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HomeMy WebLinkAbout20240815 6584 McLin Staging Yard SWMP NarrativeXcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 CONSTRUCTION STORMWATER MANAGEMENT PLAN (SWMP) Xcel T -Line: 6584 MITC-UTER McLin Staging Yard 0.75 Mile Southeast of County Road 311 and County Road 335 Intersection Unincorporated Garfield County, Colorado 81647 (39.529868, -107.610443) Prepared for: Public Service Company of Colorado, a Colorado Corporation 1800 Larimer Street, Suite 1300 Denver, Colorado 80202 Prepared by: HDR Engineering, Inc. 1670 Broadway Street Denver, CO 80202 August 2024 Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 Table of Contents Tab 1 Introduction Site Description a) Nature of the construction activity at the site b) The proposed sequence for major activities c) Disturbed area d) Existing soils data e) Existing vegetation f) Allowable non-stormwater discharges, including low -risk discharges g) Receiving waters and information regarding 50 -ft pre-existing vegetation h) Stream crossings Tab 2 Site Map a) Construction site boundaries b) Flow arrows c) All areas of ground disturbance including borrow and fill d) Soil storage areas e) Waste accumulation areas f) Dedicated asphalt, concrete batch plants, and masonry mixing stations g) Locations of al l structural control measures h) Locations of all non -structural control measures as applicable i) Locations of springs, streams, wetlands and other surface waters and 50-ft buffer where applicable j) Locations of a stream crossings within the construction boundary Tab 3 Contact Information and Qualified Stormwater Manager Tab 4 Potential Sources of Pollution a) Disturbed and stored soils b) Vehicle tracking sediments c) Management of contaminated soils d) Loading and unloading operations e) Outdoor storage activities f) Vehicle and equipment maintenance and fueling g) Significant dust o r particulate generating processes h) Routine maintenance activities involving fertilizers, pesticides, herbicides, detergents, fuels, solvents, oils etc. i) On -site waste management practice j) Concrete truck/equipment washing, including washing of the concrete truck chute and associated fixtures and equipment k) Dedicated asphalt, concrete batch plants and masonry mixing stations l) Non-industrial waste such as worker trash and portable toilets Tab 5 Effluent Limitations – Control Measures for Stormwater Pollution Prevention a) Structural and non-structural controls b) Other specific control m easures c) Documented use agreements Tab 6 Control Measure Specifications and Maintenance Requirements (Control Measure Details) Tab 7 Materials Handling , Waste Management and Disposal, Spill Prevention Tab 8 Final Stabilization and Long -Term Stormwater Management Tab 9 Inspection s and Maintenance a) Inspection f requency b) Inspection scope Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 c) Inspection reporting d) Control m easure m aintenance e) Corrective action/ replacement and f ailed controls Tab 10 SWMP General Requirements, Review and Revisions Non-Compliance Notification Tab 11 Pre-Construction Photos Tab 12 Environmental Permits Tab 13 Inspection Reports Tab 14 Miscellaneous T ab 1 Introduction Site Description Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 INTRODUCTION This is a Stormwater Management Plan (SWMP) for the Xcel T-Line: 6584 MITC-UTER McLin Staging Yard p roject being conducted by Public Service Company of Colorado (PSCo), a Colorado corporation and an Xcel Energy Company. This document has been developed as defined in the Colorado Discharge Permit System (CDPS) General Permit for Stormwater Discharges Associated with Construction Activity (Permit No. COR400000, effective April 1, 2024.) authorizing stormwater discharges from construction activities that result in a total land disturbance of one acre or greater or if a project is less than an acre but part of a larger common plan of development. This SWMP was also developed to meet the Garfield County Grading Permit. This SWMP was prepared in accordance with good engineering, hydrologic and pollution control practices. Changes or additions may be required to address changes in conditions at the project. If such changes are made, this SWMP will be updated accordingly, and revisions documented in the SWMP . SITE DESCRIPTION (§I.C.2.c.) a) Nature of the Construction Activity at the Site: This SWMP covers construction activities associated with preparation of the McLin Staging Yard for use during the Xcel 6584 Mitchell Creek (MITC) to Rifle (UTER) Transmission Line Rebuild project. The yard is one of many locations for the overnight storage of equipment and material associated with the transmission line build . All other yards and the transmission line will be permitted separately. The 15-acre yard is located 0.75 Mile Southeast of County Road 311 and County Road 335 intersection. There is one access point into the yard located off the dirt packed private access road . Construction activities will begin by installing initial control measures (CMs). Vegetation and Topography (VT) and boundary fencing (BF) will be used as perimeter control measures. If the minimum vegetative buffer cannot be met for the yard soil type, a structural erosion and sediment control measure will be implemented downgradient of any construction related disturbances. Vehicle tracking controls (VTC’s), such as an aggregate entrance or other proprietary control measures (VTRAX, FODS, etc.) will be installed at the access point to the yard. Sediment control logs (SCL’s) will be installed downgradient of planned disturbance areas. Access to the yard will be at the south east perimeter of the yard and will lead to a 2-acre stabilized staging area (SSA). The SSA will be prepared during the interim phase of construction by stripping the topsoil from the pad area and stockpiling for use during restoration. Topsoil will generally be stored at the uphill side of the work area where feasible. Stockpiles will be temporary stabilized if left undisturbed longer than 14 days by (mulch, tarping, surface roughening, etc.) Down-gradient CMs will be placed at the toe of the topsoil stockpile. Additional grading to prepare a level and flat work area may be required, with subsoils stockpiled separately from the topsoil and equipped with down-gradient CM. Once grading is complete, the contractor will lay aggregate surfacing down. The SSA will support conex containers, dumpster, trailers, portable toilets, personal vehicle, and equipment during construction. Additionally, the yard will be utilizing a helicopter for the transportation of construction material. Access from the SSA to the remainder of the yard is expected to be drive and crush. Drive and crush will naturally crush down any vegetation but is not expected to damage the root system and will likely rebound naturally once construction has vacated the yard. If access through the yard causes rutting, restoration will include stabilizing the area upon demobilization and decommission of the yard. Sediment erosion control measures (CMs) will be implemented downgradient of any disturbances. Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 Contractors will use appropriate CMs to minimize the impact of earth disturbing activities as shown on the Site Maps in Tab 2. Upon completion of earth disturbing activities, PSCo and their contractors will restore the site with vegetation. The erosion control contractor will maintain and inspect control measures until all areas are stabilized; in some cases, this may require multiple growing seasons to re-establish vegetation. Once areas are stabilized, the erosion control contractor will remove all temporary, non-biodegradable control measures in preparation for permit closeout by PSCo . Appropriate control measures will be used to minimize the impact of earth-disturbing activities as shown on the Site Maps in Tab 2. b) The Proposed Sequence for Major Activities: Estimated Project Start Date: 09/03/2024 Estimated End of Construction Date: 01/30/2025 Estimated Final Stabilization Date: 09/30/2027 The following subsection describes the phasing/sequencing of the project as well as the control measures selected for each phase. Specific locations of the control measures are indicated on the Site Maps, provided in Tab 2. Installation, implementation, and maintenance specifications for each control are included in Tab 6 or are shown on the Site Maps. Tab 4 describes the potential pollutants for the project for which these controls were selected, and Tab 5 provides descriptions of the control measures. Minimize Disturbed Area and Protect Natural Features: The project will be phased to the extent practical to limit the amount of disturbed area that is exposed at any given time. Control measure phasing is critical to stormwater management. Control measure implementation will be coordinated with the various stages of construction. Controls that manage erosion and sediment transport from initial site activities will be installed prior to earth-disturbing activities. As work progresses and additional areas are disturbed, controls targeted for erosion and sediment transport will be implemented prior to the start of earth-disturbing activities in those areas. As portions of the site are completed and previously disturbed areas are stabilized or the control measure(s) are no longer needed, they will be removed. The actual schedule for installation of each of these phases is documented by the installation and removal dates for associated control measures on the Site Maps. Permanent or temporary soil erosion control measures for all slopes, channels, ditches, or any disturbed land area and soil stockpiles, will be implemented as soon as practicable after the final earth disturbance has been completed. When it is not possible to permanently stabilize a disturbed area after an earth disturbance has been completed or where significant earth disturbance activity ceases for more than 14 days, temporary erosion control measures will be implemented as soon as practicable, and no more than 14 days after construction activity has temporarily or permanently ceased . Project Phase Control s to be Implemented During Each Phase Pre-Disturbance/Site Preparation • Develop SWMP based on site visit and design drawings. • Install structural VTCs. • Determine limits of VT buffer. • Install perimeter fencing (BF). • Install control measures (SCL, etc.) downgradient of areas that are anticipated to be disturbed. • Limit access to areas that are not to be disturbed Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 Project Phase Control s to be Implemented During Each Phase protecting existing vegetation. Construction • Unless infeasible, topsoil will be preserved by stripping and segregating for use in final restoration efforts. • Locate stockpiles in work areas with perimeter controls. • Mobilize equipment and materials to the yard. • Protect and repair CMs as necessary. • If sediment migrates through VT buffer zone, install downgradient CMs. Interim Stabilization • Leave disturbed areas (including stockpiles) in surface roughened condition once work in an area is complete. Surface roughen, or otherwise stabilize, within 14 days of area becoming inactive. • Monitor sediment migration through VT buffer zone. • Remove temporary controls where appropriate. • Remove limited stored materials and equipment from the site. Final Stabilization • Remove SSA material. • Replace topsoil layer, if revegetation is the final form of stabilization, prior to implementing final stabilization. • Perform seeding mulching per seed mix and application rates defined in the following sections of this report , unless, the land manger will use the disturbed areas for agricultural purposes . Contractor to coordinate with land manager on final stabilization. • Monitor regrowth of vegetation, irrigate and re-seed if necessary. • Remove all non-biodegradable temporary controls once required vegetative cover is reached. • Close permits as applicable. c) Disturbed Area: 1. Total area of construction site: 15 AC 2. Total area of disturbance: 14.5 AC – This represents the maximum level of disturbance allowed, but the actual disturbances may be lower (contractor to limit footprint to area necessary). 3. Acreage of seeding: 7.5 AC – Estimated based on half the yard. d) Existing Soil Data: The United States Department of Agriculture Natural Resources Conservation Services (NRCS) Web Soil Survey provides information for soil types and properties for the site. Primary soil present is a Potts loam. Hydrologic properties, wind erodibility, and sheet/rill erosion potential are discussed below. Control measures were prescribed based on information made available by the NRCS. Soil hydraulic properties range from Type A soils, having a high infiltration rate and low runoff potential (such as sands) to Type D soils, having a very low infiltration rate and high runoff potential (such as clays). The hydrologic soil group (HSG) for on -site soil is type C, indicating a moderate low infiltration rate and moderate high runoff potential. Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by water. Values of Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 K range from 0.02 to 0.69. The higher the value, the more susceptible the soil is to sheet and rill erosion by water. The erosion factor K value for the project area is 0.37, indicating a moderate high susceptibility to sheet and rill erosion. The wind erodibility group of a soil is an indicator of a soil’s susceptibility to wind erosion. Soils are assigned to groups ranging from 1 to 8 with Group 1 being the most susceptible to wind erosion, 8 being the least. The wind erodibility group for on-site soil as listed by the NRCS is 5, indicating a moderate low susceptibility to erosion due to wind. e) Existing Vegetation: The vegetative density was determined at a site visit performed by HDR on 07/24/2024. Overall vegetative diversity was very low for this previously disturbed site. There was significant coverage of cheatgrass with overall active plant growth. The native plants – sagebrush, greasewood, and rabbitbrush were dead from herbicide applications from the previous year. K napweed, cheatgrass, bindweed, and musk thistle were documented. More information can be found in the noxious weed survey and weed management plan required for Garfield’s County Grading Permit. The method used for determining pre-existing vegetation density was by gridding two ground cover photo s of the yard (captured on 07/24/2024) and evaluating the % vegetation each quadrants displays. Typical pre-existing vegetation density was approximately 40%. Pre- construction photos of the project area are document in tab 11 and includes each of the evaluated areas . During reclamation, ‘drive & crush’ staging areas will be left alone to rebound naturally so that the topsoil layer and associated root structure remain in place. If the drive and crush vegetation appear to have been denuded and/or damaged to badly then reseeding may be necessary. Reclamation efforts will also be evaluated based on surrounding undisturbed vegetative densities . HDR did not observe wetland areas during site visit and wetlands with in the project area were not identified by the US Fish and Wildlife National Wetland Inventory (NWI) Mapper. See Tab 14 for NWI Map. There are no identified wetlands disturbed by the project. f) Allowable Non-Stormwater Discharges (Also Discussed in §I.A.1.b): Except as provided in the paragraphs below, all discharges that occur during the life of this project will be composed entirely of stormwater associated with construction activity. The Colorado Discharge Permit System (CDPS) General Permit allows the following non - stormwater discharges in combination with stormwater discharges associated with construction sites, provided that the non-stormwater component of the discharge is identified in the SWMP and if they have appropriate controls measures in accordance with §I.B.1 of the CDPS General Permit: • Discharges from uncontaminated natural springs that do not originate from an area of land disturbance. • Discharges to the ground of concrete or masonry washout water associated with the washing of concrete or masonry tools and concrete or masonry mixer chutes are allowed under this SWMP, provided that: the washout water is confined in a concrete or masonry washout area and does not leave the site as surface runoff or reach receiving waters, and does not contaminate groundwater. Controls for concrete and masonry washout water from washing tools and chutes if applicable to the project are illustrated in Site Maps (Tab 2). Concrete or masonry on-site waste disposal is not authorized by this permit except in accordance with Part I.B.1.a.ii(c) of COR400000. See Tab 7, Section d for additional information on concrete and masonry washout requirements . Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 • Discharges to the ground of water used to wash vehicles, equipment, and building exteriors. These discharges may not leave the site as surface runoff or reach receiving waters as defined by COR400000. The addition of soaps, solvents, and detergents is prohibited. If vehicle, equipment, or external building washing are to occur, the Colorado Department of Public Health and Environment (CDPHE) Water Quality Control Division’s (WQCD’s) Low Risk Discharge Guidance Document Discharges from Surface Cosmetic Power Washing Operations to Land will be followed and a copy of the guidance will be added to Tab 12. • Emergency fire-fighting discharges that occur during the active emergency response . • Discharges of landscape irrigation return flow. • Discharges from diversions of state waters within the permitted site. Low Risk Discharges of groundwater that has come into contact with construction activities may be authorized under the WQCD’s Low Risk Guidance Document Discharges of Uncontaminated Groundwater to Land which requires that these discharges are applied to land and that the following conditions are met: • The water source must be uncontaminated groundwater or groundwater mixed with stormwater, no chemicals may be added, and there can’t be a visible sheen. • The groundwater cannot leave the operational control of the site and the landowner must give permission to allow dewatering. • The discharge cannot enter waters of the State or other water conveyance systems. • Control measures must be used to prevent erosion, ponding, or runoff. Discharges of material other than stormwater must either be addressed in a separate Colorado Discharge Permit System (CDPS) permit issued for that discharge or by a Water Quality Control Division Low Risk Discharge Guidance document. If there are any additional CDPS or USACE Section 404 permits associated with this project, or any low-risk discharge guidance documents used to support non-stormwater discharges associated with this project, cop ies are retained in Tab 12. g) Receiving Waters: 1. Describe the general manner and direction in which discharges leave the site. Provide the name(s ) of immediate receiving water(s) and the ultimate receiving water(s). If the stormwater discharge is to a municipal separate storm sewer system, provide the name of the entity owning that system as well. If construction activities will permanently alter the existing drainage patterns, describe the new drainage patterns that will exist upon completion of construction. This section should clearly describe how discharges from the site are conveyed from within the limits of construction to the ultimately receiving water : Stormwater runoff will flow west as surface/sheet flow. The immediate receiving water is the Ward and Reynolds Ditch. The ultimate receiving water is the Colorado River. 2. Is a receiving water within the limits of construction? No . 3. Is the immediate receiving water (classified stream segment or ultimate receiving water) listed as impaired? If yes, does it have an approved TMDL? The immediate receiving water is not listed as impaired. The ultimate receiving water, Colorado River (COLCLC01_A), is listed as impaired for total arsenic and temperature. Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 This segment does not have an approved TMDL. Construction activity will not impact this impairment by installing the proper control measures listed in tab 4 for the associated potential pollutant sources and following the associated procedures. Contractor will document and field assess if a change is needed to the SWMP. If yes and the WQCD has issued additional restrictions on the permit certification as a result of an applicable Wasteload Allocation, discuss the restrictions and planned measures used to meet the restrictions here: N/A. 4. Is the immediate receiving water (classified stream segment or ultimate receiving water) listed as an Outstanding Water (website https://www.colorado.gov/pacific/cdphe/clean - water-gis-maps ? No. If yes, describe the long-term ecological or water quality benefit, or public interest served by the Project. 5. Does the receiving water have any known additional monitoring or sampling requirements ? No . h) Stream Crossings: 1. Are there any stream crossings located within the limits of construction? No. Tab 2 Site Map Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 SITE MAP (§I.C.2.d.) The SWMP will include a legible site map(s), showing the entire site, identifying: a) Construction site boundaries , b) Flow arrows that depict stormwater flow directions on and off -site and runoff direction, c) All areas of ground disturbance including areas of borrow and fill , d) Areas used for storage of soil, e) Locations of all waste accumulation areas, including areas for liquid, concrete, masonry, and asphalt, f) Locations of dedicated asphalt , concrete batch plants and masonry mixing stations , g) Locations of other potential sources of pollution not listed in c. through f., h) Locations of all structural control measures , i) Locations of all non-structural control measures , as applicable, j) Locations and names of springs, streams, wetlands, diversions, and other state waters within or bordering the site, including areas that require pre-existing vegetation be maintained within 50 feet of a receiving water, where determined feasible in accordance with Part I.B.1.a.i.(e), k) Locations of all stream crossings located with in the construction boundary , and l) Locations where alternative temporary stabilization schedules apply. Many of these items will be illustrated on the Site Map prior to starting construction; however, other items such as stockpile locations, waste locations, parking and staging may be added or modified during construction. Any modifications associated with control measures will also be redlined in the field. Site maps are intended to be living documents modified in the field as needed. Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 Tab 3 Contact Information and Qualified Stormwater Manager Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 QUALIFIED STORMWATER MANAGER (§I.C.2.a) The PSCo Qualified Stormwater Manager is responsible for overseeing and working with the PSCo Construction Project Manager/Construction Supervisor assigning PSCo personnel, consultants, and/or contractors to aid in the development, implementation, maintenance, and revisions to the SWMP. PSCo’s Qualified Stormwater Manager, who oversees stormwater compliance for the company, works with the PSCo Construction Program Manager/Construction Supervisor to designate a site-specific Qualified Stormwater Manager for each project who is responsible for day-to-day SWMP compliance at the site and is often the SWMP inspector. Additional team members include: the SWMP D esigner and Control Measure Installer all of whom are qualified stormwater professionals. CONTACT INFORMATION PSCo is typically the Project Owner and Operator. PSCo may also have construction contractor(s) and/or subcontractors; however, PSCo is in charge of overseeing and directing work related to stormwater compliance. Contractors and subcontractors are also given trainings by PSCo Environmental Services on stormwater compliance even though third -party specialist are typically hired to perform inspections and install control measures. Contact information for Qualified Stormwater Managers and other responsible parties are provided below. PSCo Environmental Services (Qualified Stormwater Manager): Name: Tensy Thatcher Title: Environmental Analyst Address: 1800 Larimer Street, Suite 1300 Denver, CO 80202 Phone: 970-903-0595 Email: Tensy.C.Thatcher@xcelenergy.com Project Foreman: Name: Company: Address: Phone: Email: Project Manager(s)/Construction Supervisor (Part of the Stormwater Management Team): Name: Justin Eusoof Title: Project Manager Address: 9191 S. Jamaica Street Englewood, CO 80112 Phone: 719-331-9462 Email: Justin.Eusoof@xcelenergy.com SWMP Inspector (Site-Specific Qualified Stormwater Manager): Name: Company: Address: Phone: Email: SWMP and Erosion and Sediment Control Plan (ESC) Prepared by (Part of Stormwater Manager Team): Name: Brian Brown, PE Company: HDR, Inc. Address: 1670 Broadway Street, Suite 3400 Denver, CO 80202 Phone: 970-416-4404 Email: Brian.Brown@hdrinc.com Control Measure Implementation (Part of the Stormwater Management Team): Name: Company: Address: Phone: Email *This document will be redlined in the field if personnel change during the course of the Project . Add an additional page if needed. Tab 4 Potential Sources of Pollution Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 IDENTIFICATION OF POTENTIAL SOURCES OF POLLUTION (§I.C.2.e) The following potential sources of pollutants and activities have been evaluated for their ability to impact stormwater discharges. If the potential source exists at the site, the c ontrol measures used to manage that source are listed in this section and are illustrated in the Site Maps in Tab 2 . POTENTIAL SOURCE OF POLLUTANT POTENTIAL WITH THIS PROJECT? YES NO ACTIVITIES ASSOCIATED WITH THIS POLLUTION SOURCE AND CONTROL MEASURES SELECTED TO CONTROL THE SOURCE All disturbed and stored soils: Stockpiled soils (i.e., topsoil, embankments, spoils, etc.) Disturbed soils (exposed areas, staging areas, parking, etc.) Y Activities associated with this pollution source are the earth - disturbing activities during all phases of construction activities, including but not limited to grading, stockpiling, etc. Control Measures : Sediment control and stockpile containment may include usage of sediment control logs, sweeping, temporary berms, rock socks , vehicle tracking control (VTC), and other proprietary control measures (i.e., Big Red Bag , Dandy Recyclers, etc .). Erosion control may include surface roughening, mulch/mulch tackifier application, seeding and mulching, and maintain a pre-existing vegetative zone within 50 feet of a receiving water unless infeasible (See Tab 1, Section g). Additionally, temporary stabilization will be implemented for earth-disturbing activities that have permanently or temporarily ceased for more than 14 calendar days. Temporary stabilization methods may include, but are not limited to, tarps, soil tackifier, and hydroseed or mulch and/or surface roughening. Administrative controls may include phased construction to reduce the amount of open area at any given time and limiting the number of stockpiles. Vehicle tracking of sediment: Y The activity associated with this pollution source is the movement of vehicles from disturbed areas to roadways during all phases of construction activities. Control Measures : Sediment control may include stabilized construction entrance (rock, geotextiles, mud mats, and/or other proprietary products) and street sweeping. If necessary, use construction fencing to limit entry and exit points and establish perimeter control . Access may also be limited during muddy conditions , if feasible, with the construction activities and schedule. On-site waste management practices (waste piles, liquid wastes, dumpsters, etc.) Y Activities associated with this pollution source are generation of waste materials during all phases of construction activities that include but are not limited to debris , solid waste dumpsters and portable toilets . Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 POTENTIAL SOURCE OF POLLUTANT POTENTIAL WITH THIS PROJECT? YES NO ACTIVITIES ASSOCIATED WITH THIS POLLUTION SOURCE AND CONTROL MEASURES SELECTED TO CONTROL THE SOURCE Control Measures: Designated waste receptacles will be utilized. Liquids should be stored in secondary containment. Dumpsters will not typically be used on small projects. However, they will be utilized on larger projects where they will be serviced frequently by a licensed company. This potential pollutant source is part of the materials handling procedures and controls for the project. Management of contaminated soils N No known contaminated soils exist on site. If contaminated soils are encountered, all activity will be stopped until the situation can be assessed. The Project Manager will be contacted for further direction. See Contaminated Soil Process Fact Sheet at the end o f Tab 7. Loading and unloading operations Y Activities associated with this pollution source are potential spills during delivery and unloading of materials at the staging area during all phases of construction activity. Control Measures : Loading and unloading operations should occur within the disturbance limits at the staging area. For larger, longer duration projects, the staging area is generally stabilized with rock or another non-erosive surface. Administrative controls may include materials management practices, good housekeeping practices, personnel training, providing spill kits where needed, and minimizing the number of areas where loading and unloading occur . The Project Manager will be contacted immediately for all spills. Outdoor storage activities (including erodible building materials, fertilizers, chemicals, etc.) Y Activities associated with this pollution source are storage of material at the staging area and the potential for spills and leaks from these materials. Control Measures : Containment of the storage or staging area may include installation of sediment control logs, temporary berms, etc. Storage of petroleum products or other liquid chemicals in quantities of 55 gallons or more must have secondary containment, or equivalent protection. This potential pollutant source along with several others (vehicle and equipment maintenance and fueling, sanitary waste and other waste handling) constitute t he materials handling procedures and controls for the project which are detailed in Tab 7. Administrative cont rols may include materials management practices (such as covering chemicals and materials to prevent contact with stormwater where practicable, storing materials in proper containers with appropriate labeling, and only keeping limited supplies onsite), personnel training, and Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 POTENTIAL SOURCE OF POLLUTANT POTENTIAL WITH THIS PROJECT? YES NO ACTIVITIES ASSOCIATED WITH THIS POLLUTION SOURCE AND CONTROL MEASURES SELECTED TO CONTROL THE SOURCE providing spill kits where needed. The Project Manager will be contacted immediately for all spills. Vehicle and equipment maintenance and fueling Y Potential pollution sources include fuels, oils, antifreeze, and other liquids associated with equipment performance. Fueling of equipment or vehicles and equipment repair may occur during all phases of construction activity. This project anticipates (using mobile fueling to refuel equipment, having fuel tanks onsite, fueling offsite or a combination). The Qualified Stormwater Manager (QSM) will update the site maps with location of fuel tanks. Control Measures : Limit areas where fueling and equipment maintenance activities occur at the site. Where possible, s tage fueling /maintenance activities away from storm sewer system inlets/waterways. Spill kits should be staged where fueling is conducted. Use plastic sheeting, drip pans, dirt berms and other measures to contain fluids. Clean up and dispose of spilled material immediately. Administrative controls may include materials management practices, personnel training, and providing spill kits in vehicle maintenance areas . The Project Manager will be contacted immediately for all spills. Significant dust or particulate generating processes (e.g., saw cutting material, including dust) Y Activities associated with this pollution source are the earth - disturbing activities during all phases of construction activities, including but not limited to grading, etc. There is also the potential for wind /helicopter landing and departure to transport dust from disturbed areas including access roads. Additionally, saw cutting can contribute to dust. This project does not require saw cutting. Control Measures : Limit earth-disturbing activities to the extent feasible. Water disturbed areas and roads as needed during construction, use palliatives to control dust, install interim stabilization measures such as surface roughening, final stabilization, and other effective means. Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, etc. Y Activities associated with this pollution source are limited due to the short -term nature of utility installation activities. Fueling and maintenance activities involving vehicles and equipment and the potential for use of fuels, oils, solvents, etc ., are discussed above. Seeding operations typically occur during the final phase of the project and may involve use of fertilizers and tackifiers, as needed. Fertilizers are typically brought to the site by a seeding contractor during seeding operations and any remaining material is removed from the site by the contractor, thus minimizing exposure. Pesticides are not planned to be used at this site. Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 POTENTIAL SOURCE OF POLLUTANT POTENTIAL WITH THIS PROJECT? YES NO ACTIVITIES ASSOCIATED WITH THIS POLLUTION SOURCE AND CONTROL MEASURES SELECTED TO CONTROL THE SOURCE Control Measures : Liquids should be stored in secondary containment. Administrative controls may include materials management practices (such as covering chemicals and materials to prevent contact with stormwater where practicable, storing materials in proper containers with appropriate labeling, and only keeping limited supplies onsite), personnel training in proper use, and storage of materials. Concrete/masonry truck/equipment washing, including the concrete truck chute and associated fixtures and equipment Y Concrete pours are not anticipated in the laydown yard , however, CWA waste associated with the transmission line construction may be temporarily staged in the laydown yard until hauled off for disposal. Control Measures : Dedicated concrete washout areas that are clearly marked and maintained. Where applicable, urban mobile concrete washout structures can be used depending on the amount of concrete used on the project. Dedicated asphalt, concrete batch plants and masonry mixing stations N No dedicated asphalt , concrete batch plants , or masonry mixing stations are planned for this site. Non-industrial waste sources worker trash and portable toilets Y Activities associated with this potential pollutant source include the generation of non-industrial waste such as discarded building materials, litter, and sanitary waste at the construction site that may cause adverse impacts to water quality. Control Measures: Good housekeeping practices will be implemented, and trash will be collected in vehicles and disposed of offsite or in waste containers. Portable toilets should be properly anchored down and located away from the storm sewer system or waterways. Reclaimed water approved for use in construction dust suppression N Reclaimed water is not to be used for dust suppression at this site. Other areas or procedures where potential spills can occur Y Damaged or broken controls measures can act as a pollutant source. Control measures are inspected and if any are damaged, they are noted as such and repaired or removed. If any materials from the controls have been released , they are properly cleaned up and disposed of. Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 Tab 5 Effluent Limitations – Control Measures for Stormwater Pollution Prevention Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 CONTROL MEASURES USED TO MEET EFFLUENT LIMITATIONS (§I.B.1.a.i and §I.C.2.e) a) Structural Control Measures: Structural control measures are those physical structures implemented at the site to minimize erosion and sediment transport. Most structural control measures tend to be sediment controls. The structural control measures that are planned to be used for the project are described below. Specific locations for control measures implemented at the site are indicated on the Site Map s , provided in Tab 2. Installation and maintenance details for these control measures are in Tab 6 or are provided with the Site Map s. Stormwater runoff from all disturbed areas and soil storage areas for which permanent or temporary stabilization is not implemented, will flow to at least one control measure to minimize sediment in the discharge. This may be accomplished through filtering, settling, or staining. The control must contain or filter flo ws in order to prevent the bypass of flows without treatment and must be appropriate for stormwater runoff from disturbed areas and for expected flow rate, duration, and flow conditions. One goal of a SWMP is to allow for field fitting of control measures based on site -specific conditions that may favor use of one control measure over another. Each structural control measure listed below contains a brief list of other control measures that may be substituted, based on site specific conditions. Inlet protections will be inspected for damage, structural integrity, proper installation in relationship to the curb , and need for sediment removal. Maintenance may include repairing or replacing as needed, repositioning the inlet protections and/or removing accumulated sediment. Perimeter Control: Perimeter controls serve as erosion and sediment control s and, when appropriate, access control. At downgradient locations, perimeter controls will be installed where overland sheet flow has the potential to leave the site. In upgradient areas perimeter control may be added to define project boundaries, limit on - site flows or protect off-site features. Such controls should be suitable to the application. Perimeter control may consist of any number of control measures , including, but not limited to earthen berms, sediment control logs, etc. Perimeter control s will be used around bore holes, trenches, and other locations where sediment is exposed and may accumulate. Perimeter control s will remain in place until areas upgradient of controls are stabilized. Perimeter control s will be inspected for proper installation, structural integrity and accumulated sediment. Maintenance may include repairing or replacing damaged sections and removing accumulated sediment. Rock Socks/ Curb Socks : Rock socks or curb socks are wire or geotextile tubes filled with rock or gravel material. Rock socks may be used as inlet protection, outlet protection, swale protection , perimeter control, or in any area where concentrated flows need to be broken up and velocity reduced to prevent erosion. Rock socks serve to reduce water velocity allowing time for sediment to settle out, thus decreasing erosion potential and sediment transport. When used for swale protection rock socks need to extend the entire width of the expected flow with the center lower than the sides. For use as inlet or culvert protection, the rock sock should extend beyond the width of the inlet/culvert. Rock socks may be stacked to maximize performance. Delineators will be installed with curb socks for high traffic areas where installations present a potential traffic hazard or where they may be damaged by vehicles or snowplows. Rocks socks will be inspected for proper installation, structural integrity and accumulated sediment. Maintenance may include repairing or replacing damaged sections and removing accumulated sediment. Silt Fence: Silt fence consists of geotextile fabric installed with at least six inches of the fabric trenched into the soil; wooden stakes are attached on the downgradient side. Wire-backed fence may be used, or additional stakes or lathe may be added on the upgradient side for strengthening the fence around corners or in Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 high wind conditions. Silt fence provides sediment control by reducing water velocity and ponding water to facilitate the deposition of sediment on the upgradient side of the fence. Silt fence applications include, but are not limited to project perimeter control, secondary containment, back of curb protection and containment for any disturbed or staging area. Silt fence will be inspected regularly for sediment accumulation, tear or holes in the fabric, broken stakes, gaps in the fabric, or areas where the fabric needs to be re-attached to the wooden stakes. Maintenance may include repairing the items noted, removing sediment accumulation one-half the height of the fence, or replacing the fence as needed. Designated Material Staging Area: A designated and/or stabilized staging area is a specific location on or near the project site for stockpiling/staging materials and equipment for use on -site. A staging area allows for a central location for deliveries and storage of equipment when not in use and reduces disturbance of areas of the site not scheduled for disturbance through construction activities. Staging areas generally consist of a cleared area of the site with vehicle tracking control and perimeter control (e.g., sediment control log and/or construction fencing). Staging areas will be implemented as needed on site. They should be positioned to reduce the need for relocation and be placed out of areas of active construction activity. Staging areas will be inspected for adequate vehicle tracking control and perimeter control. Controls associated with staging areas should be repaired or modified as needed. Maintenance may include replacing material used to stabilize the staging area (if applicable) and repairing or replacing damaged perimeter and access control measures. Vehicle Tracking Control (VTC): Vehicle tracking control will be implemented to minimize vehicle tracking of sediment from disturbed areas per (§I.B.1.a.i.a) and may consist of an excavated area with a geotextile liner and gravel, metal grate , asphalt/concrete “rumble strip”, or other proprietary products. VTCs must include a structural control measure such as a tracking pad or wash rack, and may also include non -structural control measures, such as sweeping or restricting traffic to paved areas. VTCs are designed to cause soil to vibrate off equipment and vehicles as they transition from disturbed soils to paved areas and should drain to a control measure. The VTC will remain in place until access to the areas used by the control are no longer needed. Designated points of ingress and egress, where traffic transitions from a stabilized road surface (e.g., gravel or pavement) to disturbed soil, are likely to need vehicle tracking control or these areas must drain to a control that meets the requirements of (§I.B.1.a.i.b). VTCs may be moved or eliminated (if no longer needed) as on-site conditions and activities change. VTCs will be inspected for depth of gravel/rock, presence of excess soil, proper usage and the overall general condition. The most common maintenance items include the removal of accumulated soil and addition of gravel/rock. In vegetated areas where access is anticipated to be minimal, turf mats or cattle guards , or prop rietary products such as mud mats may be installed primarily to protect vegetation and provide a stabilized entrance. These materials will be inspected for damage and will be maintained as needed. Sediment Control Log (also known as an erosion log if using CDOT Specifications): A sediment control log consists of a net or geotextile fabric filled with straw, excelsior, wood mulch , or other fillers. Sediment control log applications include, but are not limited to, slope stabilization, perimeter control, check dams in swales, back of curb protection and temporary secondary containment for stockpiles, materials storage, or masonry. Sediment control logs reduce water velocity allowing sediment to accumulate on the upgradient side of the log. The basic installation for a net wrapped s ediment control log is to prepare a shallow trench and secure the log in the trench using a stake or landscape pin. Logs should be installed based on the manufacturer’s directions. Logs should be inspected for proper installation, structural integrity and sediment accumulation. A log that has been flattened out of round may not need to be replaced if they remain sufficient to function appropriately on the upgradient side of the log. Maintenance may include repairing or replacing damaged logs and removing accumulated sediment as specified by the control measure detail. Construction Fencing/Construction Markers (CF/CMK): Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 Construction fencing and/or construction markers will be utilized to delineate the limits of disturbance and may consist of orange plastic fencing, rope and t -posts, spray paint, staking, or other alternative markers as appropriate to site conditions and constraints. In some cases, perimeter sediment control measures may also double as a construction marker. CF/CMK is used to delineate where disturbances are permitted and to restrict access to unpermitted areas, especially s ensitive areas that are not within the limits of disturbance. CF/CMK will be installed as needed prior to mobilization to a given area on the Project and will remain in place where needed until final stabilization measures have been implemented. CF/CMK will be inspected for damage that renders the CM ineffective such as torn plastic fencing, severed ropes, or removed stakes. Maintenance may include repairing or replacing damaged or removed CF/CMK. Additional control measures may be added as site conditions change and will be identified in the SWMP prior to installation. b) Non-Structural Control Measures: Non-structural control measures are those practices which, when implemented, will minimize erosion and sediment or other pollutant transport. Practices implemented at this site include interim stabilization practices, permanent stabilization practices (see Tab 8), and site-specific scheduling for implementation of the practices, as well as site management practices, preventative maintenance, and personnel training. The potential non-structural control measures for the project are described below. Specific locations for control measure implementation at the site are indicated on the Site Map, provided in Tab 2. Tab 6 provides the installation details for each control measure identified. Mulching : Crimp mulching uses hay or straw material that is machine crimped into the soil to provide stability. Hydromulching uses fiber mulch mixed with water and sprayed onto soil to provide stability. Hydromulching mixtures also often contain a tackifier to better bond the fiber mulch together and to the soil. Mulching may be used on its own as a temporary soil stabilization method, or in conjunction with seeding for final stabilization. Mulch functions as a soil stabilizer by decreasing the velocity of sheet flow. Crimp mulch may be hay or cereal grain straw. Crimp mulch will likely be crimped into the soil using either a drill seeder or notched disk plow to the minimum depth of two inches and a maximum depth of four inches. To maximize effectiveness crimping equipment must run parallel to the contours of the land. Crimp mulch may not be appropriate for slopes that are equal to or greater than 3:1 or in areas with hard or rocky soil in which the crimper cannot penetrate. Hydromulch is better suited to areas with steeper slopes, difficult to access areas, and areas with hard or rocky soils. Inspections should look for areas where mulch is missing, thin or for areas where erosion has occurred. Maintenance items may include re- grading as necessary and reapplying as appropriate. Seed and S tabilization (Temporary and Permanent Ground Cover): Seeding involves the mechanical or hand application of specific seed mixes appropriate for the site location and soil type. Seeding provides plant growth to stabilize the soil reducing the likelihood of erosion or sediment transport. As soon as practical, after the complet ion of construction activities, soil should be properly prepared and seeded. The choice of seed mix will dictate application rates and methods. Seeding should always be accompanied by an additional control measure, such as mulching or tackifying, to protect the seed and soil from erosion during the germination and growth process. Seed areas will be inspected to ensure that the soil stabilization method (e.g., surface roughening, crimp mulch, etc.) was applied correctly and has not been compromised. The area will also be inspected for erosion and/or sediment deposition. Maintenance items may include re-grading and seeding bare or areas of thin vegetative growth and/or adding additional control measures as appropriate. If seeding cannot be accomplished due to seasonal or other constraints, temporary stabilization, such as mulch and mulch tackifier will be used. Additional discussion concerning temporary stabilization may be found in Section c in this Tab . Erosion Control Blankets (ECBs) and Turf Reinforcement Mats (TRMs): Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 ECBs/TRMs are sheets of straw, excelsior, coconut, manmade fiber, or combination thereof, usually contained between layers of netting to provide structural integrity. ECBs/TRMs function by providing ground cover that reduces erosive action. TRMs are able to handle higher levels of concentrated flows and are used mainly in channel applications. ECBs and TRMs may be used in conjunction with other velocity reducing control measures . ECB/TRM applications include, but are not limited to, slope and swale protection. ECBs can also optionally be used in cases where mulch would provide sufficient protection of the seedbed, but hydromulching or crimp mulching cannot or should not be used due to access limitations. ECBs/TRMs will be inspected for erosion underneath and at the sides of the material, sediment accumulation, rips tears and other structural problems. Maintenance may include removing sediment, re-securing material to ground and re-trenching or replacement, as needed. Street Sweeping : Soils deposited on paved surfaces will be swept or cleaned as needed to reduce the potential of sediment transport and tracking. Sweeping operations consist of scraping large quantities of sediment from pavement and/or sweeping, via hand or mechanical means to remove as much deposited sediment as possible. All streets within and immediately surrounding a construction site will be cleaned of earth material when sediment has been deposited on the roadway and is being tracked off site. Scraped or swept material will not be deposited in the storm sewer. Sweeping and vacuuming may not be effective when soil is wet or muddy. Surface Roughening : Surface roughening consists of grooves or tracks installed in the soil surface, along the contours (not up and down the slope which promotes erosion). This is a temporary soil stabilization technique that works well in areas that will remain inactive for a short time. Surface roughening works by reducing water velocity and promoting infiltration, thus decreasing the potential for erosion to occur. Any disturbed areas with no construction activity planned for longer than 14 days may be surface roughened. This may include areas where scheduling prevents the immediate implementation of final stabilization practices, the sides of stockpiles or other slopes. Surface roughening may be applied by creating a continuous furrow along the contours . This can be done with the teeth on a loader bucket, ripping, disking or plowing equipment. Surface roughening can also be created by running tracked equipment up and down the slope creating track marks along the contour. Inspection of surface roughened areas would include proper implementation, structural integrity and areas of erosion or sediment accumulation. Maintenance for surface roughening may include re-applying the technique or installation of new or additional control measures . Protection of P re-existing V egetation: Protection of existing vegetation on a construction site can be accomplished through installation of a construction fence around the area requiring protection. In cases where upgradient areas are disturbed, it may also be necessary to install perimeter controls to minimize sediment loading to sensitive areas such as wetlands. Existing vegetation may be designated for protection to maintain a stable surface cover as part of construction phasing, or vegetation may be protected in areas designated to remain in natural condition under post -development conditions (e.g., wetlands, mature trees, riparian areas, open space). A 50 horizontal foot buffer of pre-existing vegetation or equivalent controls must be maintained between work areas and receiving waters unless infeasible. Maintenance may include removing sediment by hand, replacing construction fence or other plastic fencing used to limit access. If any damage were to occur to a vegetative buffer, a new or additional control measure should be considered and the SWMP will be updated to document as to why the vegetation could not be left undisturbed . Vegetation & Topography (VT): In limited disturbance areas, not installing a control measure (CM) may be the best approach to minimize sediment transport off site. This is based on the concept that shallow overland flow may pick -up and transport sediment that is then dropped out within a vegetative buffer and installation of a downgradient physical CM is an unnecessary effort, expense, and disturbance that increases the amount of site restoration. VT as a CM was developed using a two -dimensional physically based and spatially distributed computer model with the following inputs and assumptions: Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 • Input – Site grade slopes. Assumption - Site grade slopes 10% or less allow shallow overland flow. • Input - Vegetation cover density (surface roughness) represented by Mannings ‘n’. • Input - Rainfall event specific to the project site for ECM design, typically a 5 -year 30-minute storm. • Input - Hydrologic Soil Group (HSG) for the disturbance and buffer area, typically obtained from the National Resource Conservation Service Web Soil Survey, online. • Assumption - No upgradient or disturbance area concentrated flow paths through construction site. • Assumption – 80% sediment removal, typical of sediment reduction targets for physical CMs is acceptable. • Assumption - No construction traffic or disturbance activity within the vegetation buffer • Requirement - The required vegetation buffer must be in the construction project limits and controlled by PSCo via written agreement with landowner, ownership, or easement). The inputs above (vegetation cover, slope, soil type, and rainfall) can be conservatively collapsed into a simple table showing that for a given rainfall, the four different soil types (HSG A to D) require four different minimum vegetation buffer lengths for sediment to settle out of the stormwater sheet flow. This vegetation buffer distance table is to be referenced by field crews and used in combination with the HSG data provided on the SWMP drawings. The rainfall and soil data will be specific to each project. The VT will have to be inspected to verify that sediment is not being transported beyond the buffer or project control area. In the event that the VT CM is not providing the level of sediment settling necessary, physical CMs may need to be installed or practices upgradient of the VT buffer modified. It is expected that the thin layer of sediment deposited in the VT buffer should not be removed. All control measure type modifications and movement are to be noted on the SWMP Site Map s. A comprehensive design guideline, citing good engineering, hydrologic, and pollutant control practices, principles and criteria is contained in the control measures details located in Tab 2 and 6. Wind Erosion Control: Wind erosion and dust control may be necessary if wind is transporting soil within or off site. Wind erosion control functions to stabilize the soil surface reducing the potential for wind erosion. Wind erosion control consists of applying water and/or other dust palliatives as necessary to prevent or alleviate erosion by the forces of wind. Covering small stockpiles or areas is an alternative to applying water or other dust palliatives. If needed, a soil tackifier can be applied to control wind erosion. Disturbed areas should be inspected for obvious signs of wind erosion and control measures implemented, if needed. Areas with wind erosion controls in place should be inspected for structural integrity and coverage and repaired or replaced as appropriate. Training : Employees and the contractor will be trained on good housekeeping, the proper use and storage of materials, and site management practices. PSCo construction supervisors and project managers participate in stormwater training on the company’s learning management system. Additionally, lead stormwater management supervisors have given trainings to multiple companies that work frequently for PSCo. PSCo also requires all of its SWMP developers, erosion control measure installers, and stormwater inspectors to hold either a CISEC or CPESC certification or are in training for either of these two certifications . Site Management Practices : Good housekeeping will be used to keep potential areas where pollutants exist clean and orderly. Containers, drums, and bags will be stored away from direct traffic routes to reduce the risk of accidental spills. Stack containers according to manufacturer’s instructions to avoid damaging the containers from Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 improper weight distribution. Containers will be stored on pallets or similar devices to prevent corrosion of containers that results from containers coming in contact with moisture on the ground. Liquids will be stored within curbed areas or secondary containment. c) Other Specific Control M easures Used to meet Effluent Limitations (§I.B.1.a.i and ii): Additional specific controls that must meet the following requirements: • Soil Compaction – Soil compaction must be minimized for areas where infiltration control measures will occur or where final stabilization will be achieved through vegetative cover. If compaction does occur in areas where final stabilization will be achieved through vegetative cover, then decompaction of the soil must be completed prior to planting. • Topsoil Preservation – Unless infeasible, topsoil must be preserved for those areas of a site that will utilize vegetative final stabilization. Preserved topsoil can be left in place or stockpiled. Topsoil preservation measures may include the following: ▪ Limit construction disturbance areas, including those used for access by installing construction fence or other means to limit impacts to existing topsoil. • In areas of grading or excavation, strip and segregate topsoil separately from other excavated materials. • In areas with construction traffic where topsoil is likely to mix with subsoil, strip and stockpile topsoil. • Minimize D isturbances – D isturbances will be minimized to the extent feasible, especially on steep slopes. • Temporary Stabilization – Temporary stabilization must be implemented for earth-disturbing activities on any portion of the site where earth-disturbing construction activity has permanently ceased, or temporarily ceased for more than 14 calendar days. Temporary stabilization methods may include, but are not limited to, tarps, soil tackifier, and hydroseed and although not specifically outlined in the permit may also include temporary hard surfaces . The permittee may exceed the 14-day schedule when either the function of the specific area of the site requires it to remain disturbed, or, physical characteristics of the terrain and climate prevent stabilization. The SWMP must document the constraints necessitating the alternative schedule, provide the alternate stabilization schedule, and identify all locations where the alternative schedule is applicable on the Site Maps . • Minimize Dust – On areas of exposed soil, minimize dust through the appropriate application of water or other dust suppression techniques. Water application must be conducted in a manner to prevent discharge offsite unless authorized by a separate CDPS or NPDES permit. See the Wind Erosion Control non-structural control measure in the preceding section. Other controls related to final stabilization, bulk storage , materials management , and corrective actions and releases are covered in other sections of this SWMP. d) Documented Use Agreement (§I.C.2.a.vi): All control measures planned for the PSCo project are within the project limits/construction limits . (Note: There may be nearby control measures installed for another project; however, they are not being utilized by PSCo as a control measure) Tab 6 Control Measure Specifications and Maintenance Requirements (Control Measure Details) Memo Date: Thursday, April 27, 2023 Project: Xcel Tline: Pathways Segment 3 Cheyenne County Build To: Control Measure Details From: Brian Brown, PE - HDR Subject: Use of Vegetation & Topography (VT) instead of structural erosion Control Measures (CM) This memo describes the specific conditions for which the installation of an erosion Control Measure (CM) is not recommended based on site conditions. Under certain conditions, not installing a CM may be the best approach to minimize sediment transport off site. This is based on the concept that shallow overland flow may pick-up and transport sediment that is then dropped out within a vegetative buffer depending on a variety of site conditions. Use of VT instead of a structural CM is dependent on the following factors: • Rainfall – Rainfall intensity impacts the buffer distance. The rainfall rate across the site has been calculated to be calculated 1.19” to 1.25” in a 5-year, 30-minute storm. A 1.25” 5-year, 30-minute storm was utilized for model inputs. This rainfall depth is incorporated in the Table 1 distances. • 80% sediment removal – structural CMs target 80% sediment removal. Actual removal rates vary but have been shown to be less than 80% in many studies. The 80% removal rate is one basis for the VT buffer distances reported in Table 1. • Disturbance area does not have concentrated flow – This approach is based on sediment dropping out while suspended in an overland sheet flow condition. If there is concentrated flow prior to or due to construction, i.e. rill erosion across the work/disturbance area that continues down -gradient and off-site, then structural CMs are recommended. • Low slope – local slope of the site impacts velocity, flow concentration, and other factors. Use VT should not be considered for slopes exceeding 10%. • Soil Type – Soil type impacts likelihood of soil being transported in sheet flow. The larger the soil particles, i.e. sand, the harder to pick-up and transport. The smaller the particle, i.e. clay, the longer the transport distance. The NRCS predominant Hydrologic Soil Group (HSG) soil types for the project area are A and B. The hydrologic soil groups (HSG) are A – D and as follows: o A – sand or silty sand, High infiltration rate o B – sandy silt, moderately high infiltration rate o C – clayey silt, moderate to low infiltration rate August 6, 2024 August 6, 2024Xcel 6584 MITC-UTER Murray Yard o D – clay, low infiltration rate • Vegetation cover – The vegetation cover (surface roughness) was accounted for in the VT model runs and found to provide similar buffer distances, therefore the most conservative vegetation density is reflected in Table1. • Vegetation Buffer - The buffer distance measurement is along the flow direction, and measured from the limit of the work zone to the limit of the utility easement/ROW. Vegetation buffer outside of the ROW may not be utilized for the required buffer distance. Due to the project area, there is adequate area for sediment settling on-site. • The use of this VT approach may be applied to linear and larger area disturbances that meet the parameters described in this memo. • Table 1 results below include a 15% buffer beyond calculated model buffer distances. Utilize Table 1 below for VT buffer distances. Buffer distances are an extrapolation of the ¾” and 1” rainfalls to a 1.25” rainfall. VT Buffer Soil Buffer Distance (ft) A 3 B 8 C 34 D 66 Maintenance: In the same manner that using existing conditions as a CM does not require installation of a CM, there is no maintenance of this CM. VT is either adequate or structural CMs should be installed. Inspection: Like structural CMs, the area down gradient of a VT CM should be walked and observed for the following which indicate that VT may not be adequate: • signs of new rill erosion in work area or immediately down gradient of work area • signs of sediment deposition well beyond the expected buffer distance or nearing area not controlled by Xcel property lease • observations of work area or up gradient areas that are creating concentrated flow through and down gradient of the work area. • Observe and discuss with contractor potential construction practices that could promote sheet flow and infiltration to minimize stormwater runoff from work area. In the event that VT is inadequate to keep sediment on site at any local area, that local area mu st immediately have a structural down gradient CM installed, a t a minimum. Sediment Control Log is the expected control measure. Site conditions will dictate actual CM to be used. Note: Sediment Control Logs cannot be used in across swales or drainageways. Hydrologic Soil Group for the site is type C. STABALIZED STAGING AREA MATERIAL TRAILER MATERIAL TRAILER DESCRIPTION: STABILIZED STAGING AREA IS A PORTION OF THE STAGING YARD THAT IS ANTICIPATED TO BE THE MOST HEAVILY TRAFFICKED. TOPSOIL IS TO BE STRIPPED AND STOCKPILED WITH AGGREGATE PLACED FOR TOPSOIL PRESERVATION. DESIGN, INSTALLATION, MAINTENANCE: THE LAYOUT BELOW IS AN EXAMPLE OF HOW AN SSA CAN BE SETUP. EXACT LAYOUT WILL VARY BASED ON EXISTING SITE CONDITIONS AND THE NATURE OF THE WORK. LAYOUT IS TO BE ADDED TO THE SWMP DRAWINGS ONCE CONSTRUCTED. INSPECT ALL CONTROL MEASURES IN THE SSA TO ENSURE THEY ARE FUNCTIONING PROPERLY. REPAIR OR REPLACE AS NECESSARY. ADDITIONAL NOTES: 1. SSA IS TO BE FIELD FIT BASED ON SITE CONDITIONS AND LAYOUT SHOWN IN SWMP DRAWINGS. 2. SSA IS TO BE AN AGGREGATE SURFACE PLACED AFTER TOPSOIL STRIPPED AND STOCKPILED ON SITE. 3. TOPSOIL DEPTH WILL BE DETERMINED BY GEOTECHNICAL REPORTS OR BY QUALIFIED STORMWATER MANAGER IN THE FIELD. 4. AFTER STAGING YARD IS NO LONGER IN USE, AGGREGATE WILL BE REMOVED AND TOPSOIL REPLACED AND LEFT IN A SURFACE ROUGHENED STATE. SSA VTC EM P L O Y E E P A R K I N G DUMPSTER JOB TRAILER PORTA POTTY 15,000 SF SSA BF BF ACCESS TO REMAINDER OF STAGING YARD SF SP CONTROL MEASURE LEGEND BOUNDARY FENCE OR PERIMETER CONTROL SILT FENCE STABALIZED STAGING AREA STOCK PILE VEHICLE TRACKING CONTROL SSA SP VTC SF BF FODS LLC | The Mud Stops Here | GetFods.com | 1-844-200-3637 TRACKOUTCONTROL MAT Technical Data Sheet GENERAL INFORMATION The FODS Composite trackout control system is designed to be used as a temporary construction entrance which provides site access while minimizing sediment leaving the site. The top surface of the FODS mat is a geometric pattern formed in the shape of pyramids. The mats are unidirectional and are meant to have the staggered pyramids in the direction of travel. Individual mats are connected together with hardware to form various configurations to fit your jobsite. TYPical installation layouts Each site must be evaluated to determine the proper layout, width, and duration of the FODS Trackout Control System (FTCS) based site conditions, entry and exit egress, traffic levels, site soil conditions, and ability to the maintain trackout system. Outlined below are a number of common layouts, the mats are unidirectional and due to the versatility of the mats design the FTCS can be engineered to fit the needs of any site: FEATURES & BENEFITS • Re-Usable • Increased Effectiveness at Reducing Site Trackout • U/V Stable • Highly Visible • Easy to Clean • Economical • Recyclable / Reduces Waste • Extreme Durability • Rapid Installation & Removal • Excavation not required • Chemical Resistant • Rock-less • Reduces Waste • Easy and efficient to transport from site-site • Mat Size: 12’(w) x 7’ (l) x 3 3/4” (t) (2 7/8” pyramid height) • Mat Weight: 430lbs • Pallet Size: 8-Mats • Truck-Load: 96-Mats • Hardware boxes are contained within the palletized mats FODS 1x4 FODS 1x4T FODS 2x4 FODS 1x7T FODS 2x7 FODS LLC | The Mud Stops Here | GetFods.com | 1-844-200-3637 COMMON USERS • Heavy Civil Construction • Urban Construction / Urban In-Fill • Bridge & Highway Projects • Residential Construction • Land Development • Forestry • Energy Exploration • Oil & Gas Pipeline • Electrical Power-line • Temporary Event Access • Landfill & Waste Management • Mining FODS Trackout Control Mat - Technical Data Sheet Suitable Installation Substrate • Un-Excavated Soil • Excavated Soil (Min CBR: 4) • Asphalt • Concrete FODS Trackout Control System should be installed near the site exit point, as close to the location where vehicles enter the roadway as is safely as possible. FODS mats should not be installed at a low point on the site where water will pool. FODS Anchoring Systems Cleaning / Maintenance ***Before using earth anchors, call 811 for locates to mark underground utilities*** WARNINGS • Caution is to be used when crossing mats with metal tracked equipment.• Equipment with aggressive metal tracks should not cross mats• Do not drag metal equipment across mats• Do not use mats for bridging • Skid-steer broom attachment • FODS Shovel• Street Sweeper (requires adjusted bristle head• Pressure Washer (must have ability to contain water)• Water Truck (must have ability to contain water) Mats should be cleaned once 2.5” of sediment has built up in the lane of travel. • Form-Stakes (18” or 24”) • Cable Earth Anchor • All-Thread Earth Anchor • Concrete Sleeve Anchor (asphalt) STOCKPILE PROTECTION DESCRIPTION: STOCKPILE PROTECTION IS USED TO MINIMIZE EROSION AND SEDIMENT TRANSPORT FROM SOIL STOCKPILES. DESIGN AND INTALLATION: LOCATE STOCKPILES AWAY FROM DRAINAGE SYSTEM COMPONETS, INCLUDING STORM SEWERS. CHOOSE STOCKPILE LOCATIONS THAT WILL REMAIN UNDISTURBED FOR THE LONGEST PERIOD OF TIME. INSTALL CONTROL MEASURES ON DOWNSLOPE SIDE OF STOCKPILE. STABILIZE STOCKPILE WITH SURFACE ROUGHENING, TEMPORARY SEEDING AND MULCHING, OR EROSION CONTROL BLANKETS. MAINTENANCE: INSPECT CONTROL MEASURES TO ENSURE THEY ARE FUNCTIONING PROPERLY AND NO SEDIMENT HAS BEEN DISCHARGED FROM THE STOCKPILE AREA. REPAIR AND REPLACE CONTROL MEASURES AS NEEDED. RESEEDING OR REAPPLICATION OF MULCH MAY BE NECESSARY. ADDITIONAL NOTES: 1. TOPSOIL STRIPPING WITHIN THE PROPOSED STOCKPILE FOOTPRINT IS NOT REQUIRED IF TOPSOIL WILL REMAIN AFTER STOCKPILE REMOVAL. 2. UNCOVERED STOCKPILE TO HAVE A MAXIMUM HEIGHT OF 6' AND MAXIMUM SIDE SLOPES OF 3:1. STOCKPILE WILL BE SEEDED AND MULCHED WITHIN 14 DAYS OF PLACEMENT IF PILE IS TO REMAIN DORMANT FOR THAT AMOUNT OF TIME OR LONGER. 3. PILE FOOTPRINT TO BE SURFACE ROUGHENED, SEEDED, AND MULCHED ONCE PILE IS REMOVED. DOWN-GRADIENT SCL OR SF TO REMAIN UNTIL VEGETATION REACHES REQUIRED STABILIZATION DENSITY. 4. DOWN-GRADIENT STOCKPILE CMs MAY BE ELIMINATED IF ANOTHER DOWN-GRADIENT CM MAKES STOCKPILE CMs REDUNDANT. SP 3:1 MAX SIDE SLOPE MAX HEIGHT = 6' ORSCL SF 3' (TYP.) DETERMINE NUMBER OF SECTIONS REQUIRED BASED ON SITE CONDITIONS, ANTICIPATED VEHICLE ACCESS, AND JURISDICTIONAL REQUIREMENTS FOR VTC SIZING. MINIMUM LENGTH REQUIRED IS 20'. INSTALL ADDITIONAL SEGMENTS AS NEEDED TO MINIMIZE TRACKOUT. INSTALL TRACKING PAD WHERE IDENTIFIED ON THE ATTACHED SITE MAPS WITH TAB SIDE UP. ANCHORING IS TYPICALLY NOT REQUIRED DUE TO THE WEIGHT OF THE TRACKING PADS, THOUGH IF DESIRED, DRIVE REBAR STAKES INTO THE UNDERLYING SOIL AT CONNECTION POINTS WHERE TRACKING PADS ARE INSTALLED ON UNPAVED SURFACES. INSTALL PERIMETER CONTROL, SUCH AS CONSTRUCTION FENCE, ALONG EDGE OF TRACKING PAD TO PREVENT DRIVE-AROUND, FORCING ALL VEHICLES AND EQUIPMENT TO UTILIZE STABILIZED CONSTRUCTION ACCESS. WHERE NECESSARY, ROUTE RUNOFF FROM UP-GRADIENT DISTURBED AREAS AWAY FROM STABILIZED ACCESS WITH DIVERSION. IF UNABLE TO DIVERT SURFACE FLOW FROM CROSSING TRACKING PAD, USE CMs TO MANAGE SEDIMENT LADEN WATER. INSTALLATION OF TRACKING PAD ON GRADES LESS THAN 10% RECOMMENDED TO MINIMIZE VTC MOVEMENT DUE TO VEHICLE BRAKING OR ACCELERATION. INSTALLATION OF PADS ON STEEPER GRADES WILL REQUIRE CONTRACTOR OPERATIONAL SAFETY REVIEW AND LIKELY REQUIRE ADDITIONAL ANCHORING AND INCREASED MAINTENANCE. TRACKING PAD VEHICLE TRACKING CONTROL DESCRIPTION FLEXIBLE TRACKING PAD MATS ARE MADE TO FIT THE CONTOUR OF THE LAND. EACH SECTION, 12' BY 12', IS ROUGHLY 2,200 LBS AND CAN TYPICALLY BE INSTALLED, MAINTAINED, AND REMOVED WITH ON-SITE EQUIPMENT. TRACKING PADS CAN BE USED TO PROVIDE A STABILIZED CONSTRUCTION ACCESS/EGRESS POINT TO REPLACE TRADITIONAL ROCK VTC. THIS REUSABLE PRODUCT IS PARTICULARLY BENEFICIAL FOR PAVED CONSTRUCTION ENTRANCES. INSTALLATION OF THE TRACKING PAD RESULTS IN SUBSTANTIALLY LESS DISTURBANCE COMPARED TO TRADITIONAL ROCK VTC AS THE TRACKING PAD IS INSTALLED ON THE EXISTING SURFACE AND DOES NOT REQUIRE GRADING OR EXCAVATION. MAINTENANCE OF THE TRACKING PAD IS SIMPLE TO PERFORM USING SMALL CONSTRUCTION EQUIPMENT. MAINTENANCE: INSPECTION FREQUENCY PER LOCAL JURISDICTION REQIUREMENT OR SITE SWMP. TRACKING PAD REQUIRES MAINTENANCE WHEN SECTIONS BECOME DISPLACED OR WHEN SEDIMENT FILLS HALF OF THE TRACKS TO A DEPTH EQUAL TO 50% OF THE MAXIMUM TRACK HEIGHT. LIFT MATS TO REMOVE LOOSE DEBRIS AND REPLACE MATS IN ORIGINAL LOCATION. RESET MISALIGNED OR DISPLACED MATS. REMOVE ANY SEDIMENT TRACKED FROM SITE ONTO PAVED SURFACES IMMEDIATELY. ADDITIONAL NOTES: REVIEW LOCAL JURISDICTION REQUIREMENTS FOR CM TYPES AND INSTALLATION METHODS. ENSURE APPROVAL FROM JURISDICTION PRIOR TO USE. DESIGN AND INSTALLATION VTC 12’ 11’ 5’ 8’8’ Existing Roadway Plan Flares to be attached to left and right sides of mat(s) NOTES 1. NO PICK (ROWS) 2. 12’x12’ EXPANDABLE AS NECESSARY See note 1 Do not install over jagged/rocky ground or soil May be installed over uneven ground Preferably installed over level ground INSTALLATION -PLACE MATS WITH TAB SIDE UP -NO TIE DOWN REQUIRED MAINTENANCE LIFT MATS AND REMOVE DEBRIS/ LAY MATS BACK IN PLACE 5/2/20188311 Pontiac St. Commerce City, CO, 80022 Date:Sheet:1 of 1 Tracking Pad Details CDOT APL Reference No. 3781-14 Soil Stabilization Granules for Flexible Application and Effective Erosion Control Seed Aide® Aero™ may be applied dry or hydraulically, making it a versatile and cost-effective solution where conventional erosion control equipment access is limited or unavailable. It is ideal for a range of conditions, including remote sites, dryland reclamation, post-fire reclamation, pipeline restoration, drilling pads and aerial applications. Seed Aide Aero Advantages: • Soil binding—upon wetting, the mulch granules expand and release linear anionic soil flocculant to eliminate soil particles from water runoff, reducing sediment loss • Productive seed-to-soil bond—the polysaccharide polymers create an effective bond to hold seeds in place, creating better overall vegetation distribution • Better germination—the expanded cellulose/wood granules hold water, reduce soil surface evaporation and deliver the biostimulant to enhance germination and growth Soil Stabilization Granules Can be applied aerially, via spreader, by hand or hydraulically Granules release the proprietary Seed Aide Aero formulation to help keep soil in place, increase moisture retention and promote vegetation establishment Smaller-scale jobs can easily be completed using a jet-agitated hydroseeder Green Design Engineering™ is a holistic approach that combines agronomic and engineering expertise with advanced technologies to provide cost-effective and earth-friendly solutions. Profile strives to deliver Green Design Engineering across our team of consulting professionals, innovative products and educational resources. PS3 is a free, comprehensive 24/7 online resource you can use to design a project and select the right products that address both the physical and agronomic needs of your site. It will help you develop holistic, sustainable solutions for cost-effective erosion control, vegetation establishment and subsequent reductions in sediment and other pollutants from leaving disturbed sites. Because good plans start with the soil, PS3 offers free soil testing to ensure this critical step is considered. To access the site, design your project and take advantage of a free soil analysis, visit profileps3.com. GREEN DESIGN ENGINEERING ™ EARTH-FRIENDLY SOLUTIONS FOR SUSTAINABLE RESULTS™PHYSICAL PROPERTIES*TEST METHOD TESTED VALUE Bulk Density ASTM D2978 26 ± 2 lb/ft3 (416.5 ± 32 kg/m3) Water Holding Capacity ASTM D7367 ≥ 500% Material Color Observed Green PERFORMANCE PROPERTIES* Cover Factor1 (5 in/hr event)Large Scale Testing2 ≤ 0.18 % Effectiveness3 Large Scale Testing2 ≥ 82% Functional Longevity4 ASTM D5338 ≤ 3 months ENVIRONMENTAL PROPERTIES* Ecotoxicity EPA 2021.0 48-hr LC50 > 100% Biodegradability ASTM D5338 Yes * When uniformly applied at a rate of 2,250 pounds per acre (2,520 kilograms/hectare) under laboratory conditions. 1. Cover Factor is calculated as soil loss ratio of treated surface versus an untreated control surface. 2. Large scale testing conducted at Utah Water Research Laboratory. For specific testing information please contact a Profile technical service representative at 800-508-8681 or +1-847-215-3464. 3. % Effectiveness = One minus Cover Factor multiplied by 100%. 4. Functional Longevity is the estimated time period, based upon ASTM D5338 testing and field observations, that a material can be anticipated to provide erosion control and agronomic ben- efits as influenced by composition, as well as site-specific condi- tions, including; but not limited to – temperature, moisture, light conditions, soils, biological activity, vegetative establishment and other environmental factors. Seed Aide® Aero™ Technical Data: INSTALLATION Examine substrate and conditions where materials will be applied. Apply product to geotechnically stable slopes that have been designed and constructed to divert runoff away from the face of the slope. Do not proceed with installation until satisfactory conditions are established. Strictly comply with manufacturers installation instructions and recommendations. Use approved mulch-spreading machines. To achieve performance characteristics as documented, granules must be activated by water. DIRECTIONS FOR USE Seed Aide Aero should be applied at recommended rates shown below: SA-02 02/19 Application Rate: 1,000 lb/ac (1,120 kg/ha)Application Rate: 3,000 lb/ac (3,360 kg/ha) COMPOSITION Cellulose Fibers– 70% Thermally Processed* Virgin Wood Fibers – 22% Wetting Agent - including linear anionic soil flocculants and high-viscosity colloidal polysaccharide polymers - 8% Formulation pelletized and granulated to form Seed Aide Aero granules *Heated within a pressurized vessel to a temperature greater than 380 degrees Fahrenheit (193 degrees Celsius) for 5 minutes at a pressure greater than 50 psi (345 kPa) in order to be Thermally Refined®/Processed and to achieve phyto-sanitization. For technical information or distribution, please call 800-508-8681. For customer service, call 800-366-1180. For warranty information, visit profileproducts.com. 750 W. Lake Cook Road • Suite 440 Buffalo Grove, IL 60089 profileproducts.com © 2019 PROFILE Products LLC. All rights reserved. Profile, Thermally Refined and Seed Aide are registered trademarks of PROFILE Products LLC. Aero, Solutions for your Environment, Green Design Engineering and Earth-Friendly Solutions for Sustainable Results are trademarks of PROFILE Products LLC. SLOPE GRADIENT/CONDITION ENGLISH SI ≤ 4H to 1V 450-1,000 lb/ac 500-1,120 kg/ha > 4H to 1V and ≤ 3H to 1V 1,000-1,500 lb/ac 1,120-1,680 kg/ha > 3H to 1V and ≤ 2H to 1V 1,500-3,000 lb/ac 1,680-3,360 kg/ha Slope interruption devices or water diversion techniques are recommended when slope lengths (3H:1V) exceed 30 feet (9.1 m). PACKAGING Bags: Net Weight - 50 lb (22.7 kg) Bulk Sack: Net Weight - 1,000 lb (453.6 kg) UV and weather-resistant plastic bags Pallets: 40 bags/pallet, 1 ton (907 kg)/pallet Weather-proof, stretch-wrapped with UV resistant pallet cover BOUNDARY FENCE DESCRIPTION BOUNDARY FENCE IS USED AS A PERIMETER CONTROL TO DESIGNATE PROJECT LIMITS AND PROTECT SENSITIVE NATURAL AREAS SUCH AS OPEN SPACE, WETLANDS, AND RIPARIAN AREAS. MAINTENANCE: MAINTAIN, REPLACE, AND REPAIR AS NEEDED TO ENSURE THERE IS NO DAMAGE TO TEE POSTS, LINE, AND FLAGGING. MAINTAIN LINE TENSION SO LINE SPACE BETWEEN LINE AND GROUND IS AT LEAST 3'. ADDITIONAL NOTES: REVIEW LOCAL JURISDICTION REQUIREMENTS FOR CM TYPES AND INSTALLATION METHODS. LINE WITH FLAGGING ATTACHED TEE POST 10' - 15' FLAGGING SPACING, TYP 6" ± 30'± DESIGN AND INSTALLATION TEE POSTS SPACED ~30' SHALL BE USED WITH LINE CONNECTED BETWEEN AND FLAGGING ATTACHED. SEE DETAIL BELOW. EASEMENTS, WETLANDS, AND WILDIFE AREAS TO BE STAKED OUT BY SURVEYOR BEFORE PLACEMENT OF BOUNDARY FENCE. ALL EQUIPMENT USED TO INSTALL FENCING SHALL BE KEPT ON THE CONSTRUCTION SIDE OF PROJECT. BOUNDARY FENCING SHALL BE REMOVED PRIOR TO FINAL STABILIZATION AND PERMANENT SEEDING. 1. 2. 3. 4. BF Surface Roughening (SR) EC-1 November 2010 Urban Drainage and Flood Control District SR-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph SR-1. Surface roughening via imprinting for temporary stabilization. Description Surface roughening is an erosion control practice that involves tracking, scarifying, imprinting, or tilling a disturbed area to provide temporary stabilization of disturbed areas. Surface roughening creates variations in the soil surface that help to minimize wind and water erosion. Depending on the technique used, surface roughening may also help establish conditions favorable to establishment of vegetation. Appropriate Uses Surface roughening can be used to provide temporary stabilization of disturbed areas, such as when revegetation cannot be immediately established due to seasonal planting limitations. Surface roughening is not a stand-alone BMP, and should be used in conjunction with other erosion and sediment controls. Surface roughening is often implemented in conjunction with grading and is typically performed using heavy construction equipment to track the surface. Be aware that tracking with heavy equipment will also compact soils, which is not desirable in areas that will be revegetated. Scarifying, tilling, or ripping are better surface roughening techniques in locations where revegetation is planned. Roughening is not effective in very sandy soils and cannot be effectively performed in rocky soil. Design and Installation Typical design details for surfacing roughening on steep and mild slopes are provided in Details SR-1 and SR-2, respectively. Surface roughening should be performed either after final grading or to temporarily stabilize an area during active construction that may be inactive for a short time period. Surface roughening should create depressions 2 to 6 inches deep and approximately 6 inches apart. The surface of exposed soil can be roughened by a number of techniques and equipment. Horizontal grooves (running parallel to the contours of the land) can be made using tracks from equipment treads, stair-step grading, ripping, or tilling. Fill slopes can be constructed with a roughened surface. Cut slopes that have been smooth graded can be roughened as a subsequent operation. Roughening should follow along the contours of the slope. The tracks left by truck mounted equipment working perpendicular to the contour can leave acceptable horizontal depressions; however, the equipment will also compact the soil. Surface Roughening Functions Erosion Control Yes Sediment Control No Site/Material Management No EC-1 Surface Roughening (SR) SR-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Maintenance and Removal Care should be taken not to drive vehicles or equipment over areas that have been surface roughened. Tire tracks will smooth the roughened surface and may cause runoff to collect into rills and gullies. Because surface roughening is only a temporary control, additional treatments may be necessary to maintain the soil surface in a roughened condition. Areas should be inspected for signs of erosion. Surface roughening is a temporary measure, and will not provide long-term erosion control. Surface Roughening (SR) EC-1 November 2010 Urban Drainage and Flood Control District SR-3 Urban Storm Drainage Criteria Manual Volume 3 EC-1 Surface Roughening (SR) SR-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary and Permanent Seeding (TS/PS) EC-2 June 2012 Urban Drainage and Flood Control District TS/PS-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph TS/PS -1. Equipment used to drill seed. Photo courtesy of Douglas County. Description Temporary seeding can be used to stabilize disturbed areas that will be inactive for an extended period. Permanent seeding should be used to stabilize areas at final grade that will not be otherwise stabilized. Effective seeding includes preparation of a seedbed, selection of an appropriate seed mixture, proper planting techniques, and protection of the seeded area with mulch, geotextiles, or other appropriate measures. Appropriate Uses When the soil surface is disturbed and will remain inactive for an extended period (typically 30 days or longer), proactive stabilization measures should be implemented. If the inactive period is short-lived (on the order of two weeks), techniques such as surface roughening may be appropriate. For longer periods of inactivity, temporary seeding and mulching can provide effective erosion control. Permanent seeding should be used on finished areas that have not been otherwise stabilized. Typically, local governments have their own seed mixes and timelines for seeding. Check jurisdictional requirements for seeding and temporary stabilization. Design and Installation Effective seeding requires proper seedbed preparation, selection of an appropriate seed mixture, use of appropriate seeding equipment to ensure proper coverage and density, and protection with mulch or fabric until plants are established. The USDCM Volume 2 Revegetation Chapter contains detailed seed mix, soil preparations, and seeding and mulching recommendations that may be referenced to supplement this Fact Sheet. Drill seeding is the preferred seeding method. Hydroseeding is not recommended except in areas where steep slopes prevent use of drill seeding equipment, and even in these instances it is preferable to hand seed and mulch. Some jurisdictions do not allow hydroseeding or hydromulching. Seedbed Preparation Prior to seeding, ensure that areas to be revegetated have soil conditions capable of supporting vegetation. Overlot grading can result in loss of topsoil, resulting in poor quality subsoils at the ground surface that have low nutrient value, little organic matter content, few soil microorganisms, rooting restrictions, and conditions less conducive to infiltration of precipitation. As a result, it is typically necessary to provide stockpiled topsoil, compost, or other Temporary and Permanent Seeding Functions Erosion Control Yes Sediment Control No Site/Material Management No EC-2 Temporary and Permanent Seeding (TS/PS) TS/PS-2 Urban Drainage and Flood Control District June 2012 Urban Storm Drainage Criteria Manual Volume 3 soil amendments and rototill them into the soil to a depth of 6 inches or more. Topsoil should be salvaged during grading operations for use and spread on areas to be revegetated later. Topsoil should be viewed as an important resource to be utilized for vegetation establishment, due to its water-holding capacity, structure, texture, organic matter content, biological activity, and nutrient content. The rooting depth of most native grasses in the semi-arid Denver metropolitan area is 6 to 18 inches. At a minimum, the upper 6 inches of topsoil should be stripped, stockpiled, and ultimately respread across areas that will be revegetated. Where topsoil is not available, subsoils should be amended to provide an appropriate plant-growth medium. Organic matter, such as well digested compost, can be added to improve soil characteristics conducive to plant growth. Other treatments can be used to adjust soil pH conditions when needed. Soil testing, which is typically inexpensive, should be completed to determine and optimize the types and amounts of amendments that are required. If the disturbed ground surface is compacted, rip or rototill the surface prior to placing topsoil. If adding compost to the existing soil surface, rototilling is necessary. Surface roughening will assist in placement of a stable topsoil layer on steeper slopes, and allow infiltration and root penetration to greater depth. Prior to seeding, the soil surface should be rough and the seedbed should be firm, but neither too loose nor compacted. The upper layer of soil should be in a condition suitable for seeding at the proper depth and conducive to plant growth. Seed-to-soil contact is the key to good germination. Seed Mix for Temporary Vegetation To provide temporary vegetative cover on disturbed areas which will not be paved, built upon, or fully landscaped or worked for an extended period (typically 30 days or more), plant an annual grass appropriate for the time of planting and mulch the planted areas. Annual grasses suitable for the Denver metropolitan area are listed in Table TS/PS-1. These are to be considered only as general recommendations when specific design guidance for a particular site is not available. Local governments typically specify seed mixes appropriate for their jurisdiction. Seed Mix for Permanent Revegetation To provide vegetative cover on disturbed areas that have reached final grade, a perennial grass mix should be established. Permanent seeding should be performed promptly (typically within 14 days) after reaching final grade. Each site will have different characteristics and a landscape professional or the local jurisdiction should be contacted to determine the most suitable seed mix for a specific site. In lieu of a specific recommendation, one of the perennial grass mixes appropriate for site conditions and growth season listed in Table TS/PS-2 can be used. The pure live seed (PLS) rates of application recommended in these tables are considered to be absolute minimum rates for seed applied using proper drill-seeding equipment. If desired for wildlife habitat or landscape diversity, shrubs such as rubber rabbitbrush (Chrysothamnus nauseosus), fourwing saltbush (Atriplex canescens) and skunkbrush sumac (Rhus trilobata) could be added to the upland seedmixes at 0.25, 0.5 and 1 pound PLS/acre, respectively. In riparian zones, planting root stock of such species as American plum (Prunus americana), woods rose (Rosa woodsii), plains cottonwood (Populus sargentii), and willow (Populus spp.) may be considered. On non-topsoiled upland sites, a legume such as Ladak alfalfa at 1 pound PLS/acre can be included as a source of nitrogen for perennial grasses. See Seed Mix at beginning of Tab 14 Soil Binders (SB) EC-3 November 2010 Urban Drainage and Flood Control District SB-1 Urban Storm Drainage Criteria Manual Volume 3 Description Soil binders include a broad range of treatments that can be applied to exposed soils for temporary stabilization to reduce wind and water erosion. Soil binders may be applied alone or as tackifiers in conjunction with mulching and seeding applications. Acknowledgement: This BMP Fact Sheet has been adapted from the 2003 California Stormwater Quality Association (CASQA) Stormwater BMP Handbook: Construction (www.cabmphandbooks.com). Appropriate Uses Soil binders can be used for short-term, temporary stabilization of soils on both mild and steep slopes. Soil binders are often used in areas where work has temporarily stopped, but is expected to resume before revegetation can become established. Binders are also useful on stockpiled soils or where temporary or permanent seeding has occurred. Prior to selecting a soil binder, check with the state and local jurisdiction to ensure that the chemicals used in the soil binders are allowed. The water quality impacts of some types of soil binders are relatively unknown and may not be allowed due to concerns about potential environmental impacts. Soil binders must be environmentally benign (non-toxic to plant and animal life), easy to apply, easy to maintain, economical, and should not stain paved or painted surfaces. Soil binders should not be used in vehicle or pedestrian high traffic areas, due to loss in effectiveness under these conditions. Site soil type will dictate appropriate soil binders to be used. Be aware that soil binders may not function effectively on silt or clay soils or highly compacted areas. Check manufacturer's recommendations for appropriateness with regard to soil conditions. Some binders may not be suitable for areas with existing vegetation. Design and Installation Properties of common soil binders used for erosion control are provided in Table SB-1. Design and installation guidance below are provided for general reference. Follow the manufacturer's instructions for application rates and procedures. Soil Binders Functions Erosion Control Yes Sediment Control No Site/Material Management Moderate Photograph SB-1. Tackifier being applied to provide temporary soil stabilization. Photo courtesy of Douglas County. EC-3 Soil Binders (SB) SB-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Table SB-1. Properties of Soil Binders for Erosion Control (Source: CASQA 2003) Evaluation Criteria Binder Type Plant Material Based (short lived) Plant Material Based (long lived) Polymeric Emulsion Blends Cementitious- Based Binders Resistance to Leaching High High Low to Moderate Moderate Resistance to Abrasion Moderate Low Moderate to High Moderate to High Longevity Short to Medium Medium Medium to Long Medium Minimum Curing Time before Rain 9 to 18 hours 19 to 24 hours 0 to 24 hours 4 to 8 hours Compatibility with Existing Vegetation Good Poor Poor Poor Mode of Degradation Biodegradable Biodegradable Photodegradable/ Chemically Degradable Photodegradable/ Chemically Degradable Specialized Application Equipment Water Truck or Hydraulic Mulcher Water Truck or Hydraulic Mulcher Water Truck or Hydraulic Mulcher Water Truck or Hydraulic Mulcher Liquid/Powder Powder Liquid Liquid/Powder Powder Surface Crusting Yes, but dissolves on rewetting Yes Yes, but dissolves on rewetting Yes Clean Up Water Water Water Water Erosion Control Application Rate Varies Varies Varies 4,000 to 12,000 lbs/acre Typ. Soil Binders (SB) EC-3 November 2010 Urban Drainage and Flood Control District SB-3 Urban Storm Drainage Criteria Manual Volume 3 Factors to consider when selecting a soil binder generally include:  Suitability to situation: Consider where the soil binder will be applied, if it needs a high resistance to leaching or abrasion, and whether it needs to be compatible with existing vegetation. Determine the length of time soil stabilization will be needed, and if the soil binder will be placed in an area where it will degrade rapidly. In general, slope steepness is not a discriminating factor.  Soil types and surface materials: Fines and moisture content are key properties of surface materials. Consider a soil binder's ability to penetrate, likelihood of leaching, and ability to form a surface crust on the surface materials.  Frequency of application: The frequency of application can be affected by subgrade conditions, surface type, climate, and maintenance schedule. Frequent applications could lead to high costs. Application frequency may be minimized if the soil binder has good penetration, low evaporation, and good longevity. Consider also that frequent application will require frequent equipment clean up. An overview of major categories of soil binders, corresponding to the types included in Table SB-1 follows. Plant-Material Based (Short Lived) Binders  Guar: A non-toxic, biodegradable, natural galactomannan-based hydrocolloid treated with dispersant agents for easy field mixing. It should be mixed with water at the rate of 11 to 15 lbs per 1,000 gallons. Recommended minimum application rates are provided in Table SB-2. Table SB-2. Application Rates for Guar Soil Stabilizer Slope (H:V) Flat 4:1 3:1 2:1 1:1 Application Rate (lb/acre) 40 45 50 60 70  Psyllium: Composed of the finely ground muciloid coating of plantago seeds that is applied as a wet slurry to the surface of the soil. It dries to form a firm but rewettable membrane that binds soil particles together but permits germination and growth of seed. Psyllium requires 12 to 18 hours drying time. Application rates should be from 80 to 200 lbs/acre, with enough water in solution to allow for a uniform slurry flow.  Starch: Non-ionic, cold-water soluble (pre-gelatinized) granular cornstarch. The material is mixed with water and applied at the rate of 150 lb/acre. Approximate drying time is 9 to 12 hours. Plant-Material Based (Long Lived) Binders  Pitch and Rosin Emulsion: Generally, a non-ionic pitch and rosin emulsion has a minimum solids content of 48 percent. The rosin should be a minimum of 26 percent of the total solids content. The soil stabilizer should be a non-corrosive, water dilutable emulsion that upon application cures to a water insoluble binding and cementing agent. For soil erosion control applications, the emulsion is diluted and should be applied as follows: o For clayey soil: 5 parts water to 1 part emulsion EC-3 Soil Binders (SB) SB-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 o For sandy soil: 10 parts water to 1 part emulsion Application can be by water truck or hydraulic seeder with the emulsion and product mixture applied at the rate specified by the manufacturer. Polymeric Emulsion Blend Binders  Acrylic Copolymers and Polymers: Polymeric soil stabilizers should consist of a liquid or solid polymer or copolymer with an acrylic base that contains a minimum of 55 percent solids. The polymeric compound should be handled and mixed in a manner that will not cause foaming or should contain an anti-foaming agent. The polymeric emulsion should not exceed its shelf life or expiration date; manufacturers should provide the expiration date. Polymeric soil stabilizer should be readily miscible in water, non-injurious to seed or animal life, non-flammable, should provide surface soil stabilization for various soil types without inhibiting water infiltration, and should not re-emulsify when cured. The applied compound should air cure within a maximum of 36 to 48 hours. Liquid copolymer should be diluted at a rate of 10 parts water to 1 part polymer and the mixture applied to soil at a rate of 1,175 gallons/acre.  Liquid Polymers of Methacrylates and Acrylates: This material consists of a tackifier/sealer that is a liquid polymer of methacrylates and acrylates. It is an aqueous 100 percent acrylic emulsion blend of 40 percent solids by volume that is free from styrene, acetate, vinyl, ethoxylated surfactants or silicates. For soil stabilization applications, it is diluted with water in accordance with manufacturer's recommendations, and applied with a hydraulic seeder at the rate of 20 gallons/acre. Drying time is 12 to 18 hours after application.  Copolymers of Sodium Acrylates and Acrylamides: These materials are non-toxic, dry powders that are copolymers of sodium acrylate and acrylamide. They are mixed with water and applied to the soil surface for erosion control at rates that are determined by slope gradient, as summarized in Table SB-3. Table SB-3. Application Rates for Copolymers of Sodium Acrylates and Acrylamides Slope (H:V) Flat to 5:1 5:1 to 3:1 2:2 to 1:1 Application Rate (lb/acre) 3.0-5.0 5.0-10.0 10.0-20.0  Polyacrylamide and Copolymer of Acrylamide: Linear copolymer polyacrylamide is packaged as a dry flowable solid. When used as a stand-alone stabilizer, it is diluted at a rate of 11 lb/1,000 gal. of water and applied at the rate of 5.0 lb/acre.  Hydrocolloid Polymers: Hydrocolloid Polymers are various combinations of dry flowable polyacrylamides, copolymers, and hydrocolloid polymers that are mixed with water and applied to the soil surface at rates of 55 to 60 lb/acre. Drying times are 0 to 4 hours. Cementitious-Based Binders  Gypsum: This formulated gypsum based product readily mixes with water and mulch to form a thin protective crust on the soil surface. It is composed of high purity gypsum that is ground, calcined and processed into calcium sulfate hemihydrate with a minimum purity of 86 percent. It is mixed in a hydraulic seeder and applied at rates 4,000 to 12,000 lb/acre. Drying time is 4 to 8 hours. Soil Binders (SB) EC-3 November 2010 Urban Drainage and Flood Control District SB-5 Urban Storm Drainage Criteria Manual Volume 3 Installation After selecting an appropriate soil binder, the untreated soil surface must be prepared before applying the soil binder. The untreated soil surface must contain sufficient moisture to assist the agent in achieving uniform distribution. In general, the following steps should be followed:  Follow manufacturer's written recommendations for application rates, pre-wetting of application area, and cleaning of equipment after use.  Prior to application, roughen embankment and fill areas.  Consider the drying time for the selected soil binder and apply with sufficient time before anticipated rainfall. Soil binders should not be applied during or immediately before rainfall.  Avoid over spray onto roads, sidewalks, drainage channels, sound walls, existing vegetation, etc.  Soil binders should not be applied to frozen soil, areas with standing water, under freezing or rainy conditions, or when the temperature is below 40°F during the curing period.  More than one treatment is often necessary, although the second treatment may be diluted or have a lower application rate.  Generally, soil binders require a minimum curing time of 24 hours before they are fully effective. Refer to manufacturer's instructions for specific cure time.  For liquid agents: o Crown or slope ground to avoid ponding. o Uniformly pre-wet ground at 0.03 to 0.3 gal/yd2 or according to manufacturer's recommendations. o Apply solution under pressure. Overlap solution 6 to 12 in. o Allow treated area to cure for the time recommended by the manufacturer, typically at least 24 hours. o Apply second treatment before first treatment becomes ineffective, using 50 percent application rate. o In low humidity, reactivate chemicals by re-wetting with water at 0.1 to 0.2 gal/yd2. Maintenance and Removal Soil binders tend to break down due to natural weathering. Weathering rates depend on a variety of site- specific and product characteristics. Consult the manufacturer for recommended reapplication rates and reapply the selected soil binder as needed to maintain effectiveness. Soil binders can fail after heavy rainfall events and may require reapplication. In particular, soil binders will generally experience spot failures during heavy rainfall events. If runoff penetrates the soil at the top of a slope treated with a soil binder, it is likely that the runoff will undercut the stabilized soil layer and discharge at a point further down slope. EC-3 Soil Binders (SB) SB-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Areas where erosion is evident should be repaired and soil binder or other stabilization reapplied, as needed. Care should be exercised to minimize the damage to protected areas while making repairs. Most binders biodegrade after exposure to sun, oxidation, heat and biological organisms; therefore, removal of the soil binder is not typically required. Mulching (MU) EC-4 June 2012 Urban Drainage and Flood Control District MU-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph MU-1. An area that was recently seeded, mulched, and crimped. Description Mulching consists of evenly applying straw, hay, shredded wood mulch, rock, bark or compost to disturbed soils and securing the mulch by crimping, tackifiers, netting or other measures. Mulching helps reduce erosion by protecting bare soil from rainfall impact, increasing infiltration, and reducing runoff. Although often applied in conjunction with temporary or permanent seeding, it can also be used for temporary stabilization of areas that cannot be reseeded due to seasonal constraints. Mulch can be applied either using standard mechanical dry application methods or using hydromulching equipment that hydraulically applies a slurry of water, wood fiber mulch, and often a tackifier. Appropriate Uses Use mulch in conjunction with seeding to help protect the seedbed and stabilize the soil. Mulch can also be used as a temporary cover on low to mild slopes to help temporarily stabilize disturbed areas where growing season constraints prevent effective reseeding. Disturbed areas should be properly mulched and tacked, or seeded, mulched and tacked promptly after final grade is reached (typically within no longer than 14 days) on portions of the site not otherwise permanently stabilized. Standard dry mulching is encouraged in most jurisdictions; however, hydromulching may not be allowed in certain jurisdictions or may not be allowed near waterways. Do not apply mulch during windy conditions. Design and Installation Prior to mulching, surface-roughen areas by rolling with a crimping or punching type roller or by track walking. Track walking should only be used where other methods are impractical because track walking with heavy equipment typically compacts the soil. A variety of mulches can be used effectively at construction sites. Consider the following: Mulch Functions Erosion Control Yes Sediment Control Moderate Site/Material Management No EC-4 Mulching (MU) MU-2 Urban Drainage and Flood Control District June 2012 Urban Storm Drainage Criteria Manual Volume 3  Clean, weed-free and seed-free cereal grain straw should be applied evenly at a rate of 2 tons per acre and must be tacked or fastened by a method suitable for the condition of the site. Straw mulch must be anchored (and not merely placed) on the surface. This can be accomplished mechanically by crimping or with the aid of tackifiers or nets. Anchoring with a crimping implement is preferred, and is the recommended method for areas flatter than 3:1. Mechanical crimpers must be capable of tucking the long mulch fibers into the soil to a depth of 3 inches without cutting them. An agricultural disk, while not an ideal substitute, may work if the disk blades are dull or blunted and set vertically; however, the frame may have to be weighted to afford proper soil penetration.  Grass hay may be used in place of straw; however, because hay is comprised of the entire plant including seed, mulching with hay may seed the site with non-native grass species which might in turn out-compete the native seed. Alternatively, native species of grass hay may be purchased, but can be difficult to find and are more expensive than straw. Purchasing and utilizing a certified weed-free straw is an easier and less costly mulching method. When using grass hay, follow the same guidelines as for straw (provided above).  On small areas sheltered from the wind and heavy runoff, spraying a tackifier on the mulch is satisfactory for holding it in place. For steep slopes and special situations where greater control is needed, erosion control blankets anchored with stakes should be used instead of mulch.  Hydraulic mulching consists of wood cellulose fibers mixed with water and a tackifying agent and should be applied at a rate of no less than 1,500 pounds per acre (1,425 lbs of fibers mixed with at least 75 lbs of tackifier) with a hydraulic mulcher. For steeper slopes, up to 2000 pounds per acre may be required for effective hydroseeding. Hydromulch typically requires up to 24 hours to dry; therefore, it should not be applied immediately prior to inclement weather. Application to roads, waterways and existing vegetation should be avoided.  Erosion control mats, blankets, or nets are recommended to help stabilize steep slopes (generally 3:1 and steeper) and waterways. Depending on the product, these may be used alone or in conjunction with grass or straw mulch. Normally, use of these products will be restricted to relatively small areas. Biodegradable mats made of straw and jute, straw-coconut, coconut fiber, or excelsior can be used instead of mulch. (See the ECM/TRM BMP for more information.)  Some tackifiers or binders may be used to anchor mulch. Check with the local jurisdiction for allowed tackifiers. Manufacturer's recommendations should be followed at all times. (See the Soil Binder BMP for more information on general types of tackifiers.)  Rock can also be used as mulch. It provides protection of exposed soils to wind and water erosion and allows infiltration of precipitation. An aggregate base course can be spread on disturbed areas for temporary or permanent stabilization. The rock mulch layer should be thick enough to provide full coverage of exposed soil on the area it is applied. Maintenance and Removal After mulching, the bare ground surface should not be more than 10 percent exposed. Reapply mulch, as needed, to cover bare areas. Rolled Erosion Control Products (RECP) EC-6 November 2010 Urban Drainage and Flood Control District RECP-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph RECP-1. Erosion control blanket protecting the slope from erosion and providing favorable conditions for revegetation. Description Rolled Erosion Control Products (RECPs) include a variety of temporary or permanently installed manufactured products designed to control erosion and enhance vegetation establishment and survivability, particularly on slopes and in channels. For applications where natural vegetation alone will provide sufficient permanent erosion protection, temporary products such as netting, open weave textiles and a variety of erosion control blankets (ECBs) made of biodegradable natural materials (e.g., straw, coconut fiber) can be used. For applications where natural vegetation alone will not be sustainable under expected flow conditions, permanent rolled erosion control products such as turf reinforcement mats (TRMs) can be used. In particular, turf reinforcement mats are designed for discharges that exert velocities and sheer stresses that exceed the typical limits of mature natural vegetation. Appropriate Uses RECPs can be used to control erosion in conjunction with revegetation efforts, providing seedbed protection from wind and water erosion. These products are often used on disturbed areas on steep slopes, in areas with highly erosive soils, or as part of drainageway stabilization. In order to select the appropriate RECP for site conditions, it is important to have a general understanding of the general types of these products, their expected longevity, and general characteristics. The Erosion Control Technology Council (ECTC 2005) characterizes rolled erosion control products according to these categories:  Mulch control netting: A planar woven natural fiber or extruded geosynthetic mesh used as a temporary degradable rolled erosion control product to anchor loose fiber mulches.  Open weave textile: A temporary degradable rolled erosion control product composed of processed natural or polymer yarns woven into a matrix, used to provide erosion control and facilitate vegetation establishment.  Erosion control blanket (ECB): A temporary degradable rolled erosion control product composed of processed natural or polymer fibers which are mechanically, structurally or chemically bound together to form a continuous matrix to provide erosion control and facilitate vegetation establishment. ECBs can be further differentiated into rapidly degrading single-net and double-net types or slowly degrading types. Rolled Erosion Control Products Functions Erosion Control Yes Sediment Control No Site/Material Management No EC-6 Rolled Erosion Control Products (RECP) RECP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3  Turf Reinforcement Mat (TRM): A rolled erosion control product composed of non-degradable synthetic fibers, filaments, nets, wire mesh, and/or other elements, processed into a permanent, three- dimensional matrix of sufficient thickness. TRMs, which may be supplemented with degradable components, are designed to impart immediate erosion protection, enhance vegetation establishment and provide long-term functionality by permanently reinforcing vegetation during and after maturation. Note: TRMs are typically used in hydraulic applications, such as high flow ditches and channels, steep slopes, stream banks, and shorelines, where erosive forces may exceed the limits of natural, unreinforced vegetation or in areas where limited vegetation establishment is anticipated. Tables RECP-1 and RECP-2 provide guidelines for selecting rolled erosion control products appropriate to site conditions and desired longevity. Table RECP-1 is for conditions where natural vegetation alone will provide permanent erosion control, whereas Table RECP-2 is for conditions where vegetation alone will not be adequately stable to provide long-term erosion protection due to flow or other conditions. Rolled Erosion Control Products (RECP) EC-6 November 2010 Urban Drainage and Flood Control District RECP-3 Urban Storm Drainage Criteria Manual Volume 3 Table RECP-1. ECTC Standard Specification for Temporary Rolled Erosion Control Products (Adapted from Erosion Control Technology Council 2005) Product Description Slope Applications* Channel Applications* Minimum Tensile Strength1 Expected Longevity Maximum Gradient C Factor2,5 Max. Shear Stress3,4,6 Mulch Control Nets 5:1 (H:V) ≤0.10 @ 5:1 0.25 lbs/ft2 (12 Pa) 5 lbs/ft (0.073 kN/m) Up to 12 months Netless Rolled Erosion Control Blankets 4:1 (H:V) ≤0.10 @ 4:1 0.5 lbs/ft2 (24 Pa) 5 lbs/ft (0.073 kN/m) Single-net Erosion Control Blankets & Open Weave Textiles 3:1 (H:V) ≤0.15 @ 3:1 1.5 lbs/ft2 (72 Pa) 50 lbs/ft (0.73 kN/m) Double-net Erosion Control Blankets 2:1 (H:V) ≤0.20 @ 2:1 1.75 lbs/ft2 (84 Pa) 75 lbs/ft (1.09 kN/m) Mulch Control Nets 5:1 (H:V) ≤0.10 @ 5:1 0.25 lbs/ft2 (12 Pa) 25 lbs/ft (0.36 kN/m) 24 months Erosion Control Blankets & Open Weave Textiles (slowly degrading) 1.5:1 (H:V) ≤0.25 @ 1.5:1 2.00 lbs/ft2 (96 Pa) 100 lbs/ft (1.45 kN/m) 24 months Erosion Control Blankets & Open Weave Textiles 1:1 (H:V) ≤0.25 @ 1:1 2.25 lbs/ft2 (108 Pa) 125 lbs/ft (1.82 kN/m) 36 months * C Factor and shear stress for mulch control nettings must be obtained with netting used in conjunction with pre-applied mulch material. (See Section 5.3 of Chapter 7 Construction BMPs for more information on the C Factor.) 1 Minimum Average Roll Values, Machine direction using ECTC Mod. ASTM D 5035. 2 C Factor calculated as ratio of soil loss from RECP protected slope (tested at specified or greater gradient, H:V) to ratio of soil loss from unprotected (control) plot in large-scale testing. 3 Required minimum shear stress RECP (unvegetated) can sustain without physical damage or excess erosion (> 12.7 mm (0.5 in) soil loss) during a 30-minute flow event in large-scale testing. 4 The permissible shear stress levels established for each performance category are based on historical experience with products characterized by Manning's roughness coefficients in the range of 0.01 - 0.05. 5 Acceptable large-scale test methods may include ASTM D 6459, or other independent testing deemed acceptable by the engineer. 6 Per the engineer’s discretion. Recommended acceptable large-scale testing protocol may include ASTM D 6460, or other independent testing deemed acceptable by the engineer. EC-6 Rolled Erosion Control Products (RECP) RECP-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Table RECP-2. ECTC Standard Specification for Permanent1 Rolled Erosion Control Products (Adapted from: Erosion Control Technology Council 2005) Product Type Slope Applications Channel Applications TRMs with a minimum thickness of 0.25 inches (6.35 mm) per ASTM D 6525 and UV stability of 80% per ASTM D 4355 (500 hours exposure). Maximum Gradient Maximum Shear Stress4,5 Minimum Tensile Strength2,3 0.5:1 (H:V) 6.0 lbs/ft2 (288 Pa) 125 lbs/ft (1.82 kN/m) 0.5:1 (H:V) 8.0 lbs/ft2 (384 Pa) 150 lbs/ft (2.19 kN/m) 0.5:1 (H:V) 10.0 lbs/ft2 (480 Pa) 175 lbs/ft (2.55 kN/m) 1 For TRMs containing degradable components, all property values must be obtained on the non- degradable portion of the matting alone. 2 Minimum Average Roll Values, machine direction only for tensile strength determination using ASTM D 6818 (Supersedes Mod. ASTM D 5035 for RECPs) 3 Field conditions with high loading and/or high survivability requirements may warrant the use of a TRM with a tensile strength of 44 kN/m (3,000 lb/ft) or greater. 4 Required minimum shear stress TRM (fully vegetated) can sustain without physical damage or excess erosion (> 12.7 mm (0.5 in.) soil loss) during a 30-minute flow event in large scale testing. 5 Acceptable large-scale testing protocols may include ASTM D 6460, or other independent testing deemed acceptable by the engineer. Design and Installation RECPs should be installed according to manufacturer’s specifications and guidelines. Regardless of the type of product used, it is important to ensure no gaps or voids exist under the material and that all corners of the material are secured using stakes and trenching. Continuous contact between the product and the soil is necessary to avoid failure. Never use metal stakes to secure temporary erosion control products. Often wooden stakes are used to anchor RECPs; however, wood stakes may present installation and maintenance challenges and generally take a long time to biodegrade. Some local jurisdictions have had favorable experiences using biodegradable stakes. This BMP Fact Sheet provides design details for several commonly used ECB applications, including: ECB-1 Pipe Outlet to Drainageway ECB-2 Small Ditch or Drainageway ECB-3 Outside of Drainageway Rolled Erosion Control Products (RECP) EC-6 November 2010 Urban Drainage and Flood Control District RECP-5 Urban Storm Drainage Criteria Manual Volume 3 Staking patterns are also provided in the design details according to these factors:  ECB type  Slope or channel type For other types of RECPs including TRMs, these design details are intended to serve as general guidelines for design and installation; however, engineers should adhere to manufacturer’s installation recommendations. Maintenance and Removal Inspection of erosion control blankets and other RECPs includes:  Check for general signs of erosion, including voids beneath the mat. If voids are apparent, fill the void with suitable soil and replace the erosion control blanket, following the appropriate staking pattern.  Check for damaged or loose stakes and secure loose portions of the blanket. Erosion control blankets and other RECPs that are biodegradable typically do not need to be removed after construction. If they must be removed, then an alternate soil stabilization method should be installed promptly following removal. Turf reinforcement mats, although generally resistant to biodegradation, are typically left in place as a dense vegetated cover grows in through the mat matrix. The turf reinforcement mat provides long-term stability and helps the established vegetation resist erosive forces. EC-6 Rolled Erosion Control Products (RECP) RECP-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC-6 November 2010 Urban Drainage and Flood Control District RECP-7 Urban Storm Drainage Criteria Manual Volume 3 EC-6 Rolled Erosion Control Products (RECP) RECP-8 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC-6 November 2010 Urban Drainage and Flood Control District RECP-9 Urban Storm Drainage Criteria Manual Volume 3 Wind Erosion/Dust Control (DC) EC-14 November 2010 Urban Drainage and Flood Control District DC-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph DC-1. Water truck used for dust suppression. Photo courtesy of Douglas County. Description Wind erosion and dust control BMPs help to keep soil particles from entering the air as a result of land disturbing construction activities. These BMPs include a variety of practices generally focused on either graded disturbed areas or construction roadways. For graded areas, practices such as seeding and mulching, use of soil binders, site watering, or other practices that provide prompt surface cover should be used. For construction roadways, road watering and stabilized surfaces should be considered. Appropriate Uses Dust control measures should be used on any site where dust poses a problem to air quality. Dust control is important to control for the health of construction workers and surrounding waterbodies. Design and Installation The following construction BMPs can be used for dust control:  An irrigation/sprinkler system can be used to wet the top layer of disturbed soil to help keep dry soil particles from becoming airborne.  Seeding and mulching can be used to stabilize disturbed surfaces and reduce dust emissions.  Protecting existing vegetation can help to slow wind velocities across the ground surface, thereby limiting the likelihood of soil particles to become airborne.  Spray-on soil binders form a bond between soil particles keeping them grounded. Chemical treatments may require additional permitting requirements. Potential impacts to surrounding waterways and habitat must be considered prior to use.  Placing rock on construction roadways and entrances will help keep dust to a minimum across the construction site.  Wind fences can be installed on site to reduce wind speeds. Install fences perpendicular to the prevailing wind direction for maximum effectiveness. Maintenance and Removal When using an irrigation/sprinkler control system to aid in dust control, be careful not to overwater. Overwatering will cause construction vehicles to track mud off-site. Wind Erosion Control/ Dust Control Functions Erosion Control Yes Sediment Control No Site/Material Management Moderate Stockpile Management (SP) MM-2 November 2010 Urban Drainage and Flood Control District SP-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph SP-1. A topsoil stockpile that has been partially revegetated and is protected by silt fence perimeter control. Description Stockpile management includes measures to minimize erosion and sediment transport from soil stockpiles. Appropriate Uses Stockpile management should be used when soils or other erodible materials are stored at the construction site. Special attention should be given to stockpiles in close proximity to natural or manmade storm systems. Design and Installation Locate stockpiles away from all drainage system components including storm sewer inlets. Where practical, choose stockpile locations that that will remain undisturbed for the longest period of time as the phases of construction progress. Place sediment control BMPs around the perimeter of the stockpile, such as sediment control logs, rock socks, silt fence, straw bales and sand bags. See Detail SP-1 for guidance on proper establishment of perimeter controls around a stockpile. For stockpiles in active use, provide a stabilized designated access point on the upgradient side of the stockpile. Stabilize the stockpile surface with surface roughening, temporary seeding and mulching, erosion control blankets, or soil binders. Soils stockpiled for an extended period (typically for more than 60 days) should be seeded and mulched with a temporary grass cover once the stockpile is placed (typically within 14 days). Use of mulch only or a soil binder is acceptable if the stockpile will be in place for a more limited time period (typically 30-60 days). Timeframes for stabilization of stockpiles noted in this fact sheet are "typical" guidelines. Check permit requirements for specific federal, state, and/or local requirements that may be more prescriptive. Stockpiles should not be placed in streets or paved areas unless no other practical alternative exists. See the Stabilized Staging Area Fact Sheet for guidance when staging in roadways is unavoidable due to space or right-of-way constraints. For paved areas, rock socks must be used for perimeter control and all inlets with the potential to receive sediment from the stockpile (even from vehicle tracking) must be protected. Maintenance and Removal Inspect perimeter controls and inlet protection in accordance with their respective BMP Fact Sheets. Where seeding, mulch and/or soil binders are used, reseeding or reapplication of soil binder may be necessary. When temporary removal of a perimeter BMP is necessary to access a stockpile, ensure BMPs are reinstalled in accordance with their respective design detail section. Stockpile Management Functions Erosion Control Yes Sediment Control Yes Site/Material Management Yes MM-2 Stockpile Management (SM) SP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 When the stockpile is no longer needed, properly dispose of excess materials and revegetate or otherwise stabilize the ground surface where the stockpile was located. Stockpile Management (SP) MM-2 November 2010 Urban Drainage and Flood Control District SP-3 Urban Storm Drainage Criteria Manual Volume 3 MM-2 Stockpile Management (SM) SP-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Stockpile Management (SP) MM-2 November 2010 Urban Drainage and Flood Control District SP-5 Urban Storm Drainage Criteria Manual Volume 3 MM-2 Stockpile Management (SM) SP-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Spill Prevention, Containment and Control S-2 November 2010 Urban Drainage and Flood Control District SPCC-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph SPCC-1. Use of secondary containment around supplies stored outside helps to reduce the likelihood of spill and leaks reaching the storm sewer system in runoff. Photo courtesy of Tom Gore. Also See These BMP Fact Sheets  Covering Storage/Handling Areas  Good Housekeeping  Vehicle Fueling, Maintenance, Washing & Storage  Preventative Maintenance Description Spills and leaks of solid and liquid materials processed, handled or stored outdoors can be a significant source of stormwater pollutants. Spilled substances can reach receiving waters when runoff washes these materials from impervious surfaces or when spills directly enter the storm sewer system during dry weather conditions. Effective spill control includes both spill prevention and spill response measures and depends on proper employee training for spill response measures and may also include structural spill containment, particularly at industrial locations. Structural spill containment measures typically include temporary or permanent curbs or berms that surround a potential spill site. Berms may be constructed of concrete, earthen material, metal, synthetic liners, or other material that will safely contain the spill. Spill control devices may also include valves, slide gates, or other devices that can control and contain spilled material before it reaches the storm sewer system or receiving waters. Appropriate Uses Implement spill prevention, containment and control measures at municipal, commercial and industrial facilities in areas where materials may be spilled in quantities that may adversely impact receiving waters when discharged directly or through the storm sewer system. Check local, state, and/or federal regulations to determine when spill containment and control measures are required by law. Spill Prevention, Control and Countermeasures Plans may be required for certain facilities handling oil and hazardous substances sunder Section 311(j)(1)(C) of the federal Clean Water Act. Practice Guidelines Spill Prevention Measures  Train employees on potential sources of pollution on-site and provide clear, common-sense spill prevention practices. Require that these practices be strictly followed.  Identify equipment that may be exposed to stormwater, pollutants that may be generated and possible sources of leaks or discharges.  Perform regular inspection and preventative maintenance of equipment to ensure proper operation and to check for leaks or evidence of discharge (stains). Provide clear procedures to ensure that needed repairs are completed and provide temporary leak containment until such repairs can be implemented. S-2 Spill Prevention, Containment and Control SPCC-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3  Drain or replace motor oil and other automotive fluids in a designated area away from storm sewer inlets. Collect spent fluids and recycle or dispose of properly. Never dispose of these fluids in the storm sewer or sanitary sewer.  In fueling areas, clean up spills with dry methods (absorbents) and use damp cloths on gas pumps and damp mops on paved surfaces. Never use a hose to “wash down” a fuel spill.  Where practical, reduce stormwater contact with equipment and materials by implementing indoor or covered storage, implementing stormwater run-on control measures and following good housekeeping practices. Identification of Spill Areas Identify potential spill areas, potential spill volumes, material types, frequency of material use, and drainage paths from spill areas with relation to storm sewer inlets, adjacent waterbodies, structural BMPs, and containment structures. Use this information to determine the types of spill prevention and control measures needed specific to the site conditions. Examples of potential spill locations include:  Loading and unloading areas  Outdoor storage areas  Outdoor manufacturing or processing activities  Waste disposal/storage areas  Areas that generate significant dust or particulates (that may be subsequently deposited on the ground)  Salt piles  Areas prone to spills based on past experience at the site  Locations where other routine maintenance activities occur such as equipment maintenance and cleaning, pesticide/fertilizer application, etc. Additionally, areas where smaller leaks may occur such as parking should also have basic spill cleanup procedures. Material Handling Procedures From a water quality perspective, the primary principle behind effective material handling practices is to minimize exposure to stormwater. This can be accomplished by storing the material indoors under weather-resistant covering, elevating the material off the ground by using pallets, and diverting stormwater around materials storage areas. Representative outdoor materials handling procedures include:  Keep bulk solid materials such as raw materials, sand, gravel, topsoil, compost, concrete, packing materials, metal products and other materials covered and protected from stormwater.  When practical, store materials on impermeable surfaces.  Store hazardous materials according to federal, state, and local hazardous materials requirements. Good Housekeeping S-5 November 2010 Urban Drainage and Flood Control District GH-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph GH-1. Use dry clean-up methods to remove spilled materials. Photo courtesy of Colorado Nonpoint Source Program. Description Good housekeeping practices are designed to maintain a clean and orderly work environment. The most effective first steps towards preventing pollution in stormwater from work sites simply involve using common sense to improve the facility’s basic housekeeping methods. Poor housekeeping practices result in increased waste and potential for stormwater contamination. A clean and orderly work site reduces the possibility of accidental spills caused by mishandling of chemicals and equipment and should reduce safety hazards to personnel. A well-maintained material and chemical storage area will reduce the possibility of stormwater mixing with pollutants. Some simple procedures a facility can use to promote good housekeeping include improved operation and maintenance of machinery and processes, material storage practices, material inventory controls, routine and regular clean-up schedules, maintaining well organized work areas, signage, and educational programs for employees and the general public about all of these practices. Appropriate Uses Good housekeeping practices require education and training, typically targeted to industries and businesses, municipal employees, as well as the general public. Practice Guidelines Good housekeeping practices include these general areas:  Operation and Maintenance  Material Storage  Material Inventory  Training and Participation. Operation and Maintenance Consider implementing the following practices:  Maintain dry and clean floors and ground surfaces by using brooms, shovels, vacuums or cleaning machines, rather than wet clean-up methods.  Regularly collect and dispose of garbage and waste material. S-5 Good Housekeeping GH-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3  Routinely inspect equipment to ensure that it is functioning properly without leaking and conduct preventative maintenance and needed repairs.  Train employees on proper clean up and spill response procedures.  Designate separate areas of the site for auto parking, vehicle refueling and routine maintenance.  Promptly clean up leaks, drips and other spills.  Cover and maintain dumpsters and waste receptacles. Add additional dumpsters or increase frequency of waste collection if overflowing conditions reoccur.  Where outdoor painting and sanding occur, implement these practices: o Conduct these activities in designated areas that provide adequate protection to prevent overspray and uncontrolled emissions. All operations should be conducted on paved surfaces to facilitate cleanup. o Use portable containment as necessary for outside operations. o Clean up and properly dispose of excess paint, paint chips, protective coatings, grit waste, etc.  Maintain vegetation on facility grounds in a manner that minimizes erosion. Follow the Landscape Maintenance and Pesticide, Herbicide and Fertilizer Usage BMPs to ensure that minimum amounts of chemicals needed for healthy vegetation are applied in a manner that minimizes transport of these materials in runoff. Material Storage Practices Proper storage techniques include the following:  Provide adequate aisle space to facilitate material transfer and ease of access for inspection.  Store containers, drums, and bags away from direct traffic routes to reduce container damage resulting in accidental spills.  Stack containers according to manufacturer’s instructions to avoid damaging the containers from improper weight distribution. Also store materials in accordance with directions in Material Safety Data Sheets (MSDSs).  Store containers on pallets or similar devices to prevent corrosion of containers that results from containers coming in contact with moisture on the ground.  Store toxic or hazardous liquids within curbed areas or secondary containers. Material Inventory Practices An up-to-date materials inventory can keep material costs down by preventing overstocking, track how materials are stored and handled onsite, and identify which materials and activities pose the most risk to the environment. Assign responsibility of hazardous material inventory to individuals trained to handle such materials. A material inventory should include these steps:  Identify all chemical substances present at work site. Perform a walk-through of the site, review Good Housekeeping S-5 November 2010 Urban Drainage and Flood Control District GH-3 Urban Storm Drainage Criteria Manual Volume 3 purchase orders, list all chemical substances used and obtain Material Safety Data Sheets (MSDS) for all chemicals.  Label all containers. Labels should provide name and type of substance, stock number, expiration date, health hazards, handling suggestions, and first aid information. Much of, this information can be found on an MSDS.  Clearly identify special handling, storage, use and disposal considerations for hazardous materials on the material inventory.  Institute a shelf-life program to improve material tracking and inventory that can reduce the amount of materials that are overstocked and ensure proper disposal of expired materials. Careful tracking of materials ordered can result in more efficient materials use. Decisions on the amounts of hazardous materials that are stored on site should include an evaluation of any emergency control systems that are in place. All storage areas for hazardous materials should be designed to contain spills. Training and Participation Frequent and proper training in good housekeeping techniques reduces the likelihood that chemicals or equipment will be mishandled. To promote good housekeeping, consider implementing these practices:  Discuss good housekeeping practices in training programs and meetings.  Publicize pollution prevention concepts through posters or signs.  Post bulletin boards with updated good housekeeping procedures, tips and reminders. Spill Prevention, Containment and Control S-2 November 2010 Urban Drainage and Flood Control District SPCC-3 Urban Storm Drainage Criteria Manual Volume 3  Adopt procedures that reduce the chance of spills or leaks during filling or transfer of materials.  Substitute less toxic or non-toxic materials for toxic materials.  Store containers that are easily punctured or damaged away from high traffic areas (i.e., adopt a materials flow/plant layout plan).  Add waste-capture containers such as collection pans for lubricating fluids.  Store drums and containers with liquid materials on impermeable surfaces and provide secondary containment where appropriate. Drums stored outdoors should be located on pallets to minimize contact with runoff. Spill Response Procedures and Equipment Spill response procedures should be tailored to site-specific conditions and industry-specific regulatory requirements. General spill response procedures include:  Containment and cleanup of spills should begin promptly after the spill is observed.  Sweep up small quantities of dry chemical or solids to reduce exposure to runoff. Shoveling may be used for larger quantities of materials.  Absorbents should be readily accessible in fueling areas or other areas susceptible to spills.  Wipe up small spills with a shop rag, store shop rags in appropriate containers, dispose of rags properly or use a professional industrial cleaning service.  Contain medium-sized spills with absorbents (e.g., kitty litter, sawdust) and use inflatable berms or absorbent “snakes” as temporary booms for the spill. Store and dispose of absorbents properly. Wet/dry vacuums may also be used, but not for volatile fluids.  Develop procedures and locations for containing and storing leaking containers.  Install drip pans below minor equipment leaks and properly dispose of collected material until a repair can be made.  For large spills, first contain the spill and plug storm drain inlets where the liquid may migrate off- site, then clean up the spill.  Excavation of spill areas to removed contaminated material may be required where large liquid spills occur on unpaved surfaces.  An inventory of cleanup materials should be maintained onsite and strategically located based on the types and quantities of chemicals present. Structural Spill Containment Measures Two general approaches are often used when implementing spill containment measures. The first approach is designed to contain the entire spill. The second approach uses curbing to route spilled material to a collection basin. Both containment berming and curbing should be sized to safely contain or convey to a collection basin a spill from the largest storage tank, rail car, tank truck, or other containment device in the possible spill area. The spill containment area must have an impermeable surface (e.g., S-2 Spill Prevention, Containment and Control SPCC-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Key Spill Notification Contacts in Colorado  Colorado Department of Public Health and Environment Toll- Free 24-hour Environmental Emergency Spill Reporting Line: 1-877-518-5608  National Response Center: 1- 800-424-8802 (24-hour)  Local Emergency Planning Committee (OEM): 303-273- 162  Division of Oil & Public Safety- Storage Tanks: 303-318-8547  Oil and Gas Conservation Commission: 303-894-2100 or 1-888-235-1101 (toll-free spill/complaint line) impermeable liner, asphalt or concrete) to prevent groundwater contamination. The containment system must be designed to enable collection and removal of spilled material through a pump or vacuum trucks, use of sorbent or gelling material, or other measures. Material removed from the spill area must be disposed of or recycled according to local, state, and federal standards. If the capacity of the containment berming or the collection basin is exceeded, supplemental spill control measures should be available such as a portable containment device, sorbent materials, or gelling agents that eventually solidify the material. Water that collects within containment areas due to rainfall or snowmelt must be appropriately treated before release from the spill area. Spill Plan Development Many industries are required by federal law to have a Spill Prevention, Control and Countermeasures Plan (SPCC) that meets specific regulatory criteria when certain types and quantities of materials are used or processed at a site. These plans can be instrumental in developing a spill control plan for stormwater management purposes. Even if an SPCC plan is not legally required at a site, a spill control plan for stormwater management purposes may be necessary. Representative information appropriate for a spill control plan, building on concepts previously introduced in this Fact Sheet, includes:  Site plan showing where materials are stored and handled, and where associated activities occur.  Notification procedures to be used in the event of an accident  Instructions for clean-up procedures.  A designated person with spill response and clean-up authority.  Training of key personnel in plan and clean-up procedures.  Signs posted at critical locations providing a summary of SPCC plan information, phone numbers, contacts, equipment locations, etc.  Provisions requiring spills to be cleaned up, corrective actions taken, or countermeasures implemented immediately.  Provisions for absorbents to be made available for use in fuel areas, and for containers to be available for used absorbents.  Prohibition on washing absorbents into the storm drainage system or into the sanitary sewer system via floor drains.  Provision for emergency spill containment and clean-up kits in accessible and convenient locations. Kits should contain the appropriate clean-up materials applicable to the materials stored at the site. Vehicle Maintenance, Fueling and Storage S-7 November 2010 Urban Drainage and Flood Control District VFM-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph VF-1. Use drip pans to collect leaks from vehicles until repairs can be completed. Photo courtesy of Tom Gore. Description Areas where vehicles are fueled, maintained, and stored/parked can be pollutant "hot spots" that can result in hydrocarbons, trace metals, and other pollutants being transported in stormwater runoff. Proper fueling operations, storage of automotive fluids and effective spill cleanup procedures can help reduce contamination of stormwater runoff from vehicle maintenance and fueling facilities. Fuel-related spills can occur due to inattention during fueling or "topping off" fuel tanks. Common activities at commercial, industrial and municipal maintenance shops include parts cleaning, vehicle fluid replacement, and equipment replacement and repair. Some of the wastes generated at automobile maintenance facilities include solvents (degreasers, paint thinners, etc.), antifreeze, brake fluid and brake pad dust, battery acid, motor oil, fuel, and lubricating grease. Fleet storage areas and customer and employee parking can also be a source of vehicle-related contamination from leaks, antifreeze spills, etc. Appropriate Uses These BMP guidelines are applicable to vehicle maintenance, fueling, fleet storage and parking facilities. Be aware that washing vehicles and equipment outdoors or in areas where wash water flows onto the ground can pollute stormwater. Vehicle wash water is considered process wastewater that should not be discharged to the storm sewer system. Consult state and federal discharge permit requirements for proper disposal of vehicle washwater, which is typically accomplished through discharge to the sanitary sewer system. Practice Guidelines 1  Perform maintenance activities inside or under cover. When repairs cannot be performed indoors, be sure to use drip pans or absorbents. Vehicle Maintenance The most effective way to minimize wastes generated by automotive maintenance activities is to prevent their production in the first place. Consider adopting these practices:  Keep equipment clean and free of excessive oil and grease buildup. 1 Guidelines adapted from the USEPA Menu of BMPs. S-7 Vehicle Maintenance, Fueling and Storage VFM-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3  Promptly cleanup spills using dry methods and properly dispose of waste. When water is required, use as little as possible to clean spills, leaks, and drips.  Use a solvent collection service to collect spent solvent used for parts cleaning. Where practical, use detergent-based, steam cleaning, or pressure-based cleaning systems instead of organic solvent degreasers when practical. (Be aware that cleaning water discharged into the sanitary sewer may require pre-treatment prior to discharge.)  When using liquids for cleaning, use a centralized station to ensure that solvents and residues stay in one area. Locate drip pans and draining boards to direct solvents back into a solvent sink or holding tank for reuse.  Store used oil for recycling in labeled tanks. Locate used oil tanks and drums away from storm drains, flowing streams, and preferably indoors.  Use non-hazardous or less hazardous alternatives when practical. For example, replace chlorinated organic solvents with non-chlorinated ones like kerosene or mineral spirits.  Properly recycle or dispose of grease, oil, antifreeze, brake fluid, cleaning solutions, hydraulic fluid, batteries, transmission fluid, worn parts, filters, and rags.  Drain and crush oil filters before recycling or disposal.  Drain all fluids and remove batteries from salvage vehicles and equipment.  Closely monitor parked vehicles for leaks and place pans under any leaks to collect the fluids for proper disposal or recycling.  Install berms or other measures to contain spills and prevent work surface runoff from entering storm drains.  Develop and follow a spill prevention plan. This includes a variety of measures such as spill kits and knowing where storm drains are located and how to protect them (e.g., drain mat, berm) when larger spills occur. (See the Spill Prevention, Containment and Control BMP for more information.)  Conduct periodic employee training to reinforce proper disposal practices.  Promptly transfer used fluids to recycling drums or hazardous waste containers.  Store cracked batteries in leak-proof secondary containers.  Inspect outdoor storage areas regularly for drips, spills and improperly stored materials (unlabeled containers, auto parts that might contain grease or fluids, etc.). This is particularly important for parking areas for vehicles awaiting repair.  Structural stormwater BMPs in vehicle hotspot areas require routine cleanout of oil and grease, sometimes monthly or more frequently. During periods of heavy rainfall, cleanout is required more often to ensure that pollutants are not washed through the trap. Sediment removal is also required on a regular basis to keep the BMP working efficiently. Vehicle Maintenance, Fueling and Storage S-7 November 2010 Urban Drainage and Flood Control District VFM-3 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Fueling  Designated fueling areas should be designed to prevent stormwater runoff and spills. For example, fuel-dispensing areas should be paved with concrete or an equivalent impervious surface, with an adequate slope to prevent ponding, and separated from the rest of the site by a grade break or berm that prevents run-on of stormwater.  Fuel dispensing areas should be covered. The cover's minimum dimensions must be equal to or greater than the area within the grade break or the fuel dispensing area so that the fueling area is completely covered. It may be necessary to install and maintain an oil capture device in catch basins that have the potential to receive runoff from the fueling area.  For facilities where equipment is being fueled with a mobile fuel truck, establish a designated fueling area. Place temporary "caps" over nearby catch basins or manhole covers so that if a spill occurs, it is prevented from entering the storm drain. A form of secondary containment should be used when transferring fuel from the tank truck to the fuel tank. Storm drains in the vicinity should also be covered. Install vapor recovery nozzles to help control drips, as well as reduce air pollution.  Keep spill response information and spill cleanup materials onsite and readily available.  Fuel-dispensing areas should be inspected regularly and repair promptly completed. Inspectors should: o Check for external corrosion and structural failure in aboveground tanks. o Check for spills and overfills due to operator error. o Check for failure of any piping systems. o Check for leaks or spills during pumping of liquids or gases from a truck or rail car to a storage facility or vice versa. o Visually inspect new tank or container installations for loose fittings, poor welds, and improper or poorly fitted gaskets. o Inspect tank foundations, connections, coatings, tank walls, and piping systems. Look for corrosion, leaks, cracks, scratches, and other physical damage that may weaken the tank or container system.  Aboveground and belowground tanks should be tested periodically for integrity by a qualified professional.  Dry cleanup methods should be employed when cleaning up fuel-dispensing areas. Such methods include sweeping to remove litter and debris and using rags and absorbents for leaks and spills. Water should not be used to wash these areas. During routine cleaning, use a damp cloth on the pumps and a damp mop on the pavement, rather than spraying with a hose. Fuel dispensing nozzles should be fitted with "hold-open latches" (automatic shutoff) except where prohibited by local fire departments. Signs can be posted at the fuel dispenser or island warning vehicle owners/operators against "topping off" vehicle fuel tanks.  Written procedures that describe these BMPs should be provided to employees who will be using fueling systems. Use of Pesticides, Herbicides and Fertilizers S-8 November 2010 Urban Drainage and Flood Control District PHF-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph PHF-1. Pesticide, fertilizer, and herbicide applications should be applied in the minimum quantities necessary to achieve specific landscaping objectives, while keeping chemicals out of storm drain systems. Photo courtesy of WWE. Description Pesticides, herbicides, fertilizers, fuel and other landscape maintenance chemicals must be properly applied, stored, handled and disposed of to prevent contamination of surface water and groundwater. Misuse of pesticides and herbicides can result in adverse impacts to aquatic life, even at low concentrations. Misuse of fertilizer can result in increased algae growth in waterbodies due to excessive phosphorus and nitrogen loading. Appropriate Uses This BMP applies to both commercial and municipal landscaping operations, as well as to homeowners and homeowner associations. For commercial operations, the scale of chemical usage and handling is greater; therefore, additional measures are often required under federal and state law. Practice Guidelines 1 Public education regarding appropriate landscape chemical application and handling is an important action that local governments can take to reduce the likelihood that landscape chemicals are washed into storm drains and receiving waters through runoff. Local governments can make landscape care information available on websites, in utility mailers, lawn care centers, and other locations. A variety of professional organizations for lawn care professionals already exist and can be contacted for additional information or partnered with for both public education and landscape professional educational efforts and certification programs (See www.ext.colostate.edu and www.greenco.org.). General Guidelines for Pesticide, Herbicide, and Fertilizer Application  Apply fertilizers, pesticides, and other chemicals according to manufacturer's directions. The label is the law for pesticide usage. Apply pesticides and herbicides only when needed and use in a manner to minimize off-target effects. See the Landscape Management Fact Sheet for fertilizer application guidelines.  Accurately diagnose the pest. Disease and insect symptoms can mimic each other in many plants. A fungicide will not control an insect, and an insecticide will not control a disease.  Be aware that commercial chemical applicators must receive thorough training, licensure and proper certification prior to chemical use. Consult Colorado Department of Agriculture (CDA) Regulations for specific requirements. 1 These practice guidelines have been adapted from the GreenCO Best Management Practices for the Conservation and Protection of Water Quality in Colorado: Moving Toward Sustainability (GreenCO and WWE 2008). See that manual for additional detail and references. S-8 Use of Pesticides, Herbicides and Fertilizers PHF-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Integrated Pest Management (IPM) Integrated pest management (IPM) (also known as Plant Health Care) is the practice of using targeted biological, chemical, cultural, and physical measures to manage pests while minimizing or eliminating the use of chemical pesticides. IPM measures benefit the landscape and help reduce the likelihood that lawn chemicals will be washed into storm drainage systems in stormwater runoff. The pros and cons of various tools should be weighed and used in an integrated manner to achieve pest control objectives in a safe, effective, and cost-effective manner. Basic IPM practices that can be adopted include:  Consider spot treatments of pests rather than treating the entire area.  Consider pest occurrence and history when developing pest management strategies.  Time pesticide application to minimize host plant damage and maximize pest control.  Rotate annual garden plants to reduce the buildup of soil-borne pests. Clean up plant litter and remove weeds before they go to seed. Remove infested plant residue from the garden in the fall so that pests do not over-winter there.  Implement cultural controls such as proper plant selection, planting time, and planting method to reduce susceptibility to insects, pests, and diseases, thereby reducing pesticide usage.  Implement mechanical and physical controls where practical as an alternative to chemical application. Examples include a wide variety of practices such as "collars" around seedlings, mulching, solar heating, syringing, handpicking, mowing, hoeing, and traps.  Use biological controls where appropriate to reduce pesticide usage. For example, introduce natural enemies of pests such as lady beetles and green lacewings. (Note: pesticides may kill these natural enemies.)  Consider applying environmentally friendly chemical alternatives such as insecticidal soaps, horticultural oils, and other such measures when practical and effective and when mechanical approaches are impractical.  Know characteristics of the application site, including soil type and depth to groundwater to avoid migration of chemicals into groundwater.  Select pesticides and herbicides best suited to the characteristics of the target site and the particular pest or weed. Half-life, solubility, and adsorption should be compared to site characteristics to determine the safest chemical. Choose least toxic and less persistent sprays whenever possible based on comparison of labels and associated material safety data sheets.  Employ application techniques that increase efficiency and allow the lowest effective application rate. Carefully calibrate application equipment and follow all label instructions.  Recognize that it is not realistic for a landscape to be completely pest-free or weed-free. Consider using Integrated Pest Management (IPM) strategies to minimize chemical usage.  Keep pesticide and fertilizer equipment properly calibrated according to the manufacturer's instructions and in good repair. Recalibrate equipment periodically to compensate for wear in pumps, nozzles and metering systems. Calibrate sprayers when new nozzles are installed.  All mixing and loading operations must occur on an impervious surface. Use of Pesticides, Herbicides and Fertilizers S-8 November 2010 Urban Drainage and Flood Control District PHF-3 Urban Storm Drainage Criteria Manual Volume 3 Managing Mosquitoes in Stormwater Facilities (Adapted from: Peairs and Cranshaw 2007) The key to mosquito control is larval management. Larvae occur in specific areas and can be controlled by modifying the habitat through drainage or insecticides applied to larval breeding sites. Weekly mosquito inspections at stormwater facilities with targeted treatments are frequently less costly and more effective than regular widespread application of insecticides. These inspections can be performed by a mosquito control source and typically start in mid-May and extend to mid-September. Mosquito control measures must be cost effective and environmentally sound. Consider alternatives before application of conventional chemical insecticides.  Habitat Modification: Eliminating breeding sites, or habitat modification, is an effective and long-term solution. Proper maintenance of stormwater BMPs to avoid shallow standing water is important.  Natural Predators: Fish, dragonfly nymphs, and diving beetles are natural predators of mosquito larvae; dragonflies, birds, and bats feed on adults. Consult the Colorado Division of Wildlife for recommendations, restrictions and regulations regarding mosquito-eating fish.  Insecticides: Microbial insecticides such as the bacteria "Bti" (Bacillus thuringiensis israeliensis) can be as effective as chemical insecticides. Bti is toxic only to mosquito and midge larvae. It is not hazardous to non-target organisms but can reduce midge populations that serve as fish food. "Soft" chemical insecticides, such as the insect growth regulator methoprene, are toxic only to insects and other arthropods. They are similar to certain insect hormones and create imbalances in the levels of hormones needed for proper mosquito growth and development. They do not directly harm fish or other wildlife but can reduce the amount of available food. Mosquito larvae also can be controlled by the application of larvicidal oils or chemical insecticides to the water where they occur or are suspected to occur. Remember, several alternatives to conventional chemical larvicides have been developed because of concerns about applying chemicals to water that might be used for drinking or that contains fish and other aquatic life. If larval control fails, adult mosquito control may be necessary. Adult control generally is done with insecticide applications using ground equipment or aircraft. For more information visit: www.ext.colostate.edu/westnile/mosquito_mgt.html or www.ext.colostate.edu/westnile/faq.html. Application Practices  Keep records of pesticide application and provide signage as required by law.  Do not apply pesticides or herbicides during high temperatures, windy conditions or immediately prior to heavy rainfall or irrigation.  Treat for and control noxious weeds prior to installing the landscape using an herbicide targeted to the weeds that are present and applied in accordance with the product label.  Be aware that some pesticide formulations are not compatible with other pesticides and combining them may result in increased potency and phytotoxicity. S-8 Use of Pesticides, Herbicides and Fertilizers PHF-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Figure PHF-1. Example Combined Pesticide and Fertilizer Storage and Mixing Area. Figure courtesy of Designing Facilities for Pesticides and Fertilizer Containment, Midwest Planning Service, Agricultural Engineering, Iowa State University 1991.  Maintain a buffer zone around wells or surface water where pesticides are not applied. Consult local regulations and landscape ordinances, as well as the product label, for distances, which may vary depending on the type of chemical and the sensitivity of the waterbody. The purpose of this practice is to keep pesticides and herbicides out of surface waterbodies. Storage Practices  Storage areas should be secure and covered, preventing exposure to rain and unauthorized access. Commercial and municipal facilities should provide basic safety equipment such as fire extinguishers, warning signs (e.g., "no smoking"), adequate light and ventilation, and spill clean-up materials should be present. Floors and shelves should be non-porous (e.g., metal, concrete) to prevent sorption of chemicals. If possible, temperature control should be provided to avoid excessive heat or cold. Storage areas should be kept clear of combustible material and debris.  Commercial operations handling large quantities of pesticides and fertilizers should consult the Colorado Department of Agriculture for storage and handling requirements. Commercial greenhouses and nurseries that are storing recycled water laden with fertilizer may need to provide secondary containment to contain the water in the event of a tank rupture or leak.  Store chemicals in their original containers, tightly closed, with labels intact. Also inspect them regularly for leaks. Store nitrate-based and other oxidizing fertilizers separately from solvents, fuels, and pesticides to reduce fire risk. Follow the general principle of storing like chemicals together. Dry chemicals should be stored above liquids and on pallets to ensure that they do not get wet.  Locate chemical storage and maintenance areas, as well as vehicle refueling and maintenance areas, away from wells and surface waterbodies in accordance with local regulations, typically at least 50 to 100 feet away. Use of Pesticides, Herbicides and Fertilizers S-8 November 2010 Urban Drainage and Flood Control District PHF-5 Urban Storm Drainage Criteria Manual Volume 3 For More Information on Legal Requirements Many federal and state regulations address pesticide, herbicide, and other chemical usage. These sources should be consulted for the most current legal requirements related to chemical handling, storage, application, disposal, and reporting of chemical spills. Examples include the federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the Superfund Amendments and Reauthorization Act (SARA), the Emergency Planning and Community-Right-to-Know Act (EPCRA), and Occupational Safety and Health Administration (OSHA) requirements, particularly the Hazard Communication Standard. Colorado-related regulations include the Colorado Pesticide Applicator's Act, and the Colorado Water Quality Control Act (25-8-601 and 25-8-606), Senate Bill 90-126, and The Agricultural Chemicals and Groundwater Protection Act, which identifies special requirements for facilities handling more than 3,000 pounds (or 500 gallons) of bulk-formulated pesticides.  Make available all Material Safety Data Sheets (MSDSs) in a readily accessible area. A list of all hazardous chemicals in the work place must be completed to ensure that all MSDSs are readily available.  Do not store large quantities of pesticides for long periods of time. Adopt the "first in, first out" principle, using the oldest products first to ensure that the shelf life does not expire. Buy smaller quantities of pesticides and fertilizers, thereby reducing storage issues. Spills and Disposal  Never pour lawn and garden chemicals or rinse water down storm drains (or sanitary drains) and keep chemicals off impervious surfaces (e.g., streets, gutters) during application.  Follow label directions for disposal. This typically involves triple-rinsing empty containers, puncturing and crushing. All visible chemicals should be cleaned from the container prior to disposal. Use local recycling or hazardous waste collection centers to dispose of unused chemicals.  Properly manage chemical spills by cleaning them up as soon as possible, controlling actively spilling or leaking materials, containing the spilled material (e.g., with absorbents, sand), collecting the spilled material, storing or disposing of the spilled material, and following relevant spill reporting requirements. "Washing down" a spill with water is not an appropriate cleanup approach.  Commercial operations should be aware of and comply with basic spill reporting requirements required by law, and keep chemical spill cleanup equipment, personal protective equipment and emergency phone numbers available when handling chemicals and their containers. Street Sweeping and Cleaning S-11 November 2010 Urban Drainage and Flood Control District SWC-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph SSC-1. Monthly street sweeping from April through November removed nearly 40,690 cubic yards of sediment/debris from Denver streets in 2009. Photo courtesy of Denver Public Works. Description Street sweeping uses mechanical pavement cleaning practices to reduce sediment, litter and other debris washed into storm sewers by runoff. This can reduce pollutant loading to receiving waters and in some cases reduce clogging of storm sewers and prolong the life of infiltration oriented BMPs and reduce clogging of outlet structures in detention BMPs. Different designs are available with typical sweepers categorized as a broom and conveyor belt sweeper, wet or dry vacuum-assisted sweepers, and regenerative-air sweepers. The effectiveness of street sweeping is dependent upon particle loadings in the area being swept, street texture, moisture conditions, parked car management, equipment operating conditions and frequency of cleaning (Pitt et al. 2004). Appropriate Uses Street sweeping is an appropriate technique in urban areas where sediment and litter accumulation on streets is of concern for aesthetic, sanitary, water quality, and air quality reasons. From a pollutant loading perspective, street cleaning equipment can be most effective in areas where the surface to be cleaned is the major source of contaminants. These areas include freeways, large commercial parking lots, and paved storage areas (Pitt et al. 2004). Where significant sediment accumulation occurs on pervious surfaces tributary to infiltration BMPs, street sweeping may help to reduce clogging of infiltration media. In areas where construction activity is occurring, street sweeping should occur as part of construction site stormwater management plans. Vacuuming of permeable pavement systems is also considered a basic routine maintenance practice to maintain the BMP in effective operating condition. See the maintenance chapter for more information on permeable pavement systems. Not all sweepers are appropriate for this application. Practice Guidelines 1 1. Post street sweeping schedules with signs and on local government websites so that cars are not parked on the street during designated sweeping days. 2. Sweeping frequency is dependent on local government budget, staffing, and equipment availability, but monthly sweeping during non-winter months is a common approach in the metro Denver urban 1 Practice guidelines adapted from CASQA (2003) California Stormwater BMP Handbook, Practice SC-70 Road and Street Maintenance. S-11 Street Sweeping and Cleaning SWC-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Changes in Street Sweeper Technology (Source: Center for Watershed Protection 2002) At one time, street sweepers were thought to have great potential to remove stormwater pollutants from urban street surfaces and were widely touted as a stormwater treatment practice in many communities. Street sweeping gradually fell out of favor, largely as a result of performance monitoring conducted as part of the National Urban Runoff Program (NURP). These studies generally concluded that street sweepers were not very effective in reducing pollutant loads (USEPA, 1983). The primary reason for the mediocre performance was that mechanical sweepers of that era were unable to pick up fine-grained sediment particles that carry a substantial portion of the stormwater pollutant load. In addition, the performance of sweepers is constrained by that portion of a street’s stormwater pollutant load delivered from outside street pavements (e.g., pollutants that wash onto the street from adjacent areas or are directly deposited on the street by rainfall). Street sweeping technology, however, has evolved considerably since the days of the NURP testing. Today, communities have a choice in three basic sweeping technologies to clean their urban streets: traditional mechanical sweepers that utilize a broom and conveyor belt, vacuum-assisted sweepers, and regenerative-air sweepers (those that blast air onto the pavement to loosen sediment particles and vacuum them into a hopper). For more information, see http://www.cwp.org/Resource_Library/Center_Docs/PWP/ELC_PWP121.pdf area. Consider increasing sweeping frequency based on factors such as traffic volume, land use, field observations of sediment and trash accumulation, proximity to watercourses, etc. For example:  Increase the sweeping frequency for streets with high pollutant loadings, especially in high traffic and industrial areas.  Conduct street sweeping prior to wetter seasons to remove accumulated sediments.  Increase the sweeping frequency for streets in special problem areas such as special events, high litter or erosion zones. 3. Perform street cleaning during dry weather if possible. 4. Avoid wet cleaning the street; instead, utilize dry methods where possible. 5. Maintain cleaning equipment in good working condition and purchase replacement equipment as needed. Old sweepers should be replaced with more technologically advanced sweepers (preferably regenerative air sweepers) that maximize pollutant removal. 6. Operate sweepers at manufacturer recommended optimal speed levels to increase effectiveness. 7. Regularly inspect vehicles and equipment for leaks and repair promptly. 8. Keep accurate logs of the number of curb-miles swept and the amount of waste collected. 9. Dispose of street sweeping debris and dirt at a landfill. 10. Do not store swept material along the side of the street or near a storm drain inlet. Silt Fence (SF) SC-1 November 2010 Urban Drainage and Flood Control District SF-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph SF-1. Silt fence creates a sediment barrier, forcing sheet flow runoff to evaporate or infiltrate. Description A silt fence is a woven geotextile fabric attached to wooden posts and trenched into the ground. It is designed as a sediment barrier to intercept sheet flow runoff from disturbed areas. Appropriate Uses A silt fence can be used where runoff is conveyed from a disturbed area as sheet flow. Silt fence is not designed to receive concentrated flow or to be used as a filter fabric. Typical uses include:  Down slope of a disturbed area to accept sheet flow.  Along the perimeter of a receiving water such as a stream, pond or wetland.  At the perimeter of a construction site. Design and Installation Silt fence should be installed along the contour of slopes so that it intercepts sheet flow. The maximum recommended tributary drainage area per 100 lineal feet of silt fence, installed along the contour, is approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no steeper than 3:1. Longer and steeper slopes require additional measures. This recommendation only applies to silt fence installed along the contour. Silt fence installed for other uses, such as perimeter control, should be installed in a way that will not produce concentrated flows. For example, a "J-hook" installation may be appropriate to force runoff to pond and evaporate or infiltrate in multiple areas rather than concentrate and cause erosive conditions parallel to the silt fence. See Detail SF-1 for proper silt fence installation, which involves proper trenching, staking, securing the fabric to the stakes, and backfilling the silt fence. Properly installed silt fence should not be easily pulled out by hand and there should be no gaps between the ground and the fabric. Silt fence must meet the minimum allowable strength requirements, depth of installation requirement, and other specifications in the design details. Improper installation of silt fence is a common reason for silt fence failure; however, when properly installed and used for the appropriate purposes, it can be highly effective. Silt Fence Functions Erosion Control No Sediment Control Yes Site/Material Management No SC-1 Silt Fence (SF) SF-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Photograph SF-2. When silt fence is not installed along the contour, a "J-hook" installation may be appropriate to ensure that the BMP does not create concentrated flow parallel to the silt fence. Photo courtesy of Tom Gore. Maintenance and Removal Inspection of silt fence includes observing the material for tears or holes and checking for slumping fence and undercut areas bypassing flows. Repair of silt fence typically involves replacing the damaged section with a new section. Sediment accumulated behind silt fence should be removed, as needed to maintain BMP effectiveness, typically before it reaches a depth of 6 inches. Silt fence may be removed when the upstream area has reached final stabilization. Silt Fence (SF) SC-1 November 2010 Urban Drainage and Flood Control District SF-3 Urban Storm Drainage Criteria Manual Volume 3 SC-1 Silt Fence (SF) SF-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC-2 November 2015 Urban Drainage and Flood Control District SCL-1 Urban Storm Drainage Criteria Manual Volume 3 Photographs SCL-1 and SCL-2. Sediment control logs used as 1) a perimeter control around a soil stockpile; and, 2) as a "J-hook" perimeter control at the corner of a construction site. Description A sediment control log is a linear roll made of natural materials such as straw, coconut fiber, or compost. The most common type of sediment control log has straw filling and is often referred to as a "straw wattle." All sediment control logs are used as a sediment barrier to intercept sheet flow runoff from disturbed areas. Appropriate Uses Sediment control logs can be used in the following applications to trap sediment:  As perimeter control for stockpiles and the site.  As part of inlet protection designs.  As check dams in small drainage ditches. (Sediment control logs are not intended for use in channels with high flow velocities.)  On disturbed slopes to shorten flow lengths (as an erosion control).  As part of multi-layered perimeter control along a receiving water such as a stream, pond or wetland. Sediment control logs work well in combination with other layers of erosion and sediment controls. Design and Installation Sediment control logs should be installed along the contour to avoid concentrating flows. The maximum allowable tributary drainage area per 100 lineal feet of sediment control log, installed along the contour, is approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no steeper than 3:1. Longer and steeper slopes require additional measures. This recommendation only applies to sediment control logs installed along the contour. When installed for other uses, such as perimeter control, it should be installed in a way that will not produce concentrated flows. For example, a "J-hook" installation may be appropriate to force runoff to pond and evaporate or infiltrate in multiple areas rather than concentrate and cause erosive conditions parallel to the BMP. Sediment Control Log Functions Erosion Control Moderate Sediment Control Yes Site/Material Management No SC-2 Sediment Control Log (SCL) SCL-2 Urban Drainage and Flood Control District November 2015 Urban Storm Drainage Criteria Manual Volume 3 Although sediment control logs initially allow runoff to flow through the BMP, they can quickly become a barrier and should be installed as if they are impermeable. Design details and notes for sediment control logs are provided in the following details. Sediment logs must be properly installed per the detail to prevent undercutting, bypassing and displacement. When installed on slopes, sediment control logs should be installed along the contours (i.e., perpendicular to flow). Improper installation can lead to poor performance. Be sure that sediment control logs are properly trenched (if lighter than 8 lb/foot), anchored and tightly jointed. Maintenance and Removal Be aware that sediment control logs will eventually degrade. Remove accumulated sediment before the depth is one-half the height of the sediment log and repair damage to the sediment log, typically by replacing the damaged section. Once the upstream area is stabilized, remove and properly dispose of the logs. Areas disturbed beneath the logs may need to be seeded and mulched. Sediment control logs that are biodegradable may occasionally be left in place (e.g., when logs are used in conjunction with erosion control blankets as permanent slope breaks). However, removal of sediment control logs after final stabilization is typically appropriate when used in perimeter control, inlet protection and check dam applications. Compost from compost sediment control logs may be spread over the area and seeded as long as this does not cover newly established vegetation. Sediment Control Log (SCL) SC-2 November 2015 Urban Drainage and Flood Control District SCL-3 Urban Storm Drainage Criteria Manual Volume 3 SC-2 Sediment Control Log (SCL) SCL-4 Urban Drainage and Flood Control District November 2015 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC-2 November 2015 Urban Drainage and Flood Control District SCL-5 Urban Storm Drainage Criteria Manual Volume 3 SC-2 Sediment Control Log (SCL) SCL-6 Urban Drainage and Flood Control District November 2015 Urban Storm Drainage Criteria Manual Volume 3 Rock Sock (RS) SC-5 November 2010 Urban Drainage and Flood Control District RS-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph RS-1. Rock socks placed at regular intervals in a curb line can help reduce sediment loading to storm sewer inlets. Rock socks can also be used as perimeter controls. Description A rock sock is constructed of gravel that has been wrapped by wire mesh or a geotextile to form an elongated cylindrical filter. Rock socks are typically used either as a perimeter control or as part of inlet protection. When placed at angles in the curb line, rock socks are typically referred to as curb socks. Rock socks are intended to trap sediment from stormwater runoff that flows onto roadways as a result of construction activities. Appropriate Uses Rock socks can be used at the perimeter of a disturbed area to control localized sediment loading. A benefit of rock socks as opposed to other perimeter controls is that they do not have to be trenched or staked into the ground; therefore, they are often used on roadway construction projects where paved surfaces are present. Use rock socks in inlet protection applications when the construction of a roadway is substantially complete and the roadway has been directly connected to a receiving storm system. Design and Installation When rock socks are used as perimeter controls, the maximum recommended tributary drainage area per 100 lineal feet of rock socks is approximately 0.25 acres with disturbed slope length of up to 150 feet and a tributary slope gradient no steeper than 3:1. A rock sock design detail and notes are provided in Detail RS-1. Also see the Inlet Protection Fact Sheet for design and installation guidance when rock socks are used for inlet protection and in the curb line. When placed in the gutter adjacent to a curb, rock socks should protrude no more than two feet from the curb in order for traffic to pass safely. If located in a high traffic area, place construction markers to alert drivers and street maintenance workers of their presence. Maintenance and Removal Rock socks are susceptible to displacement and breaking due to vehicle traffic. Inspect rock socks for damage and repair or replace as necessary. Remove sediment by sweeping or vacuuming as needed to maintain the functionality of the BMP, typically when sediment has accumulated behind the rock sock to one-half of the sock's height. Once upstream stabilization is complete, rock socks and accumulated sediment should be removed and properly disposed. Rock Sock Functions Erosion Control No Sediment Control Yes Site/Material Management No SC-5 Rock Sock (RS) RS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rock Sock (RS) SC-5 November 2010 Urban Drainage and Flood Control District RS-3 Urban Storm Drainage Criteria Manual Volume 3 Vegetated Buffers (VB) SC-9 November 2010 Urban Drainage and Flood Control District VB-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph VB-1. A vegetated buffer is maintained between the area of active construction and the drainage swale. Photo courtesy of WWE. Description Buffer strips of preserved natural vegetation or grass help protect waterways and wetlands from land disturbing activities. Vegetated buffers improve stormwater runoff quality by straining sediment, promoting infiltration, and slowing runoff velocities. Appropriate Uses Vegetated buffers can be used to separate land disturbing activities and natural surface waters or conveyances. In many jurisdictions, local governments require some type of setback from natural waterways. Concentrated flow should not be directed through a buffer; instead, runoff should be in the form of sheet flow. Vegetated buffers are typically used in combination with other perimeter control BMPs such as sediment control logs or silt fence for multi- layered protection. Design and Installation Minimum buffer widths may vary based on local regulations. Clearly delineate the boundary of the natural buffer area using construction fencing, silt fence, or a comparable technique. In areas that have been cleared and graded, vegetated buffers such as sod can also be installed to create or restore a vegetated buffer around the perimeter of the site. Maintenance and Removal Inspect buffer areas for signs of erosion such as gullies or rills. Stabilize eroding areas, as needed. If erosion is due to concentrated flow conditions, it may be necessary to install a level spreader or other technique to restore sheet flow conditions. Inspect perimeter controls delineating the vegetative buffer and repair or replace as needed. Vegetated Buffers Functions Erosion Control Moderate Sediment Control Yes Site/Material Management Yes Protection of Existing Vegetation (PV) SM-2 November 2010 Urban Drainage and Flood Control District PV-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph PV-1. Protection of existing vegetation and a sensitive area. Photo courtesy of CDOT. Description Protection of existing vegetation on a construction site can be accomplished through installation of a construction fence around the area requiring protection. In cases where upgradient areas are disturbed, it may also be necessary to install perimeter controls to minimize sediment loading to sensitive areas such as wetlands. Existing vegetation may be designated for protection to maintain a stable surface cover as part of construction phasing, or vegetation may be protected in areas designated to remain in natural condition under post-development conditions (e.g., wetlands, mature trees, riparian areas, open space). Appropriate Uses Existing vegetation should be preserved for the maximum practical duration on a construction site through the use of effective construction phasing. Preserving vegetation helps to minimize erosion and can reduce revegetation costs following construction. Protection of wetland areas is required under the Clean Water Act, unless a permit has been obtained from the U.S. Army Corps of Engineers (USACE) allowing impacts in limited areas. If trees are to be protected as part of post-development landscaping, care must be taken to avoid several types of damage, some of which may not be apparent at the time of injury. Potential sources of injury include soil compaction during grading or due to construction traffic, direct equipment-related injury such as bark removal, branch breakage, surface grading and trenching, and soil cut and fill. In order to minimize injuries that may lead to immediate or later death of the tree, tree protection zones should be developed during site design, implemented at the beginning of a construction project, as well as continued during active construction. Design and Installation General Once an area has been designated as a preservation area, there should be no construction activity allowed within a set distance of the area. Clearly mark the area with construction fencing. Do not allow stockpiles, equipment, trailers or parking within the protected area. Guidelines to protect various types of existing vegetation follow. Protection of Existing Vegetation Functions Erosion Control Yes Sediment Control Moderate Site/Material Management Yes SM-2 Protection of Existing Vegetation (PV) PV-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Surface Cover During Phased Construction Install construction fencing or other perimeter controls around areas to be protected from clearing and grading as part of construction phasing. Maintaining surface cover on steep slopes for the maximum practical duration during construction is recommended. Open Space Preservation Where natural open space areas will be preserved as part of a development, it is important to install construction fencing around these areas to protect them from compaction. This is particularly important when areas with soils with high infiltration rates are preserved as part of LID designs. Preserved open space areas should not be used for staging and equipment storage. Wetlands and Riparian Areas Install a construction fence around the perimeter of the wetland or riparian (streamside vegetation) area to prevent access by equipment. In areas downgradient of disturbed areas, install a perimeter control such as silt fence, sediment control logs, or similar measure to minimize sediment loading to the wetland. Tree Protection 1  Before beginning construction operations, establish a tree protection zone around trees to be preserved by installing construction fences. Allow enough space from the trunk to protect the root zone from soil compaction and mechanical damage, and the branches from mechanical damage (see Table PV-1). If low branches will be kept, place the fence outside of the drip line. Where this is not possible, place fencing as far away from the trunk as possible. In order to maintain a healthy tree, be aware that about 60 percent of the tree's root zone extends beyond the drip line. Table PV-1 Guidelines for Determining the Tree Protection Zone (Source: Matheny and Clark, 1998; as cited in GreenCO and WWE 2008) Distance from Trunk (ft) per inch of DBH Species Tolerance to Damage Young Mature Over mature Good 0.5' 0.75' 1.0' Moderate 0.75' 1.0' 1.25' Poor 1.0' 1.25' 1.5' Notes: DBH = diameter at breast height (4.5 ft above grade); Young = <20% of life expectancy; Mature = 20%-80% of life expectancy; Over mature =>80% of life expectancy  Most tree roots grow within the top 12 to 18 inches of soil. Grade changes within the tree protection zone should be avoided where possible because seemingly minor grade changes can either smother 1 Tree Protection guidelines adapted from GreenCO and WWE (2008). Green Industry Best Management Practices (BMPs) for the Conservation and Protection of Water Resources in Colorado: Moving Toward Sustainability, Third Release. See www.greenco.org for more detailed guidance on tree preservation. Protection of Existing Vegetation (PV) SM-2 November 2010 Urban Drainage and Flood Control District PV-3 Urban Storm Drainage Criteria Manual Volume 3 roots (in fill situations) or damage roots (in cut situations). Consider small walls where needed to avoid grade changes in the tree protection zone.  Place and maintain a layer of mulch 4 to 6-inch thick from the tree trunk to the fencing, keeping a 6-inch space between the mulch and the trunk. Mulch helps to preserve moisture and decrease soil compaction if construction traffic is unavoidable. When planting operations are completed, the mulch may be reused throughout planting areas.  Limit access, if needed at all, and appoint one route as the main entrance and exit to the tree protection zone. Within the tree protection zone, do not allow any equipment to be stored, chemicals to be dumped, or construction activities to take place except fine grading, irrigation system installation, and planting operations. These activities should be conducted in consultation with a landscaping professional, following Green Industry BMPs.  Be aware that soil compaction can cause extreme damage to tree health that may appear gradually over a period of years. Soil compaction is easier to prevent than repair. Maintenance and Removal Repair or replace damaged or displaced fencing or other protective barriers around the vegetated area. If damage occurs to a tree, consult an arborist for guidance on how to care for the tree. If a tree in a designated preservation area is damaged beyond repair, remove and replace with a 2-inch diameter tree of the same or similar species. Construction equipment must not enter a wetland area, except as permitted by the U.S. Army Corps of Engineers (USACE). Inadvertent placement of fill in a wetland is a 404 permit violation and will require notification of the USACE. If damage to vegetation occurs in a protected area, reseed the area with the same or similar species, following the recommendations in the USDCM Revegetation chapter. Construction Fence (CF) SM-3 November 2010 Urban Drainage and Flood Control District CF-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph CF-1. A construction fence helps delineate areas where existing vegetation is being protected. Photo courtesy of Douglas County. Description A construction fence restricts site access to designated entrances and exits, delineates construction site boundaries, and keeps construction out of sensitive areas such as natural areas to be preserved as open space, wetlands and riparian areas. Appropriate Uses A construction fence can be used to delineate the site perimeter and locations within the site where access is restricted to protect natural resources such as wetlands, waterbodies, trees, and other natural areas of the site that should not be disturbed. If natural resource protection is an objective, then the construction fencing should be used in combination with other perimeter control BMPs such as silt fence, sediment control logs or similar measures. Design and Installation Construction fencing may be chain link or plastic mesh and should be installed following manufacturer’s recommendations. See Detail CF-1 for typical installations. Do not place construction fencing in areas within work limits of machinery. Maintenance and Removal  Inspect fences for damage; repair or replace as necessary.  Fencing should be tight and any areas with slumping or fallen posts should be reinstalled.  Fencing should be removed once construction is complete. Construction Fence Functions Erosion Control No Sediment Control No Site/Material Management Yes SM-3 Construction Fence (CF) CF-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Construction Fence (CF) SM-3 November 2010 Urban Drainage and Flood Control District CF-3 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 November 2010 Urban Drainage and Flood Control District VTC-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph VTC-1. A vehicle tracking control pad constructed with properly sized rock reduces off-site sediment tracking. Description Vehicle tracking controls provide stabilized construction site access where vehicles exit the site onto paved public roads. An effective vehicle tracking control helps remove sediment (mud or dirt) from vehicles, reducing tracking onto the paved surface. Appropriate Uses Implement a stabilized construction entrance or vehicle tracking control where frequent heavy vehicle traffic exits the construction site onto a paved roadway. An effective vehicle tracking control is particularly important during the following conditions:  Wet weather periods when mud is easily tracked off site.  During dry weather periods where dust is a concern.  When poorly drained, clayey soils are present on site. Although wheel washes are not required in designs of vehicle tracking controls, they may be needed at particularly muddy sites. Design and Installation Construct the vehicle tracking control on a level surface. Where feasible, grade the tracking control towards the construction site to reduce off-site runoff. Place signage, as needed, to direct construction vehicles to the designated exit through the vehicle tracking control. There are several different types of stabilized construction entrances including: VTC-1. Aggregate Vehicle Tracking Control. This is a coarse-aggregate surfaced pad underlain by a geotextile. This is the most common vehicle tracking control, and when properly maintained can be effective at removing sediment from vehicle tires. VTC-2. Vehicle Tracking Control with Construction Mat or Turf Reinforcement Mat. This type of control may be appropriate for site access at very small construction sites with low traffic volume over vegetated areas. Although this application does not typically remove sediment from vehicles, it helps protect existing vegetation and provides a stabilized entrance. Vehicle Tracking Control Functions Erosion Control Moderate Sediment Control Yes Site/Material Management Yes SM-4 Vehicle Tracking Control (VTC) VTC-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Photograph VTC-2. A vehicle tracking control pad with wheel wash facility. Photo courtesy of Tom Gore. VTC-3. Stabilized Construction Entrance/Exit with Wheel Wash. This is an aggregate pad, similar to VTC-1, but includes equipment for tire washing. The wheel wash equipment may be as simple as hand-held power washing equipment to more advance proprietary systems. When a wheel wash is provided, it is important to direct wash water to a sediment trap prior to discharge from the site. Vehicle tracking controls are sometimes installed in combination with a sediment trap to treat runoff. Maintenance and Removal Inspect the area for degradation and replace aggregate or material used for a stabilized entrance/exit as needed. If the area becomes clogged and ponds water, remove and dispose of excess sediment or replace material with a fresh layer of aggregate as necessary. With aggregate vehicle tracking controls, ensure rock and debris from this area do not enter the public right-of-way. Remove sediment that is tracked onto the public right of way daily or more frequently as needed. Excess sediment in the roadway indicates that the stabilized construction entrance needs maintenance. Ensure that drainage ditches at the entrance/exit area remain clear. A stabilized entrance should be removed only when there is no longer the potential for vehicle tracking to occur. This is typically after the site has been stabilized. When wheel wash equipment is used, be sure that the wash water is discharged to a sediment trap prior to discharge. Also inspect channels conveying the water from the wash area to the sediment trap and stabilize areas that may be eroding. When a construction entrance/exit is removed, excess sediment from the aggregate should be removed and disposed of appropriately. The entrance should be promptly stabilized with a permanent surface following removal, typically by paving. Vehicle Tracking Control (VTC) SM-4 November 2010 Urban Drainage and Flood Control District VTC-3 Urban Storm Drainage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) VTC-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 November 2010 Urban Drainage and Flood Control District VTC-5 Urban Storm Drainage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) VTC-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Stabilized Staging Area (SSA) SM-6 November 2010 Urban Drainage and Flood Control District SSA-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph SSA-1. Example of a staging area with a gravel surface to prevent mud tracking and reduce runoff. Photo courtesy of Douglas County. Description A stabilized staging area is a clearly designated area where construction equipment and vehicles, stockpiles, waste bins, and other construction-related materials are stored. The contractor office trailer may also be located in this area. Depending on the size of the construction site, more than one staging area may be necessary. Appropriate Uses Most construction sites will require a staging area, which should be clearly designated in SWMP drawings. The layout of the staging area may vary depending on the type of construction activity. Staging areas located in roadways due to space constraints require special measures to avoid materials being washed into storm inlets. Design and Installation Stabilized staging areas should be completed prior to other construction activities beginning on the site. Major components of a stabilized staging area include:  Appropriate space to contain storage and provide for loading/unloading operations, as well as parking if necessary.  A stabilized surface, either paved or covered, with 3-inch diameter aggregate or larger.  Perimeter controls such as silt fence, sediment control logs, or other measures.  Construction fencing to prevent unauthorized access to construction materials.  Provisions for Good Housekeeping practices related to materials storage and disposal, as described in the Good Housekeeping BMP Fact Sheet.  A stabilized construction entrance/exit, as described in the Vehicle Tracking Control BMP Fact Sheet, to accommodate traffic associated with material delivery and waste disposal vehicles. Over -sizing the stabilized staging area may result in disturbance of existing vegetation in excess of that required for the project. This increases costs, as well as requirements for long-term stabilization following the construction period. When designing the stabilized staging area, minimize the area of disturbance to the extent practical. Stabilized Staging Area Functions Erosion Control Yes Sediment Control Moderate Site/Material Yes SM-6 Stabilized Staging Area (SSA) SSA-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 See Detail SSA-1 for a typical stabilized staging area and SSA-2 for a stabilized staging area when materials staging in roadways is required. Maintenance and Removal Maintenance of stabilized staging areas includes maintaining a stable surface cover of gravel, repairing perimeter controls, and following good housekeeping practices. When construction is complete, debris, unused stockpiles and materials should be recycled or properly disposed. In some cases, this will require disposal of contaminated soil from equipment leaks in an appropriate landfill. Staging areas should then be permanently stabilized with vegetation or other surface cover planned for the development. Minimizing Long-Term Stabilization Requirements  Utilize off-site parking and restrict vehicle access to the site.  Use construction mats in lieu of rock when staging is provided in an area that will not be disturbed otherwise.  Consider use of a bermed contained area for materials and equipment that do not require a stabilized surface.  Consider phasing of staging areas to avoid disturbance in an area that will not be otherwise disturbed. Stabilized Staging Area (SSA) SM-6 November 2010 Urban Drainage and Flood Control District SSA-3 Urban Storm Drainage Criteria Manual Volume 3 SM-6 Stabilized Staging Area (SSA) SSA-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Street Sweeping and Vacuuming (SS) SM-7 November 2010 Urban Drainage and Flood Control District SS-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph SS-1. A street sweeper removes sediment and potential pollutants along the curb line at a construction site. Photo courtesy of Tom Gore. Description Street sweeping and vacuuming remove sediment that has been tracked onto roadways to reduce sediment transport into storm drain systems or a surface waterway. Appropriate Uses Use this practice at construction sites where vehicles may track sediment offsite onto paved roadways. Design and Installation Street sweeping or vacuuming should be conducted when there is noticeable sediment accumulation on roadways adjacent to the construction site. Typically, this will be concentrated at the entrance/exit to the construction site. Well-maintained stabilized construction entrances, vehicle tracking controls and tire wash facilities can help reduce the necessary frequency of street sweeping and vacuuming. On smaller construction sites, street sweeping can be conducted manually using a shovel and broom. Never wash accumulated sediment on roadways into storm drains. Maintenance and Removal  Inspect paved roads around the perimeter of the construction site on a daily basis and more frequently, as needed. Remove accumulated sediment, as needed.  Following street sweeping, check inlet protection that may have been displaced during street sweeping.  Inspect area to be swept for materials that may be hazardous prior to beginning sweeping operations. Street Sweeping/ Vacuuming Functions Erosion Control No Sediment Control Yes Site/Material Management Yes Tab 7 Materials Handling, Waste Management and Disposal, and Spill Prevention and Response Plan Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 MATERIALS HANDLING (§I.C.2.f) Consistent with the permit requirements, all potential pollutants other than sediment will be handled and disposed of in a manner that does not cause contamination of stormwater. Non -sediment pollutants that may be present during construction activities include, but are not limited to: • Exposed storage of building materials, • Petroleum products including fuel, lubricants, hydraulic fluids, and form oil (this includes storage, leaks, and fueling), • Condensate, • Antifreeze, • Pipe joining materials and waste, • Landscaping materials, • Fertilizers or chemicals, • Sanitary waste materials, • Trash and equipment maintenance, • Concrete, mortar, or similar products, and • Solvents, paints, or similar products. If these materials are used, then the following practices will be implemented. These materials, and other materials used during construction with the potential to impact stormwater, will be stored, managed, used, and disposed of in a manner that minimizes the potential for releases to the environment and especially into the stormwater system. Several of these activities and their controls are also described in Tab 4 as potential sources of pollut ion. a) Vehicle Maintenance: Vehicles entering the construction site should be properly maintained to prevent spills or leaks of hazardous fluids that would be exposed to stormwater. Vehicles used on -site will be inspected for leaks. Leaking vehicles will not be allowed to stay on-site or will use drip pans until the leak is repaired. The vehicle operator will be responsible for immediately commencing any necessary containment and clean up. Vehicles will not be parked in or near retention areas, natural drainage areas or surface waters. Drip pans will be used for secondary protection of on-site vehicles, if necessary. Maintenance and fueling areas, if needed, will be indicated on the Site Map. A spill kit will be available on site to clean up any spills or leaks. b) Stockpiles: Different types of earth material may need to be stockpiled on the job site during the earth moving activities. All stockpiles will have erosion and/or sediment control measures implemented around the toe of the pile or will be located within an area with perimeter controls . c) Solid Waste: Large amounts of solid waste are not anticipated to be generated during this project. The majority of solid waste will be collected in worker vehicles, removed from site, and properly disposed of . If larger quantities are generated than can be handled by individuals on site, then dumpsters will be provided in convenient, level locations away from traffic areas, storm drains, drainage areas, or retention areas. A licensed company will be contracted to empty the dumpsters, as needed. The site project managers will be responsible for monitoring the site to ensure that all site personnel and subcontractors use the proper waste disposal practices and facilities. Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 d) Concrete Washout Activities: A concrete washout is designed to capture wastewater and waste products resulting from the cleaning of concrete and masonry equipment and is the main control measure for concrete washout waste . A concrete washout may not be necessary if all washout operations are performed off -site. If a concrete washout is needed, it will be installed or provided prior to any construction activities that include the handling of materials containing cement (e.g., concrete, masonry, etc.). Concrete washouts may include small excavations located within the limits of disturbance or watertight vessels such as, small dumpsters, buckets, or a mobile disposal unit, etc. Concrete washouts require appropriate access control, tracking and containment. Signs should be placed at the washout area and elsewhere, as necessary, to clearly indicate the location of the concrete washout. If needed, the designated washout facility or facilities will be installed on site and the locations added to the Site Map . Concrete pours are not anticipated in the laydown yard , however, CWA waste associated with the transmission line construction may be temporarily staged in the laydown yard until hauled off for disposal. Maintenance may include the removal and proper disposal of excess material, cleaning or replacing the tracking material and general structural integrity of the installation, as needed. Concrete washouts will be cleaned of excess water and solids on a regular basis to maintain the proper function of the control measure. The hardened concrete and/or excess wash water will be hauled away by an approved contractor to a designated facility designed to receive such materials. No concrete waste will be discharged directly onto the ground without a containment feature and the washing activities cannot contribute pollutants to stormwater runoff . Discharges that may reach groundwater must flow through soil that has buffering capacity prior to reaching groundwater as necessary to meet the effluent limitations of the permit. Concrete washout water will not be discharged to state surface waters or to storm sewer systems. If unlined pits are used to contain concrete washout water, the following management practices must be implemented: • The washout site must be temporary (less than 1 year), • The washout site may not be located in an area where shallow groundwater may be present, such as near natural drainages, springs, or wetlands , and • 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. e) Portable Sanitary Facilities: Portable sanitary facilit y locations will be evaluated in the field and the most appropriate locations determined. Some factors that may influence the location will be access, convenience, level ground, traffic patterns , curb flowlines, paved surfaces, storm drains, and waterways or other stormwater conveyance areas. A licensed company will be hired to maintain and clean the units, inspect for any deficiencies, and keep the units in good working order. Portable sanitary facilities will be adequately anchored to prevent tipping over. SPILL PREVENTION AND RESPONSE PLAN (§I.B.1.a.ii.) a) Spill Prevention: Spills and leaks must be minimized. Upon identification, spills and leaks must immediately be contained and mitigated per the spill prevention and response plan, as applicable (i.e. oil, grease, fluids associated with vehicle and equipment maintenance, toxic chemicals, hazardous substances, etc.). Spills and leaks will not be hosed down unless the wash water is adequately captured and appropriately disposed of. The contractors on site will take all measures necessary to prevent spills that could impact stormwater. This includes, but is not limited to: Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 • Proper storage of all materials and chemicals , • Proper maintenance and protection of all containers , and • Proper handing/dispensing materials and chemicals. Bulk storage, 55 gallons or greater, for petroleum products and other liquid chemicals will have secondary containment, or equivalent protection, in order to contain spills and to prevent spilled material from entering state waters. b) Spill Response Procedures and Notifications: Spill response procedures are outlined in Environmental Directive for Contractors , a copy of which is at the end of this tab. Additional contacts are listed below. Contacts and Notifications for Spills or Releases : Xcel Environmental Group – 303-571-7100 (Xcel Environmental will make all necessary notifications to regulatory agencies including CDPHE.) Local Emergency Number – 911 CDPHE – 1-877-518-5608 NRC – 1-800-424-8802 Contaminated Soil Process Soils contaminated with hazardous materials or wastes can be encountered during installation of new electric or gas underground services and while maintaining existing services. This fact sheet outlines the process by which crews and planners should respond to contaminated soil. How to Determine if Contaminated Soil is Present Resources on XpressNet •Industrial Hygiene webpage HAZWOPER resources and HAZWOPER written program and Environmental Pages (‘All Media Checklist’) •http://xpressnet/Safety/Workplace_Safety/Programs_G_-_O/Industrial_Hygiene_Program For guidance/assistance when encountering contaminated soils contact Environmental Services on call #: NSP - (612) 330-7873, PSCO - (303) 571-7100, SPS - (806) 674-1890 **Environmental Services will contact Industrial Hygiene and Safety •Contaminated soil may exhibit staining or unusual odors. •Contaminated soil may be encountered in industrial areas, landfills or other areas of known environmental impacts like underground storage tanks from gas station operations, or associated with buried containers. What to do if you encounter contaminated soil during work Stop work and contact Environmental Services** Pre-Planning Process For project work in the design phase where there is a potential to encounter contamination – near by gas/fueling stations, industrial areas, landfills, railroads, or known, or potential areas of contamination •Contact Environmental Services to assist in the site assessment and characterization process to evaluate and determine the need to address potential contamination, and health and safety needs. •Each group has different criteria that need to be considered •Environmental – Ensure regulatory compliance and protection of public health and the environment, to minimize Company liability •Industrial Hygiene and Safety – worker protection driven by OSHA regulations Last Revised 11/3/2022 1 2022 Xcel Energy, Inc. R:\ES-ESG-ES\EnvSvcsResources\Manuals\Environmental Directives for Contractors\Current ENV 8.150 G01 Rev 3.2 Environmental Directives For Contractors Xcel Energy Environmental Services November 3, 2022 Last Revised 11/3/2022 2 2022 Xcel Energy, Inc. R:\ES-ESG-ES\EnvSvcsResources\Manuals\Environmental Directives for Contractors\Current Xcel Energy Environmental Directives for Suppliers Supplier has entered into one or more contracts (the “Contract”) with Xcel Energy Inc., or its subsidiaries or affiliates (referred to herein as “Xcel Energy”). As provided in the Contract, Supplier must comply with all applicable provisions of Xcel Energy's plant, Project, facility or Site policies and procedures, including but not limited to any instructions and procedures pertaining to plant or facility Site security, industrial safety, environmental directives, work authorization, equipment control and hazardous materials. As such, Supplier must comply with these Environmental Directives for Suppliers (“Directives”). Xcel Energy expects Supplier to support environmental compliance through its own policies and procedures, maintain all compliance, ensure the protection of human health and the environment, and to promote Xcel Energy’s reputation as an environmental leader in the communities Xcel Energy serves. Supplier should consider energy efficiency, pollution prevention, conservation, and performing operations in an environmentally responsible manner in all decision-making and work activities. Supplier must communicate these same values and requirements to its employees and subcontractors. The information in these Directives does not supersede any specific requirements listed in the Contract. Supplier is required to comply with all federal, state, and local laws, regulations, and requirements and any additional requirements or policies that may be required by Xcel Energy for the specific work at issue in the Contract. The subject areas listed in these Directives are not meant to provide an exhaustive list or complete summary of the types of safety, environmental or other concerns that Supplier must consider. Supplier is an independent Supplier. By providing these Directives to Supplier, Xcel Energy in no way assumes any of the duties, obligations, or liabilities attributed to Supplier under the Supplier or any obligations that Supplier must comply with federal, state, and local laws, regulations, and requirements to the extent there is a conflict between these Directives and the Contract, the Contract shall control. The Xcel Energy Contract Manager will identify the appropriate Xcel Energy Environmental Services (XEES) staff to serve as the contact(s) for the project. XEES staff may be located in one of Xcel Energy’s Corporate offices, a field office or service center, or at a power plant. Due to the complexity of some activities and the regulations, Supplier may have contact with more than one Xcel Energy “Subject Matter Expert” during performance of a Contract. Environmental and emergency contact numbers are listed at the end of these Directives for any inquires or notifications Supplier may have. Adherence to these Directives does not constitute completion of Supplier’s obligations under Xcel Energy’s Supplier Safety Program or Safety Program requirements identified by Xcel Energy’s Corporate Safety Department. Supplier is responsible for meeting all applicable safety requirements, including, but not limited to, the appropriate use of Personal Protective Equipment. Last Revised 11/3/2022 3 2022 Xcel Energy, Inc. R:\ES-ESG-ES\EnvSvcsResources\Manuals\Environmental Directives for Contractors\Current Supplier’s Responsibilities A. Planning Planning includes everything that happens before a Supplier begins work in the field. Supplier is tasked with several activities during this planning phase of work. The scope of work developed for various projects will determine the level of involvement and define roles and responsibilities for each contract and/or project. During the planning stages of a project, the Supplier should review all applicable laws, rules, regulations, permit requirements, and site- specific conditions that may impact or apply to the work. Supplier should also prepare for any spills, leaks, or accidents (or any unforeseen project emergency) that could occur during project implementation, so that Supplier is prepared to implement the appropriate response measures. Further details are provided below regarding spill response and reporting procedures. Before starting work, Supplier should identify an Emergency Coordinator and know the work location (the physical address where Supplier will be working) in the event an emergency arises. Before starting work, Supplier must also contact the XEES representative that has been designated as the representative for the project to discuss steps the Supplier is taking to ensure all activities are compliant with applicable environmental laws and regulations. B. Hazard Analysis Many activities performed by Supplier may be in or near areas that are contaminated or that were previously contaminated and have been remediated. To the extent practical, these areas should be identified in advance to avoid problem and delays caused by unforeseen site conditions. Supplier should conduct an appropriate site hazard analyses or undertake appropriate environmental due diligence prior to commencement of the work. Supplier should also have contingency plans in place in the event hazards are encountered. When unexpected contamination is discovered in the field - stop work, and immediately provide notification to your Xcel Energy Contract Manager and XEES representative to coordinate any immediate response actions and/or agency reporting. See further information below regarding spill response and reporting procedures. C. Permitting Permits apply to specific activities at specific locations and may have requirements that are more stringent than environmental laws and regulations. Supplier is responsible for identifying all necessary permits for Supplier work affecting Xcel Energy facilities or operations. Notwithstanding anything to the contrary set forth in the Contract, before starting work, Supplier must contact the designated XEES representative for the project to discuss whether Supplier or Xcel Energy will be the named applicant on the permit and whether the Supplier or Xcel Energy will be responsible for conducting permit research or preparing the permit application. Xcel Energy must be involved with any communications with regulatory agencies or made aware of any such communications prior to Supplier outreach to the regulatory agencies. Communication with regulatory agencies for Xcel Energy must include XEES and not be performed by the Supplier without XEES presence or permission. This includes permit discussions, application submittals, negotiation on permit conditions, and/or permit agreements. Supplier bears the responsibility for compliance with the permit terms and specified actions, limitations, notifications, and reporting requirements for Supplier’s and its Subcontractor’s activities. Failure to comply may subject the Supplier to significant fines and penalties as well as to project delays and potential shutdowns. Last Revised 11/3/2022 4 2022 Xcel Energy, Inc. R:\ES-ESG-ES\EnvSvcsResources\Manuals\Environmental Directives for Contractors\Current D. Chemical Control Supplier must review, approve, and track all chemicals used while working on Xcel Energy projects. This helps ensure that employees and Suppliers are not exposed to overly hazardous products, Safety Data Sheets (SDSs) are available for each product, and information for all required agency reporting is available. When selecting chemicals for use, Supplier should consider reducing disposal costs, reducing safety risks, buying only quantities needed to do the job, storing chemicals properly, checking expiration dates, and considering alternative products that may be an appropriate less-hazardous option. Supplier is responsible for ensuring that chemicals are used in accordance with all labels. Supplier must remove all unused chemicals and products at the completion of each job and as specified in the Contract. Supplier is not to abandon unused products at any Xcel Energy facility or jobsite. Unless Supplier receives permission from XEES, Supplier will not use products containing chemicals present on Xcel Energy’s Targeted Ingredients List and Supplier will not use products that it knows, or should know, contains Per and Polyfluoroalkyl Substances (also referred to as PFAS or PFCs) including PFOA, PFOS, GenX and other replacement PFAS. The listing of a chemical on the Targeted Ingredients List indicates that its use is restricted. This means that specific requirements must be met in order to use the product in a manner that complies with the applicable regulations. Xcel Energy’s Targeted Ingredients List can be found in Appendix D of Xcel Energy’s Chemical Hazard Communication Program or can be obtained from XEES or the designated Contract Manager upon Supplier’s request. If the Supplier desires to use a chemical or product that contains PFAS or is on the Targeted Ingredient List, before using the chemical or product Supplier must provide documentation to XEES explaining why the use of the product or chemical is necessary and why chemical alternatives that are not on the Targeted Ingredients List with a lower overall risk are not suitable for the specified application, as well as any other information that Xcel Energy may reasonably request, such as any safety precautions Supplier intends to adopt. Proposed restricted chemicals cannot be used until permission to proceed has been given by XEES. By giving permission to proceed with the use of a chemical or product, Xcel Energy in no way assumes any of the duties, obligations, or liabilities attributed to Supplier under the Contract and in no way is endorsing the use of the chemical for any particular application. E. Protected Species Supplier must follow all requirements associated with Protected Species. Protected Species means all plants and animals that are listed as a threatened or endangered species under the Endangered Species Act, or are otherwise protected under federal, state or local laws and may include birds, animals, plants, or fish, as well as their nests and habitat. Supplier is responsible for knowing if its work is being performed in an area where Protected Species may be present. Supplier must adhere to all requirements for working in areas with Protected Species and/or habitat and must not remove or destroy an active nest of a Protected Species. Any incident involving death, injury or removal of a Protected Species or an active nest shall be immediately reported to XEES. Supplier should assume that all birds are a Protected Species and shall confer with XEES for determination of the bird’s status as a Protected Species. F. Waste Supplier must comply with all applicable regulatory requirements, as well as Xcel Energy policies, for waste handling, including, but not limited to, hazardous wastes, universal wastes, Last Revised 11/3/2022 5 2022 Xcel Energy, Inc. R:\ES-ESG-ES\EnvSvcsResources\Manuals\Environmental Directives for Contractors\Current solid wastes, and special wastes. Supplier must coordinate closely with its Xcel Energy Contract Manager as well as directly with XEES. Supplier requirements include the following: • Correctly identify wastes by type and keep wastes separate, accumulate wastes in appropriate containers, label all containers according to XEES requirements or the appropriate regulations, and conduct inspections as required. • Store wastes only in areas that have been approved by the Xcel Energy Contract Manager or XEES. Storage areas for liquid wastes shall not be adjacent to storm intercepts, wetlands or surface waters. Storage areas must be inspected at least monthly. • Supplier should segregate scrap metals and other recyclable wastes. Supplier must contact Xcel Energy Contract Manager for handling instructions if not previously arranged. • Supplier may be responsible for handling and disposal of non-hazardous refuse (construction and demolition debris, scrap lumber, office waste, etc.). All such disposal must be at an appropriately permitted landfill. • Supplier is responsible for notifying Xcel Energy Contract Manager and coordinating with XEES all handling and disposal of Hazardous, Universal, and/or special wastes. • Supplier shall use waste vendors on Xcel Energy’s Approved Vendor List when feasible. Supplier shall provide XEES with 30 days’ advanced notice if it intends to use a vendor that is not on the Approved Vendor List. Supplier may obtain Xcel Energy’s Approved Vendor List form the designated Xcel Energy Contract Manger. Note that many Supplier-generated wastes are specific to a particular project and must be managed as specified in the Contract. Supplier should consider, and use commercially reasonable efforts to: • Use nonhazardous materials instead of hazardous materials • Reduce waste generation • Recycle and reuse materials rather than dispose G. Electrical Equipment (Oil-Filled) Transformers, capacitors, and other electrical equipment often contain oil. The oil in this equipment may contain polychlorinated biphenyls (PCBs). PCBs are highly regulated, and the Supplier must know the regulations associated with PCB management. Supplier shall immediately alert the Contract Manager or XEES representative of any spills or releases from oil-filled electrical equipment. See further information below regarding spill response and reporting procedures. Supplier crews should assume that electrical equipment contains PCB in regulated concentrations until it is determined that it does not contain PCBs in regulated concentrations (i.e., known to be <50 ppm.) The Supplier is to deliver electrical equipment to the designated service center or disposal outlet as specified by the Contract. H. Gas Pipeline and Gas Liquids Management Gas liquids (gas condensate) are defined as liquid hydrocarbons that condense from natural gas because of changes in temperature, pressure, and/or flow. Xcel Energy has specific requirements identified in the Gas Standards Manual (in addition to applicable Federal, State, and other requirements) concerning handling of gas liquids. These requirements are available to the Supplier upon request. Prior to any gas work, removing gas liquids from the system, or performing work that may result in the removal of such from the system, Supplier must Last Revised 11/3/2022 6 2022 Xcel Energy, Inc. R:\ES-ESG-ES\EnvSvcsResources\Manuals\Environmental Directives for Contractors\Current coordinate activities with its Xcel Energy Contract Manager, site manager, and XEES. Supplier must assume that PCBs are present in the gas liquids, the liquids are ignitable, and pipe wrap coatings have asbestos unless and until it is verified that these conditions are not present. When gas liquids are present within these systems, samples must be collected for analysis and proper disposal. I. Tank Management Supplier is expected to comply with all applicable federal, state and local regulations and requirements for aboveground and underground storage tanks. Most States and localities have adopted regulations for tanks that, while similar to Federal regulations, may be different and more stringent. Local requirements may include the Uniform Fire Code or National Fire Protection Agency (NFPA) guidelines. Supplier must be aware of local requirements and contact the Fire Marshall, fire department, or appropriate local response agency as necessary, specified in the Contract or agreed upon with XEES. In addition, Xcel Energy may impose certain requirements for tanks above and beyond these regulations due to various circumstances. These requirements will be noted prior to contracting and will not supersede Contract conditions. Additionally, Supplier must follow all applicable Spill Prevention Control and Countermeasures (SPCC) requirements associated with any tank activities. Prior to installing a new tank, modifying an existing tank, adding materials, or performing maintenance, the Supplier must contact the Contract Manager or XEES representative to discuss steps Supplier has taken to ensure all applicable requirements have been met. These requirements can also include unique site-specific requirements for hazardous materials and tanks. In the event of a release to the environment of any regulated substance, Supplier must perform cleanup activities associated with the spill. See further information below regarding spill response and reporting procedures. J. Demolition Activities Supplier shall conduct a building hazard assessment prior to demolishing any building at Xcel Energy facilities. This assessment shall be conducted by a qualified professional as defined by the regulatory body governing such activities. Assessments shall include a determination as to whether regulated materials, including, but not limited to, lead, asbestos, or radioactive sources exist. These regulated materials must be properly managed prior to the demolition of the building. K. Storm Water Management Supplier is expected to comply with all applicable regulations, requirements, plans, and permits for the management of industrial and construction storm water. Supplier is responsible for ensuring that activities including but not limited to material handling and storage, maintenance and cleaning, construction, industrial processing and other operations occur in a manner consistent with the site’s or facility’s existing industrial or construction storm water management plan (SWMP). Supplier is responsible for controlling runoff from areas affected by its work to prevent the discharge of pollutants into nearby waterbodies or indirectly via storm sewer systems. Supplier shall complete routine site inspections of the worksite on a schedule consistent with the site’s existing SWMP. Supplier is responsible for taking immediate corrective action on identified deficiencies associated with its storm water control measures. Many states and localities have adopted industrial and construction storm water regulations that are consistent with, but more stringent than the federal requirements. If not specified in the Last Revised 11/3/2022 7 2022 Xcel Energy, Inc. R:\ES-ESG-ES\EnvSvcsResources\Manuals\Environmental Directives for Contractors\Current Contract, Supplier is responsible for working with its Xcel Energy Contract Manager, site manager, and XEES to define who is responsible for obtaining construction storm water permit coverage for the proposed activity, paying permitting fees, submitting the Notice of Intent, installing and inspecting the best management practices (BMPs) and completing the Notice of Termination. Unless specified otherwise in the Contract, the Supplier is responsible for temporary stabilization of the site until final restoration is completed. Supplier is expected to immediately report uncontrolled releases or damages to BMPs to the Xcel Energy Contract Manager. L. Dewatering Activities Dewatering activities need to be addressed as project planning is occurring. Supplier is responsible for contacting its Xcel Energy Contract Manager, site manager, and XEES in advance of dewatering activities to ensure that the proper authorizations are obtained. XEES is responsible for evaluating treatment options and assessing whether a dewatering permit is necessary, and if so, obtaining the permit. The Supplier is responsible for ensuring that the required sampling intervals are met, when applicable. Supplier is responsible for coordinating dewatering events with its Xcel Energy Contract Manager, site manager, and XEES to ensure that the required sampling can be arranged. M. Other Common Substances and Hazards Supplier understands that the project site may currently or historically have been used for electric or gas gathering, storage, transmission, distribution, or related facilities. Natural gas facilities may now transport and may continue to transport natural gas at significant pressures. Electric facilities may now transmit and may continue to transmit electric current at significant voltages, and conductors on electric lines may not be insulated. Power may have been generated historically or may currently be generated onsite by various means, including for example, nuclear, coal, wind, solar, hydro, gas or other means. Supplier may encounter hazardous or other regulated materials, including, but not limited to, petroleum, volatile organic compounds, coal ash, oil, lead, asbestos, naturally occurring radioactive materials, radioactive sources, or PCBs. Supplier must take necessary precautions for ensuring its work is performed safely and in compliance with all applicable laws and regulations with respect to these potential site conditions. N. Spill Response and Reporting Spill Prevention. Supplier must become familiar with Xcel Energy facility formal spill response plans and procedures. If a spill plan is not required or does not exist (as is often the case for non-Xcel Energy locations or Rights-of-Way), Supplier must still be prepared to take appropriate prevention and response measures. Supplier should have spill response kits and Personal Protective Equipment readily available on site to respond to spills. • Good spill prevention measures should be implemented including, for example, good housekeeping – work area should be cleaned up immediately after the completion of jobs, minimize amount of chemicals in storage, etc. • Store chemicals properly – store in fireproof cabinets or in designated areas, store drums away from traffic and run-off or sewers/waterways, keep drums closed, etc. • Storage areas should be inspected on a regular basis to identify containers that may be in poor condition or leaking. • Absorbent materials/pads should be available during all handling and transfer operations. Last Revised 11/3/2022 8 2022 Xcel Energy, Inc. R:\ES-ESG-ES\EnvSvcsResources\Manuals\Environmental Directives for Contractors\Current • Properly labeled drip pans should be in place when dispensing products from drums. • Pump connections and hoses should be inspected for integrity and proper connection prior to each use. • All chemicals or oil transfer operations must be continuously monitored to prevent overfill and spills. • Know location of spills kits – replace any items used. Spill Response. Supplier personnel performing an emergency response must be trained appropriately and cleanup spills, even small spills, immediately. Supplier must (1) protect its employees, subcontractors, and the public, and (2) protect the environment if a spill occurs. If a spill occurs, Supplier must evacuate the area if necessary and appropriate. The Supplier must ensure that all persons are kept away from the area of contamination until additional assistance arrives. In addition, to the extent that it is safe, the Supplier must make every effort to prevent the spread of contamination. Containing the flow of liquids, preventing contamination from entering a sewer or waterway, and preventing physical contact with the spilled material are all important. Spill Reporting. There are federal, state, and local spill reporting laws that may apply in the event of a spill and Supplier may be responsible for spill reporting to federal, state, or local agencies. If it is an emergency, call “911” first to activate fire, police, or medical personnel as required. Next, notify the facility emergency number, if applicable. Finally, the Supplier must promptly notify the Xcel Energy Contract Manager and call the appropriate XEES emergency contact number identified below in Section P so that Xcel Energy can coordinate with the Supplier all spill reporting and communications with regulatory agencies and third parties about the spill. In the event of a chemical release or if a spill might reach or has reached water, a sewer, food, feed, garden, residential property, or school, or has otherwise gone off-site, contact XEES immediately (e.g., within 15 minutes of the spill)). If the Supplier activity identifies a potential historical release, work must be immediately stopped in the affected area to determine appropriate next steps. Upon identification of potential historical releases, Supplier shall immediately contact Xcel Energy Contract Manager and appropriate XEES staff. Once notified of a current or historic spill, Xcel Energy may decide to independently report the spill in addition to, or in lieu of, the Supplier. However, the Supplier remains responsible for all spill reporting obligations it may also have under applicable laws and regulations. Supplier shall make best efforts to coordinate with Xcel Energy on any communications to regulatory agencies and third parties about the spill, and Supplier shall keep Xcel Energy informed of all such communications. O. Regulatory Inspections Supplier shall notify the project manager and/or XEES when an authorized environmental governmental agency staff member is on site. Notice shall be provided as soon as the Supplier is aware that such a site visit or inspection will occur. XEES shall be provided the opportunity to participate in any scheduled site visit. Supplier will cooperate with authorized inspections at the direction of the XEES representative. Supplier will be prepared for inspections. Supplier must all ensure that records and documentation are kept up to date, and if appropriate or required by law, kept on site. Supplier will maintain good housekeeping practices for the work area. If agency sampling is planned, XEES staff will determine whether it is appropriate to take split samples and if so, who will take the samples. Last Revised 11/3/2022 9 2022 Xcel Energy, Inc. R:\ES-ESG-ES\EnvSvcsResources\Manuals\Environmental Directives for Contractors\Current P. Environmental and Emergency Contacts ENVIRONMENTAL SERVICES EMERGENCY CONTACT NUMBERS Colorado Texas New Mexico Oklahoma Minnesota South Dakota North Dakota Wisconsin Michigan Emergency Phone / Pager: (303) 571-7100 (806) 674-1890 If no answer leave message with Name, Phone, Location, and Nature of Emergency. You will be contacted as soon as possible. Spill Hotline (612) 330-5972 (24 hrs.) Spill Hotline (715) 577-0003 24 Hour Hotline: (800) 541-0918 General Office Number: (303) 294-2213 (806) 378-2196 (612) 330-7873 (715) 737-1346 Tab 8 Final Stabilization and Long-Term Stormwater Management Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 FINAL STABILIZATION AND LONG-TERM STORMWATER MANAGEMENT (§I.B.1.a.iii and §I.C.2.j) a) Description of Final Stabilization Practices: Upon completion of earth-disturbing activities, the site will be restored with vegetation in areas that currently have vegetation and with hard surfaces in areas that are currently paved, graveled, or otherwise hard surfaced. Disturbed areas of private land will be restored with landscaping to match the original landscaping or as agreed to by the landowner. For disturbed areas that will be stabilized with vegetation, final stabilization will consist of seeding in combination with another stabilization measure, such as crimp mulching, and/or installation of rolled erosion control products as appropriate for the site slope. Stabilization must be implemented within 14 days of achieving final grade or temporary stabilization measures must be employed. Areas where s tabilization measures have been employed will be inspected and maintained until final stabilization is achieved . The Site Map (Tab 2) will be updated to indicate which c ontrol measures will be used at specific locations during final stabilization. The Site Map is a dynamic document changing with field conditions. Proposed control measures are initially placed on the Site Map and then it is updated in the field to reflect changes as the project moves forward and final stabilization measures occur. In some cases, several maps are prepared indicating initial, interim and final control measures . Final stabilization for disturbed areas within roadways or road shoulders will be to return areas to their original condition – compacted with applicable re-installation of rock or gravel materials or paved with asphalt or concrete. b) Final Stabilization Methods: Final stabilization includes those measures taken to control pollutants in stormwater after soil disturbing activities are complete. Practices implemented to achieve final stabilization include: • Seed mix selection and application methods , • Soil preparation and possible amendment of the soil prior to seed application , • Use of salvaged topsoil preserved during construction , • Soil stabilization methods (e.g., crimped mulch or rolled erosion control products), • Permanent pavement, hardscaping, xeriscape, stabilized driving surfaces, and other alternative stabilization practices as applicable , • Conversion of construction site back to prior cropland use. The permittee is not required to plant to crop prior to termination. • Maintenance of appropriate erosion and sediment control measures until final stabilization is achieved , and • Removal of temporary control measures once work is completed and final stabilization achieved. c) Seed M ixes and Application Rate: The seed mix provided in the revegetation plan to be submitted to the County for approval will be utilized , see tab 14. Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 d) Final Stabilization Achievement: Final stabilization is achieved when construction activities at the site have been completed, permanent stabilization has been installed in all areas and has met the thresholds described below, and temporary control measures are removed. Areas being stabilized with a vegetative cover must have evenly distributed perennial vegetation, which may include trees and shrubs. The vegetation coverage must be, at a minimum, equal to 70 percent of what would have been provided by native vegetation in a local, undisturbed area or adequate reference site. Areas not stabilized with vegetative cover must receive equivalent permanent, physical erosion reduction methods. When final stabilization is achieved, temporary erosion and sediment control measures will be removed. e) Long-Term Stormwater Management: Long -term stormwater management for this project will be restoring the site to pre -condition conditions. There are no anticipated post -construction detention or water quality c ontrol measures that will be installed as part of this project. Tab 9 Inspections and Maintenance Inspection Frequency Inspection Scope Blank Inspection Report Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 INSPECTIONS AND MAINTENANCE (§I.D.1 through 5 and §I.B.1.b and c) a) Inspection Frequency (§1.D.2): The site will be inspected thoroughly by a Qualified Stormwater Manager at one of the following frequencies : • At least one inspection every 7 calendar days. Or • At least one inspection every 14 calendar days, if post -storm event inspections are conducted within 24 hours after the end of any precipitation or snowmelt event that causes surface erosion. Post -storm inspections may be used to fulfill the 14 -day routine inspection requirement. The first site inspection should start within 7 calendar days of the commencement of construction activities. Or • An alternate schedule approved by the CDPHE Water Quality Control Division. • An alternate schedule approved by Garfield County. b) Reduced Inspection Frequency (§I.D.4): The site will be inspected thoroughly by a qualified stormwater manager at the following reduced frequencies when one of the following conditions exists: • Post -Storm Inspections at Temporarily Idle Sites – For permittees choosing to combine 14 -day inspections and post -storm event inspections, if no construction activities will occur following a storm event, post -storm event inspections must be conducted prior to re -commencing construction activities, but no later than 72 hours after the end of any precipitation or snowmelt event that causes surface erosion. The delay of any post -storm event inspection must be documented in the inspection record. Routine inspections must still be conducted at least every 14 calendar days. • Inspections at Sites Awaiting Final Stabilization – When the site, or portions of a site are awaiting establishment of a vegetative ground cover and final stabilization, the permittee must conduct a thorough inspection of the construction site and control measures at least once every 30 days. Post -storm event inspections are not required under this schedule. This reduced inspection schedule is allowed if all of the following criteria are met: o All construction activities resulting in ground disturbance are complete , o All activities required for final stabilization, in accordance with the SWMP, have been completed, with the exception of the application of sod or seed that has not occurred due to seasonal conditions or the necessity for additional seed application to augment previous efforts , and o The SWMP has been amended to locate those areas to be inspected in accordance with the reduced schedule allowed for in this paragraph. • Winter Conditions Inspections Exclusion – Typically, this exclusion applies to elevations or locations where snow melt does not occur in the winter months. Inspections are not required for sites that meet all of the following conditions: construction activities are temporarily halted for the winter season, snow cover exists over the entire site for an extended period (i.e. high-elevation winter season), and melting conditions posing a risk of surface erosion do not exist. This inspection exception is applicable only during the period where melting conditions do not exist, and applies to the routine 7-day, 14-day and monthly inspections, as well as the post -storm-event inspections. When this inspection exclusion is implemented, the following information must be documented and retained: o D ates when snow cover existed , o D ate when construction activities ceased , and o D ate melting conditions began. Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 c) Inspection Scope (§I.D.5): 1) Areas to be Inspected (§I.D.5.a): The following items will be examined for evidence of, or the potential for, pollutants leaving the construction site boundaries, entering the stormwater drainage system, or discharging to state waters during the inspection and reported o n the inspection reports (§I.D.5.a): • Construction site perimeter, • All disturbed areas including areas that are temporarily stabilized, • Designated haul routes , • Material and/or waste storage areas that are exposed to precipitation, • Locations of pumped stormwater, • Locations where stormwater has the potential to discharge offsite , and • Locations where vehicles exit the site. All erosion and sediment control practices identified in the SWMP will be evaluated to ensure that they are maintained and operating correctly. 2) Inspection Requirements (§I.D.5.b): • Visually verify whether all implemented control measures are in effective operational condition and are working as designed in their specifications to minimize pollutant discharges. • Determine if there are new potential sources of pollutants. • Assess the adequacy of control measures at the site to identify areas requiring new or modified control measures to minimize pollutant discharges. • Identify all areas of non–compliance with the permit requirements and, if necessary, implement corrective action in accordance with the permit. 3) Inspection Report (§I.D.5.c): The inspection report form is located at the end of the tab. Inspection reports must identify any incidents of non-compliance with the terms and conditions of the general permit. The inspection record will note evidence of, or the potential for, pollutants leaving the construction site boundaries, entering the stormwater drainage system, or discharging to state waters. Inspection records must be retained for three years from the expiration or inactivation of permit coverage. However, PSCo’s internal policy requires all records associated with this permit to be maintained for 10 years. The inspection report will include: • The inspection date, • Name(s) and title(s) of personnel making the inspection , • Weather conditions at time of inspection, • Phase of construction at time of inspection , • Estimated acreage of disturbance at time of inspection , • Location(s) of discharges of sediment or other pollutants from the site , • Location(s) of control measures that are still operating but need to be maintained , • Location(s) of control measures that failed to operate as designed or proved inadequate for a particular location, • Location(s) where additional control measures are needed that were not in place at the time of inspection, Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 • D escription of the minimum inspection frequency utilized when conducting each inspection, • Deviations from the minimum inspection schedule , and • After adequate corrective action(s) have been taken, or where a report does not identify any incidents requiring corrective action, the report must contain the flowing statement and provide the date of the statement: “I verify that, to the best of my knowledge and belief, that if any corrective action items were identified during the inspection, those corrective actions are complete, and the site is currently in compliance with the permit.”; and • Inspection reports must be signed by the individual(s) designated as a Qualified Stormwater Manager. d) Control Measure Routine Maintenance (§I.B.1.b): All erosion and sediment control practices and other protective measures identified in the SWMP will be maintained in effective operating condition. Control measures that are not adequately maintained in accordance with good engineering, hydrologic and pollution control practices are considered to be no longer operating effectively and will be modified or replaced. Control measures implemented at the site must be adequately designed and maintained to provide control for potential pollutant sources associated with the construction activity to prevent pollution or degradation of state waters. Observations leading to the required maintenance of control measures can be made during a site inspection, or during general observations of site conditions. The necessary repairs or modifications to a control measure requiring routine maintenance must be conducted to maintain an effective operating condition. Routine maintenance of control measures will occur anytime that the condition of the control measure or the accumulation of sediment or debris adversely impacts the functioning of the control measure. e) Corrective Actions/Replacement and Failed Control Measures (§I.B.1.c): Adequate site assessment will be performed as part of comprehensive inspection and maintenance procedures, to assess the adequacy of control measures at the site, and the necessity of changes to those control measures to ensure continued effective performance. Where site assessment results in the determination that new or replacement control measures are necessary, the control measures will be installed or maintained in accordance with this SWMP. Where control measures have failed, resulting in noncompliance, they will be addressed as soon as possible, immediately in most cases, to minimize the discharge of pollutants. When new control measures are installed or control measures are replaced, the SWMP will be updated. If a control cannot be repaired or installed immediately a statement of why this could not occur will be added to the SWMP along with a proposed schedule. If any unauthorized release or discharge of sediment or other materials has occurred, it will be cleaned up to the extent feasible to minimize discharges in subsequent storm events. CONSTRUCTION STORMWATER INSPECTON REPORT Project Name: Project Location (i.e. address, cross streets): Xcel Project Manager/Construction Supervisor: Xcel Onsite QC Inspector (if applicable): Construction Contractor Supervisor/Foreman: Qualified Stormwater Manager: Stormwater Inspector – Alternate SW Manager (name & title) Control Measure/BMP Installation Contractor: Is the Inspector a Qualified Stormwater Manager? Yes No Date of Inspection: NPDES/CDPS Certification #: Local/MS4/GESC Permit #: Inspection Start Time: Inspection Stop Time: Current weather at time of inspection: Phase of Construction Pre-Construction Initial Interim Final/Waiting for Growth Permit Closeout Estimated Acreage of Disturbance at time of Inspection: Type of Inspection Routine 7 day Inspection. At least one inspection every 7 calendar days (note that local MS4 may still require post storm inspections). Routine 14 day Inspection. At least one inspection every 14 calendar days, if post-storm event inspections are conducted within 24 hours after the end of any precipitation or snowmelt event that causes surface erosion. Post-storm inspections may be used to fulfill the 14-day routine inspection requirement. Inspection for Discharges to Outstanding Waters. (Permittees must conduct site inspections at least once every 7 calendar days for sites that discharge to a water body designated as an Outstanding Water by the Water Quality Control Commission). Runoff Event (Post-storm event inspections must be conducted within 24 hours after the end of any precipitation or snowmelt event with potential to cause surface erosion. If no construction activities will occur following a storm event, post-storm event inspections will be conducted prior to re-commencing construction activities, but no later than 72 hours following the storm event). Storm Start Date: _______________ Storm Stop Date: _______________ Approximate Amount:_______________ Inspections at Completed Sites/Areas. When the site or portions of a site are awaiting establishment of a vegetative ground cover and final stabilization, the permittee must conduct a thorough inspection of the stormwater management system at least once every 30 days. (Post-storm event inspections are not required under this schedule but the local MS4 may still require post storm inspections). Winter Conditions Inspections Exclusion. Inspections are not required for sites that meet all of the following conditions: 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 inspection exception is applicable only during the period where melting conditions do not exist, and applies to the routine 7-day, 14-day and monthly inspections, as well as the post-storm-event inspections. When this inspection exclusion is implemented, the following information must be documented: dates when snow cover existed, date when construction activities ceased, and date melting conditions began. Other: When site conditions make the schedule required in this section impractical, the permittee may petition the Division to grant an alternate inspection schedule. The alternative inspection schedule may not be implemented prior to written approval by the division and incorporation into the SWMP. The primary Qualified Stormwater Manager must approve any schedule deviations and subsequent petition to the Division. SWMP Management Yes No N/A Comments Is the Permit(s) (Federal, State and/or Local/MS4/GESC) retained in the SWMP Notebook? Is the SWMP Notebook located onsite? If not, provide a copy of documentation that was submitted requesting and granting alternate location? Location of SWMP Is a site specific EPA SPCC Plan included in the SWMP (applies to bulk storage of hydrocarbon products greater than 1,320 gallons)? Are changes to the SWMP Documents noted (i.e. new or altered narratives, control measure details, site map updates, haul roads/routes, access points, etc)? Are inspection reports retained in the SWMP Notebook? Are corrective actions/maintenance items from previous inspection complete (if not show items on page 2)? Are there any new potential sources of pollutants onsite? Control Measures at time of inspection In SWMP Design In Use Not Needed at this time In SWMP Design In Use Not Needed at this time Erosion Control Measures Sediment Control Measures Seeding Stabilized Construction Entrance (i.e. VTC, mud mat, VTRAX, FOD, other) Mulch/Mulch Tackifier Sediment Basin/Trap Soil Binder Inlet Protection Retention Blankets (i.e. ECB/TRM) Outlet Protection Embankment Protector Sediment Control Log Grading (i.e. Surface Roughening, etc) Silt Fence Berm/Diversion (i.e. water bars) Rock Socks Protection of Existing Vegetation Velocity dissipation device (i.e. check dams, water bars) Hot or Cold Patch: Big Reds/Dandy Recyclers Other: (specify) Vegetation and Topography Other: (specify) Other: (specify) Control Measures for Special Conditions Materials Handling, Spill Prevention, Waste Management and General Pollution Prevention Dewatering Structure Stockpile Management Temporary Stream Crossing Erodible building materials Clear Water Diversion Concrete Waste Management Sensitive Area Fencing Solid Waste/Trash Access/Boundary Controls (i.e. construction fence) Vehicle and Equipment Management 50 foot vegetative buffer to receiving water Liquids (stored in secondary containment) Other: (specify) Sweeping Other: (specify) Sanitary Facility Other: (specify) Other: (specify) Other: (specify) Other: (specify) GENERAL NOTES CONSTRUCTION SITE ASSESSMENT ***off site Pollutant Discharges are a violation of the Permit and Reason for Stop Work*** When conducting a site inspection, the following areas, if applicable, must 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: construction site perimeter, all disturbed areas, designated haul routes, material and waste storage areas exposed to precipitation, locations where stormwater has the potential to discharge offsite, and locations where vehicles exit the site. The permittee must ensure all control measures remain in effective operating condition and are working as designed in their specifications to minimize pollutant discharges. Determine if there are new potiential sources of pollutants. Assess the adequacy of control measures at the site to identify areas requiring new or modified control measures to minimize pollutant discharges. Identify all areas of non-compliance with the permit requirements and, if necessary, implement corrective actions. Control Measures must be maintained in accordance with good engineering, hydrologic and pollution control practices. Control Measure Requiring Routine Maintenance is defined as any control measure that is still operating in accordance with its design and the requirements of this permit, but requires maintenance to prevent a breach of the control measure. See also inadequate control measure. The permittee must assess the adequacy of control measures at the site, and the need for changes to those control measures to ensure continued effective performance. When an inadequate control measure is identified (i.e., new or replacement control measures become necessary), the following corrective action requirements apply. The permittee is in noncompliance with the permit until the inadequate control measure is replaced or corrected and returned to effective operating condition in compliance. If the inadequate control measure results in noncompliance that meets the conditions of Part II.L., the permittee must also meet the requirements of that section. Inadequate Control Measure is defined as any control measure that is not designed or implemented in accordance with the requirements of the permit and/or any control measure that is not implemented to operate in accordance with its design. If a new control measures is needed the inspector must determine if that new control measure is categorized as “inadequate or maintenance” based on the definitions above. All control measures identified in the SWMP shall be evaluated to ensure that they are maintained and operating correctly. Identify the condition of the control measure as either inadequate or in need of maintenance as defined above. Continuous and proactive maintenance is required on all Control Measures. Control Measures that are not operating effectively, have proven to be inadequate, or failed must be addressed as soon as possible, immediate in most cases. Date of Initial Finding Location (station #, pole #, intersection, etc) Control Measure Condition (Inadequate/Maintenance) Description of Corrective Action/Comment Date Complete & Initials CONSTRUCTION SITE ASSESSMENT ***off site Pollutant Discharges are a violation of the Permit and Reason for Stop Work*** (a) Is there evidence of discharge of sediment or other pollutants from the site? Yes No *If yes, explain the location of discharge and the corrective actions in the Construction Site Assessment section or General Notes (b) Has sediment or other pollutants discharging from the site reached state waters or municipal separate storm sewer system? Yes No *If yes, contact Xcel Energy’s Environmental Services (303)294-2189. No individual shall notify local or State offices on Xcel Energy’s behalf. INSPECTION CERTIFICATION I certify this inspection 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. Qualified Stormwater Manager/Inspector (Name, Title, Company & Signature) Date: COMPLIANCE CERTIFICATON I verify that, to the best of my knowledge and belief, all corrective action and maintenance items identified during the inspection are complete, and the site is currently in compliance with the permit. Qualified Stormwater Manager/Designee (Name, Title, Company & Signature) Date: Tab 10 SWMP General Requirements, Review and Revisions Non-Compliance Notification Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 SWMP GENERAL REQUIREMENTS (§I.C.1) a) SWMP Development (§I.C.1.a): A SWMP will be developed for each construction site covered by this permit. The SWMP must be prepared in accordance with good engineering, hydrologic and pollution control practices. b) SWMP Implementation (§I.C.1.b): The permittee must implement the provisions of the SWMP as written and updated, from commencement of construction activity until final stabilization is complete. The division may review the SWMP. For public emergency related sites, a SWMP will be created no later than 14 days after the commencement of construction activities. c) SWMP Retention (§I.C.1.c): A copy of the SWMP must be retained on-site unless another location, specified by the permittee, is approved by the Division. The plan and inspection reports may be prepared, signed, and kept electronically, rather than in paper form, if the records are: • In a format that can be read in a similar manner as a paper record; and • Immediately accessible to the inspector during an inspection to the same extent as a paper copy stored at the site would be. PSCo stores its SWMPs digitally in StormPro. Due to the nature of this utility project, a request may be made to keep a copy of this SWMP at a central location and copies at the site when there is active construction. SWMP REVIEW AND REVISIONS (§I.C.3) The SWMP will be revised: 1. When there is a change in design, construction, operation, or maintenance of the site, which would require the implementation of new or revised c ontrol measures , 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 3. When control measures are no longer necessary and are removed , or 4. Corrective actions are taken onsite that result in a change to the SWMP. For SWMP revisions made following a change(s) onsite, including revisions to sections addressing site conditions and control measures, a notation must be included in the SWMP prior to the onsite change that identifies the time and date of the site change, the control measure removed, or modified, the location(s) of those control measures, and the proposed changes to the control measure . The methods for notation may include notations on site maps, a log of changes, redline changes in the, or other measures . The permittee must ensure the site changes are reflected in the SWMP. The permittee is noncompliant with the permit until the SWMP revisions have been made. SWMP AVAILABILITY (§I.C.4) A copy of the SWMP will be provided upon request to the Water Quality Control Division, EPA, or any local agency in charge of approving sediment and erosion plans, grading plans or stormwater Xcel T-Line: 6584 MITC-UTER McLin Staging Yard August 2024 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.A.3 and Part II.K of the permit, certifying that the SWMP is complete and meets all permit requirements. This SWMP will be available to the public under Section 308(b) of the CWA and Section 61.5(4) of the Colorado Discharge Permit System Regulations. PSCo will make plans available to members of the public upon request. However, PSCo may claim any portion of a SWMP as confidential in accordance with 40 CFR Part 2. NONCOMPLIANCE NOTIFICATION (§II.L.7): a) What to Report: The following instances of noncompliance will be reported to the PSCo Project Manager as soon as they are discovered (§II.L.6): 1. Any noncompliance which may end anger health or the environment , 2. Any unanticipated bypass which exceeds any effluent limitations in the permit , 3. Any upset which causes an exceedance of any effluent limitation in the permit , or Daily maximum violations for any of the pollutants limited by Part I.A of the state discharge permit, including any toxic pollutant or hazardous substance or any pollutant specifically identified as the method to control any toxic pollutant or hazardous substance. The report shall contain a description of the noncompliance and its cause; 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; and steps taken or planned to reduce, eliminate, and prevent reoccurrence of the noncompliance. b) Verbal Notification: It is PSCo’s policy that the Environmental Services Group performs all regulatory reporting for all of PSCo’s activities. If an instance of noncompliance such as those listed above occurs at the site, immediately contact the PSCo Project manager, who will then call the Environmental Services Emergency Number. This number is 303-571-7100. This phone number is staffed 24 hours a day, 7 days a week by Environmental Services personnel. They will assist in determining the severity of the event and they will then make the appropriate notifications. Under no circumstance are non-Environmental Service personnel authorized to contact regulatory agencies. c) Written Notification: The Environmental Services Group must also report all instances of noncompliance at the time monitoring reports are due. If no monitoring reports are required, these reports are due at least annually . The annual report must contain all instances of non -compliance. T ab 1 1 Pre-Construction Photos Pre-Construction Photos – McLin Yard Site Visit Date: July 24, 2024 1. View southwest at the north perimeter of the yard . 2. View east at the north perimeter of the yard. Pre-Construction Photos – McLin Yard Site Visit Date: July 24, 2024 3. View southeast at the center of the yard . 4. View southeast at the northeast perimeter of the yard . Pre-Construction Photos – McLin Yard Site Visit Date: July 24, 2024 5. View north from the center of the eastern perimeter of the yard . Road access. 6. View south from the center of the eastern perimeter of the yard. Road access. Pre-Construction Photos – McLin Yard Site Visit Date: July 24, 2024 7. Photo of vegetative ground cover. Preexisting veg etation ~40%. 8. Photo of vegetative ground cover. Preexisting veg etation ~40%. Tab 1 2 Environmental Permits COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Water Quality Control Division CDPS GENERAL PERMIT STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY AUTHORIZATION TO DISCHARGE UNDER THE COLORADO DISCHARGE PERMIT SYSTEM (CDPS) COR400000 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. 1 251 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.A.1. 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 to discharge 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 becomes effective on April 1, 2019, and shall expire at midnight March 31, 2024. Issued and signed this 28th day of January, 2021. Meg Parish, Permits Section Manager Water Quality Control Division COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Permit History Minor Modification Issued January 28, 2021 Effective February 1, 2021 Modification Issued December 31, 2020 Effective February 1, 2021 Originally signed and issued October 31, 2018; effective April 1, 2019 Page 2 of 32 Permit No. COR400000 Table of Contents PART I ............................................................................................................................................ 3 A. COVERAGE UNDER THIS PERMIT .................................................................................................. 3 1. Authorized Discharges ...................................................................................................... 3 2. Limitations on Coverage ................................................................................................... 3 3. Permit Certification and Submittal Procedures ....................................................................... 4 B. EFFLUENT LIMITATIONS ............................................................................................................ 8 1. Requirements for Control Measures Used to Meet Effluent Limitations ........................................... 8 2. Discharges to an Impaired Waterbody .................................................................................. 11 3. General Requirements .................................................................................................... 12 C. STORMWATER MANAGEMENT PLAN (SWMP) REQUIREMENTS ................................................................ 12 1. SWMP General Requirements ............................................................................................ 12 2. SWMP Content .............................................................................................................. 13 3. SWMP Review and Revisions .............................................................................................. 15 4. SWMP Availability .......................................................................................................... 16 D. SITE INSPECTIONS .................................................................................................................. 16 1. Person Responsible for Conducting Inspections ...................................................................... 16 2. Inspection Frequency ...................................................................................................... 16 3. Inspection Frequency for Discharges to Outstanding Waters ....................................................... 17 4. Reduced Inspection Frequency .......................................................................................... 17 5. Inspection Scope ........................................................................................................... 17 E. DEFINITIONS ......................................................................................................................... 19 F. MONITORING ........................................................................................................................ 22 G. OIL AND GAS CONSTRUCTION .................................................................................................... 22 PART II: STANDARD PERMIT CONDITIONS .................................................................................................. 24 A. DUTY TO COMPLY .................................................................................................................. 24 B. DUTY TO REAPPLY ................................................................................................................. 24 C. NEED TO HALT OR REDUCE ACTIVITY NOT A DEFENSE ....................................................................... 24 D. DUTY TO MITIGATE ................................................................................................................ 24 E. PROPER OPERATION AND MAINTENANCE ....................................................................................... 24 F. PERMIT ACTIONS .................................................................................................................... 24 G. PROPERTY RIGHTS ................................................................................................................. 24 H. DUTY TO PROVIDE INFORMATION ............................................................................................... 25 I. INSPECTION AND ENTRY ........................................................................................................... 25 J. MONITORING AND RECORDS ...................................................................................................... 25 K. SIGNATORY REQUIREMENTS ...................................................................................................... 26 1. Authorization to Sign: ..................................................................................................... 26 2. Electronic Signatures ...................................................................................................... 26 Page 2 of 32 Permit No. COR400000 3. Change in Authorization to Sign ......................................................................................... 26 L. REPORTING REQUIREMENTS ...................................................................................................... 27 1. Planned Changes ........................................................................................................... 27 2. Anticipated Non-Compliance ............................................................................................. 27 3. Transfer of Ownership or Control ....................................................................................... 27 4. Monitoring reports ......................................................................................................... 27 5. Compliance Schedules .................................................................................................... 27 6. Twenty-four Hour Reporting ............................................................................................. 28 7. Other Non-Compliance .................................................................................................... 28 8. Other Information .......................................................................................................... 28 M. BYPASS ............................................................................................................................... 28 1. Bypass Not Exceeding Limitations ....................................................................................... 28 2. Notice of Bypass ............................................................................................................ 28 3. Prohibition of Bypass ...................................................................................................... 28 N. UPSET ................................................................................................................................ 29 1. Effect of an upset .......................................................................................................... 29 2. Conditions Necessary for Demonstration of an Upset ............................................................... 29 3. Burden of Proof ............................................................................................................ 29 O. RETENTION OF RECORDS ......................................................................................................... 29 1. Post-Expiration or Termination Retention ............................................................................. 29 2. On-site Retention .......................................................................................................... 29 P. REOPENER CLAUSE ................................................................................................................. 30 1. Procedures for Modification or Revocation ............................................................................ 30 2. Water Quality Protection ................................................................................................. 30 Q. SEVERABILITY ....................................................................................................................... 30 R. NOTIFICATION REQUIREMENTS ................................................................................................... 30 1. Notification to Parties .................................................................................................... 30 S. RESPONSIBILITIES ................................................................................................................... 30 1. Reduction, Loss, or Failure of Treatment Facility ................................................................... 30 T. OIL AND HAZARDOUS SUBSTANCE LIABILITY ................................................................................... 30 U. EMERGENCY POWERS .............................................................................................................. 31 V. CONFIDENTIALITY .................................................................................................................. 31 W. FEES ................................................................................................................................. 31 X. DURATION OF PERMIT ............................................................................................................. 31 Y. SECTION 307 TOXICS ............................................................................................................... 31 P a g e Page 3 of 32 Permit No. COR400000 Part I Note: At the first mention of terminology that has a specific connotation for the purposes of this permit, the terminology is electronically linked to the definitions section of the permit in Part I.E. A. COVERAGE UNDER THIS PERMIT Authorized Discharges This general permit authorizes permittee(s) to discharge the following to state waters: stormwater associated with construction activity and specified non-stormwater associated with construction activity. The following types of stormwater and non-stormwater discharges are authorized under this permit: a. Allowable Stormwater Discharges i. Stormwater discharges associated with construction activity. ii. Stormwater discharges associated with producing earthen materials, such as soils, sand, and gravel dedicated to providing material to a single contiguous site, or within ¼ m ile of a construction site (e.g. borrow or fill areas). iii. Stormwater discharges associated with dedicated asphalt, concrete batch plants and masonry mixing stations (Coverage under this permit is not required if alternative coverage has been obtained.) b. Allowable Non-Stormwater Discharges The following non-stormwater discharges are allowable under this permit if the discharges are identified in the stormwater management plan in accordance with Part I.C and if they have appropriate control measures in accordance with Part I.B.1. i. Discharges from uncontaminated springs that do not originate from an area of land disturbance. ii. Discharges to the ground of concrete washout water associated with the washing of concrete tools and concrete mixer chutes. Discharges of concrete washout water must not leave the site as surface runoff or reach receiving waters as defined by this permit. Concrete on-site waste disposal is not authorized by this permit except in accordance with Part I.B.1.a.ii(b). iii. Discharges of landscape irrigation return flow. iv. Discharges from diversions of state waters within the permitted site. c. Emergency Fire Fighting Discharges resulting from emergency firefighting activities during the active emergency response are authorized by this permit. Limitations on Coverage Discharges not authorized by this permit include, but are not limited to, the discharges and activities listed below. Permittees may seek individual or alternate general permit coverage for the discharges, as appropriate and available. a. Discharges of Non-Stormwater Discharges of non-stormwater, except the authorized non-stormwater discharges listed in Part P a g e Page 4 of 32 Permit No. COR400000 I.A.1.b., are not eligible for coverage under this permit. b. Discharges Currently Covered by another Individual or General Permit c. Discharges Currently Covered by a Water Quality Control Division (division) Low Risk Guidance Document Permit Certification and Submittal Procedures a. Duty to Apply The following activities shall apply for coverage under this permit: i. Construction activity that will disturb one acre or more; or ii. Construction activity that is part of a common plan of development or sale; or iii. Stormwater discharges that are designated by the division as needing a stormwater permit because the discharge: Contributes to a violation of a water quality standard; or Is a significant contributor of pollutants to state waters. b. Application Requirements To obtain authorization to discharge under this permit, applicants applying for coverage following the effective date of the renewal permit shall meet the following requirements: i. Owners and operators submitting an application for permit coverage will be co - permittees subject to the same benefits, duties, and obligations under this permit. ii. Signature requirements: Both the owner and operator (permittee) of the construction site, as defined in Part I.E., must agree to the terms and conditions of the permit and submit a completed application that includes the signature of both the owner and the operator. In cases where the duties of the owner and operator are managed by the owner, both application signatures may be completed by the owner. Both the owner and operator are responsible for ensuring compliance with all terms and conditions of the permit, including implementation of the stormwater management plan. iii. The applicant(s) must develop a stormwater management plan (SWMP) in accordance with the requirements of Part I.C. The applicant(s) must also certify that the SWMP is complete, or will be complete, prior to commencement of any construction activity. iv. In order to apply for certification under this general permit, the applicant(s) must submit a complete, accurate, and signed permit application form as provided by the division by electronic delivery at least 10 days prior to the commencement of construction activity , except those construction activities that are in response to a public emergency related site; public emergency related sites shall apply for coverage no later than 14 days after the commencement of construction activities. The provisions of this part in no way remove a violation of the Colorado Water Quality Control Act if a point source discharge occurs prior to the issuance of a CDPS permit. v. The application in its entirety must be submitted via the division’s online permitting system unless a waiver is granted by the division. If a waiver is granted, the application in its entirety, including signatures by both the owner and operator, must be submitted to: P a g e Page 5 of 32 Permit No. COR400000 Colorado Department of Public Health and Environment Water Quality Control Division Permits Section, WQCD-PS-B2 4300 Cherry Creek Drive South Denver, CO 80246 vi. The applicant(s) must receive written notification that the division granted permit coverage prior to conducting construction activities except for construction activit ies that are in response to a public emergency related site. c. Division Review of Permit Application Within 10 days of receipt of the application, and following review of the application, the division may: i. Issue a certification of coverage; ii. Request additional information necessary to evaluate the discharge; iii. Delay the authorization to discharge pending further review; iv. Notify the applicant that additional terms and conditions are necessary; or v. Deny the authorization to discharge under this general permit. d. Alternative Permit Coverage i. Division Required Alternative Permit Coverage: The division may require an applicant or permittee to apply for an individual permit or an alternative general permit if it determines the discharge does not fall under the scope of this general permit, including if any additional terms and conditions are necessary in order to ensure that discharges authorized by this permit shall not cause, have the reasonable potential to cause, or measurably contribute to an exceedance of any applicable water quality standard, including narrative standards for water quality. In this case, the division will notify the applicant or permittee that an individual permit application is required. ii. Permittee Request for Alternative Permit Coverage: A permittee authorized to discharge stormwater under this permit may request to be excluded from coverage under this general permit by applying for an individual permit. In this case, the permittee must submit an individual application, with reasons supporting the request, to the division at least 180 days prior to any discharge. When an individual permit is issued, the permittee’s authorization to discharge under this permit is terminated on the effective date of the individual permit. e. Submittal Signature Requirements Documents required for submittal to the division in accordance with this permit, including applications for permit coverage and other documents as requested by the division, must include signatures by both the owner and the operator, except for instances where the duties of the owner and operator are managed by the owner. Signatures on all documents submitted to the division as required by this permit must meet the Standard Signatory Requirements in Part II.K of this permit in accordance with 40 C.F.R. 122.41(k). i. Signature Certification Any person(s) signing documents required for submittal to the division must make the following P a g e Page 6 of 32 Permit No. COR400000 certification: “I certify under penalty of law that this document and all attachm ents 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.” f. Compliance Document Signature Requirements Documents which are required for compliance with the permit, but for which submittal to the division is not required unless specifically requested by the division, must be signed by the individual(s) designated as the Qualified Stormwater Manager, as defined in Part I.E. i. Any person(s) signing inspection documents required for compliance with the permit per Part I.D.5.c.xiii must make the following statement and provide the date of the statement: “I verify that, to the best of my knowledge and belief, that if any corrective action items were identified during the inspection, those corrective actions are complete, and the site is currently in compliance with the permit.” g. Field Wide Permit Coverage for Oil and Gas Construction At the discretion of the division, a single permit certification may be issued to a single oil and ga s permittee to cover construction activity related discharges from an oil and gas field at multiple locations that are not necessarily contiguous. h. Permit Coverage without Application Qualifying Local Program: When a small construction site is within the jurisdiction of a qualifying local program, the owner and operator of the construction activity are authorized to discharge stormwater associated with small construction activity under this general permit without the submittal of an application to the division. Sites covered by a qualifying local program are exempt from the following sections of this general permit: Part I.A.3.a.; Part I.A.3.b.; Part I.A.3.c.; Part I.A.3.d.; Part I.A.3.g.; Part I.A.3.i.; Part I.A.3.j.; Part I.A.3.k. Sites covered by a qualifying local program are subject to the following requirements: i. 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. ii. Permit Coverage Termination: When a site under a Qualifying Local Program is finally stabilized, coverage under this permit is automatically terminated. iii. Compliance with Qualifying Local Program: Qualifying Local Program requirements that are equivalent to the requirements of this permit are incorporated by reference. Permittees authorized to discharge under this permit, must comply with the equivalent requirements of the Qualifying Local Program that has jurisdiction over the site as a condition of this permit. iv. Compliance with Remaining Permit Conditions. Requirements of this permit that are in addition to or more stringent than the requirements of the Qualifying Local Program apply in addition to the requirements of the Qualifying Local Program. v. Written Authorization of Coverage: The division or local municipality may require any permittee within the jurisdiction of a Qualifying Local Program covered under this permit to P a g e Page 7 of 32 Permit No. COR400000 apply for, and obtain written authorization of coverage under this permit. The permittee must be notified in writing that an application for written authorization of coverage is required. i. Permittee Initiated Permit Actions Permittee initiated permit actions, inc luding but not limited to modifications, contact changes, transfers, and terminations, shall be conducted following Part II.L, division guidance and using appropriate division-provided forms. j. Sale of Residence to Homeowner Residential construction sites only: The permittee may remove residential lots from permit coverage once the lot meets the following criteria: i. The residential lot has been sold to the homeowner(s) for private residential use; ii. A certificate of occupancy, or equivalent, is maintained on-site and is available during division inspections; iii. The lot is less than one acre of disturbance; iv. All construction activity conducted on the lot by the permittee is complete; v. The permittee is not responsible for final stabilization of the lot; and vi. The SWMP was modified to indicate the lot is no longer part of the construction activity. If the residential lot meets the criteria listed above then activities occurring on the lot are no longer considered to be construction activities with a duty to apply and maintain permit coverage. Therefore, the permittee is not required to meet the final stabilization requirements and may terminate permit coverage for the lot. k. Permit Expiration and Continuation of Permit Coverage Authorization to discharge under this general permit shall expire at midnight on March 31, 2024. While Regulation 61.4 requires a permittee to submit an application for continuing permit coverage 180 days before the permit expires, the division is requiring that permittees desiring continued coverage under this general permit must reapply at least 90 days in advance of this permit expiration. The division will determine if the permittee may continue to discharge stormwater 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. If this permit is not reissued or replaced prior to the expiration date, it will be administratively continued and remain in force and effect. For permittees that have applied for continued permit coverage, discharges authorized under this permit prior to the expiration date will automatically remain covered by this permit until the earliest of: i. An authorization to discharge under a reissued permit, or a replacement of this permit, following the timely and appropriate submittal of a complete application requesting authorization to discharge under the new permit and compliance with the requirements of the new permit; or ii. The issuance and effect of a termination issued by the division; or iii. The issuance or denial of an individual permit for the facility’s discharges; or iv. A formal permit decision by the division not to reissue this general permit, at which time the division will identify a reasonable time period for covered dischargers to seek coverage under P a g e Page 8 of 32 Permit No. COR400000 an alternative general permit or an individual permit. Coverage under this permit will cease when coverage under another permit is granted/authorized; or v. The division has informed the permittee that discharges previously authorized under this permit are no longer covered under this permit. B. EFFLUENT LIMITATIONS Requirements for Control Measures Used to Meet Effluent Limitations The permittee must implement control measures to minimize the discharge of pollutants from all potential pollutant sources at the site. Control measures must be installed prior to commencement of construction activities. Control measures must be selected, designed, installed and maintained in accordance with good engineering, hydrologic and pollution control practices . Control measures implemented at the site must be designed to prevent pollution or degradation of state waters. a. Stormwater Pollution Prevention The permittee must implement structural and/or nonstructural control measures that effectively minimize erosion, sediment transport, and the release of other pollutants related to construction activity. i. Control Measures for Erosion and Sediment Control Control measures for erosion and sediment control may include, but are not limited to, wattles/sediment control logs, silt fences, earthen dikes, drainage swales, sediment traps, subsurface drains, pipe slope drains, inlet protection, outlet protection, gabions, sediment basins, temporary vegetation, permanent vegetation, mulching, geotextiles, sod stabilization, slope roughening, maintaining existing vegetation, protection of trees, and preservation of mature vegetation. Specific control measures must meet the requirements listed below. Structural and nonstructural vehicle tracking controls shall be implemented to minimize vehicle tracking of sediment from disturbed areas and may include tracking pads, minimizing site access, wash racks, graveled parking areas, maintaining vehicle traffic to paved areas, street sweeping and sediment control measures. Stormwater runoff from all disturbed areas and soil storage areas must utilize or flow to one or more control measures to minimize erosion or sediment in the discharge. The control measure(s) must be selected, designed, installed and adequately sized in accordance with good engineering, hydrologic and pollution control practices for the intended application. The control measure(s) must contain or filter flows in order to prevent the bypass of flows without treatment and must be appropriate for stormwater runoff from disturbed areas and for the expected flow rate, duration, and flow conditions (e.g. sheet or concentrated flow). Selection of control measures should prioritize the use of structural and nonstructural control measures that minimize the potential for erosion (i.e. covering materials). Selection should also prioritize phasing construction activities to minimize the amount of soil disturbance at any point in time throughout the duration of construction. Outlets that withdraw water from or near the surface shall be installed when discharging from basins and impoundments, unless infeasible. Maintain pre-existing vegetation or equivalent control measures for areas within 50 horizontal feet of receiving waters as defined by this permit, unless infeasible. P a g e Page 9 of 32 Permit No. COR400000 Soil compaction must be minimized for areas where infiltration control measures will occur or where final stabilization will be achieved through vegetative cover. Unless infeasible, topsoil shall be preserved for those areas of a site that will utilize vegetative final stabilization. Minimize the amount of soil exposed during construction activity, including the disturbance of steep slopes. Diversion control measures must minimize soil transport and erosion within the entire diversion, minimize erosion during discharge, and minimize run-on into the diversion. The permittee must minimize the discharge of pollutants throughout the installation, implementation and removal of the diversion. Diversions must meet one or more of the following conditions: Lined or piped structures that result in no erosion in all flow conditions. Diversion channels, berms, and coffer dams must be lined or composed of a material that minimizes potential for soil loss in the entire wetted perimeter during anticipated flow conditions (e.g. vegetated swale, non -erosive soil substrate). The entire length of the diversion channel must be designed with all of the following considerations: maximum flow velocity for the type of material(s) exposed to the anticipated flows to ensure that the calculated maximum shear stress of flows in the channel is not expected to result in physical damage to the channel or liner and result in discharge of pollutants. Additionally, the conditions relied on to minimize soil loss must be maintained for the projected life of the diversion (i.e. a vegetated swale must be limited to a period of time that ensures vegetative growth, minimizes erosion and maintains stable conditions). An alternative diversion criteria, approved by the division prior to implementation. The diversion method must be designed to minimize the discharge of pollutants and to prevent the potential for pollution or degradation to state waters as a result of the diverted flow through the diversion structure. In addition, the alternative diversion method must minimize the discharge of pollutants throughout the installation, implementation and removal of the diversion. ii. Practices for Other Common Pollutants Bulk storage, individual containers of 55 gallons or greater, for petroleum products and other liquid chemicals must have secondary containment, or equivalent protection, in order to contain spills and to prevent spilled material from entering state waters. Control measures designed for concrete washout waste must be implemented. This includes washout waste discharged to the ground as authorized under this permit and washout waste from concrete trucks and masonry operations contained on sit e. The permittee must ensure the washing activities do not contribute pollutants to stormwater runoff, or receiving waters in accordance Part I.A.1.b.ii. Discharges that may reach groundwater must flow through soil that has buffering capacity prior to reaching groundwater, as necessary to meet the effluent limits in this permit, including Part I.B.3.a. The concrete washout location must not be located in an area where shallow groundwater may be present and would result in buffering capacity not being adequate, such as near natural drainages, springs, or wetlands. This permit authorizes discharges to the ground of concrete washout waste, but does not authorize on-site waste disposal per Part I.B.3.d. In the event that water remains onsite and contains pollutants either from the P a g e Page 10 of 32 Permit No. COR400000 firefighting activities or picked up from the site (i.e. in a gutter, sediment basin, etc.) after active emergency response is complete, the permittee must ensure the remaining water containing pollutants is properly removed and disposed of in order to minimize pollutants from discharging from the site, unless infeasible. iii. Stabilization Requirements The following requirements must be implement ed for each site. (a) Temporary stabilization must be implemented for earth disturbing activities on any portion of the site where ground disturbing construction activity has permanently ceased, or temporarily ceased for more than 14 calendar days. Temporary stabilization methods may include, but are not limited to, tarps, soil tackifier, and hydroseed. The permittee may exceed the 14-day schedule when either the function of the specific area of the site requires it to remain disturbed or physical characteristics of the terrain and climate prevent stabilization. The SWMP must document the constraints necessitating the alternative schedule, provide the alternate stabilization schedule, and identify all locations where the alternative schedule is applicable on the site map. Minimum inspection frequency and scope, as directed in Part I.D., must be followed for temporarily stabilized areas. (b) Final stabilization must be implemented for all construction sites covered under this permit. Final stabilization is reached when (1), (2), and (3) below are complete: (1) All construction activities are complete. (2) Permanent stabilization methods are complete. Permanent stabilization methods include, but are not limited to, permanent pavement or concrete, hardscape, xeriscape, stabilized driving surfaces, vegetative cover, or equivalent permanent alternative stabilization methods. The division may approve alternative final stabilization criteria for specific operations. Vegetative cover must meet the following criteria: a. Evenly distributed perennial vegetation, and b. Coverage, at a minimum, equal to 70 percent of what would have been provided by native vegetation in a local, undisturbed area or adequate reference site, and The permittee must ensure all temporary control measures ar e removed from the construction site once final stabilization is achieved, except when the control measure specifications allow the control measure to be left in place (i.e. bio- degradable control measures). Final stabilization must be designed and installed as a permanent feature. Final stabilization measures for obtaining a vegetative cover or alternative stabilization methods include, but are not limited to, the following as appropriate: Seed mix selection and application methods; Soil preparation and amendments; Soil stabilization methods to provide adequate protection to minimize erosion (e.g. crimped straw, hydro mulch or rolled erosion control products); Appropriate sediment control measures as needed until final stabilization is achieved; P a g e Page 11 of 32 Permit No. COR400000 Permanent pavement, hardscape, xeriscape, stabilized driving surfaces; Other alternative stabilization practices as applicable. b. Maintenance The permittee must ensure that all control measures remain in effective operating condition and are protected from activities that would reduce their effectiveness. Control measures must be maintained in accordance with good engineering, hydrologic and pollution control practices. Observations leading to the required maintenance of control measures can be made during a site inspection, or during general observations of site conditions. The necessary repairs or modifications to a control measure requiring routine maintenance, as defined in Part I.E., must be conducted to maintain an effective operating condition. This section is not subject to the requirements in Part I.B.1.c below. c. Corrective Actions The permittee must assess the adequacy of control measures at the site, and the need for changes to those control measures, to ensure continued effective performance. When an inadequate control measure, as defined in Part I.E., is identified (i.e., new or replacement control measures become necessary), the following corrective action requirements apply. The permittee is in noncompliance with the permit until the inadequate control measure is replaced or corrected and returned to effective operating condition in compliance with Part I.B.1 and the general requirements in Part I.B.3. If the inadequate control measure results in noncompliance that meets the conditions of Part II.L., the permittee must also meet the requirements of that section. i. The permittee must take all necessary steps to minimize or prevent the discharge of pollutants from the permitted area and manage any stormwater run-on onto the site until a control measure is implemented and made operational and/or an inadequate control measure is replaced or corrected and returned to effective operating condition. If it is infeasible to install or repair the control measure immediately after discovering the deficiency, the following must be documented in the SWMP in Part I.D.5.c and kept on record in accordance with the recordkeeping requirements in Part II. (a) Describe why it is infeasible to initiate the installation or repair immediately; and (b) Provide a schedule for installing or repairing the control measure and returning it to an effective operating condition as soon as possible. ii. If applicable, the permittee must remove and properly dispose of any unauthorized release or discharge within and from the permitted area (e.g., discharge of non-stormwater, untreated stormwater containing pollutants, spill, or leak not authorized by this permit.) The permittee must also clean up any contaminated surfaces, if feasible, to minimize discharges of the material in subsequent storm events, including water remaining from the response that contains pollutants after active emergency firefighting response is complete. Discharges to an Impaired Waterbody a. Total Maximum Daily Load (TMDL) If the discharge from the site of permit coverage flows to or could reasonably be expected to flow to any water body for which a TMDL has been approved, and stormwater discharges associated with construction activity were assigned a pollutant-specific Wasteload Allocation (WLA) under the TMDL, the division may: i. Ensure the WLA is implemented properly through alternative local requirements, such as by a P a g e Page 12 of 32 Permit No. COR400000 municipal stormwater permit; or ii. Notify the permittee of the WLA and amend the permittee’s certification to add specific effluent limits and other requirements, as appropriate. The permittee may be required to do the following: Under the permittee’s SWMP, implement specific control measures based on requirements of the WLA, and evaluate whether the requirements are met through implementation of existing stormwater control measures or if additional control measures are necessary. Document the calculations or other evidence demonstrating that the requirements are expected to be met; and If the evaluation shows that additional or modified control measures are necessary, describe the type and schedule for the control measure additions or modifications. iii. 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. General Requirements a. Discharges authorized by this permit shall not cause, have the reasonable potential to cause, or measurably contribute to an exceedance of any applicable water quality standard, including narrative standards for water quality. b. The division may require sampling and testing, on a case -by-case basis, in the event that there is reason to suspect that the SWMP is not adequately minimizing pollutants in stormwater or in order to measure the effectiveness of the control measures in removing pollutants in the effluent. Such monitoring may include Whole Effluent Toxicity testing. c. The permittee must comply with the lawful requirements of federal agencies, municipalities, counties, drainage districts and other local agencies including applicable requirements in Municipal Stormwater Management Programs developed to comply with CDPS permits. The permittee must comply with local stormwater management requirements, policies and guidelines including those for erosion and sediment control. d. All construction site wastes must be properly managed to prevent potential pollution of state waters. This permit does not authorize on-site waste disposal. e. This permit does not relieve the permittee of the reporting requirements in 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.L of the permit). C. STORMWATER MANAGEMENT PLAN (SWMP) REQUIREMENTS SWMP General Requirements a. A SWMP shall be developed for each construction site listed under Part I.A.3.a, including but not limited to, construction activity that will disturb one acre or more and/or are part of a common plan of development or sale covered by this permit. The SWMP must be prepared in accordance with good engineering, hydrologic and pollution control practices. i. For public emergency related sites, a SWMP shall be created no later than 14 days after the commencement of construction activities. b. The permittee must implement the provisions of the SWMP as written and updated, from commencement of construction activity until final stabilization is complete. The division may review the SWMP. P a g e Page 13 of 32 Permit No. COR400000 c. A copy of the SWMP must be retained onsite or be onsite when construction activ ities are occurring at the site unless the permittee specifies another location and obtains approval from the division. SWMP Content a. The SWMP, at a minimum, must include the following elements. i. Qualified Stormwater Manager. The SWMP must list individual(s) by title and name who are designated as responsible for implementing the SWMP in its entirety and meet the definition of a Qualified Stormwater Manager. This role may be filled by more than one individual. ii. Spill Prevention and Response Plan. The SWMP must have a spill prevention and response plan. The plan may incorporate by reference any part of a Spill Prevention Control and Countermeasure (SPCC) plan under section 311 of the Clean Water Act (CWA) or a Spill Prevention Plan required by a separate CDPS permit. The relevant sections of any referenced plans must be available as part of the SWMP consistent with Part I.C.4. iii. Other CDPS Permits. The SWMP must list the applicable CDPS permits associated with the permitted site and the activities occurring on the permitted site (e.g. a CDPS Dewatering Permit). iv. Materials Handling. The SWMP must describe handling procedures of all control measures implemented at the site to minimize impacts from handling significant materials that could contribute pollutants to runoff. These handling procedures can include control measures for pollutants and activities such as, exposed storage of building ma terials, paints and solvents, landscape materials, fertilizers or chemicals, sanitary waste material, trash and equipment maintenance or fueling procedures. v. Potential Sources of Pollution. The SWMP must list all potential sources of pollution which may reasonably be expected to affect the quality of stormwater discharges associated with construction activity from the site. This may include, but is not limited to, the following pollutant sources: Disturbed and stored soils; Vehicle tracking of sediments; Management of contaminated soils, if known to be present, or if contaminated soils are found during construction; Loading and unloading operations; Outdoor storage activities (erodible building materials, fertilizers, chemicals, etc.); Vehicle and equipment maintenance and fueling; Significant dust or particulate generating processes (e.g., saw cutting material, including dust); Routine maintenance activities involving fertilizers, pesticides, herbicides, detergents, fuels, solvents, oils, etc.; On-site waste management practices (waste piles, liquid wastes, dumpsters); Concrete truck/equipment washing, including washing of the concrete truck chute and associated fixtures and equipment; Dedicated asphalt, concrete batch plants and masonry mixing stations; P a g e Page 14 of 32 Permit No. COR400000 Non-industrial waste sources such as worker trash and portable toilets. vi. Implementation of Control Measures. The SWMP must include design specifications that contain information on the implementation of all the structural and nonstructural control measures in use on the site in accordance with good engineering, hydrologic and pollution control practices; including, as applicable, drawings, dimensions, installation information, materials, implementation processes, control measure-specific inspection expectations, and maintenance requirements. The SWMP must include a documented use agreement between the permittee and the owner or operator of any control measures located outside of the permitted area, that are utilized by the permittee’s construction site for compliance with this permit, but not under the direct control of the permittee. The permittee is responsible for ensuring that all control measures located outside of their permitted area, that are being utilized by the pe rmittee’s construction site, are properly maintained and in compliance with all terms and conditions of the permit. The SWMP must include all information required of and relevant to any such control measures located outside the permitted area, including location, installation specifications, design specifications and maintenance requirements. vii. Site Description. The SWMP must include a site description which includes, at a minimum, the following: The nature of the construction activity at the site; The proposed schedule for the sequence for major construction activities and the planned implementation of control measures for each phase. (e.g. clearing, grading, utilities, vertical, etc.); Estimates of the total acreage of the site, and the acreage expected to be disturbed by clearing, excavation, grading, or any other construction activities; A summary of any existing data and sources used in the development of the construction site plans or SWMP that describe the soil types found in the permitted area and the erodibility of the identified soil types; A description of the percent cover of native vegetation on the site if the site is undisturbed, or the percent cover of native vegetation in a similar, local undisturbed area or adequate reference area if the site is disturbed. Include the source or methodology for determining the percentage. If a percent cover is not appropriate for the site location (i.e. arid), describe the technique and justification for the identified cover of native vegetation; A description of any allowable non-stormwater discharges at the site, including those being discharged under a separate CDPS permit or a division low risk discharge guidance policy, and applicable control measures installed; A description of the drainage patterns from the site, including a description of the immediate source receiving the discharge and the receiving water(s) of the discharge, if different than the immediate source. If the stormwater discharge is to a municipal separate storm sewer system, include the name of the entity owning that system, the location(s) of the stormwater discharge, and the receiving water(s); A description of all stream crossings located within the construction site boundary ; and A description of the alternate temporary stabilization schedule, if applicable (Part I.B.1.a.iii(a)). P a g e Page 15 of 32 Permit No. COR400000 A description of the alternative diversion criteria as approved by the division, if applicable (Part I.B.1.a.i(i)(3)). viii. Site Map. The SWMP must include a site map which includes, at a minimum, the following: Construction site boundaries; Flow arrows that depict stormwater flow directions on-site and runoff direction; All areas of ground disturbance including areas of borrow and fill; Areas used for storage of soil; Locations of all waste accumulation areas, including areas for liquid, concrete, masonry, and asphalt; Locations of dedicated asphalt, concrete batch plants and masonry mixing stations; Locations of all structural control measures; Locations of all non-structural control measures (e.g. temporary stabilization); Locations of springs, streams, wetlands, diversions and other state waters, including areas that require pre-existing vegetation be maintained within 50 feet of a receiving water, where determined feasible in accordance with Part I.B.1.a.i(e); Locations of all stream crossings located within the construction site boundary; and Locations where alternative temporary stabilization schedules apply. ix. Temporary Stabilization, Final Stabilization and Long Term Stormwater Management. The SWMP must document the constraints necessitating an alternative temporary stabilization schedule, as referenced in Part I.B.1.a.iii(a), provide the alternate stabilization schedule, and identify all locations where the alternative schedule is applicable on the site map. The SWMP must describe and locate the methods used to achieve final stabilization of all disturbed areas at the site, as listed in Part I.B.1.a.iii(b). The SWMP must describe the measures used to establish final stabilization through vegetative cover or alternative stabilization method, as referenced in Part I.B.1.a.iii(c), and describe and locate any temporary control measures in place during the process of final stabilization. The SWMP must describe and locate any planned permanent control measures to control pollutants in stormwater discharges that will occur after construction operations are completed, including but not limited to, detention/retention ponds, rain gardens, stormwater vaults, etc. x. Inspection Reports. The SWMP must include documented inspection reports in accordance with Part I.D.5.c. SWMP Review and Revisions Permittees must keep a record of SWMP changes made that includes the date and identification of the changes. The SWMP must be amended when the following occurs: a. A change in design, construction, operation, or maintenance of the site requiring implementation P a g e Page 16 of 32 Permit No. COR400000 of new or revised control measures; b. The SWMP proves ineffective in controlling pollutants in stormwater runoff in compliance with the permit conditions; c. Control measures identified in the SWMP are no longer necessary and are removed; and d. Corrective actions are taken onsite that result in a change to the SWMP. e. The site or areas of the site qualifying for reduced frequency inspections under Part I.D.4. For SWMP revisions made prior to or following a change(s) onsite, including revisions to sections addressing site conditions and control measures, a notation must be included in the SWMP that identifi es the date of the site change, the control measure removed, or modified, the location(s) of those control measures, and any changes to the control measure(s). The permittee must ensure the site changes are reflected in the SWMP. The permittee is noncompliant with the permit until the SWMP revisions have been made. SWMP Availability A copy of the SWMP must be provided upon request to the division, EPA, and any local agency with authority for approving sediment and erosion plans, grading plans or stormwater management plans within the time frame specified in the request. If the SWMP is required to be submitted to any of these entities, the submission must include a signed certification in accordance with Part I.A.3.e, certifying that the SWMP is complete and compliant with all terms and conditions of the permit. All SWMPs required under this permit are considered reports that must be available to the public under Section 308(b) of the CWA and Section 61.5(4) of the CDPS regulati ons. The permittee must 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. D. SITE INSPECTIONS Site inspections must be conducted in accordance with the following requirements. The required inspection schedules are a minimum frequency and do not affect the permittee’s responsibility to implement control measures in effective operating condition as prescribed in the SWMP, Part I.C.2.a.vi, as proper maintenance of control measures may require more frequent inspections. Site inspections shall start within 7 calendar days of the commencement of construction activities on site. Person Responsible for Conducting Inspections The person(s) inspecting the site may be on the permittee’s staff or a third party hired to conduct stormwater inspections under the direction of the permittee(s). The permittee is responsible for ensuring that the inspector meets the definition of a Qualified Stormwater Manager. The inspector may be different than the individual(s) listed in Part I.C.2.a.i. Inspection Frequency Permittees must conduct site inspections in accordance with on the following minimum frequencies, unless the site meets the requirements of Part I.D.3. All inspections must be recorded per Part I.D.5.c. a. At least one inspection every 7 calendar days; or b. At least one inspection every 14 calendar days, if post-storm event inspections are conducted within 24 hours after the end of any precipitation or snowmelt event that causes surface erosion. Post-storm inspections may be used to fulfill the 14-day routine inspection requirement. c. When site conditions make the schedule required in this section impractical, the permittee may P a g e Page 17 of 32 Permit No. COR400000 petition the division to grant an alternate inspection schedule. The alternative inspection schedule must not be implemented prior to written approval by the divisio n and incorporation into the SWMP. Inspection Frequency for Discharges to Outstanding Waters Permittees must conduct site inspections at least once every 7 calendar days for sites that discharge to a water body designated as an Outstanding Water by the Water Quality Control Commission. Reduced Inspection Frequency The permittee may perform site inspections at the following reduced frequencies when one of the following conditions exists: a. Post-Storm Inspections at Temporarily Idle Sites For permittees choosing an inspection frequency pursuant to Part I.D.2.b and if no construction activities will occur following a storm event, post-storm event inspections must be conducted prior to re-commencing construction activities, and no later than 72 hours following the storm event. If the post-storm event inspection qualifies under this section, the inspection delay must be documented in the inspection record per Part I.D.5.c. Routine inspections must still be conducted at least every 14 calendar days. b. Inspections at Completed Sites/Areas When the site, or portions of a site, are awaiting establishment of a vegetative ground cover and final stabilization, the permittee must conduct a thorough inspection of the stormwater management system at least once every 30 days. Post-storm event inspections are not required under this schedule. This reduced inspection schedule is allowed if all of the following criteria are met: i. All construction activities resulting in ground disturbance are complete; ii. All activities required for final stabilization, in accordance with Part I.B.1.a.iii(b) & (c) and 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 locate those areas to be inspected in accordance with the reduced schedule allowed for in this paragraph. c. Winter Conditions Inspections Exclusion Inspections are not required for sites that meet all of the following conditions: 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 inspection exception is applicable only during the period where melting conditions do not exist, and applies to the routine 7-day, 14-day and monthly inspections, as well as the post-storm-event inspections. When this inspection exclusion is implemented, the following information must be documented in accordance with the requirements in Part I.C.3 and Part I.D.5.c: i. Dates when snow cover existed; ii. Date when construction activities ceased; and iii. Date melting conditions began. Inspection Scope P a g e Page 18 of 32 Permit No. COR400000 a. Areas to Be Inspected When conducting a site inspection the following areas, if applicable, must 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: i. Construction site perimeter; ii. All disturbed areas; iii. Locations of installed control measures; iv. Designated haul routes; v. Material and waste storage areas exposed to precipitation; vi. Locations where stormwater has the potential to discharge offsite; and vii. Locations where vehicles exit the site. b. Inspection Requirements i. Visually verify whether all implemented control measures are in effective operational condition and are working as designed in their specifications to minimize pollutant discharges. ii. Determine if there are new potential sources of pollutants. iii. Assess the adequacy of control measures at the site to identify areas requiring new or modif ied control measures to minimize pollutant discharges. iv. Identify all areas of non–compliance with the permit requirements and, if necessary, implement corrective action(s) in accordance with Part I.B.1.c. c. Inspection Reports The permittee must keep a record of all inspections conducted for each permitted site. Inspection reports must identify any incidents of noncompliance with the terms and conditions of this permit. All inspection reports must be signed and dated in accordance with Part I.A.3.f. Inspection records must be retained in accordance with Part II.O. At a minimum, the inspection report must include: i. The inspection date; ii. Name(s) and title(s) of personnel conducting the inspection; iii. Weather conditions at the time of inspection; iv. Phase of construction at the time of inspection; v. Estimated acreage of disturbance at the time of inspection; vi. Location(s) and identification of control measures requiring routine maintenance; vii. Location(s) and identification of discharges of sediment or other pollutants from the site; viii. Location(s) and identification of inadequate control measures; ix. Location(s) and identification of additional control measures needed that were not in pl ace at the time of inspection; P a g e Page 19 of 32 Permit No. COR400000 x. Description of corrective action(s) for items vii, viii, ix, above, dates corrective action(s) were completed, including requisite changes to the SWMP, as necessary; xi. Description of the minimum inspection frequency (either in accordance with Part I.D.2, Part I.D.3 or Part I.D.4.) utilized when conducting each inspection. xii. Deviations from the minimum inspection schedule as required i n Part I.D.2. This would include documentation of division approval for an alternate inspection schedule outlined in Part I.D.2.c; xiii. After adequate corrective action(s) have been taken, or where a report does not identify any incidents requiring corrective action, the report shall contain a statement as required in Part I.A.3.f. E. DEFINITIONS For the purposes of this permit: (1) Bypass the intentional diversion of waste streams from any portion of a treatment facility in accordance with 40 CFR 122.41(m)(1)(i) and Regulation 61.2(12). (2) 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, but remain related. The division has determined that “contiguous” means construction activities located in close proximity to each other (within ¼ mile). Construction activities are considered to be “related” if they share the same development plan, builder or contractor, equipment, storage areas, etc. “Common plan of development or sale” includes construction activities that are associated with the construction of field wide oil and gas permits for facilities that are related. (3) Construction Activity - Ground surface disturbing and associated activities (land disturbance), 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 the original line and grade, hydraulic capacity, or original purpose of the facility. Activities to conduct repairs that are not part of routine maintenance or for replacement are construction activities and are not routine maintenance. Repaving activities where underlying and/or surrounding soil is exposed as part of the repaving operation are considered construction activities. Construction activity is from initial ground breaking to final stabilization regardless of ownership of the construction activities. (4) Control Measure - Any best management practice or other method used to prevent or reduce the discharge of pollutants to state waters. Control measures include, but are not limited to, best management practices. Control measures can include other methods such as the installation, operation, and maintenance of structural controls and treatment devices. (5) Control Measure Requiring Routine Maintenance - Any control measure that is still operating in accordance with its design and the requirements of this permit, but requires maintenance to prevent a breach of the control measure. See also inadequate control measure. (6) Dedicated Asphalt, Concrete Batch Plants and Masonry Mixing Stations – Are batch plants or mixing stations located on, or within ¼ mile of, a construction site and that provide materials only to that specific construction site. (7) Diversion – Discharges of state waters that are temporarily routed through channels or structures (e.g. in-stream, uncontaminated springs, non-pumped groundwater, temporary rerouting of surface waters). (8) Final Stabilization - The condition reached when construction activities at the site have been P a g e Page 20 of 32 Permit No. COR400000 completed, permanent stabilization methods are complete, and temporary control measures are removed. Areas being stabilized with a vegetative cover must have evenly distributed perennial vegetation. The vegetation coverage must be, at a minimum, equal to 70 percent of what would have been provided by native vegetation in a local, undisturbed area or adequate reference site. (9) Good Engineering, Hydrologic and Pollution Control Practices: are methods, procedures, and practices that: a. Are based on basic scientific fact(s). b. Reflect best industry practices and standards. c. Are appropriate for the conditions and pollutant sources. d. Provide appropriate solutions to meet the associated permit requirements, including practice based effluent limits. (10) Inadequate Control Measure - Any control measure that is not designed or implemented in accordance with the requirements of the permit and/or any control measure that is not implemented to operate in accordance with its design. See also Control Measure R equiring Routine Maintenance. (11) Infeasible – Not technologically possible, or not economically practicable and achievable in light of best industry practices. (12) Minimize - reduce or eliminate to the extent achievable using control measures that are technologically available and economically practicable and achievable in light of best industry practice. (13) Municipality - A city, town, county, district, association, or other public body created by, or under, State law and having jurisdiction over disposal of sewage, industrial wastes, or other wastes, or a designated and approved management agency under section 208 of CWA (1987). (14) Municipal Separate Storm Sewer System (MS4) - A conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains): a. Owned or operated by a State, city, town, county, district, association, or other public body (created by or pursuant to State law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or a designated and approved management agency under section 2 08 of the CWA that discharges to state waters; i. Designed or used for collecting or conveying stormwater; ii. Are not a combined sewer; and iii. Are not part of a Publicly Owned Treatment Works (POTW). See 5 CCR 1002- 61.2(62). (15) Municipal Stormwater Management Program - A stormwater program operated by a municipality, typically to meet the requirements of the municipalities MS4 discharge certification. (16) Operator - The party that has operational control over day -to-day activities at a project site which are necessary to ensure compliance with the permit. This party is authorized to direct individuals at a site to carry out activities required by the permit (i.e. the general contractor). P a g e Page 21 of 32 Permit No. COR400000 (17) Outstanding Waters - Waters designated as outstanding waters pursuant to Regulation 31, Section 31.8(2)(a). The highest level of water quality protection applies to certain waters that constitute an outstanding state or national resource. (18) Owner - The party that has overall control of the activities and that has funded the implementation of the construction plans and specifications. This is the party that may have ownership of, a long term lease of, or easements on the property on which the construction activity is occurring (e.g. the developer). (19) Permittee(s) - The owner and operator named in the discharge certification issued under this permit for the construction site specified in the certification. (20) Point Source - Any discernible, confined, and discrete conveyance, including, but not limited to, any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. Point source does not include irrigation return flow. See 5 CCR 102-61.2(75). (21) 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. See 5 CCR 1002-61.2(76). (22) Presentation of credentials – a government issued form of identification, if in person; or (ii) providing name, position and purpose of inspection if request to enter is made via telephone, email or other form of electronic communication. A Permittee’s non-response to a request to enter upon presentation of credentials constitutes a denial to such request, and may result in violation of the Permit. (23) 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. (24) Public Emergency Related Site - a project initiated in response to an unanticipated emergency (e.g., mud slides, earthquake, extreme flooding conditions, disruption in essential public services), for which the related work requires immediate authorization to avoid imminent endangerment to human health or the environment, or to reestablish essential public services. (25) Qualified Stormwater Manager - An individual knowledgeable in the principles and practices of erosion and sediment control and pollution prevention, and with the skills to assess conditions at construction sites that could impact stormwater quality and to assess the effectiveness of stormwater controls implemented to meet the requirements of this permit. (26) Qualifying Local Program - A municipal program for stormwater discharges associated with small construction activity that was formally approved by the division as a qualifying local program. (27) Receiving Water - Any classified or unclassified surface water segment (including tributaries) in the State of Colorado into which stormwater associated with construction activities discharges . This definition includes all water courses, even if they are usually dry, such as borrow ditches, arroyos, and other unnamed waterways. (28) Severe Property Damage - substantial physical damage to property, damage to the treatment facilities which causes them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. Severe property damage does not mean economic loss caused by delays in production. See 40 CFR 122.41(m)(1)(ii). (29) Significant Materials - Include, but not limited to, raw materials; fuels; materials such as solvents, detergents, and plastic pellets; finished materials such as metallic products; raw materials used in P a g e Page 22 of 32 Permit No. COR400000 food processing or production; hazardous substances designated under section 101(14) of CERCLA; any chemical the permittee is required to report under section 313 of Title III of the Superfund Amendments and Reauthorization Act (SARA); fertilizers; pesticides; and waste products such as ashes, slag and sludge that have the potential to be released with stormwater discharges. (30) Small Construction Activity - The discharge of stormwater from construction activities that result in land disturbance of equal to, or greater than, one acre and less than fiv e 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 ultimately disturbs equal to, or greater than, one acre and less than five acres. (31) Spill - An unintentional release of solid or liquid material which may pollute state waters. (32) State Waters - means any and all surface and subsurface waters which are contained in or flow in or through this state, but does not include waters in sewage systems, waters in treatment works of disposal systems, waters in potable water distribution systems, and all water withdrawn for use until use and treatment have been completed. (33) Steep Slopes: where a local government, or industry technical manual (e.g. stormwater BMP manual) has defined what is to be considered a “steep slope”, this permit’s definition automatica lly adopts that definition. Where no such definition exists, steep slopes are automatically defined as those that are 3:1 or greater. (34) Stormwater - Precipitation runoff, snow melt runoff, and surface runoff and drainage. See 5 CCR 1002-61.2(103). (35) Total Maximum Daily Loads (TMDLs) -The sum of the individual wasteload allocations (WLA) for point sources and load allocations (LA) for nonpoint sources and natural background. For the purposes of this permit, a TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources. A TMDL includes WLAs, LAs, and must include a margin of safety (MOS), and account for seasonal variations. See section 303(d) of the CWA and 40 C.F.R. 130.2 and 130.7. (36) Upset - an exceptional incident in which there is unintentional and temporary noncompliance with permit effluent 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 in accordance with 40 CFR 122.41(n) and Regula tion 61.2(114). F. MONITORING The division may require sampling and testing, on a case-by-case basis. If the division requires sampling and testing, the division will send a notification to the permittee. Reporting procedures for any monitoring data collected will be included in the notification. If monitoring is required, the following applies: 1. The thirty (30) day average must be determined by the arithmetic mean of all samples collected during a thirty (30) consecutive-day period; and 2. A grab sample, for monitoring requirements, is a single “dip and take” sample. G. OIL AND GAS CONSTRUCTION Stormwater discharges associated with construction activities directly related to oil and gas exploration, production, processing, and treatment operatio ns or transmission facilities are regulated under the Colorado Discharge Permit System Regulations (5 CCR 1002 -61), and require coverage under this permit in accordance with that regulation. However, references in this permit to specific authority under th e CWA do not apply to P a g e Page 23 of 32 Permit No. COR400000 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. P a g e Page 24 of 32 Permit No. COR400000 Part II: Standard Permit Conditions A. DUTY TO COMPLY The permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of the Water Quality Control Act and is grounds for: 1. Enforcement action; 2. Permit termination, revocation and reissuance, or modification; or 3. Denial of a permit renewal application. B. DUTY TO REAPPLY If the permittee wishes to continue an activity regulated by this permit after the expiration date of this permit, the permittee must apply for and obtain authorization as required by Part I.A.3.k. of the permit. C. NEED TO HALT OR REDUCE ACTIVITY NOT A DEFENSE It shall not be a defense for a permittee in an enforcement action that it would have been necessary to halt or reduce the permitted activity in order to maintain compliance with the conditions of this permit. D. DUTY TO MITIGATE A permittee must take all reasonable steps to minimize or prevent any discharge in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment. E. PROPER OPERATION AND MAINTENANCE A permittee must at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) that are installed or used by the permittee to achieve compliance with the conditions of this permit. Proper operation and maintenance also includes adequate laboratory controls and appropriate quality assurance procedures. This provision requires the operation of backup or auxiliary facilities or similar systems which are installed by the permittee only when the operat ion is necessary to achieve compliance with the conditions of this permit. This requirement can be met by meeting the requirements for Part I.B., I.C., and I.D. above. See also 40 C.F.R. § 122.41(e). F. PERMIT ACTIONS This permit may be modified, revoked and reissued, or terminated for cause. The permittee request for a permit modification, revocation and reissuance, or termination, or a notification of planned changes or anticipated noncompliance does not stay any permit condition. Any request for modificatio n, revocation, reissuance, or termination under this permit must comply with all terms and conditions of Regulation 61.8(8). G. PROPERTY RIGHTS In accordance with 40 CFR 122.41(g) and 5 CCR 1002 -61, 61.8(9): 1. The issuance of a permit does not convey any property or water rights in either real or personal property, or stream flows or any exclusive privilege. 2. The issuance of a permit does not authorize any injury to person or property or any invasion of personal rights, nor does it authorize the infringement of f ederal, state, or local laws or regulations. 3. Except for any toxic effluent standard or prohibition imposed under Section 307 of the Federal act or any standard for sewage sludge use or disposal under Section 405(d) of the Federal act, compliance with a permit during its term constitutes compliance, for purposes of enforcement, with Sections 301, P a g e Page 25 of 32 Permit No. COR400000 302, 306, 318, 403, and 405(a) and (b) of the Federal act. However, a permit may be modified, revoked and reissued, or terminated during its term for cause as set f orth in Section 61.8(8) of the Colorado Discharge Permit System Regulations. H. DUTY TO PROVIDE INFORMATION The permittee shall furnish to the division, within a reasonable time, any information which the division may request to determine whether cause exists for modifying, revoking and reissuing, or terminating 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 in accordance with 40 CFR 122.41(h) and/or Regulation 61.8(3)(q). I. INSPECTION AND ENTRY The permittee shall allow the division and the authorized representative, upon the presentation of credentials as required by law, to allow for inspections to be conducted in accordance with 40 CFR 122.41(i), Regulation 61.8(3), and Regulation 61.8(4): 1. 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; 2. At reasonable times to have access to and copy any records required to be kept under the terms and conditions of this permit; 3. At reasonable times, inspect any monitoring equipment or mo nitoring method required in the permit; and 4. To enter upon the permittee's premises in a reasonable manner and at a reasonable time to inspect or investigate, any actual, suspected, or potential source of water pollution, or any violation of the Colorado Water Quality Control Act. The investigation may include: sampling of any discharges, stormwater or process water, taking of photographs, interviewing site staff on alleged violations and other matters related to the permit, and assessing any and all facilities or areas within the site that may affect discharges, the permit, or an alleged violation. The permittee shall provide access to the division or other authorized representatives upon presentation of proper credentials. A permittee’s non-response to a request to enter upon presentation of credentials constitutes a denial of such request, and may result in a violation of the permit. J. MONITORING AND RECORDS 1. Samples and measurements taken for the purpose of monitoring must be representative of the volume and nature of the monitored activity. 2. The permittee must retain records of all monitoring information, including all calibration and maintenance records and all original strip chart recordings for continuous monitoring instrumentation, copies of all reports required by this permit, and records of all data used to complete the application for this permit, for a period of at least three years from the date the permit expires or the date t he permittee’s authorization is terminated. This period may be extended by request of the division at any time. 3. Records of monitoring information must include: a. The date, exact place, and time of sampling or measurements; b. The individual(s) who performed the sampling or measurements; c. The date(s) analyses were performed P a g e Page 26 of 32 Permit No. COR400000 d. The individual(s) who performed the analyses; e. The analytical techniques or methods used; and f. The results of such analyses. 4. Monitoring must be conducted according to test procedures approved under 40 CFR Part 136, unless other test procedures have been specified in the permit. K. SIGNATORY REQUIREMENTS Authorization to Sign: All documents required to be submitted to the division by the permit must be signed in accordance with the following criteria: a. For a corporation: by a responsible corporate officer. For the purpose of this subsection, a responsible corporate officer means: i. A president, secretary, treasurer, or vice president of the corporation in charge of a principal business function, or any other person who performs similar policy - or decision-making functions for the corporation, or ii. The manager of one or more manufacturing, production, or operating facilities, provided, the manager is authorized to make management decisions which govern th e operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for permit application requirements; and where authority to sign documents has been assigned or delegate d to the manager in accordance with corporate procedures. b. For a partnership or sole proprietorship: by a general partner or the proprietor, respectively; or c. For a municipality, state, federal, or other public agency: By either a principal executive officer or ranking elected official. For purposes of this subsection, a principal executive officer of a federal agency includes i. The chief executive officer of the agency, or ii. A senior executive officer having responsibility for the overall operations of a principal geographic unit of the agency. (e.g. Regional Administrator of EPA) Electronic Signatures For persons signing applications for coverage under this permit electronically, in addition to meeting other applicable requirements stated above, such signatures must meet the sam e signature, authentication, and identity-proofing standards set forth at 40 CFR § 3.2000(b) for electronic reports (including robust second-factor authentication). Compliance with this requirement can be achieved by submitting the application using the Colorado Environmental Online Service (CEOS) system. Change in Authorization to Sign If an authorization is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization must be submitted to the division, prior to the re-authorization, or together with any reports, information, or applications to be signed by an authorized representative. P a g e Page 27 of 32 Permit No. COR400000 L. REPORTING REQUIREMENTS Planned Changes The permittee shall give advance notice to the division, in writing, of any planned physical alterations or additions to the permitted facility in accordance with 40 CFR 122.41(l) and Regulation 61.8(5)(a). Notice is required only when: a. The alteration or addition to a permitted facility may meet one of the criteria for determining whether a facility is a new source in 40 CFR 122.29(b); or b. The alteration or addition could significantly change the nature or increase the quantity of pollutants discharged. This notification applies to pollutants which are subject neither to effluent limitations in the permit, nor to notification requirements under 40 CFR 122.41(a)(1). Anticipated Non-Compliance The permittee shall give advance notice to the division, in writing, of any planned changes in the permitted facility or activity that may result in noncompliance with permit requirements. The timing of notification requirements differs based on the type of non-compliance as described in subparagraphs 5, 6, 7, and 8 below. Transfer of Ownership or Control The permittee shall notify the division, in writing, ten (10) calendar days in advance of a proposed transfer of the permit. This permit is not transferable to any person except after notice is given to the division. a. Where a facility wants to change the name of the permittee, the original permittee (the first owner or operators) must submit a Notice of Termination. b. The new owner or operator must submit an application. See also signature requirements in Pa rt II.K, above. c. A permit may be automatically transferred to a new permittee if: i. The current permittee notifies the division in writing 30 calendar days in advance of the proposed transfer date; and ii. The notice includes a written agreement between the existing and new permittee(s) containing a specific date for transfer of permit responsibility, coverage and liability between them; and iii. The division does not notify the existing permittee and the proposed new permittee of its intent to modify, or revoke and reissue the permit. iv. Fee requirements of the Colorado Discharge Permit System Regulations, Section 61.15, have been met. Monitoring reports Monitoring results must be reported at the intervals specified in this permit per the requirements of 40 CFR 122.41(l)(4). Compliance Schedules Reports of compliance or noncompliance with, or any progress reports on, interim and final requirements contained in any compliance schedule in the permit, shall be submitted on the date listed P a g e Page 28 of 32 Permit No. COR400000 in the compliance schedule section. The fourteen (14) calendar day provision in Regulation 61.8(4)(n)(i) has been incorporated into the due date. Twenty-four Hour Reporting In addition to the reports required elsewhere in this permit, the permittee shall report the following circumstances orally within twenty-four (24) hours from the time the permittee becomes aware of the circumstances, and shall mail to the division a written report containing the information requested within five (5) working days after becoming aware of the following c ircumstances: a. Circumstances leading to any noncompliance which may endanger health or the environment regardless of the cause of the incident; b. Circumstances leading to any unanticipated bypass which exceeds any effluent limitations in the permit; c. Circumstances leading to any upset which causes an exceedance of any effluent limitation in the permit; d. Daily maximum violations for any of the pollutants limited by Part I of this permit. This includes any toxic pollutant or hazardous substance or any pollutant specifically identified as the method to control any toxic pollutant or hazardous substance. e. The division may waive the written report required under subparagraph 6 of this section if the oral report has been received within 24 hours. Other Non-Compliance A permittee must report all instances of noncompliance at the time monitoring reports are due. If no monitoring reports are required, these reports are due at least annually in accordance with Regulation 61.8(4)(p). The annual report must contain all instances of non-compliance required under either subparagraph 5 or subparagraph 6 of this subsection. Other Information Where a permittee becomes aware that it failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application, or in any report to the Permitting Authority, it has a duty to promptly submit such facts or information. M. BYPASS Bypass Not Exceeding Limitations The permittees may allow any bypass to occur which does not cause effluent limitations to be exceeded, but only if it also is for essential maintenance to assure efficient operation. These bypasses are not subject to the provisions of Part II.M.2 of this permit. See 40 CFR 122.41(m)(2). Notice of Bypass a. Anticipated bypass. If the permittee knows in advance of the need for a bypass, the permittee must submit prior notice, if possible at least ten days before the date of the bypass. ee 40 CFR §122.41(m)(3)(i) and/or Regulation 61.9(5)(c). b. Unanticipated bypass. The permittee must submit notice of an unanticipated bypass in accordance with Part II.L.6. See 40 CFR §122.41(m)(3)(ii). Prohibition of Bypass P a g e Page 29 of 32 Permit No. COR400000 Bypasses are prohibited and the division may take enforcement action against the permittee for bypass, unless: a. The bypass is unavoidable to prevent loss of life, personal injury, or severe property damage; b. There were no feasible alternatives to the bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, or maintenance during normal periods of equipment downtime. This condition is not satisfied if adequate backup equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass which occurred during norma l periods of equipment downtime or preventive maintenance; and c. Proper notices were submitted to the division. N. UPSET Effect of an upset An upset constitutes an affirmative defense to an action brought for noncompliance with permit effluent limitations if the requirements of Part II.N.2. of this permit 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 in accordance with Regulation 61.8(3)(j). Conditions Necessary for Demonstration of an Upset A permittee who wishes to establish the affirmative defense of upset shall demonstrate through properly signed contemporaneous operating logs, or other relevant evid ence that: a. An upset occurred and the permittee can identify the specific cause(s) of the upset; b. The permitted facility was at the time being properly operated and maintained; and c. The permittee submitted proper notice of the upset as required in Part II.L.6.(24- hour notice); and d. The permittee complied with any remedial measure necessary to minimize or prevent any discharge or sludge use or disposal in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment. In addition to the demonstration required above, a permittee who wishes to establish the affirmative defense of upset for a violation of effluent limitations based upon water quality standards shall also demonstrate through monitoring, modeling or other methods that the relevant standards were achieved in the receiving water. Burden of Proof In any enforcement proceeding, the permittee seeking to establish the occurrence of an upset has the burden of proof. O. RETENTION OF RECORDS Post-Expiration or Termination Retention Copies of documentation required by this permit, including records of all data used to complete the application for permit coverage to be covered by this permit, must be retained for at least three years from the date that permit coverage expires or is terminated. This period may be extended by request of EPA at any time. On-site Retention The permittee must retain an electronic version or hardcopy of the SWMP at the construction site from P a g e Page 30 of 32 Permit No. COR400000 the date of the initiation of construction activities to the date of expiration or inactivation of permit coverage; unless another location, specified by the permittee, is approved by the division. P. REOPENER CLAUSE Procedures for Modification or Revocation Permit modification or revocation of this permit or coverage under this permit will be conducted according to Regulation 61.8(8). Water Quality Protection If there is evidence indicating that the stormwater discharges authorized by this permit cause, have the reasonable potential to cause or contribute to an excursion above any applicable water quality standard, the permittee may be required to obtain an individual permit, or the permit may be modified to include different limitations and/or requirements. Q. SEVERABILITY The provisions of this permit are severable. If any provisions or the application of any provision of this permit to any circumstances, is held invalid, the application of such provision to other circumstances and the application of the remainder of this permit shall not be affected. R. NOTIFICATION REQUIREMENTS Notification to Parties All notification requirements, excluding information submitted using the CEOS portal, shall be directed as follows: a. Oral Notifications, during normal business hours shall be to: Clean Water Compliance Section Water Quality Control Division Telephone: (303) 692-3500 b. Written notification shall be to: Clean Water Compliance Section Water Quality Control Division Colorado Department of Public Health and Environment WQCD-WQP-B2 4300 Cherry Creek Drive South Denver, CO 80246-1530 S. RESPONSIBILITIES Reduction, Loss, or Failure of Treatment Facility The permittee has the duty to halt or reduce any activity if necessary to maintain compliance with the effluent limitations of the permit. 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. T. OIL AND HAZARDOUS SUBSTANCE LIABILITY 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 to which the permittee is or may be subject to under Section 311 (Oil and Hazardous Substance Liability) of the CWA. P a g e Page 31 of 32 Permit No. COR400000 U. EMERGENCY POWERS Nothing in this permit shall be construed to prevent or limit application of any emergency power of the division. V. CONFIDENTIALITY Any information relating to any secret process, method of manufacture or production, or sal es 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 Water Quality Control 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. W. FEES The permittee is required to submit payment of an annual fee as set forth in the 2016 amendments to the Water Quality Control Act. Section 25-8-502 (1.1) (b), and the Colorado Discharge Permit System Regulations 5 CCR 1002-61, Section 61.15 as amended. 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. X. DURATION OF PERMIT The duration of a permit shall be for a fixed term and shall not exceed five (5) years. If the permittee desires to continue to discharge, a permit renewal application shall be submitted at least ninety (90) calendar days before this permit expires. Filing of a timely and complete application shall cause the expired permit to continue in force to the effective date of the new permit. The permit's duration may be extended only through administrative extensions and not through interim modifications. If th e permittee anticipates there will be no discharge after the expiration date of this permit, the division should be promptly notified so that it can terminate the permit in accordance with Part I.A.3.i. Y. SECTION 307 TOXICS If a toxic effluent standard or prohibition, including any applicable schedule of compliance specified, is established by regulation pursuant to Section 307 of the Federal Act for a toxic pollutant which is present in the permittee's discharge and such standard or prohibition is more stringent than any limitation upon such pollutant in the discharge permit, the division shall institute proceedings to modify or revoke and reissue the permit to conform to the toxic effluent standard or prohibition Tab 1 3 Inspection Reports Tab 1 4 Miscellaneous Seed mix Restoration will consist of re-contouring staging areas per grading plans and reseeding the area with the following native seed mix. The timing of subsequent seeding efforts will be based on the life of the selected herbicide. Table 1. Semi-Desert Loam Revegetation Seed Mixture* Species Pounds per Acre** Number of Seeds*** Western wheatgrass (Pascopyrum smithii) 3.00 8 Indian ricegrass (Achnatherum hymenoides ) 2.00 6 Prairie junegrass (Koeleria macrantha) 0.50 26 Sandberg bluegrass (Poa secunda ssp. Sandbergii) 1.00 24 Galleta grass (Pleuraphis jamesii) 2.00 7 Bluebunch wheatgrass (Pseudoroegneria spicata ssp. Spicata) 2.00 6 Bottlebrush squirreltail (Elymus elymoides ) 2.00 9 Western yarrow (Achillea millefolium var. occidentalis ) 0.10 6 Sulfur flower (Eriogonum umbellatum) 1.00 5 American vetch (Vicia americana) 2.00 2 Prairie aster (Machaeranthera tanacetifolia) 0.50 6 Total 16.10 106 *The seed mix shown in Table 1 was developed by Granite Seed and Erosion Control based on existing native grasses that occur in this region. Seed mix may be obtained from other suppliers. ** Pure Live Seed ***Per Square Foot Xcel TLine: 6584 Material Staging Yard U.S. Fish and Wildlife Service, National Standards and Support Team,wetlands_team@fws.gov Wetlands Estuarine and Marine Deepwater Estuarine and Marine Wetland Freshwater Emergent Wetland Freshwater Forested/Shrub Wetland Freshwater Pond Lake Other Riverine August 7, 2024 0 0.1 0.20.05 mi 0 0.2 0.40.1 km 1:7,335 This page was produced by the NWI mapperNational Wetlands Inventory (NWI) This map is for general reference only. The US Fish and Wildlife Service is not responsible for the accuracy or currentness of the base data shown on this map. All wetlands related data should be used in accordance with the layer metadata found on the Wetlands Mapper web site. United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Rifle Area, Colorado, Parts of Garfield and Mesa Counties Natural Resources Conservation Service July 3, 2024 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map (McLin Material Yard)............................................................................9 Legend................................................................................................................10 Map Unit Legend (McLin Material Yard).............................................................12 Map Unit Descriptions (McLin Material Yard).....................................................12 Rifle Area, Colorado, Parts of Garfield and Mesa Counties............................14 55—Potts loam, 3 to 6 percent slopes........................................................14 56—Potts loam, 6 to 12 percent slopes......................................................15 Soil Information for All Uses...............................................................................16 Soil Properties and Qualities..............................................................................16 Soil Erosion Factors........................................................................................16 K Factor, Whole Soil (McLin Material Yard).................................................16 Wind Erodibility Group (McLin Material Yard).............................................20 Soil Qualities and Features.............................................................................24 Hydrologic Soil Group (McLin Material Yard)..............................................24 References............................................................................................................30 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 9 Custom Soil Resource Report Soil Map (McLin Material Yard) 43 7 8 7 4 0 43 7 8 8 0 0 43 7 8 8 6 0 43 7 8 9 2 0 43 7 8 9 8 0 43 7 9 0 4 0 43 7 8 7 4 0 43 7 8 8 0 0 43 7 8 8 6 0 43 7 8 9 2 0 43 7 8 9 8 0 43 7 9 0 4 0 275330 275390 275450 275510 275570 275630 275690 275750 275810 275870 275330 275390 275450 275510 275570 275630 275690 275750 275810 275870 39° 31' 55'' N 10 7 ° 3 6 ' 5 0 ' ' W 39° 31' 55'' N 10 7 ° 3 6 ' 2 7 ' ' W 39° 31' 43'' N 10 7 ° 3 6 ' 5 0 ' ' W 39° 31' 43'' N 10 7 ° 3 6 ' 2 7 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 100 200 400 600 Feet 0 35 70 140 210 Meters Map Scale: 1:2,580 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 16, Aug 22, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 25, 2021—Sep 5, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background Custom Soil Resource Report 10 MAP LEGEND MAP INFORMATION imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 11 Map Unit Legend (McLin Material Yard) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes 14.5 83.8% 56 Potts loam, 6 to 12 percent slopes 2.8 16.2% Totals for Area of Interest 17.3 100.0% Map Unit Descriptions (McLin Material Yard) The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The Custom Soil Resource Report 12 delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 13 Rifle Area, Colorado, Parts of Garfield and Mesa Counties 55—Potts loam, 3 to 6 percent slopes Map Unit Setting National map unit symbol: jnyr Elevation: 5,000 to 7,000 feet Farmland classification: Prime farmland if irrigated Map Unit Composition Potts and similar soils:85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Potts Setting Landform:Valley sides, benches, mesas Down-slope shape:Convex, linear Across-slope shape:Convex, linear Parent material:Alluvium derived from basalt and/or alluvium derived from sandstone and shale Typical profile H1 - 0 to 4 inches: loam H2 - 4 to 28 inches: clay loam H3 - 28 to 60 inches: loam Properties and qualities Slope:3 to 6 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:15 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water supply, 0 to 60 inches: High (about 10.3 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3c Hydrologic Soil Group: C Ecological site: R048AY306UT - Upland Loam (Wyoming Big Sagebrush) Hydric soil rating: No Custom Soil Resource Report 14 56—Potts loam, 6 to 12 percent slopes Map Unit Setting National map unit symbol: jnys Elevation: 5,000 to 7,000 feet Farmland classification: Farmland of statewide importance Map Unit Composition Potts and similar soils:85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Potts Setting Landform:Valley sides, benches, mesas Down-slope shape:Convex, linear Across-slope shape:Convex, linear Parent material:Alluvium derived from basalt and/or alluvium derived from sandstone and shale Typical profile H1 - 0 to 4 inches: loam H2 - 4 to 28 inches: clay loam H3 - 28 to 60 inches: loam Properties and qualities Slope:6 to 12 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:15 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water supply, 0 to 60 inches: High (about 10.3 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: R048AY306UT - Upland Loam (Wyoming Big Sagebrush) Hydric soil rating: No Custom Soil Resource Report 15 Soil Information for All Uses Soil Properties and Qualities The Soil Properties and Qualities section includes various soil properties and qualities displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each property or quality. Soil Erosion Factors Soil Erosion Factors are soil properties and interpretations used in evaluating the soil for potential erosion. Example soil erosion factors can include K factor for the whole soil or on a rock free basis, T factor, wind erodibility group and wind erodibility index. K Factor, Whole Soil (McLin Material Yard) Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by water. Factor K is one of six factors used in the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE) to predict the average annual rate of soil loss by sheet and rill erosion in tons per acre per year. The estimates are based primarily on percentage of silt, sand, and organic matter and on soil structure and saturated hydraulic conductivity (Ksat). Values of K range from 0.02 to 0.69. Other factors being equal, the higher the value, the more susceptible the soil is to sheet and rill erosion by water. "Erosion factor Kw (whole soil)" indicates the erodibility of the whole soil. The estimates are modified by the presence of rock fragments. Factor K does not apply to organic horizons and is not reported for those layers. 16 17 Custom Soil Resource Report Map—K Factor, Whole Soil (McLin Material Yard) 43 7 8 7 4 0 43 7 8 8 0 0 43 7 8 8 6 0 43 7 8 9 2 0 43 7 8 9 8 0 43 7 9 0 4 0 43 7 8 7 4 0 43 7 8 8 0 0 43 7 8 8 6 0 43 7 8 9 2 0 43 7 8 9 8 0 43 7 9 0 4 0 275330 275390 275450 275510 275570 275630 275690 275750 275810 275870 275330 275390 275450 275510 275570 275630 275690 275750 275810 275870 39° 31' 55'' N 10 7 ° 3 6 ' 5 0 ' ' W 39° 31' 55'' N 10 7 ° 3 6 ' 2 7 ' ' W 39° 31' 43'' N 10 7 ° 3 6 ' 5 0 ' ' W 39° 31' 43'' N 10 7 ° 3 6 ' 2 7 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 100 200 400 600 Feet 0 35 70 140 210 Meters Map Scale: 1:2,580 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Soil Rating Lines .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Soil Rating Points .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 16, Aug 22, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 25, 2021—Sep 5, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background Custom Soil Resource Report 18 MAP LEGEND MAP INFORMATION imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 19 Table—K Factor, Whole Soil (McLin Material Yard) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes .37 14.5 83.8% 56 Potts loam, 6 to 12 percent slopes .37 2.8 16.2% Totals for Area of Interest 17.3 100.0% Rating Options—K Factor, Whole Soil (McLin Material Yard) Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Layer Options (Horizon Aggregation Method): Surface Layer (Not applicable) Wind Erodibility Group (McLin Material Yard) A wind erodibility group (WEG) consists of soils that have similar properties affecting their susceptibility to wind erosion in cultivated areas. The soils assigned to group 1 are the most susceptible to wind erosion, and those assigned to group 8 are the least susceptible. Custom Soil Resource Report 20 21 Custom Soil Resource Report Map—Wind Erodibility Group (McLin Material Yard) 43 7 8 7 4 0 43 7 8 8 0 0 43 7 8 8 6 0 43 7 8 9 2 0 43 7 8 9 8 0 43 7 9 0 4 0 43 7 8 7 4 0 43 7 8 8 0 0 43 7 8 8 6 0 43 7 8 9 2 0 43 7 8 9 8 0 43 7 9 0 4 0 275330 275390 275450 275510 275570 275630 275690 275750 275810 275870 275330 275390 275450 275510 275570 275630 275690 275750 275810 275870 39° 31' 55'' N 10 7 ° 3 6 ' 5 0 ' ' W 39° 31' 55'' N 10 7 ° 3 6 ' 2 7 ' ' W 39° 31' 43'' N 10 7 ° 3 6 ' 5 0 ' ' W 39° 31' 43'' N 10 7 ° 3 6 ' 2 7 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 100 200 400 600 Feet 0 35 70 140 210 Meters Map Scale: 1:2,580 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons 1 2 3 4 4L 5 6 7 8 Not rated or not available Soil Rating Lines 1 2 3 4 4L 5 6 7 8 Not rated or not available Soil Rating Points 1 2 3 4 4L 5 6 7 8 Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 16, Aug 22, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 25, 2021—Sep 5, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background Custom Soil Resource Report 22 MAP LEGEND MAP INFORMATION imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 23 Table—Wind Erodibility Group (McLin Material Yard) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes 5 14.5 83.8% 56 Potts loam, 6 to 12 percent slopes 5 2.8 16.2% Totals for Area of Interest 17.3 100.0% Rating Options—Wind Erodibility Group (McLin Material Yard) Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Lower Soil Qualities and Features Soil qualities are behavior and performance attributes that are not directly measured, but are inferred from observations of dynamic conditions and from soil properties. Example soil qualities include natural drainage, and frost action. Soil features are attributes that are not directly part of the soil. Example soil features include slope and depth to restrictive layer. These features can greatly impact the use and management of the soil. Hydrologic Soil Group (McLin Material Yard) Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Custom Soil Resource Report 24 Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Custom Soil Resource Report 25 26 Custom Soil Resource Report Map—Hydrologic Soil Group (McLin Material Yard) 43 7 8 7 4 0 43 7 8 8 0 0 43 7 8 8 6 0 43 7 8 9 2 0 43 7 8 9 8 0 43 7 9 0 4 0 43 7 8 7 4 0 43 7 8 8 0 0 43 7 8 8 6 0 43 7 8 9 2 0 43 7 8 9 8 0 43 7 9 0 4 0 275330 275390 275450 275510 275570 275630 275690 275750 275810 275870 275330 275390 275450 275510 275570 275630 275690 275750 275810 275870 39° 31' 55'' N 10 7 ° 3 6 ' 5 0 ' ' W 39° 31' 55'' N 10 7 ° 3 6 ' 2 7 ' ' W 39° 31' 43'' N 10 7 ° 3 6 ' 5 0 ' ' W 39° 31' 43'' N 10 7 ° 3 6 ' 2 7 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 100 200 400 600 Feet 0 35 70 140 210 Meters Map Scale: 1:2,580 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 16, Aug 22, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 25, 2021—Sep 5, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background Custom Soil Resource Report 27 MAP LEGEND MAP INFORMATION imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 28 Table—Hydrologic Soil Group (McLin Material Yard) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes C 14.5 83.8% 56 Potts loam, 6 to 12 percent slopes C 2.8 16.2% Totals for Area of Interest 17.3 100.0% Rating Options—Hydrologic Soil Group (McLin Material Yard) Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Custom Soil Resource Report 29 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 30 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 31