not limited to, construction of natural gas well pads, natural gas pipelines, water
transfer pipelines, compressor stations, access roads, and construction activities associated with oil and
gas production and exploration. There are existing natural gas facilities within the field and new facilities
and well pads will be constructed using conventional cut and fill earthmoving techniques.
Some new access roads will connect the well pads to existing roads. Drilling cuttings trenches and pits
will be used during drilling to hold drilling fluids and cuttings. Cuttings trenches will be designed,
constructed, and reclaimed according to Colorado Oil and Gas Conservation Commission (COGCC)
requirements.
In addition to the well pads, access roads, gathering and sales pipelines, staging areas, natural gas
treatment and compression facilities, and other areas will be constructed as needed for production of
natural gas. This SWMP is intended to address all activities within the boundaries of the lease areas. This
SWMP will be appended by Site Specific SWMPs that will be prepared as new construction activities are
planned (Appendix H). Development of natural gas resources and construction of necessary
improvements on new sites within this well field will likely continue for the next five to ten years.
b) Sequence of Construction Activities
Typical operational phases for a well pad include the construction of an access road and the drill pad, well
drilling and completion, installation of production facilities, and interim reclamation of areas not needed
for long-term production. The operational portions of the well pad will remain in place for 20 to 30 years
or more, until the well is no longer productive. At this time the well will be plugged and abandoned and
surface facilities will be removed. Final contouring and reclamation will be implemented at this time.
During drill pad and access road construction, topsoil will be stripped and stockpiled near the site for use
during interim and final reclamation. Soil materials will be managed so that erosion and sediment
transport are minimized. BMPs will be installed as necessary throughout the construction area to
minimize sediment transport. Nearby drainages will be protected using appropriate BMPs.
During drilling operations, drill cuttings will be managed in pits or trenches on site and surrounded by an
earthen berm to prevent runoff, in accordance with COGCC regulations and permits. BMPs and spill
preventions practices described in this SWMP and Williams' Spill Prevention and Response (SPRP) and
Spill Prevention Control and Countermeasures (SPCC) plans will be utilized during drilling operations.
After drilling and well completion activities are finished, the drilling pad will be graded to reduce the
pad's working surface to approximately 1/4 acre, access roads will remain in place for well operation and
maintenance activities. Interim reclamation will occur on portions of the drill pad no -longer needed for
production, according to Williams' interim reclamation plan, and as described in Section 1).
Wells which are no longer producing will be plugged according to COGCC rules. Following plugging,
the pad area will be reclaimed to approximate pre -construction contours as practicable; unless otherwise
authorized by the landowner or land management agency. Final stabilization and reclamation will be
conducted as described in Section 1).
c) Site Area
The Parachute Gas Field is located in Garfield County, Colorado (see Figure 1). The Parachute Field
includes natural gas leases and associated development that encompasses approximately 47,000 total
acres in Townships 6 and 7 South; Range 95 West, near Parachute, Colorado. The area is owned by a
3
combination of Federal and private surface and mineral owners. Williams is the lease operator and
developer, and is actively conducting exploration and development of natural gas resources.
Currently, there are actively producing wells and natural gas facilities within the Parachute Field.
Additional disturbance is expected during the next several years as more wells are drilled and new
facilities are constructed. Additionally, reclamation will occur on pads with areas no longer needed for
drilling or construction.
Specific well pad dimensions vary depending on the type of drill rig used, the number of wells to be
drilled from each pad, and local conditions. Specific areas currently, and expected to be, disturbed by
clearing, excavation, grading and other construction activities are detailed in Appendix H.
d) Site Characteristics
There are a wide variety of soil types and slopes found in the Parachute field. The Natural Resources
Conservation Service rates erosion potential on a scale of 0.02 (not highly erodible) to 0.69 (extremely
erodible). Site specific soil types are presented in Appendix H. Predominant soil types within the
Parachute Field include:
Soil Types Slopes Rating
Arvada loam 1-20% .37
Bucklon-Inchau loams 25-50% .24
Cochetopa loam 9-50% .20
Ildefonso stony loam 6-45% .28
Potts-Ildefonso complex 3-45% .28
Potts loam 6-12% .28
Parachute -Rhone loams 5-30% .20
Torriorthents, Camborthids, steep to very steep Null
Runoff characteristics are based on site topography, soil type, and soil/vegetative cover. Surface elevation
in the Parachute Field ranges from approximately 5,500 to 9,000 feet. Surface soils vary from sands, silts,
and clays to exposed bedrock. Natural slopes range from zero to over 100 percent. Existing and future
facilities are typically located on valley floors and hillsides. The estimated pre -construction runoff
coefficient is expected to range from 0.1 to 0.3. The estimated post -construction runoff coefficient is 0.3.
e) Predominant Vegetation
The Parachute Field includes a variety of vegetative cover types. Prominent vegetation includes pinyon -
juniper woodlands with understory grasses and desert shrub communities, with minor areas of irrigated
agriculture hayfields of alfalfa and smooth brome. A description of existing vegetation for each site and
an estimate of the percent vegetative ground cover are included in the site specific SWMPs found in
Appendix H.
f) Potential Pollution Sources
The primary potential stormwater contaminant is sediment from grading, excavating, and stockpiling
materials. This and other potential pollutant sources are evaluated in Section 3)b). Structural and non-
structural BMPs will be used to reduce pollutant loading in stormwater releases associated with the
construction activities at the sites covered by this field -wide SWMP.
In addition to sediment that is released by construction activities, natural sediment erosion occurs in this
region. The area surrounding the Rulsion Field is typical of western Colorado in that it is dominated by
tree and shrub communities that often have little herbaceous ground cover. This leads to a high rate of
sediment runoff even in systems where no disturbance occurs. It is likely that the sediment control
4
g)
structures installed by Williams receive additional loading by non -construction -related, naturally
occurring, sediment transport.
Allowable Sources of Non-Stormwater Discharge
Stormwater includes surface water runoff and drainage due to a storm event or due to snowmelt. All other
discharges constitute non-stormwater discharges. Non-Stormwater components of discharge will be
indentified in the site specific SWMPs, and may include uncontaminated springs, landscape irrigation
return flow, construction dewatering, and concrete washout
h) Receiving Waters of the Parachute Field
There are numerous named and unnamed perennial, intermittent, and ephemeral streams, creeks, and
drainages within the Parachute Field which ultimately flow into the Colorado River. It is estimated that
over 75% of these drainages are ephemeral. Receiving waters for individual well sites will be discussed in
the Site Specific SWMPs located in Appendix H. In some locations, oil and gas operations come within
several hundred feet of the Colorado River. The Parachute Field contains no discrete discharge points or
outfalls.
5
2) SITE MAPS
Site specific maps for each well pad site are included in Appendix H. Site maps show the following;
• Construction site boundaries;
• All areas of ground surface disturbance;
• Areas of cut and fill;
• Areas used for storage of building materials, equipment, soil, or waste;
• Locations of dedicated asphalt or concrete batch plants;
• Locations of all structural BMPs;
• Locations of non-structural BMPs as applicable;
• Locations of springs, streams, wetlands and other surface waters.
6
3) STORMWATER MANAGEMENT CONTROLS
a) SWMP Administrator
The SWMP administrator for the Parachute Field is Mr. Mike Shoemaker, Environmental Specialist. Mr.
Shoemaker works in the Parachute office and can be contacted at:
Williams Production RMT Co.
1058 County Road 215
P.O. Box 370
Parachute, Colorado 81635
Phone: (970) 263-2769
Cell: (970) 250-5778
Mike.shoemaker@williams.com
Williams will be in charge of all aspects of the property and this project. Williams' environmental staff
will serve as the primary contact for CDPHE inspections. Contractor(s) will perform the actual
construction and drilling, but Williams' environmental staff will ensure that all aspects of the plan are
complied with, and will provide oversight for:
• Plan implementation;
• Identification of potential pollutant sources;
• BMP installation and maintenance;
• Inspections and corrective activities;
• Modification and updates to the Field Wide and Site Specific SWMPs as required, corresponding
with changes phases of construction.
The operator of the Parachute Field is Williams Production RMT Company.
Williams Production RMT Co.
1515 Arapahoe Street, Tower 3 - Suite 1000
Denver, Colorado 80202
Ph (303) 572-3900
Mr. Alan Harrison, Vice President
b) Potential Stormwater Contaminants
All potential pollutant sources, including materials and activities, at well pad sites have been evaluated for
the potential to contribute pollutants to stormwater discharges. The primary potential stormwater
contaminant is sediment from grading, excavating, and stockpiling of materials. This includes disturbed
and stored soils and vehicle tracking of sediments.
Potential pollution sources during construction activities at the project site, other than sediment, include
accidental releases of the following:
• Fuel and lubricants associated with construction equipment;
• Drilling fluids;
7
• Fluids used during fracturing;
• Flow back water;
• Produced water;
• Condensate;
• Stored chemicals and materials;
• Garbage and sanitary waste;
• Operations Fluids.
The BMPs that will be implemented to adequately control sediment and other potential pollutant sources
are addressed in section 1)c).
c) Best Management Practices for Stormwater Pollution Prevention
Water -borne sediment is the main potential pollutant of concern in the Parachute Field. Each construction
project may employ a variety of BMPs as necessary to minimize sediment in stormwater runoff. The
objective of erosion and sediment controls is to minimize the release of sediments during stormwater
runoff. This can be accomplished through the use of both structural and nonstructural controls, as
appropriate to the site. This section describes erosion and sediment controls which may be implemented at
active construction sites to minimize possible sediment impacts to stormwater runoff.
Sediment and stormwater management controls will be accomplished through a combination of
construction techniques, vegetation management, and temporary or permanent structural features. BMPs
include a wide variety of procedures, inspection schedules, prohibition of activities, and other
management strategies to prevent contamination of stormwater runoff. BMPs can also include practices
that prevent contact between pollutants and runoff, or, if contact is made, reduce levels or remove
pollutants in runoff.
i) Structural Best Management Practices for Erosion and Sediment Control
Structural controls are features constructed to minimize erosion and sediment transport so that sediment
levels are in turn minimized in stormwater runoff. The site specific SWMPs indicate the specific
structural BMPs utilized at each site based on its conditions and characteristics. The Stormwater and 404
Manual of Best Management Practices (Williams' "Stormwater Manual"), found in Appendix D, provides
installation specifications and maintenance techniques for specific structural BMPs. However,
specifications and techniques provided in this manual may be modified based on individual site specific
conditions to provide practical and effective stormwater management. Manufacturer suggested
installation and maintenance guidelines and other sources will be used as necessary to supplement the
Stormwater Manual. BMP guidance documents from the Colorado Department of Transportation and the
United States Bureau of Land Management were also utilized in preparation and implementation of the
Stormwater Manual.
ii) Non -Structural Best Management Practices for Erosion and Sediment Control
Non-structural controls include, in part, preservation of vegetated cover, construction scheduling, training
of personnel, site inspections, and site management. Site management includes good housekeeping
practices intended to reduce sediment and other pollutants exposed to stormwater run off both during and
after construction. Routing of pipelines, access roads, and sites should be designed as to avoid
unnecessary crossings and fills of Waters of the United States and areas subject to erosion and
sedimentation. However, such measures shall not impede safe entry for equipment and construction
access. Personnel working in the Parachute Field will be advised of the components and goals of the
SWMP. They will be instructed to properly implement erosion and sediment controls; spill prevention
8
and response, materials handling, good housekeeping, and disposal and control of waste. They will also
be instructed to fuel and wash equipment in a manner to prevent contamination of surface and ground
waters. Non-structural practices are described in Appendix F.
The structural and non-structural BMPs listed in Appendix D and Appendix E are intended to include all
BMPs that may be used for gas gathering projects. However, there may be situations where a BMP not
included in the appendices is more appropriate to site conditions. Should the need arise for additional
BMPs this SWMP will be updated to include the additional BMP description.
iii) Phased BMP Implementation
For new disturbances, BMPs will be installed prior to, during, and immediately following construction as
practicable with consideration given to safety, access, operational constraints, topography, and ground
conditions (e.g. frozen ground) at the time of construction.
Initial BMP installations will occur as practicable before ground disturbing activities commence. This
may include activities such as installing silt fence or protecting ponds or waterways. As construction
activities proceed, additional measures will be implemented as necessary to adequately control each
pollutant source.
After construction activities are complete, long term or permanent BMPs will be implemented and
regularly inspected to ensure the long term management of sediment until the site adequately revegetated.
iv) Materials Handling and Spill Prevention
(1) Fuels and Chemicals Management
(a) Petroleum Products
Petroleum products that may be present at the construction/drilling sites include: gasoline, diesel fuel,
lubricant oils, hydraulic oils, used oils, and solvents. Gasoline and diesel fuel will be stored in portable
storage tanks with secondary containment. Lubricant, hydraulic, and miscellaneous oils and solvents will
be stored in sealed containers of various sizes.
The following guidelines for storing petroleum products will be used.
• All product containers will be clearly labeled;
• Drums will be kept off the ground within secondary containment and stored under cover if
needed;
• Fuel tanks will be stored within secondary containment;
• Lids of drummed materials will be securely fastened;
• In the event of a spill, procedures outline in Williams' Spill Response Plan will be followed.
Persons trained in handling spills will be available;
• Spill clean up and containment materials (absorbent, shovels, etc.) will be easily accessible. Spills
will be immediately cleaned up and contaminated materials will be properly stored on site until
they can be disposed of in accordance with applicable regulations;
• Storage areas and containers will be regularly monitored for leaks and repaired or replaced as
necessary. Workers should be reminded about proper storage and handling of materials during
weekly subcontractor or safety meeting;
• Shallow trenches may be installed around the drilling rig to provide secondary containment of
potential spills below the rig.
9
(b) Other Chemicals
Additional materials will be used and stored on site for use in well drilling, construction, and completion.
These materials will be stored appropriately and managed to minimize spills and leaks. Storage areas will
be regularly inspected and any minor spills or leaks will be cleaned up immediately.
(2) Spill Prevention
During drilling and workover operations drilling contractors are responsible for Spill Prevention Control
and Countermeasures (SPCC) plans for each drilling location. Williams personnel are trained on the
requirements of the SPCC Plan and the Spill Prevention and Response Plan (SPRP) during new hire
training and then annually after employment. If a spill occurs during drilling activities, contractors are
instructed to notify their Williams contact immediately. If the spill or leak can safely be stopped,
employees/contractors should do so. The spill should be contained and resources for spill cleanup
employed. Responsibility for agency notifications depends on whether the spill is by a contractor or
Williams personnel.
Spill prevention measures included in the Williams SPCC plan include:
• Fuel storage tanks stored on the project site shall have secondary containment such as soil berms,
bermed visqueen, a double walled lining, or steel mote.
• Dry drilling materials will be stored on pallets and covered to avoid contact with precipitation,
stormwater, and wind. Dry and liquid drilling materials or equipment lubricants will be stored on
pallets in secondary containment, such as soil berms or bermed visqueen, to capture accidental
spills or leaks.
• Wastes generated from materials imported to the construction site will be removed and disposed
in a timely fashion, including sanitary sewage facilities (typically portable).
• Sanitary facilities will be located away from drainage areas, inlets and areas of high traffic.
Portable sanitary sewage facilities will be stabilized in windy areas to prevent discharge as a
result of being blown or knocked over. Sanitary sewage waste will be properly disposed of by a
licensed and approved sanitary/septic waste hauler.
• In case of a produced water or hydrocarbon product leak or spill, containment strategies will be
implemented to control the release. Containment strategies will include, but are not limited to,
utilization of spill kits, creation of diversion ditches and containment berms, and removal of free
liquid by vacuum truck. Hydrocarbon contaminated soils and materials will land farmed within
bermed areas on site or will be properly stored in sealed containers to prevent contact with
stormwater until removed for proper disposal. The proposed BMPs implemented for erosion and
sediment control will aid in the retention of spills or leaks. The use of secondary containment and
inspections of equipment for leaks will also reduce the likelihood of spills or leaks.
• In case of a dry drilling material spill or leak the affected soil will land farmed within bermed
areas onsite if appropriate or removed and temporarily stored in a sealed container to prevent
contact with stormwater until removed for proper disposal. If a spill occurs prompt cleanup is
required to minimize any commingling of waste materials with stormwater runoff.
If a spill or release of a hazardous substance or oil occurs resulting in a discharge of a reportable
quantity, the State of Colorado and the National Response Center will be notified. Written reports,
notifications, and updates to the SWMP will be completed as required.
v) Dedicated Asphalt or Concrete Batch Plants
There are no, nor will there be, dedicated asphalt or concrete batch plants in the Parachute Field.
10
vi) Offsite Vehicle Tracking Control
If necessary, access roads may be stabilized with base coarse or gravel to reduce erosion. Alternatively,
tracking pads may be installed at site and access road intersections and at access points to asphalt and/or
public roadways to prevent tracking of mud and sediment. If necessary, street sweeping will be utilized to
remove sediment deposits that have been tracked onto asphalt public roadways by vehicles used on this
project (manual or hired service).
Unimproved county roads exist in the Parachute Field and are used by entities other than personnel
working on Williams' interests. Off site tracking of soil by entities not assigned to Williams' interests in
the Parachute Field is not the responsibility of Williams.
vii) Waste Management & Disposal
Well pad construction and drilling will generate various types of waste during the course of construction.
Waste may include the following:
• Trees and shrubs from clearing operations;
• Trash and debris from construction materials and workers;
• Drill cuttings;
• Drilling, completion, and production fluids;
• Sanitary sewage.
Each of these wastes will be managed so as to not contribute to stormwater pollution. Trees and shrubs
may be piled along the toe of well pad fill slopes to provide additional sediment control. Construction
trash and debris will be collected in containers and hauled off-site for disposal in suitable landfills.
Sanitary waste will be containerized in portable toilets or other storage tanks with waste materials
regularly pumped and transported off-site for disposal at approved facilities. All drilling fluids will be
circulated within tanks or placed within the cuttings trench. A minimum of two feet of freeboard will be
maintained at the cuttings trench at all times to minimize the potential for overflowing. Prior to pit closure
all non-exempt materials and liquids which have been placed in the pit may be hauled to the next well site
to be drilled or will be allowed to dry before backfilling the pit. Alternatively, pit fluids may also be
removed and disposed of at a certified disposal facility.
(1) Construction Site Housekeeping
Well pad housekeeping will consist of neat and orderly storage of materials and containerized fluids.
Wastes will be temporarily stored in sealed containers and regularly collected and disposed of at off-site,
suitable facilities. If spills occur prompt cleanup is required to minimize any commingling of waste
materials with stormwater runoff.
The drilling contractor will maintain an equipment storage (lay down) or staging area for equipment and
materials storage at each site. These areas will be maintained with good housekeeping and will be
inspected on a regular basis for spills, leaks, and potential contamination. Excavations at the well pads not
needed for completion and production operations will be filled immediately upon release of the drilling
rig from the location.
Routine equipment maintenance will be limited to fueling and lubrication of equipment. Any waste
product from maintenance will be containerized and transported off site for disposal or recycling. There
will be no major equipment overhauls conducted on site. Equipment will be transported off site for major
overhauls.
11
viii) Groundwater and Stormwater Dewatering
Currently there are no dewatering activities taking place in the Parachute Field. If dewatering activities
become necessary, appropriate rules and regulations will be followed and any necessary discharge permits
will be obtained in advance.
12
4) FINAL STABILIZATION AND LONG-TERM STOMRWATER MANAGEMENT
a) Final Stabilization
i) Interim Reclamation
When well pad, pipeline installation, access road preparation, and well installation are complete at a site,
interim reclamation activities will be initiated. Sites within the Parachute Field that are located on
cropland will be reclaimed in accordance with appropriate COGCC regulations and Private landowner
requirements. All other sites will be reclaimed for the interim as described below.
Interim reclamation activities include:
• Debris and waste materials such as well completion and drilling mud materials, drill pipe, and
excess materials and equipment will be managed in accordance with appropriate regulations.
• All pits and cuttings trenches will be closed according to COGCC regulations and the pits will be
re-contoured to avoid ponding of stormwater.
• In disturbed areas no longer needed for well installation or production, alleviation of compaction
may be implemented according to COGCC regulations.
• Unpaved access roads and pipelines may be stabilized with base coarse or gravel in such as way
as to minimize erosion. Permanent erosion control structures may be installed at slopes or ditches.
• Waterbars, and supplemental BMPs, will be installed on slopes greater than 20%, as needed.
• Rock check dams, or equivalent structures, may be installed in drainage channels that may be
susceptible to erosion.
• The slope of the area, the natural landscape of the surrounding area, and the proximity to channels
that could carry sediments to any nearby drainage will be used to select the placement of BMPs.
• Areas requiring re -seeding will be ripped or harrowed and seeded with an appropriate seed mix,
as described in section 1)b).
ii) Final Reclamation
Upon plugging and abandonment of each well, final reclamation of a site may be completed in
accordance with the current COGCC final reclamation regulations, unless other agreements have been
made with the landowner or land management agency. The remaining pits and boreholes required for
production may be backfilled, and debris and equipment will be removed. Access roads may be closed,
graded, and re-contoured, and culverts removed. In most cases, the site will be re-contoured as nearly as
practicable to match the natural topography and grade of the surrounding land. Compaction alleviation
methods will be applied per COGCC requirements, and the topsoil will be replaced over the site and
prepared by disking or ripping. The site will be seeded for final reclamation as described in section 1)b).
b) Establishment of Vegetative Cover and Seeding Guidelines
Seeding for Temporary, Interim, and Final Reclamation will be accomplished by drill seeding, hydro
seeding (with or without a tackifier), or hand broadcasting. Seeding methods include the following:
• Drill seeding on the contour of the landscape may be implemented using a range drill. In areas of
fine soils that have low surface rock, straw mulch may be crimped or trackwalked into place.
• Hand -broadcast seeding may be used in areas where drill seeding is not possible due to slope
gradient or limited access; the area may be hand broadcast and hand mulched with straw and/or
vegetation cleared from the right-of-way.
13
• Alternatively, hydro seeding with or without a tackifier may be applied to areas for stabilization.
Seed mixes will be selected, based on habitat type, from those prescribed by the BLM's Glenwood
Springs Energy Office (GSEO). Seed mixes are listed in Appendix F. Other seed mixes may be utilized
on private lands in agreement with the landowner. All disturbed areas will be reclaimed in accordance
with COGCC or other appropriate agency regulations.
c) Final Stabilization and Permit Termination
Final stabilization is reached when disturbed areas have been either built on, compacted, graveled, paved,
or a uniform vegetative cover has been established with an individual plant density of at least 70 percent
of pre -disturbance levels, or equivalent permanent, physical erosion reduction methods have been
employed.
Once final stabilization requirements have been met at a site, stormwater inspections will no longer be
required. When all sites under a Field Permit are finally stabilized, coverage under the Stormwater
Construction permit can be terminated by submitting an Inactivation Notice to the CDPHE.
14
5) INSPECTION AND MAINTENANCE
a) Minimum Inspection Schedule
Visual inspections of the active sites will be performed every 14 -calendar days dependant upon weather,
access, and operational constraints. Inspections will also be conducted as soon as possible, but no later
than 24 -hours, after a precipitation or snowmelt event that may cause erosion. The amount of
precipitation or snow melt that will require post -storm inspections and possible maintenance will be
determined by the observation of the construction sites and may vary depending on site conditions., If
timing is appropriate, the post -storm inspections may be used to fulfill the 14 -day inspection requirement.
Allowable modifications to the Minimum Inspection Schedule are described below. Additionally, if site
conditions make the inspection schedule described here impractical, Williams may petition the
Stormwater Division of CHDPE to grant an alternate inspection schedule.
i) Post -Storm Event Inspections at Temporarily Idle Sites
If construction activities will not occur at a site following a storm event, inspections may be delayed,
either up to 72 hours after the event, or before constructions activities begin- whichever comes first. The
delay must be noted in the post -storm inspection report, and routine inspections must still occur every 14
days.
ii) Inspections at Completed Sites
At completed sites, inspection frequencies may be reduced to a minimum of once per month. Completed
sites are sites where all construction activities that will result in surface ground disturbance are
completed; all activities required for final stabilization (in accordance with the SWMP) have been
completed, with the exception of the application of seed that has not occurred due to seasonal conditions
or the necessity for additional seed application to augment previous efforts; and the SWMP has been
amended to indicate those areas that will be inspected in accordance with the reduced schedule. Final
stabilization requirements for well pads and lease roads are listed in Section B.2 of the "Stormwater Fact
Sheet -Construction at Oil and Gas Facilities," provided in Appendix B. Inspection schedules for each
specific site are listed in Appendix F.
iii) Winter Conditions
Inspections are not required at sites with snow cover as defined by Part I.D.3 of the "CDPS General
Permit for Stormwater Discharges Associated with Construction Activity" in Appendix C. Winter
conditions are defined as "where construction activities are temporarily halted, where snow cover exists
over the entire site for an extended period of time and melting conditions posing a risk of surface erosion
do not exist." The following information must be documented in the inspection record for use of this
exclusion: dates when snow cover occurred, date when construction activities ceased, and date melting
conditions began.
b) Inspection Requirements
The SWMP coordinator or qualified designee will conduct the inspections. Inspections are intended to
verify that the structural BMPs are in good condition and are minimizing erosion. The inspection will also
verify that the procedures used to prevent stormwater contamination from construction materials and
petroleum products are effective.
Areas to be inspected, at a minimum, include:
• Construction site perimeter;
• Disturbed areas;
15
• Erosion and sediment control BMPs identified in Appendix F;
• Locations where vehicles enter or exit the project location;
• Areas used for materials storage that are exposed to precipitation;
• Discharge locations.
Inspection reports will note evidence of, or potential for, sediment leaving the area of disturbance, as well
as condition of, or need for maintenance to, BMPs In addition to visual inspection to determine the
effectiveness of BMPs, the Williams Stormwater Manual (Appendix D) will be referenced to verify that
the correct maintenance procedures and schedules are being followed. At a minimum, inspection reports
will include:
• The inspection date;
• Name(s) and title(s) of personnel making the inspection;
• Location(s) of discharges of sediment or other pollutants from the site;
• Location(s) of BMPs that need to be maintained;
• Location(s) of BMPs that failed to operate as designed or proved inadequate for a particular
location;
• Location(s) where additional BMPs are needed that were not in place at the time of inspection;
• Deviations from the minimum inspection schedule as provided in Part I.D.6.a above;
• Description of corrective action for items above, dates corrective action(s) taken, and measures
taken to prevent future violations, including requisite changes to the SWMP, as necessary;
• After adequate corrective action(s) has been taken, or where a report does not identify any
incidents requiring corrective action, the report shall contain a signed statement indicating the site
is in compliance with the permit to the best of the signer's knowledge and belief.
An Inspection Checklist will be completed during each site inspection and the site map will be updated as
necessary. Completed inspection reports are kept in electronic format at the Williams office for at least
three years following final stabilization. The original site maps, and outdated inspection forms are kept in
electronic format in the Williams Production Field Office (located at 1058 County Road 215 in Parachute,
Colorado), while the most recent site maps and inspection forms are kept in the field inspectors' Site
Specific Map Book. An example Inspection Checklist is provided in Appendix E.
Inspectors will be properly trained and/or have the proper experience to effectively conduct stormwater
management inspections. Inspectors will also be able to appropriately suggest modifications and verify
the proper installation of BMPs.
c) Maintenance
Maintenance of erosion and sediment control BMPs will be conducted as necessary to ensure that the
BMPs are functioning properly. Maintenance procedures include, but are not limited to:
• Silt and sediment will be removed from BMPs as necessary;
• Evidence of bank erosion within the project area will be stabilized with appropriate control
measures as listed in Section 4.3 above;
Specific maintenance procedures for each BMP are included in the Stormwater Manual in Appendix D.
Repairs and maintenance activities should begin as soon as practicable after the inspections.
16
6) REFERENCES
Bureau of Land Management - Glenwood Springs Energy Office, 2007. "Revisions to BLM Energy
Office Revegetation Requirements." Letter to Operators dated April 16, 2007.
Colorado Department of Public Health and Environment Water Quality Division- Stormwater Program,
2009. "Stormwater Discharges Associated with Construction Activity, General Permit Application and
Stormwater Management Plan Preparation Guidance." Revised March 2009.
Colorado Department of Public Health and Environment Water Quality Division- Stormwater Program,
2008. "Colorado's Stormwater Program Fact Sheet- Construction." Revised February 2008..
Colorado Department of Public Health and Environment Water Quality Division- Stormwater Program,
2007. "Stormwater Fact Sheet- Construction" and "Stormwater Fact Sheet- Construction at Oil and Gas
Facilities." Revised July 2007.
Colorado Department of Public Health and Environment Water Quality Division- Stormwater Program,
2007. "CDPS General Permit Stormwater Discharges Associated with Construction Activity,
Authorization to Discharge Under the Colorado Discharge Permit System." Effective July 2007.
Colorado Department of Transportation, 2002. "Erosion Control and Stormwater Quality Guide", 2002.
National Resources Conservation Service Web Soil Survey URL: http:websoilsurvey.nrcs.usda.gov,
January 30, 2006.
Soil Survey Staff, Natural Resources Conservation Service, United States Department of
Agriculture. Soil survey of Rifle Area and Parts of Garfield and Mesa Counties, Colorado. [Online
WWW]. Available URL: "http://soildatamart.nrcs.usda.gov/Survey.aspx?State=CO" [Accessed 30 June
2009]
Urban Drainage and Flood Control District Denver Colorado, October 2005. "Urban Storm Drainage
Criteria Manual, volume 3 -best management practices", October 2005.
United Stated Bureau of Land Management. "Gold Book Surface Operating Standards and Guidelines for
Oil and Gas Exploration and Development", fourth edition, 2006
Williams Spill Prevention and Response Plan. March 2009. Revision 5.
Williams Stormwater and 404 Handbook of Best Management Practices (BMPs). January 2006
17
7) CERTIFICATIONS
I certify under penalty of law that this document and all attachments were prepared under my direction or
supervision in accordance with a system designed to assure that qualified personnel properly gathered and
evaluated the information submitted. Based on my inquiry of the person or persons who manages the
system, or those persons directly responsible for the gathering the information, the information submitted
is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are
significant penalties for submitting false information, including the possibility of fine and imprisonment
for knowing violations.
Signature:
Title:
Date:
18
Figure 1
Field Map
Legend
Parachute Field Boundary
Figure 1
Parachute Field Boundaries
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