HomeMy WebLinkAbout20240815 6584 McLin Staging Yard SWMP ESC PlansFILE NAME
Sheet No.
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MICROFILM No.
SCALE
CALL UTILITY NOTIFICATION CENTER OF COLORADO
(UNCC) AT 811 BEFORE DIGGING. ALLOW MINIMUM
48-HOURS FOR UTILITY LOCATION SERVICES.
REV DATE PROJ. No.REVISION DESCRIPTION DWN DSN ENG CHK FILM
-SIZE REV
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G a r f i e l d
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N e w C a s t l e
G l e n w o o d
S p r i n g s
Material Yard
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County Road 3 3 5
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Material Yard
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LOCATION MAPVICINITY MAP
PROJECT AREA
HDR Engineering, Inc.
1670 Broadway Street, Suite 3400
Denver, CO 80202
Project Manager: Brian Brown, PE
(970) 416-4404
Xcel Energy
9191 S. Jamaica Street
Englewood, CO 80112
Project Manager: Justin Eusoof
(719) 331-9462
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SHEET
INDEX OF DRAWINGS
XCEL TLINE: 6584 MITC-UTER McLIN STAGING YARD
0.75 Mile Southeast of County Road 311 and County Road 335 Intersection
Unincorporated Garfield County, CO 81647
(39.529868, -107.610443)
August 2024
6584 MITC - UTER
McLIN YARD
1
COVER AND INDEX SHEET
AUGUST
2024
XCEL TLINE: 6584 MITC - UTER
McLIN YARD
AS SHOWN
COVER AND INDEX SHEET
GENERAL NOTES
INITIAL PHASE
INTERIM PHASE
FINAL PHASE
VT MEMO
TITLE OF SHEET
McLin Yard
McLin Yard
REV DATE PROJ. No.REVISION DESCRIPTION DWN DSN ENG CHK FILM
FILE NAME SCALE
SHEET No.MICROFILM No.
SIZE DWG No.REV
GENERAL NOTES
6584 MITC - UTER
McLIN YARD
2
GENERAL NOTES
XCEL TLINE: 6584 MITC - UTER
McLIN YARD
NO SCALE
THIS STORMWATER MANAGEMENT PLAN (SWMP) HAS BEEN DEVELOPED IN ACCORDANCE WITH GOOD ENGINEERING, HYDROLOGIC, AND POLLUTION CONTROL PRACTICES TO MEET STANDARDS SET FORTH IN
THE COLORADO DISCHARGE PERMIT SYSTEM (CDPS) GENERAL PERMIT FOR STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY – PERMIT CERTIFICATION COR400000, EFFECTIVE APRIL 1,
2024 AND EXPIRING MARCH 31, 2029.
THE PERMITTEE AND THEIR CONTRACTORS MUST IMPLEMENT PROVISIONS OF THE SWMP AS WRITTEN AND UPDATED, FROM COMMENCEMENT OF CONSTRUCTION ACTIVITY UNTIL FINAL STABILIZATION IS
ACHIEVED.
THE PLAN MUST REMAIN ON SITE OR BE ON SITE WHEN CONSTRUCTION ACTIVITIES ARE OCCURRING AT THE SITE UNLESS THE PERMITTEE HAS SPECIFIED AN ALTERNATE LOCATION AND OBTAINED APPROVAL
FROM THE WATER QUALITY CONTROL DIVISION (WQCD).
THIS SWMP SHOULD BE VIEWED AS A LIVING DOCUMENT CONTINUOUSLY REVIEWED AND MODIFIED AS PART OF THE OVERALL PROCESS OF ASSESSING AND MANAGING STORMWATER QUALITY ISSUES AT THE
SITE. THE SWMP MUST BE AMENDED WHEN THE FOLLOWING OCCURS:
SWMP REVISIONS MUST INCLUDE A NOTATION THAT IDENTIFIES: THE DATE OF SITE CHANGE, THE CM(s) REMOVED, OR MODIFIED; LOCATION(S) OF THOSE CMs; AND ANY CHANGES TO THE CMs. UNDOCUMENTED
CHANGES AND OUTSTANDING REVISIONS RENDER THE SWMP NON-COMPLIANT WITH THE GENERAL PERMIT.
ALL TEMPORARY STRUCTURAL PERIMETER CMs ON THE SWMP SHEETS WILL BE INSTALLED BEFORE ANY CONSTRUCTION ACTIVITIES TAKE PLACE IN THAT AREA.
CMs WILL BE FIELD FIT TO ON-SITE CONDITIONS AND CONSTRUCTION DISTURBANCES. DIMENSIONS OF STRUCTURAL CMs MAY BE DIFFERENT THAN INDICATED AND SHOULD BE REVISED ON THE PLAN ONCE
INSTALLED.
UNLESS INFEASIBLE, TOPSOIL WILL BE PRESERVED FOR AREAS OF THE SITE THAT WILL UTILIZE VEGETATIVE COVER FOR FINAL STABILIZATION.
CONSTRUCTION CONTRACTOR WILL MINIMIZE TO THE EXTENT FEASIBLE DISTURBANCES TO EXISTING VEGETATION AT THE SITE, INCLUDING LIMITING CONSTRUCTION FOOTPRINT WITHIN THE MAPPED LIMITS OF
DISTURBANCE.
TEMPORARY STABILIZATION MUST BE IMPLEMENTED FOR EARTH DISTURBING ACTIVITIES AT ANY PORTION OF THE SITE WHERE SUCH ACTIVITIES HAVE CEASED FOR MORE THAN 14 CALENDAR DAYS, UNLESS
THE FUNCTION OF THE AREA REQUIRES IT TO REMAIN DISTURBED, OR PHYSICAL CHARACTERISTICS OF THE TERRAIN OR CLIMATE PREVENT STABILIZATION.
FOR AREAS WHICH EXCEED THE 14-DAY STABILIZATION TIMELINE, THE SWMP MUST DOCUMENT CONSTRAINTS NECESSITATING THE ALTERNATE SCHEDULES, PROVIDE THE ALTERNATE STABILIZATION
SCHEDULE, AND IDENTIFY ALL LOCATIONS WHERE ALTERNATIVE SCHEDULES ARE APPLICABLE ON THE SITE MAP.
BULK STORAGE (55 GALLONS OR GREATER) OF PETROLEUM PRODUCTS OR OTHER CHEMICALS WILL HAVE ADEQUATE PROTECTION TO CONTAIN ALL SPILLS AND PREVENT ANY SPILLED MATERIAL FROM
LEAVING THE SITE OR ENTERING THE STORMWATER SYSTEM OR SURFACE WATERS.
SOLID WASTE, INDUSTRIAL WASTE, YARD WASTE, AND ANY OTHER POLLUTANTS MUST BE CONTROLLED USING CMs.
THERE ARE NO STORMWATER INLETS WITHIN THE PROJECT AREA.
LIMITS OF DISTURBANCE TO INCLUDE ALL GRADING AND SURFACE DISTURBING WORK (FENCE INSTALLATION, CM INSTALLATION, RUTTING OVER 3 IN. OR DEEPER, ETC.).
A.
B.
C.
D.
E.
CHANGE IN DESIGN, CONSTRUCTION, OPERATION, OR MAINTENANCE OF THE SITE REQUIRING IMPLEMENTATION OF NEW OR REVISED CONTROL MEASURES (CMs),
THE SWMP PROVES INEFFECTIVE IN CONTROLLING POLLUTANTS IN STORMWATER RUNOFF IN COMPLIANCE WITH THE PERMIT CONDITIONS,
CONTROL MEASURES IDENTIFIED IN THE SWMP ARE NO LONGER NECESSARY AND ARE REMOVED;
CORRECTIVE ACTIONS ARE TAKEN ON SITE THAT RESULT IN A CHANGE TO THE SWMP; AND
IF THE SITE, OR AN AREA OF THE SITE, QUALIFIES FOR AND IMPLEMENTS A REDUCED INSPECTION FREQUENCY.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
AUGUST
2024
Material Yard
5
6
70
5660
5650
5640
5
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3
0
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6
2
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5
6
1
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5
6
0
0
5
5
9
0
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5
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55
3
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5
5
7
0
556
0
555
0
5
5
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0
5
5
3
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5
5
2
0
568
0
569
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5
5
2
0
5510
5660
5
650
55
1
0
5 6 5 0
5520
5
520
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D i v i d e C r e e k
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0 100 200
Feet
1" = 150'¯
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3
1
1
McLin Yard
VTC
Avoid irrigation
connection.
Area excluded
due to irrigation
pumping
equipment.LOC
Install
barbed wire.
~3,155 LF
~15 AC
~14.5 AC
LOD
Major Contour (10')
Minor Contour (2')
Watercourse (NHD)
Waterbody (NHD)
Wetland (NWI)
Material Staging Yard Boundary
Surface Flow Direction
Helicopter Landing Zone
Vegetation and
Topography buffer,
34' width.
Soil Grou
p
C
S
o
i
l
G
r
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u
p
C
SM
CF
VTC
SCL
SSA
VT
Limits of Construction
Limits of Disturbance
Stabilized Staging Area
Sediment Control Log
Construction Fence
Vehicle Tracking Control
Vegetation and Topography
Seed and Mulch
LOC
LOD
XCEL 6584 MITC-UTER
McLIN STAGING YARD
INITIAL PHASE
SHEET 3
1.
2.
3.
4.
5.
Install CMs (i.e., VTC, perimeter controls, etc.) prior to any ground disturbing activities within the limits of construction.
Contractor is to keep within predefined construction limits. SWMP inspector to update site map with locations of construction/boundary
fencing (CF/BF) once determined by construction.
VTC to be aggregate surfaced, proprietary tracking pad, or other structural control measure. Contractor to manage track out by cleaning
vehicles and cleaning track out off of county road immediately following occurrence.
Flow direction shown where surface flow direction is discernible given topography. SWMP Inspector to update active site maps with flow
arrows accordingly.
Permitted limits of disturbance shown. Entire yard will not have topsoil surface removal. Majority of yard is expected to be drive & crush
where root zone will remain intact. Given the drive & crush use of majority of yard, combined with other factors, VT is an appropriate erosion
control measure. See VT memo.
INITIAL PHASE SWMP NOTES
See Note 3.
LZ
VT
See Note 5.
See Note 5.
Material Yard
5
6
70
5660
5650
5640
5
6
3
0
5
6
2
0
5
6
1
0
5
6
0
0
5
5
9
0
5
5
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0
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5
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0
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5
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0
5
5
5
0
5
5
4
0
55
3
0
5
5
7
0
556
0
555
0
5
5
4
0
5
5
3
0
5
5
2
0
568
0
569
0
5
5
2
0
5510
5660
5
650
55
1
0
5 6 5 0
5520
5
520
D
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D i v i d e C r e e k
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0 100 200
Feet
1" = 150'¯
C
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R
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3
1
1
McLin Yard
VTC
SSA
Avoid irrigation
connection.
Area excluded
due to irrigation
pumping
equipment.
LZ
STABILIZED SURFACE AREA LAYOUT
NOTE: Equipment layout on stabilized staging area will be
adjusted based on contractor layout preference. Equipment
shown indicates typical items expected on SSA.
Crew Parking
Office
Portable
Toilets
Generator
Optional Trailer
Dumpster
Conex
Equipment Storage
Heli-Fuel Truck
Water Truck
Install 32'
gate.
Barbed wire.
LOD
Major Contour (10')
Minor Contour (2')
Watercourse (NHD)
Waterbody (NHD)
Wetland (NWI)
Material Staging Yard Boundary
Surface Flow Direction
Helicopter Landing Zone
Vegetation and
Topography Buffer,
34' width.
SM
CF
VTC
SCL
SSA
VT
LOC
LOD
INTERIM PHASE
SHEET 4
INTERIM PHASE SMWP NOTES
LZ
1.
2.
3.
4.
5.
CMs that are greyed out were installed in the initial phase of construction and do no need to be reinstalled, only maintained.
SWMP inspector to update site maps with location of all significant material storage (fuel tanks, portable toilets, CWA, and other pollutants
within the yard boundary). Portable toilets must be properly anchored to prevent tipping. Fuel storage must be equipped with secondary
containment.
Stabilized staging area to be prepared by:
Contractor to temporarily stabilize disturbed areas by surface roughening if left dormant for 14 days.
SWMP inspector to monitor depicted VT buffer for evidence of sediment migration. If sediment migrates from the site or is expected to
migrate from the site, install down-gradient structural control measures where needed.
A. Stripping and stockpiling topsoil.
B. Installing down-gradient CMs at topsoil stockpiles (side slopes not to exceed 2:1).
C. SWMP inspector to update the site map with stockpile locations.
D. Stabilize stockpile with seed and mulch, tarping, and or surface roughening to prevent erosion.
E. Placement of aggregate surfacing.
VT
LOC
~15 AC
~14.5 AC
See Note 5.
Limits of Construction
Limits of Disturbance
Stabilized Staging Area
Sediment Control Log
Construction Fence
Vehicle Tracking Control
Vegetation and Topography
Seed and Mulch
XCEL 6584 MITC-UTER
McLIN STAGING YARD
~2 AC
Material Yard
5
6
70
5660
5650
5640
5
6
3
0
5
6
2
0
5
6
1
0
5
6
0
0
5
5
9
0
5
5
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0
5
5
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0
5
5
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0
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5
5
0
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5
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0
55
3
0
5
5
7
0
556
0
555
0
5
5
4
0
5
5
3
0
5
5
2
0
568
0
569
0
5
5
2
0
5510
5660
5
650
55
1
0
5 6 5 0
5520
5
520
D
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C
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D i v i d e C r e e k
W
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s
a
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R
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o
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D
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0 100 200
Feet
1" = 150'¯
C
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u
n
t
y
R
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a
d
3
1
1
McLin Yard
Avoid irrigation
connection.
Area excluded
due to irrigation
pumping
equipment.
LOD
Major Contour (10')
Minor Contour (2')
Watercourse (NHD)
Waterbody (NHD)
Wetland (NWI)
Material Staging Yard Boundary
Surface Flow Direction
Helicopter Landing Zone SM
CF
VTC
SCL
SSA
VT
Limits of Construction
Limits of Disturbance
Stabilized Staging Area
Sediment Control Log
Construction Fence
Vehicle Tracking Control
Vegetation and Topography
Seed and Mulch
LOC
LOD
FINAL PHASE
SHEET 5
FINAL PHASE SWMP NOTES
LZ
SM
See Note 5.
1.
2.
3.
4.
5.
Yard likely to be restored in a phased manner as construction reduces use of area of yard. Contractor to phase surface roughening and seed
and mulch for reclamation. SWMP inspector to update maps accordingly. CM installer should relocate perimeter controls throughout phased
restoration to protect areas that are in reclamation from construction impacts.
Stabilized staging area restoration:
Non-aggregate stabilized areas are assumed to be drive and crush and have minimal compaction. Where compaction or obvious rutting has
occurred, restoration contractor to restore.
Vehicle tracking control to be removed with aggregate surface material.
Seed and mulch estimated to be ~7 acres. Actual reclamation area and location of reclamation, will be based on actual yard disturbance.
Disturbance outside the stabilized staging area will be dependent on soil moisture, delivery schedule, and material movement which all
influence potential rutting occurrence. Contractor to coordinate with land manger on final stabilization implementation. Land owner could
used disturbed areas for agricultural purposes.
Remove aggregate surface material.
Compacted subgrade below access drive path to be ripped to 12-inch depth at 24-inches spacing in two perpendicular passes.
Topsoil to be replaced and surface roughened.
Seed and mulch disturbed areas.
Remove down-gradient SCLs, if previously installed, once upgradient required vegetation density has been met.
LOC
~15 AC
~14.5 AC
See Note 5.
A.
B.
C.
D.
F.
VTC
See Note 4.
XCEL 6584 MITC-UTER
McLIN STAGING YARD
Remove
barbed wire.
Remove
32' gate.
Remove LZ.
REV DATE PROJ. No.REVISION DESCRIPTION DWN DSN ENG CHK FILM
FILE NAME SCALE
SHEET No.MICROFILM No.
SIZE DWG No.REV
6584 MITC - UTER
McLIN YARD
6
VT MEMO
XCEL TLINE: 6584 MITC - UTER
McLIN YARD
NO SCALE
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
July 5, 2024
Xcel 6584 MITC-UTER Material 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 practic es 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.
Vegetation and Topography Memo
AUGUST
2024
August 6, 2024
Hydrologic Soil Group
for the site is type C.
McLin Yard
