HomeMy WebLinkAbout1.22 Storm water management planStormwater Management Plan Beaver Creek Pipeline Project, 2008 ETC Canyon Pipeline, LLC Prepared By: ASPEN ENVIRONMENTAL FIELD SERVICES, LLC Project COHlIJliancc Management · Pemliltjng
, Site Rew)yalioll
TABLE OF CONTENTS 1.0 INTRODUCTION......................................................................... 2 2.0 SITE DESCRIPTION.....................................................................
2 2.1 Nature of Construction Activities............................................... 2 2.2 Sequence of Major Activities.................................................... 3 2.3 Acreage
Disturbed by Construction Activities............................. ... 4 2.4 Soil Description and Potential for Erosion..................................... 4 2.5 Description of Existing
Vegetation... ....... ..... .............................. 4 2.6 Potential Pollutant Sources...................................................... 4 2.7 Non-Stonnwater Discharges.. ..........
...... ...... ......... ..................... 5 2.8 Receiving Waters.............................................................. .... 5 3.0 SITE MAP................................................
.................................. 5 4.0 STORMW ATER MANAGEMENT CONTROLS................................. ... 5 4.1 SWMP Administrator............................................................
5 4.2 Potential Pollutant Sources...................................................... 6 4.3 Best Management Practices for Stonnwater Pollution Prevention......... 6 4.3.1 Structural
Practices for Erosion and Sediment Control............. 6 4.3.2 Non-Structural Practices for Erosion and Sediment Control....... 6 4.3.3 Phased BMP Implementation.....................................
..... 7 4.3.4 Materials Handling and Spill Prevention.......................... ... 7 4.3.5 Dedicated Concrete or Asphalt Batch Plants..................... .... 7 4.3.6 Vehicle Tracking
Control.............................................. 7 4.3.7 Waste Management and Disposal, Including Concrete Washout. 8 4.3.8 Groundwater and Stonnwater Dewatering.......................
.... 8 5.0 FINAL STABILIZATION AND LONG-TERM STORMWATER ............... 8 5.1 Final Stabilization................................................................ 8 5.2 Long-Tenn Stonnwater
Management...................................... ... 9 6.0 INSPECTION AND MAINTENANCE............................................... 9 6.1 Inspection. . . . . . . . . . . . . . . . ..
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .. 9 6.1.1 Construction.............................................................
9 6.1.2 Maintenance............................................................. 10 6.1.3 Winter Inspection Exclusions....................................... ... 10 6.2 Maintenance...................
................................................... 10 LIST OF ATTACHMENTS 1
Attachment 1 -Site Maps 2
1.0 INTRODUCTION This Stormwater Management Plan (SWMP) identifies measures to be taken on the Beaver Creek Pipeline Project (project) to meet requirements set forth by Colorado Department
of Public Health and Environment (CDPHE) Division of Water Quality Control, for controlling stormwater discharges associated with construction activity. Measures identified in this plan
apply to ETC Canyon Pipeline, LLC (ETC) and the contractor(s) (Contractor) it employs to construct the pipeline. Measures in this plan pertain to the entire project, which is defined
as the right-of-way (ROW), temporary use areas, access roads, and all other areas utilized during construction activities. This SWMP describes procedures to minimize the potential for
erosion, sedimentation, and the discharge of pollutants, both on and off ROW, by the use of proper construction techniques and the adoption of appropriate Best Management Practices (BMPs).
These BMPs will be implemented and maintained during all active construction activities and maintained until the terms and conditions of the associated stormwater permits have been fulfilled.
This plan is required, by CDPHE Division of Water Quality, to be available on-site during active construction and during site inspections. ETC currently holds two storm water discharge
permits which cover the geographical area in which construction will take place. The permit numbers and expiration dates are listed below: Certification Number Expiration Date COR038333
06110/2010 COR038335 0611012010 These two permits will be modified to reflect the additional amount of acreage disturbed by the project. 2.0 SITE DESCRIPTION 2.1 Nature of Construction
Activities The Beaver Creek Pipeline Project involves installing 2.6 miles of natural gas pipeline. The pipeline will be constructed of 16 inch and 4 inch steel pipe, which will be buried
to an average depth of 5 to 6 feet. The purpose of this project is to increase natural gas transportation capacities within the area of the proposed project. This project will create
an additional 45 million cfld capacity, which will transport anticipated, increased natural gas production in this area. 2.2 Sequence of Major Activities 3
Construction is planned to begin in the fall of 2008 and is anticipated to be completed by late December of 2008. The project will utilize standard linear pipeline construction techniques.
These techniques will sequence as follows: \.) Clearing-2.) Grading-3.) Trenching-4.) Stringing-5.) Welding-6.) Lowering-7.) Backfill-As necessary for safety and construction feasibility,
vegetation, rocks, and debris will be removed or relocated to either outer edge of the ROW. Clearing activities will prepare the ROW for the grading process to follow. During grading
activities, topsoil is removed, as required, and is segregated and stored on the ROW for later redistribution. Grading activities will also involve leveling the ROW where slopes present
an unsafe construction environment. Trenching involves excavation of the trench used to bury the pipeline. Sections of pipe will be strung in linear fashion after the ROW has been prepared
by clearing and grading activities. During welding activities, the pipe sections will be welded, coated, and possibly x-rayed to allow the pipe to be lowered into the trench. Welded
sections of pipe are lowered into the trench. After the pipe is lowered into the trench, the subsoil is returned to the trench to cover the pipe. 8.) Cleanup -Once the pipeline has been
installed, the right-of-way will be prepped for road construction activities. All slopes will be recontoured for reseeding. 9.) Restoration-10.) Tie-In-Restoration involves reseeding,
mulching, and spreading removed vegetation and rock over the ROW. During restoration, the permanent BMPs will also be installed. Tie-ins will occur over the entire length of the project
where initial construction efforts were unable to continue building linear pipeline (road crossings, wetlands, etc.). Tie-in locations will utilize the nine processes described above.
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2.3 Acreage Disturbed by Construction Activities The project will utilize a 60 foot wide construction right-of-way over the entire length of the 2.6 mile project. The maximum amount
of soil disturbance associated with ROW construction is 18.9 acres. The project is designed to disturb the minimal amount of acreage within the construction ROW, while maintaining a
safe and effective work environment. The actual amount of disturbed acreage is anticipated to be notably less than the maximum amount of potential soil disturbance. 2.4 Soil Description
and Potential for Erosion Surface soils range from sandy to clay soil types. Sections of the project contain a significant amount of rock in the surface layer. The pipeline's route generally
follows foot hills terrain with slopes of less than 5% to 10%. The post-construction runoff coefficient will be between 0.20 and 0.79, depending on slopes, soil types, and soil stabilization
activities. Pre-construction runoff coefficients are estimated to be lower on average, but not significantly different than postconstruction coefficients. 2.5 Description of Existing
Vegetation The project primarily follows flat or rolling foothills, with the elevation ranging from about 5,500 feet to near 7,000 feet. Vegetation on mesa tops range from grass, shrub,
and woodland species to agricultural/pasture vegetation. Steeper drainages are characterized by more shrub and woodland species of vegetation. The percentage of ground cover ranges greatly
from 0% to 100%. Typical ground cover over the length of the project is 40%-75%. 2.6 Potential Pollutant Sources The four primary sources of potential pollutants associated with construction
of the project are listed below. These potential pollution sources will be possible over the entire length of the project. • Vehicles & Equipment -Fuel, hydraulic and motor oil, lubricants,
other greases • Painting & Coating -Paint, solvents, coating materials • Herbicide Treatment -Herbicides, buffers, and drift-control agents • Construction Activities -Loose soil, dust
The release of these potential pollutants during construction or storage will be minimized by adhering to the Hazardous Materials Management and Spill Prevention and Countermeasure Plan,
Soil Conservation, Sedimentation, and Erosion Control Plan, Fugitive Dust Control Plan, and the Reclamation Plan. 5
2.7 Non-Stormwater Discharges The project may require non-stormwater discharge in the form of trench dewatering. In the event a trench is filled with ground water, or after a storm event,
the water will be pumped out of the trench to facilitate construction efforts. Discharge from trench dewatering will be directed to a well-vegetated area or other measures will be taken
to prevent the discharge from scouring the land. Discharge of heavily silt-laden water will be minimized by controlling the location of the pump's intake and/or discharging through a
sediment bag or functionally equivalent device. 2.8 Receiving Waters The project is located within the Colorado River Basin and the Colorado River will be the ultimate receiving water
for all waterbodies crossed by the project. The project is in the vicinity of Beaver Creek and is within the City of Rifle Beaver Creek Watershed. 3.0 SITE MAP The Beaver Creek Pipeline
Project resides entirely in Garfield County, Colorado. Maps are included as Attachment 1 and illustrate the location of the project boundaries and associated ground disturbance, location
of anticipated BMPs, and the location of water bodies. 4.0 STORMWATER MANAGEMENT CONTROLS 4.1 SWMP Administrator ETC Canyon Pipeline, LLC will employ contractors to provide SWMP administration
over the project. Aspen Environmental Field Services, LLC is responsible for developing the SWMP. The Environmental Inspector and/or Stormwater Inspector will be responsible for implementing,
maintaining, and revising the SWMP during active construction. The Stormwater Inspector will be responsible for maintaining and revising the SWMP after construction is complete. The
SWMP will be maintained until final restoration is complete and requirements of any associated permits have been fulfilled. 6
4.2 Potential Pollutant Sources In accordance to the Stormwater Management Plan contents guideline, the following pollutant sources are evaluated for discharge potential as related to
this project. I.) All Disturbed and Stored Soils -Potential Pollutant 2.) Vehicle Tracking of Sediments -Potential Pollutant 3.) Management of Contaminated Soils -Potential Pollutant
4.) Loading and Unloading OQerations -Potential Pollutant 5.) Outdoor Storage Activities -Potential Pollutant 6.) Vehicle and EguiQment Maintenance and Fueling -Potential Pollutant 7.)
Significant Dust or Particulate Generating Process -Potential Pollutant 8.) Routine Maintenance -Potential Pollutant 9.) On-Site Waste Management-Potential Pollutant 10.) Concrete TruckiEguiQment
Washing Potential Pollutant 11.) Dedicated ASQhaltiConcrete Batch Plants -No Pollutant Potential 12.) Non-Industrial Waste-Potential Pollutant 13.) Activities Identified in Section 2.6
Potential Pollutant 4.3 Best Management Practices for Stormwater Pollution Prevention 4.3.1 Structural Practices for Erosion and Sediment Control Structural practices employed by this
project will represent the primary control measures in preventing or minimizing stormwater discharges of sediment and erosion control. The anticipated locations of structural erosion
and sediment control measures are located in the maps included as Attachment 1. The project parallels an existing natural gas ROW. The approach taken for sediment and erosion control
by use of structural measures, will be to extend control measures currently in place on the existing, paralleling ROW to include the new disturbance from this project. The project will
use waterbars, sediment basins, straw waddles, check dams, rock aprons, and culverts to perform the structural erosion and sediment control. Other devices may be utilized if found appropriate
during the time of construction or during follow-up maintenance. 4.3.2 Non-Structural Practices for Erosion and Sediment Control Non-structural erosion and sediment control practices
will be used in conjunction with structural practices to deliver effective stormwater erosion and sediment control. Removal of existing vegetation will be minimized during clearing and
grading activities, with emphasis being placed on preserving existing trees and other mature vegetation. The removal of such vegetation will be limited to only that vegetation that must
be removed to install the pipeline or provide a safe working environment. 7
Planting of temporary and permanent vegetation will be utilized in conjunction with mulching, geotextile fabrics and slope roughing to perform the majority of soil stabilization. These
nonstructural practices will be employed over the entire length of the project as able and/or required by the associated landowner. 4.3.3 Phased BMP Implementation The application of
BMPs will be used over the entire course of the project construction and maintenance activities. During active construction, sediment, erosion, and pollutant discharges will be addressed
primarily by the installation of temporary waterbars, straw waddles, sediment fence, and adhering to the Hazardous Materials Management and Spill Prevention and Countermeasure Plan.
During final restoration efforts, several structural and non-structural practices will be deployed. These include, but are not limited to, seeding, mulching, geotextile fabric, slope
roughing, permanent waterbars, sediment traps and other structural and non-structural practices. Practices deployed during final restoration will also be utilized, as needed, during
the maintenance period of the project to provided continued soil stabilization and sediment control. 4.3.4 Materials Handling and Spill Prevention Material handling and spill prevention
are addressed in detail in the Hazardous Materials Management and Spill Prevention and Countermeasure Plan. Project compliance will be handled by adhering to this plan. Spill prevention
will be attained by properly using secondary containment systems and storing hazardous materials away from sensitive areas. Immediate countermeasures will be taken in the event of a
hazardous material spill. 4.3.5 Dedicated Concrete or Asphalt Batch Plants This project will not be utilizing dedicated concrete or asphalt batch plants. 4.3.6 Vehicle Tracking Control
It is the Contractor's responsibility to install vehicle tracking control measures and to remove sediment once tracking has occurred. The intersections of all access roads and the ROW
that intersect paved roads will be cleared, as necessary, of vehicle tracked sediment at the end of each work day. Severe vehicle tracking that posses a safety concern will be immediately
removed. The Contractor will utilize street sweepers, scraping equipment, hand tools, or pressurized water to remove sediment tracked onto paved roads. The Contractor may install gravel
approaches to paved roads to assist in controlling vehicle tracking. Geotextile or similar fabric will be placed beneath gravel to promote easy removal when the approach is no longer
needed. The Environmental Inspector may also direct the installation of gravel approaches as he/she sees fit. 8
4.3.7 Waste Management and Disposal, Including Concrete Washout Minimal concrete is anticipated to be used on this project. Concrete may be used in the installation of mainline valves,
pig launchers, or other assembly directly related to the pipeline. During these types of concrete applications, the Contractor will ensure that concrete washout water is discharged into
the associated, exposed trench or other nearby like areas. The concrete washout water will be discharged onto subsoil which is below surrounding grade to prevent stormwater discharge
ofthe concrete. Refuse dumpsters, recycling bins, portable toilets, or any other containers storing liquid or solid waste will only be utilized under the following guidelines: • Containers
will be located a minimum of 100 feet away from sensitive areas • Containers will be emptied at an appropriate location, or hauled off by an appropriate company • Containers will be
emptied on a regular basis to prevent overflow Contractor shall enforce good housekeeping skills on entire project staff. Dumping of any debris, regardless of size or type, onto the
project will not be allowed. 4.3.8 Groundwater and Stormwater Dewatering Groundwater and storm water dewatering will only occur if groundwater or storm water presents an obstacle for
construction. Dewatering will only occur in the form of trench dewatering and wells will not be used to lower groundwater levels. An Industrial Wastewater Discharge Permit is being obtained
by the project to permit discharging of groundwater not otherwise covered by the stormwater permit. 5.0 FINAL STABILIZATION AND LONG-TERM STORMWATER MANAGEMENT 5.1 Final Stabilization
Final stabilization of the project will be considered during all phases of construction activity. All things being equal, choices made during construction will favor those options that
will enhance the final stabilization process. Clearing and grading activities will give extra attention to the final stabilization process. During clearing and grading activities, the
minimum amount of soil and vegetation will be disturbed while providing a safe and efficient work area. In particular, the removal of trees will be limited to only those that must absolutely
be removed. Where feasible, root systems will be left in place and the herbaceous vegetative crown will be maintained where grading of the ROW and extra work spaces is not necessary.
Vegetation removed during clearing activities will be placed on the edge of the ROW to be redistributed after final grading has occurred. 9
Only those portions of the ROW that require grading will have topsoil removed and stored on the edge of the ROW to be redistributed during cleanup activities. Where topsoil is graded,
the entire topsoil layer, up to 12", will be stripped unless otherwise stipulated by the individual landowner. Cut and fill technique will be utilized only where slopes present a safety
concern for construction activities to follow. By minimizing vegetation and soil disturbance and protecting the topsoil resource, vegetation will be able to be effectively restored over
the entire ROW. Final stabilization will be achieved by the proper placement and installation of BMPs, planting the correct seed and/or plants, during the correct season, for the applicable
soil type, and installing additional soil stabilizer, such as crimped mulch, where necessary. The location and type of BMPs are outlined in this plan or will be identified in the field
by the Environmental Inspector. The proper selection of seed and/or plants will be identified by the landowner or by the recommendations of the National Resources Conservation Service.
Soil stabilizers will be installed at the direction of the Environmental Inspector. 5.2 Long-Term Stormwater Management Oversight of long-term stormwater management will be the responsibility
of the Stormwater Inspector assigned to the project after construction is complete. The Stormwater Inspector will conduct monthly inspections of BMPs and note areas of erosion or poor
vegetation return. Maintenance requests will be made by the inspector to ETC or assigned contractor to make necessary repairs as needed. 6.0 INSPECTION AND MAINTENANCE 6.1 Inspection
The project's Environmental Inspector and/or Stormwater Inspector will be responsible for performing inspections of all project BMPs and completing the associated inspection reports.
6.1.1 Construction In areas of active construction, BMPs will be inspected on a daily basis. Areas of active construction, includes those portions of the project being used to access
construction sites and temporary use areas with associated activity. BMPs located in areas without activity must be inspected every 14 days. All BMPs will be inspected within 24 hours
of a 0.5 inch, or greater, precipitation event. If ROW conditions do not allow for timely, post-storm inspection ofBMPs, the inspection will take 10
place within 72 hours and prior to the re-commencing of construction activities. Any such delays in inspection ofBMPs must be documented in the inspection report. 6.1.2 Post-Construction
Portions of the project where active construction is complete, BMP inspection intervals may be reduced to once a month as long as the following conditions exist: • All ground disturbance
construction activities are complete • All activities identified in the SWMP for final restoration are complete (seeding not required) • SWMP has been amended to indicate areas under
reduced inspection intervals BMPs identified as being insufficient will continue to be properly maintained and/or reinstalled as necessary. 6.1.3 Winter Inspection Exclusions Routine
14-day, monthly, and post-storm inspections are not required for those areas of the ROW where there is no active construction, snow cover exists over the entire ROW, and melting conditions
are not present. This exclusion should be properly documented in the inspection report. 6.2 Maintenance The Contractor will be responsible for correctly installing erosion and sediment
control measures. The Contractor is also responsible for properly maintaining these sites after installed. Maintenance of BMPs will be performed by the Contractor, as needed, within
24 hours of discovery or notification, or as soon as ROW conditions will allow. 11