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HomeMy WebLinkAbout20131662.tiffWhiting Petroleum Corporation Red Tail Gas Plant Site EROSION CONTROL AND STORMWA TER MANAGEMENT PLAN (SWMP) Weld County, COLORADO March 2013 PREPARED FOR: (APPLICANT) Whiting Petroleum Corporation Red Tail Gas Plant c/o GWD Design Mike Kraft 621 17th St, Ste 1200 Denver, CO 80293 (303)951-9337 PREPARED BY: Diamondback Engineering & Surveying. Inc. 12640 W. Cedar Dr. Ste C LAKEWOOD. COLORADO 80228 (303) 985-4204 PROJECT MANAGER: JOHN ENOCI-IS, P.E. • `aQ�ooQ Op►►en ,9, 0 26051 too TABLE OF CONTENTS GENERAL INFORMATION AND SITE DESCRIPTION I STORM WATER MANAGEMENT CONTROLS 3 OTHER CONTROLS 12 INSPECTION AND MAINTENANCE 13 RECORD KEEPING IS RECORD RETENTION, MONITORING, NOTIFICATIONS AND FINAL STABILIZATION 16 CALCULATIONS 17 REFERENCES 17 APPENDIX Vicinity Map SCS Soils Map Calculations FEMA Firm Map (Not Printcd) GENERAL INFORMATION AND SITE DESCRIPTION This report represents an Erosion Control Report and a Stonnwater Management Plan for the Whiting Petroleum - Red Tail Gas Plant site improvements. It was prepared meeting the regulatory requirements and guidelines set forth by Weld County. Urban Drainage and Flood Control District, the Colorado Department of Health and Environment - Water Quality Control Division as well as appropriate provisions of the Colorado Water Control Act and the Federal Water Pollution Control Act. The Red Tail Gas Plant site is located to the southwest of the intersection of WCR 127 and WCR 116 in unincorporated Weld County. Red Tail Gas Plant Site is located in the Northeast ''A of Section 21, Township 10 North, Range 58 West of the Sixth Principal Meridian, County of Weld, State of Colorado (see Vicinity Map in the Appendix). The existing site is bounded in all directions by agricultural land. County Road 127 borders the property to the cast. Description The proposed project includes construction of a gas plant and installation of a water quality detention pond. The surrounding arca is agricultural. Existing topography of the site slopes at about 134 from the north to the south. The site will be graded with a I% slope from north to south. Runoff will be captured in a ditch located along the southern end of the pad. The ditch will convey the runoff to a storm water quality pond located to the south of the pad. The site is 40 acres in size. The proposed gas plant pad is 5.7 acres and lies in the southwestern portion of the overall site. The gas plant site will be surfaced with road base. The earthwork for the proposed site is expected to be balanced. Proposed raw cut is estimated at 3,950 cubic yards with 3,950 cubic yards of raw fill. The arca surrounding the site is made up of agricultural land. Pre -Disturbance Conditions The site is undeveloped. There arc not any existing wetlands located on this site. Soils Information Soils arc predominantly Kim -Mitchell complex, 0-9% slopes as determined by U.S. Department of Agriculture Soil Conservation Service. These soils exhibit properties characteristic of Hydrologic Type B soils. Refer to the SCS Soils Map located in the Appendix. The runoff coefficient for the existing site in the major 100 -year storm event is approximately 0.50 as partially developed ground (2% impervious). Upon completion of the proposed improvements, the anticipated 100 -year runoff coefficient is anticipated to be between 0.50 and 0.55 and 6.7% impervious. Potential Pollution Sources Potential pollution sources anticipated from the site may be those associated with vehicle maintenance and fueling activities during construction, piping materials, and waste management (trash and debris). Please refer to the Materials Handling section of this report regarding minimization of the impacts of these potential pollutants. No dedicated concrete or asphalt batch plants shall exist on this site. Receiving Waters The existing site drains via overland flow onto the adjacent agricultural land. Thcrc is a drainage located approximately 1,500 feet down gradient from the site. This drainage is a dry arroyo with intermittent flows. The existing site is not located in the 100 year flood plain. Thcrc arc no FIRM Flood Insurance Rate Maps printed for this area. 2 z uoryeJodio3 tun �m 0I n T T O p��t 0y H o rZ 0 S.-- 0 z STORMWATER MANAGEMENT CONTROLS SWMP Administrator The general contractor or their designated agent shall be the Stormwater Administrator and have responsibility of supervision and control of all erosion and sediment control conditions on -site. This individual shall be responsible for developing, implementing, maintaining and revising the SWMP. Additionally, the SWMP administrator is responsible for obtaining, transferring and maintaining local and CDHPE permits, orienting and training of staff / workers; certifications, inspections, inspection logs, and meeting the regulations of all local and governmental authorities. This individual shall have any necessary training and hold certifications as required by Jefferson County, the CDHPE and the EPA. Erosion and Sediment Control Plan The entire disturbed site shall be paved or landscaped to minimize wind and water erosion. The methods used to control erosion and sediment during development of the subject property will comply with Jefferson County Regulations and the non-structural and structural Best Management Practices (BMP's) described in Volume 3 of the Urban Storm Drainage Criteria Manual. The predominant pollution expected at the site during construction and under permanent conditions is sediment in stormwatcr runoff. Proposed erosion control measures and details arc shown on the Erosion and Sediment Control plans accompanying this report. The following descriptions arc of specific BMP's utilized during construction of this project. Refer to the BMP details in the plan set for additional installation and maintenance specifications. Structural BMP Descriptions Concrete Washout Area (('W4) Purpose: A concrete washout area is a shallow excavation with a small perimeter berm used to isolate concrete truck washout operations. Install prior to concrete work on -site construction. Remove at completion of concrete activities on -site. Sketch: Refer to the Concrete Washout Detail located in the plans accompanying this report. 3 Method of Installation: Concrete washout facility should be constructed with a recommended width and length of I0 feet. The quantity and volume should be sufficient to contain all liquid and concrete waste =enerated by washout operations. Maintenance: The concrete washout facility should be maintained to provide adequate holding capacity with a minimum freeboard of 12 inches below grade. Hardened concrete should he removed and disposed of regularly to return the facility to a functional condition. Erosion Conn'ol Blanket (1:(B) Purpose: A blanket made of Straw, Coconut or Excelsior to protect erosion from concentrated flows in swalcs or drainageways. Erosion control Blankets arc also used to protect steep slopes greater than 4:1 from erosion. Install at the completion of grading activities. Sketch: Refer to the Erosion Control Blanket Detail located in the plans accompanying this report. Method of Installation: Roll blanket on area to be covered horizontally on the slope or Swale. Key in blanket by burying the top edge of the blanket using a 6'X6' trench at the top. Secure to the blanket to the ground using pins per manufacturer's recommendations. Overlap blankets such that the downgrade blanket is below the upgrade blanket. Maintenance: Review blanket for rips, tears and damage after every storm event. Repair and replace as necessary. .Sediment Basin (571) Purpose: A basin or pond which captures sediment -laden runoff and releases it slowly proving prolonged settlement times to capture coarse sand and fine grained soil particles. Install prior to construction and remove upon construction of the on -site detention facility. Sketch: Refer to the Sediment Basin Detail located in the plans accompanying this report. Method of Installation: Sediment basins shall be excavated per grades in the accompanying detail. Side Slopes of the 4 facility shall have a maximum slope of 3: I . An outlet pipe with perforations as shown in the details and a riprap reinforced overflow weir shall also be constructed. Maintenance: Sediment Basins and their outlet pipe shall be inspected bi-weekly and after every storm event. Make repairs and replace riprap logs as necessary. Sediment should be removed once it has accumulated to one-half the depth of the basin. Sediment Coning Log (S'('1) Purpose: A sediment control log consists of rolled straw, compost, coconut or excelsior fiber. A sediment control log is used to filter sediment as runoff passes through the rolled fibers. Install at commencement of construction or installation of concrete pans. Remove at final stabilization of site. Sketch: Refer to the Sediment Control Log Detail located in the plans accompanying this report. Method of Installation: Sediment Control Logs should be placed on the contour. The sediment control log is placed in a trench (minimum 2" deep) and staked to the ground to prevent movement. Adjacent logs shall be firmly paced against each other to eliminate all gaps. Sediment Control Logs shall be staked in an alternating pattern every 24" installed at a 90 degree orientation through the center of the sediment control log. Maintenance: Sediment Control Logs should be inspected every day and after every storm event. Make repairs and replace logs as necessary. Sediment should be removed once it has accumulated to one-half the original height of the barrier. .Silt Pence (SP) Purpose: A temporary sediment barrier constructed of woven fabrics stretched across supporting posts. The bottom edge of the fabric is placed in an anchor trench that is backfilled with compacted soils. Silt fence is used to filter sediment as runoff passes through the woven fabric. Install at commencement of construction. Remove at final stabilization of site. Sketch: Refer to the Silt Fence Detail located in the plans accompanying this report. 5 Method of Installation: Silt fence should be placed on the contour. On slopes with grades greater than 7%, the silt fence should be located at least 5 to 7 feet beyond the base. Turn the ends of the silt fence upslope so that a certain depth of stormwater may be retained in front of the silt fence. The impounded depth should be at least 12 inches, but no more than the height of the silt fence. The bottom edge of the fence must be entrenched and backfilled to be effective. The silt fence should be purchased in a continuous roll cut to the length of the barrier to avoid the use of joints. When joints arc unavoidable, filter cloth should be spliced together only at a supporting post, with a minimum 6 -inch overlap, and securely sealed. Maintenance: Silt fence should be inspected within 24 hours of a storm event of .25 inches or greater, and at least once every fourteen calendar days. Sediment should be removed once it has accumulated to one-half the original height of the barrier. Filter fabric should be replaced whenever it has deteriorated to such an extent that the effectiveness of the fabric is reduced. Silt fence should remain in place until disturbed areas have been permanently stabilized. All sediment accumulated at the fence should be removed and properly disposed of before the fence is removed. Vehicle Tracking Control (1 W ) Purpose: Consists of a rock pad of at all entrancelexit points for a site that is intended to help strip mud from tires prior to vehicles leaving the construction site. Install at commencement of construction. Remove at final stabilization. Sketch: Refer to the Vehicle Tracking Control Detail located in the plans accompanying this report. Method of Installation: Gravel pad installed should use 6" aggregate material at a thickness of at least 9 inches. The tracking pad should be at least 20 feet wide and 50 feet long and a method of controlling vehicle egress through the tracking pad should be established. Maintenance: Inspect for areas where mud has passed through the gravel pad. Add additional granular material as necessary. 6 Non -Structural BMP Descriptions Certain non-structural BMP's including watering to control wind erosion and dust, protection of existing landscaping and trees, surface roughening and seeding and mulching will occur as need throughout the entire construction process. Watering: A watering truck shall be used to prevent dust pollution and wind erosion from occurring on -site. Site watering shall occur as necessary before, during and after site grading is complete. Seeding and Mulching (SM) Drill or broadcast seeding on disturbed areas with grasses and crimping in straw mulch to provide immediate protection against raindrop and wind erosion and as grass cover becomes established, provide long-term stabilization of exposed soils. Install upon completion of land disturbance. Surface Roughening (SR) Creating a series of grooves or furrows perpendicular to the slope along the contour in all disturbed, graded areas to trap rainfall, reduce the formation of rill, and gully formation. Install upon completion of land disturbance prior to seeding/ mulching. Phased BMP Implementation and Project Phasing For a site of this size and level of disturbance, initial structural erosion and sediment control measures including the Construction Fence, Silt Fcncc, Vehicle Tracking Control and Inlet Protection on existing storm sewer inlets and culverts will be implemented prior to construction and maintained throughout construction until final stabilization is achieved. Interim measures Sediment Basin and Inlet Protection on proposed inlets shall occur upon completion of the proposed storm scwcr construction. Sediment Control Logs, surface roughening and seeding and mulching shall occur upon completion of the overlot grading phase of construction. Concrete wash out areas will be constructed prior to construction of Curb and Gutter and the proposed building addition. The anticipated start of construction will begin in May 2013 with a completion date in July of 2013. Construction of activities will occur overlapping but will generally follow the sequence below. 7 Project mobilization — May 2013 Installation of all initial erosion control methods — May 2013 Overlot Grading Activities — May 2013 Construction of Facilities — June —July 2013 Interim erosion control methods Water Quality Pond, seeding/ mulching — May 2013 Removal of Erosion Control Measures — August 2013 Materials Handling/ Storage and Waste Management Materials handled on -site shall be done in such a manner to prevent pollutants from entering runoff or water sources. Exposed storage of building materials shall be completed at a location a minimum of 100 feet way from any sources of concentrated flow. Building materials that will be left dormant for extended periods of time shall be covered. Trash, debris and spoils shall be properly contained at the end of each day. Wash water from concrete equipment, masonry and stucco operations arc to be deposited into the designated concrete washout (CWA). Construction dumpster(s) will be located on -site to collect construction waste and general trash. The construction dumpster(s) shall be located a minimum IOU' away from any source of concentrated flow and be accessible to all construction crews. The general contractor shall regularly review the level of material in the dumpster(s). When the waste in the dumpster(s) nears the top of the unit, the dumpstcr provider will be notified to pick up the dumpstcr and return an empty unit in its place. All trash, debris and left over materials at the construction site shall be removed promptly. Burying of wastes on -site is prohibited. Portable toilets shall be used on -site at a location designated by the Stormwatcr Administrator away from areas of concentrated flows. These facilities shall be anchored on all four corners to prevent tipping and spillage of waste. The level of waste shall be monitored and the portable unit provider contacted to replace the existing unit with an empty unit on -site. 8 Fuel tanks and vehicle maintenance, if necessary, shall be at a yet to be determined designated area in the project and within a lined fuel storage berm minimum 12 -inch high capable of retaining potential spills. It is at this location that fueling and maintenance of equipment shall occur. It shall be the responsibility of the Stornnvater Administrator to designate this area and take appropriate actions to ensure pollution of stormwater does not occur. Fueling' maintenance areas shall be at least I0) feet from drainage channels/ ditches, waterways, wetlands, storm sewer systems or environmentally sensitive area. The heavy equipment contractor shall be responsible for protecting the soil from contamination due to any hydrocarbon and other hazardous spills associated with his contractual obligations. Chemicals and fertilizers which may be utilized on -site must be stored in clean dry locations or covered outdoors. If these materials arc stored outdoors, these pollutant sources shall be located a minimum 100' away from any sources of concentrated flow and located in leak tight containers. Typical BMP's for material storage and waste management arc described as follows. I. Construct an enclosure, container or dike located around the perimeter of toxic materials or petroleum products storage areas. 2. Store materials or chemicals in a covered area to protect them from rainfall and wind dispersal. 3. Locate material storage and construction staging as far away from drainage courses as possible. 4. Perform wash out of concrete trucks and materials off -site or in designated wash out areas on -site only. Spill Prevention, Control and Countermeasure Plan A Spill, Prevention, Control and Countermeasure (SPCC) plan shall be prepared for any areas where potential spills can occur. This plan shall be prepared prior to the introduction of potential spill sources to the site and completed per State regulations addressing spill prevention measures, secondary containment and response procedures in the event of a spill. A spill kit shall be kept at a designated location on -site at all times throughout the construction process and clearly marked. This kit will contain the necessary items to contain a spill and prevent discharge into areas of concentrated runoff and drainagcways. This kit at a minimum 9 shall include materials for absorbents, plastics. shovels, instructions for clean up procedures and materials for the recording of incidents. Containers shall be made available for used absorbents. After every spill event used spill prevention materials shall be properly disposed of and the spill kit replenished. All spills, discharges, overflows, upsets. events and leaky equipment shall be recorded and documented in the SWMP and MAP immediately. In the event of a spill, excessive run-off, or any other threat to Stormwater conditions, the following actions shall take place immediately: • On -site Stormwater Administrator shall be notified immediately of the concern • The on -site Stormwater Administrator will assess the situation and develop and implement a corrective action plan • The on -site Stormwater Administrator will then document the issue and resolution for review with the local City or County. • A copy of the event documentation and resolution shall be mailed/ emailed to the engineer or plan preparer. Contact Information The following agencies shall be contacted in the event of a spill at the site. • Tri-County Health Department (303) 220-9200 • Colorado Department of Public Health and the Environment (303) 692-3500 • Jefferson County (303) 271-8700 Non -Hazardous Spill Response Procedures A non -hazardous spill involves the unplanned spillage of any material onto the jobsite that may enter the stormwater drainage system. Examples include: concrete, petroleum fuel products, etc. A. Minor Spill — A minor spill involves the spillage of any non -hazardous material that can be contained. A minor spill is generally defined to be less than 5 gallons in volume. Response Procedure I. Stop the spill at the source. 2. Capture, contain and properly dispose of all spilled materials. 3. Notify Stormwatcr Administrator of spill. 10 4. Stormwater Administrator to document spill in SWMP log. 5. Stormwater Administrator to notify local City or County Stormwatcr Management team of spill immediately. 6. Stormwater Administrator to conduct post-mortem and education with parties involved with spill incident to ensure appropriate precautions can help avoid similar issue in the future. B. Significant Spill — A significant spill involves the spillage of any non -hazardous material that cannot be contained, but is generally more than 5 gallons in volume, or any spilled materials that enter the storm sewer system. Response Procedure I. Stop the spill at the source. 2. Capture, Contain and properly dispose of all spilled materials. 3. Notify Stormwater Administrator of spill. 4. Stormwater Administrator to document spill in SWMP log. 5. Stormwater Administrator to notify local City or County Stormwater Management team of spill and the CDHPE immediately and provide all parties written documentation of the event within 5 days. 6. Stormwater Administrator to conduct post-mortem and education with the parties involved with spill incident to ensure appropriate precautions can help avoid similar issue in the future. Hazardous Spill Response Procedures A hazardous spill involves the unplanned spillage of any hazardous material over one liter onto the jobsite that may enter the stomnvater drainage system. Response Procedure I. Evacuate immediate area, and restrict access to general area. 2. Attend to any injured individuals resulting from spill. 3. Contact local Police and Fire Department. 4. Notify local City or County Stormwater Management team and the CDHPE of spill immediately and provide them written documentation of the event in 5 days. 5. Stormwater Administrator to document spill in SWMP log 11 6. Stormwater Administrator to conduct post-mortem and education with parties involved with spill incident to ensure appropriate precautions can help avoid similar issue in the future. Identification of Potential Pollutant Sources Below is a list of potential pollutant sources that contribute pollutants to stormwater runoff and the likely hood of these sources impacting the proposed project. 1. Disturbed and Stored Soils — High 2. Vehicle Tracking of Sediments — High 3. Management of Contaminated Soils — Low 4. Loading and Unloading Operations — Low 5. Outdoor Storage Activities (Building Materials, Fertilizers, Chemicals, etc) — Moderate 6. Vehicle Equipment Maintenance and Fueling — Low 7. Significant Dust or Particulate Generating Processes — Moderate 8. Routine Maintenance Activities Involving Fertilizers, Pesticides, Detergents, Fuels, Solvents, Oils, etc. — Low 9. On -Site Waste Management Practices (Waste Piles, Liquid Wastes, Dumpsters, etc. - High 10. Concrete Truck/ Equipment Washing — Moderate I I. Wastes from Geotechnical Testing - Low 12. Dedicated Asphalt and Concrete Batch Plants — N/A 13. Non -Industrial Waste Sources (Worker Trash and Portable Toilets) — Low 14. Other Areas or Procedures Where Potential Spills Can Occur. - Low OTHER CONTROLS Erosion and Sediment Control Plans Please refer to the Erosion and Sediment Control plans accompanying this report. Groundwater and Stormwater Dewatering Groundwater was not encountered during initial Gcotcchnical testing and is unlikely to be encountered during construction. If groundwater is encountered during construction, dewatering shall be discharged away from areas of concentrated flow and storm sewers. There arc no wells 12 or mints located on or adjacent to this site. Proper state permits shall be obtained for all dewatering activities on -site. INSPECTION AND MAINTENANCE Inspections of sediment control measures shall occur after any significant wind, precipitation or snowmelt event that may cause erosion. As a minimum, inspection of all sediment and erosion control facilities shall be conducted at least every 7 days from March IS through October 31 (i.e. during the rainfall season) and at least twice a month the remaining portion of the year. In either case all facilities should be inspected whenever storm events cause runoff. Upon completion of site inspection, new BMP's shall be installed in areas where erosion and sediment control is evident and existing BMP's are undersized, inadequate or non-existent. Please note that the SWMP must be modified as necessary based on additions or deletions of erosion and sediment measures based on site inspection. Inspection Scope • Construction Site Perimeter and discharge locations. • All disturbed areas. • Areas used for material storage that arc exposed to precipitation. • Locations where vehicles access the site for evidence of pollutants leaving the construction site boundaries. • Pollutants entering the storm sewer system or discharging to state waters. • Areas determined to have a significant potential for stormwatcr pollution. • BMP's identified in the SWMP for installation and maintenance. Inspection Report/ Records Results of each inspection shall be recorded on the reporting form (see the Appendix) that will be kept with the constriction company or their representative. Additional information on inspection and maintenance can be found in the Appendix. At a minimum, shall include the following information. I. Inspection Date. 13 2. Name(s) and title(s) of personnel making the inspection. 3. Location(s) of discharges (transport) of sediment or other pollutants from the construction site. 4. Location(s) of BMP's that need to be maintained. 5. Location(s) of BMP's that failed to operate as designed or proved inadequate for a particular location. 6. Location(s) where additional BMP's arc needed that were not in place at the time of inspection. 7. Deviations from the minimum inspection schedule. R. Descriptions of corrective actions for items 3, 4, 5 and 6 above, dates corrective action(s) taken, and measures taken to prevent future violations, including requisite changes to the SWMP, as necessary; and... 9. After adequate corrective action(s) has been taken, or where a report does not identify any incidents requiring corrective action, the report shall contain a signed statement indicating the site is in compliance with the permit to the best of the signer's knowledge and belief. Required Actions Following Site Inspections Upon completion of site inspection, repair of existing BMP's shall occur and new BMP's shall be installed in areas where erosion and sediment control is evident and existing BMP's arc undersized, inadequate or non-existent. Please note that the SWMP must be modified based on additions or deletions of erosion and sediment measures and deficiencies in the SWMP identified during site inspections made in accordance with part LD.5.c of the CDPS Stormwatcr Construction Permit. The Stormwater Administrator and/or agent must begin to update the SWMP information immediately after a deficiency is observed. Complex correction(s) such as redesign and approval must be completed within 72 hours. BMP Maintenance Mitigation measures shall be inspected for at least the following. • Accumulation of excess sediment and determination of the effectiveness of each structure is significantly reduced. Removal of accumulated sediment shall occur once a 14 50'%, reduction of the design storage capacity becomes evident. • Damage to structures that need repairing to ensure their effectiveness. • Addition or elimination of sediment and/or erosion control measures that are designed to control the movement of soil particles in a practical and effective manner. • Immediate repair and/or replacement of necessary mitigation measures when total failures are found. • Maintenance of BMP's that arc found to no longer function as needed and/ or designed. BMP Replacement and Additions BMP's shall be replaced or new BMP's installed to adequately address pollutant sources based on the findings from inspections. The SWMP must be modified based on modifications to BMP's made in the field. These modifications must be implemented in a timely manner not more than seven (7) calendar days following the inspection. RECORD KEEPING The project owner shall retain a copy of the approved SWMP and CDPS Stormwater Construction Permit Approval Letter and Certification from CDHPE. Additionally, the owner shall retain a copy of any and all inspection documents completed on -site including those required by the CPDS Ston mwater Permit. All documents shall be retained from the date of project initiation to the date of final inspection and stabilization at the construction site. In addition to permit retention and modification(s) of the SWMP, the following information must also be retained in order to document the required site inspections in all inspection reports. I. Date of Inspection. 2. Incidences of non-compliance. 3. Measures taken to remediate problems. 4. After measures have been taken to correct any problems and recorded in the report, or where a report does not identify any incidence(s) of non-compliance, a signed certification indicating that the site is in compliance must be included in the report. 5. Notes on the need for and performance of preventative maintenance and repairs. BMP Maintenance Records The SWMP must include site inspection and maintenance records describing maintenance of 15 BMP's that arc found to no longer function as designed or have proven inadequate. RECORD RETENTION, MONITORING, NOTIFICATIONS AND FINAL STABILIZATION Retention of Records The permittee shall retain copies of the SWMP and all reports required by this permit and records of all data used to complete the application to be covered by the permit for a period of three (3) years after expiration or inactivation of permit coverage. Monitoring The CDHPE Water Quality Control Division reserves the right to require water quality sampling and testing on a case by case basis. Final Stabilization Final stabilization shall be achieved by installation of permanent erosion control methods. Permanent erosion control for this project shall include one or more of the following methods. • Paving • Landscaping • Establishing dry land vegetation • Placing riprap Final stabilization shall be considered complete when a uniform vegetative cover has been established with a density of at least 70% of the pre -disturbance cover exists or equivalent permanent, physical erosion reduction methods have been employed. Refer to the plans, notes, details and County Criteria for the appropriate seed mix, installation methods and sediment control methods to achieve final stabilization. Notifications The CDHPE Water Quality Control Division shall be notified for the following items. • Amendment of the Permit Certification. Amendments to the permit shall be in writing noting changes to the to the information provided in the permit application, including legal contact, the project legal description or map originally submitted with the application, or the planned 16 total disturbed acreage. • Non-compliance Notification. The permitter shall notify the Division at 1-877-518-5608 within twenty-four (24) hours to report the following instances of non-compliance. I. Any non-compliance which may endanger the health of the environment. 2. Any spill or discharges of hazardous substances or chemicals to the waters of the state. 3. Any discharge of stormwater which may exceed the water quality standard. The CDHPE Water Quality Control Division reserves the right to require water quality sampling and testing on a case by case basis. CALCULATIONS Refer to the Structural BMP's sizing calculations in the Appendix of this report. REFERENCES I. Weld County Storm Drainage Design and Technical Criteria. Weld County, Colorado 2. Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District (latest edition). 3. FEMA FIRM Flood Insurance Rate Map Map No 0802660100O 4. Soil Survey of the Weld County, Colorado, US Department of Agriculture. 17 APPENDIX VICINITY MAP SOILS MAP CALCULATIONS EROSION AND SEDIMENT CONTROL PLANS AND DETAILS • SITE f' y'1 tit 11. h. 1r 4 r $,jY ^ :Lan te • 21 a 4 ---( Y l 44 5 aJ..p NE 1/4 / 4r ` ..- 1 6 . I 4 y� Y i t C.R. 116 ><fb , i . 1, ;.'C- ' f Y c� ' ti --. at. • y 1 I 1L • NW 1/4 :-- d .t --ot • 7 4 r • 41 t I 4 •; +e,µ:.4^. Rr \ � , " a �. � •,... ' :, SW 1/4�•.. - r,r �)'• J _ SE 1/4 y y 'v 1 � • ' HWY114 . 'I- • • • Y t r. VICINITY MAP SITE LOCATION: SECTION 21, T,10N., R.58W. of the 6th P.M. COUNTY OF WELD, STATE OF COLORADO 0 NO SCALE WHITING PETROLEUM CORPORATION REDTAIL GAS PLANT Diamondback Engineering & Surveying, Inc. 12640 West Cedar Drive, Suite C, Lakewood, CO 80228-2030 Office: 303-985-4204 Fax: 303-985-4214 www.dlamondbackeng.com Web Soil Survey Page 1 of 1 So.' Sur Srnu. Link Legout Soil Map Sod Data' Shc pp.ra Cart'-ree', Printable Version] Add to Shopping Cart I !Y. Search Map Unit Legend Weld County, Colorado, Northern Part (C0617) Map Unit Map Unit Name Acres in Percent of Symbol AOI AOI K Nit_'rei ccnsle.c, C to E ce ref. _.00ns 17 7 Totals for Area of interest 33.0 100.0% Li_S•.J p J !. - .•]IW A Scale - Warning: Soil Map may not be valid at this scale. you have zooned in beyond the scale at Much the soil map for this area is intendedto be used. Ma pi surveys that comprise your A01 were mapped at 1:24,000 -The design of map units and the level of di dependent on that map scale, Enlargement of maps beyond the scale of napping can cause misunderstanding of the detail of mappir do not show the small areas of contrasting soils that could have been shown at a more detailed Yale, Fl cn sure Use Meters/Kilometers To measure a distance for a polyiir.e on the map, click the 'nap to define the be glnn•. ng cf the first segment, then dick once to defne the end of eadr segment. To finish, double-click ;or CTRL -click; the Last point. To remove the current pplyllne and start over, press the Escape (ESC) key. As you define each segment, the length d that segment and the cumulative length so far are displayed in this panel. When you fin sh the polyp ne, the bngth of the fnal segment and the total length are displayed. This tool is currently reporting measirements in feet or miles. To report in meters or kilometers, cl-ck the Use Meters/Kilometers button. FOIA I Access.bdlty Statement Privacy Policy Norm.Discnmri ab on Statement .r`ormat on Q..ally USA,gov White House • http:, w'ebsoilsurv-e} nres.usda.govi'app%\\ebSoilSurv'ey'.aspx 3 -&?013 \\'eh Soil Survey z“--TRDo Page 1 of sc\ Contract Us Download Soils Data Archived Soil Surveys Soil Survey Status Glossary Preferences Link Area of Interest Aol; Soil Flap Soil Data Explorer Shopping Cart ;Free; Logout .r r � Help A A A Vern So I Informaton By use. A' Uses Printable Version Shopping to Add I tanJ �y- lntm to Soils Su itabilities and Linv[ations for Use Soil Properties and Qualities Search Map — Hydrologic Soil Group Properties and Qualities Rltti non Open All Close All 501 011Cm:.ca'i Prmedies Sc. I Erosion Factors Soi'. Pnys cal Pr opelfres Soil Qualities and Features - - 055HTo Group C'assifiration 'Surface, Depth to a Seleded Soil Restrictive Layer Depth to Any Soil Restrictive Layer 1 cT Drainage Class Frost Action Frosl'F: ee Days Hydrologic Soil Group View Description I View Rating View Options lap -abe Jesrr:ption of Rating Rat no Opt one I Detailed Description Advanced Options Aggregation Dorm rant Condition - Pfethod Curndonerlt Percent Cutoff Tie -break Rue Ecological Site Assessment Soil Reports -_-010 J Sula Warning: Soil Ratings Map may not be valid at this scale. I You have doomed In beyond the scale at which the sal map for Mrs area r5 Intended to be used. Map soil surveys that comprise your AOI were napped at 1'.24,000. The desgn of map units and the !earl dependent on that map scale. Enlargement of reap; beyond the scale of mapping can cause misunderstanding of the detaiI of mapl) maps do not shos the small areas of contrasting soils that could have been shown at a more detailed Measure Higher To measure a d.stance for a poi, -line on the map, click the map to define die beginn.ng o' the frst View Description I View Rating segment, then click once to def:ne the end of each segment. To finish, double-click ' or CTRL -click` the last point. To remove the current poiyline and start over, press the Escape (ESC) key. rap c.nit "ramp Parent Maternal Na ills ore orsetaI i.e Slocc xlli Use Meters/Rllometersl cc Sml assf_ation 51:' ..ate' reatu res As you define eah segment, the length of that segment and the mmulatve length so far are di5payed in this panel. When you Lrsh the pdyline, the length of the foal segment and the total length are displayed. Ths sod is adrentiy reportmq nleasu rements In reet cr ri'es. To report in metes or ki loiterers, cl-k the Use Meters/Kilometers button. Tables — Hydrologic Soil Group — Summary By Map Unit Summary by Map Unit — Weld County, Colorado, Northern Part (C0617) Map unit symbol Map unit name rl-Elie nell come _s, 9 to o ;errant sores 32 e eukrittneil ecreptes, 5 s 9 percent lcces Totals for Area of Interest Rating Acres in AOI Percent of A01 Description — Hydrologic Soil Group 15.3 33.0 53 3,4, 455 ,o 100.0°/0 If Imp:..websoilsurvev.nres.usda.godapp:WebSoilSurcey.aspx 3/8/2013 \V'eb Soil Survey Page 2 of? Hydrologic so I groups are based on estimates of runoff potential Soils are assigned to one of four groups according to the rate or Aare, infitratior rfen the soils are not protected by vegetator, are tnoro.:ghy -:etand rerewe preci pitatior from long -duration storms. The soils in the Unted Oates are assigned to far groups CA. B. C. and Dl and three dual classes IND BID, and C,DC The groups .re defined as follows: Group A. Soils having a high Fl ato to (low undf potenCa) when thoroughly wet. These consist mainly of deep well reamed toexcessively drained sands cr grave -.y sands. These sods have a high rate of water transtransra seon. Group B. Soils ha'oing a moderate - f It a[ on rate when thou ghly wet These consist chreffe of moderately deep or deep, moderately wel drained or well drained soils that have moderately fine texture to moderately coarse texture. These sods have a moderate rate of water transmission. I Group C. Soils having a slow infiltration rate when thoraghly wet, These consist chiefly of soils having a layer that lnpedes the downward movement of water or soils or moderately fee texture a' fine texture. These soils have a slow rate of weer transmission. Group D. Soils having a very slow rnfilt ration rate {high runoff potential; when thoroughly wet. These consist chefly of clays that have a high shrink -swell potential, sods that have a high water table. soils • that have a claypan a' c'ay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very Sow rate or water transmiss-on. If a soil is assigned to a dual hydrolog. c group (ND, B/D, or G0;, the frst letter is for drained areas and the second is for u id rained areas Only the soils that in their natura, condition are in group D are assigned to dual classes. Rating Options — Hydrologic Soil Group Aggregation Method: Dominant Cond tior Component Percent Cutoff: '.Oc Specified Tie -break Rule: HIGHT- FO A Access.tility Stele nee I Privacy 00nic', n,- _ scr'eiraten Statement I Information Q.:a rty--A.gov 'hte Hcuue "websoilsurvev.nres.usda.gov/app,WebSoilSurvey.aspx 3/8/2013 Whiting Red Tail Gas Plant 3/15/2013 By; JDE Total Site Area = Disturbed Surface Area= Existing Surface = Existing Perviousness = Developed Area Surfacing Developed Area Perviousness = Total Site Perviousness Total Site Area Developed Area Undeveloped Area = 40.00 Acres 1,742,400 SF 5.66 Acres 248,298 SF Agricultural Land 2% Road Base 40% 40 Acres 5.66 Acres 34.34 Acres Diamondback Engineering & Surveying ....ai.monee.n.ny..om Total Perviousness = [(Developed Area / Total Area)*40%] + [(Undeveloped Area / Total Area)*2%] Total Developed Site Perviousness = [(5.66/40)*0.4]+[(34.34/40)*0.02)] = 7.4% Pervious Whiting Red Tail Water Quality Pond Sizing 3/15/2013 By; JDE Diamondback Engineering 6 Surveying .ec.venterm Dn'e c. www m.mondb.aoy.com Water Quality Volume = (100 -year Detention Volume Plus WQCV) - (100 -year Detention Volume Including WQCV) Detention Volume Plus WQCV = Detention Volume Including WQCV = Water Quality Capture Volume = 0.50-4.04 = Water Quality Capture Volume = 0.50 Acre -Feet 0.40 Acre -Feet 0.10 Acre -Feet 4356 Cubic Feet DETENTION VOLUME BY THE FULL SPECTRUM METHOD Project: Whiting Red Tail Basin ID: Runoff Voume - Inches 2 50 2 00 1 50 • 1 CO • C 50 CCC 0 Area of Watershed (acres) Subwatershed Imperviousness Level of Minimizing Directly Connected Impervious Area (MDCIA) Effective Imperviousness' Hydrologic Soil Type Type A Type B Type C or D Excess Urban Runoff Volume° 100 -year Detention Volume plus WQCV s 5.66 40.0% * User input data shown in blue. 0 40.0% Percentage of Area Area (acres) 00 100.0% 5.7 0.0 Recommended Horton's Equation Parameters for CUHP Infiltration (inches per hour) Decay Coefficient --m Initial --f, Final fo 4.5 0.6 0.0018 Detention Volumes 2.5 Maximum Allowable Release Rate, cfs3 (watershed inches) (acre-feet) 0 51 0.24 Design Oulet to Empty EURV in 72 Hours 1.05 0.50 4.81 2C 40 60 80 Percent Total Imperviousness 100 I Notes: 1) Effective imperviousness is based on Figure ND -1 of the Urban Storm Drainage Criteria Manual (USDCM). 2) Results shown reflect runoff reduction from Level 1 or 2 MDCIA and are plotted at the watershed's total imperviousness value. the impact of MDCIA is reflected by the results being below the curves. 3) Maximum allowable release rates for 100 -year event are based on Table SO -1. Outlet for the Excess Urban Runoff Volume (EURV) to be designed to empty out the EURV in 72 hours. Outlet design is similar to one for the WQCV outlet of an extended detention basin (i.e.. perforated plate with a micro -pool) and extends to top of EURV water surface elevation. 4) EURV approximates the difference between developed and pre -developed runoff volume. 5) User has opted to add the WQCV to the 100 -year detention volume to satisfy local regulations. This is not required per the USDCM. UD-Detention_v2. 31 xIs 3/15/2013, 1023 AM DETENTION VOLUME BY THE FULL SPECTRUM METHOD Project: Whiting Red Tail Basin ID: Runoff Voume - Inches 2 50 200 1 5C 1 ca 050 Area of Watershed (acres) Subwatershed Imperviousness Level of Minimizing Directly Connected Impervious Area (MDCIA) Effective Imperviousness' Hydrologic Soil Type Type A Type B Type C or D Excess Urban Runoff Volume4 100 -year Detention Volume Including WOCV s 5.66 J 40.0 % ' User input data shown in blue. 0 0 40 0% Percentage of Area Area (acres) 0.0% 0.0 100.0% 5 7 00% 0.0 Recommended Horton's Equation Parameters for CUHP Infiltration (inches per hour) Decay Coefficient --a Initial --f, Final--jo 4.5 0.6 0.0018 Detention Volumes 2.5 Maximum Allowable Release Rate, cfs3 (watershed inches) (acre-feet) 0.51 0 24 Design Oulet to Empty EURV in 72 Hours 0.85 0 40 4.81 20 40 60 80 Percent Total Imperviousness 1C0 4# Notes: 1 I Effective imperviousness is based on Figure ND -1 of the Urban Storm Drainage Criteria Manual (USDCM). 21 Results shown reflect runoff reduction from Level 1 or 2 MDCIA and are plotted at the watershed's total imperviousness value: the impact of MDCIA is reflected by the results being below the curves. 31 Maximum allowable release rates for 100 -year event are based on Table SO -1. Outlet for the Excess Urban Runoff Volume (EURV) to be designed to empty out the EURV in 72 hours. Outlet design is similar to one for the WOCV outlet of an extended detention basin (ie., perforated plate with a micro -pool) and extends to top of EURV water surface elevation. 4) EURV approximates the difference between developed and pre -developed runoff volume. 51100-yr detention volume includes EURV. No need to add more volume for WOCV or EURV UD-Detention_v2. 31. xIs 3/8/2013, 3.57 PM Temporary and Permanent Seeding (TS/PS) EC -2 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, gcotcxtilcs, 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. Photograph TS/PS -1. Equipment used to drill seed. Photo courtesy of I )ouelas County. 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 Rervge/a/ion 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 hydrosecding or hydromulching. Seedbed Preparation Prior to seeding, ensure that areas to be revegetated have soil conditions capable of supporting vegetation. Overlot wading 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 November 20 I0 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 TS/PS-I EC -2 Temporary and Permanent Seeding (TS/PS) 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 rcvcgetatcd 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 arca is 6 to 18 inches. At a minimum, the upper 6 inches of topsoil should be stripped, stockpiled, and ultimately resprcad across areas that will be rcvcgetatcd. 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 finn, 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 arca arc listed in Table TS/PS-1 . These arc 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 Resegetation 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 sccd 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 rabbitbntsh (('hn'sothamnn.c nauseosus), fourwing saltbush (Alriplev c(71nescens) and skunkbrush sumac (Rims ti//obata) could be added to the upland secdmixes at 0.25, 0.5 and I pound PLS/acre, respectively. In riparian zones, planting root stock of such species as American plum (Prunus arnericana), woods rose (Rosa wooden), plains cottonwood (Poplins sargenifi), and willow (Paptdns App.) may be considered. On non-topsoiled upland sites, a legume such as Ladak alfalfa at I pound PLS/acre can be included as a source of nitrogen for perennial grasses. TS/PS-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary and Permanent Seeding (TS/PS) EC -2 Seeding dates for the highest success probability of perennial species along the Front Range are generally in the spring from April through early May and in the fall after the first of September until the ground freezes. If the area is irrigated, seeding may occur in summer months, as well. Sec Table TS/PS-3 for appropriate seeding dates. Table TS/PS-1. Minimum Drill Seeding Rates for Various Temporary Annual Grasses Species' (Common name) Growth h Season Pounds of Pure Live Seed (PLS)/acre Planting Depth (inches) I . Oats Cool 35 - 50 1 - 2 2. Spring wheat Cool 25 - 35 1 - 2 3. Spring barley Cool 25 - 35 1 - 2 4. Annual ryegrrass Cool 10 - 15 L 5. Millet Warm 3 - 15 L-'/4 6. Sudangrass Warm 5-10 % - 3A 7. Sorghum Warm 5-10 / - 3/4 8. Winter wheat Cool 20-35 1 - 2 9. Winter barley Cool 20-35 I - 2 10. Winter rye Cool 20-35 1 - 2 11. Triticale Cool 25-40 1 - 2 " Successful seeding of annual grass resulting in adequate plant growth will usually produce enough dead -plant residue to provide protection from wind and water erosion for an additional year. This assumes that the cover is not disturbed or mowed closer than 8 inches. Hydraulic seeding may be substituted for drilling only where slopes arc steeper than 3:1 or where access limitations exist. When hydraulic seeding is used, hydraulic mulching should be applied as a separate operation, when practical, to prevent the seeds from being encapsulated in the mulch. I' See Table TS/PS-3 for seeding dates. Irrigation, if consistently applied, may extend the use of cool season species during the summer months. ' Seeding rates should be doubled if seed is broadcast, or increased by 50 percent if done using a Brillion Drill or by hydraulic seeding. November 20 I0 Urban Drainage and Flood Control District TS/PS-3 Urban Storm Drainage Criteria Manual Volume 3 EC -2 Temporary and Permanent Seeding (TS/PS) Table TS/PS-2. Minimum Drill Seeding Rates for Perennial Grasses Common'' Name Botanical Name Growth Season' Growth Form Seeds/ Pound Pounds of PLS/acre Alakali Soil Seed Mix Alkali sacaton Spm'ubo/us uiruic/es Cool Bunch 1.750.000 025 Basin wildrye Elytn tc cinereuc Cool Bunch 165,0(111 2.5 Sodar streambank whcatgrass :Igrnprron riparillnl'Sndar' Cool Sod I71),(10U 2.5 Jose (all wheat grass .lgropl'1'Un elongate'', :lose' Cool Bunch 79.000 7.0 Alriba western whealgrass rig/up-trill? SHIM] ii '.-Irribo' Cool Sod 110,000 5.5 Total 17.75 Fertile Loamy Soil Seed Mix Lphriam crested 'hi.ILrass .-lgrnprrot criclanun 7lphrimn' Cool Sod 175,000 2.0 Dural hard Fescue Fesaueu mono 'drn'iuccla°' Cool Bunch 565,000 1,0 Lincoln smooth bionic /iron ox Inc'l'llll.T /CUSS ', 'Lincoln' Cool Sod 130,000 3.0 Sodar streambank wheat gross .-tgrnprrun ripariuin 'S'ndar' Cool Sod 170,(1(111 2.5 Aniba western wheat grass .Igrnplrun .cnlidlii '.drribu' Cool Sod 110,(1(111 711 Total 15.5 High Water Table Soil Seed Mix Meadow. litxtail ,-1/npeclu'uxpruleacic Cool Sod 900,000 0,5 Redtop ,Igramiv olbn Warr Open sod 000.000 (1 25 Reed canarygrass /'ha/oris nnnx/inacen Cool Sod 68.0(111 0.5 Lincoln smooth brome Bxnnme inernli.c /e'ce,v 1.inenln' Cool Sod 130,0011 3.0 Pathfinder swilchgrass Paltcum rt'gunnu Toth/index' Warm Sod 389,000 1.0 Alkar tall wheatgrass ,lgrnprrnn elongate'',Cool ':I/kur' Bunch 79/11111 5.5 Total 10.75 Transition Turf Seed Mix' Ruebens Canadian bluegrass Pod cunlpressa Mechem' Cool Sod 2.500.000 0.5 Dural hard fescue Pesmco Drina 'duriuscula' Cool Bunch 565,000 111 Citation perennial ryegrass Lathan perete n' 'Citation' Cool Sod 247,000 3.11 _incoln 131bOn,s lilexllli.s !CUSS smooth bronze Cool Sod 130,(1(10 'Lincoln' 3.11 Total 7.5 TS/PS-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Temporary and Permanent Seeding (TS/PS) EC -2 Table TS/PS-2. Minimum Drill Seeding Rates for Perennial Grasses (cont.) Common Name Botanical Name Growth Seasonb Growth Form Seeds/ Pound Pounds of PLS/acre Sandy Soil Seed Mix Blue erama 13omeloaa,,racil(s WarmSod-tanning bunehgR6s S25O(10 0.5 Camper little bluestem .\e11Ct i'lllai aehseo RIfull: l 1 't .al'. alp' Warm Bunch 240,000 1.0 Prairie sandreed ( alut?un'll/a iongnats Warm ( )pen sod 274,000 1.t) Sand dropseed Sporn/0)/0s ('np(alu/ra9 Cool launch 5.29 8 11011 (1.25 Vaughn sideoats erumi Bnruelnuu cur(ipradlll" Warm Sod 191,000 2.0 Arriba western wheatgrass Agroprran slnifhii 'Anita' Cool Sod 110,001) 5.5 Total 10.25 Heavy Clay, Rocky Foothill Seed Mix Lphriam crested wheaturassd el,Kroprroll cri.vlafom 7:phrialn' Cool Sod 175,000 15 Oahe Intermediate wheatgrass;Igruprrun inlrrnreclionl 'Oahe' Cool Sod 115,001) 55 Vaughn sideoats grams` Boweluo curlipea`la/o 'I imghn' Warm Sod 191 000 2_0 Lincoln smooth brome animus WOWS 'CUSS 'Lincoln' Sod 130,001) 3.11 Aniba western wheatgrass Agroprron snliihii '.drribu' Cool Sod 110,000 5.5 Total 17.5 a All of the above seeding mixes and rates are based on drill seeding followed by Lumped hay or straw mulch. I hese rates should be doubled if seed is broad ast and should be increased by 50 percent if the seeding is dill e using a Brill on Drill or is applied through hydraulic seeding. Hydraulic seeding may be sill slit tiled her drilling only where slopes are Mice ter than 3:1. If hydraulic seeding is used. hydra ilic mulching should be done as a separate operation. I' See -Fable TS'PS-3 for seeding dates. ' If site is to he irrigated, the transit in turf seed rates should be doubled. `I Crested wheatgrass should not he used on slopes steeper than III to IV. ' Can substitute 0.5 lbs PI 5 111 binc granla for the 2.0 lbs PLS of Vaughn sideoais crania_ November 20 ICI Urban Drainage and Flood Control District TS/PS-5 Urban Storm Drainage Criteria Manual Volume 3 EC -2 Temporary and Permanent Seeding (TS/PS) Table TS/PS-3. Seeding Dates for Annual and Perennial Grasses Annual Grasses (Numbers in table reference species in Table TS/PS-1) Perennial Grasses Seeding Dates Warm Cool Warm Cool January 1 —March 15 ✓ ✓ March 16 —April 30 4 I.2.3 ✓ ✓ May I —May IS 4 ✓ May I6 —June 30 4,5,6,7 July 1 —July 15 5,6,7 July 16 —August 31 September 1 —September 30 8,9,10, 11 I October 1 —December 31 ✓ V Mulch Cover seeded areas with mulch or an appropriate rolled erosion control product to promote establishment of vegetation. Anchor mulch by crimping, netting or use of a non-toxic tackifier. See the Mulching BMP Fact Sheet for additional guidance. Maintenance and Removal Monitor and observe seeded areas to identify areas of poor growth or areas that fail to germinate. Reseed and mulch these areas, as needed. An area that has been permanently seeded should have a good stand of vegetation within one growing season if irrigated and within three growing seasons without irrigation in Colorado. Reseed portions of the site that fail to germinate or remain bare after the first growing season. Seeded areas may require irrigation, particularly during extended dry periods. Targeted weed control may also be necessary. Protect seeded areas from construction equipment and vehicle access. TS/PS-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Mulching (MU) EC -4 Description Mulching consists of evenly applying straw, hay, shredded wood mulch, 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 tackificr. Appropriate Uses Photograph MU -1. An area that was recently seeded. mulched. and crimped_ 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 arc impractical because track walking with heavy equipment typically compacts the soil. A variety of mulches can be used effectively at construction sites, including the following types: Mulch Functions Erosion Control Ycs Sediment Control Moderate Site/Material Management No November 20 I0 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 MU -I EC -4 Mulching (MU) Clean, weed- and seed -free, long-stemmed grass hay (preferred) or cereal grain straw. Hay is preferred because it is less susceptible to removal by wind. Mulch should be applied evenly at a rate of 2 tons per acre and must be tacked or fastened by an approved method suitable for the type of mulch used. At least 50 percent of the grass hay mulch, by weight, should be 10 inches or more in length. Grass hay 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 arc dull or blunted and set vertically; however, the frame may have to be weighted to afford proper soil penetration. On small areas sheltered from the wind and heavy runoff, spraying a tackificr 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 tackificr) 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. MU -2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) 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 EC -6 ^iiw iskeTN.I.cf• • Photograph RECP-1. I rosion control blanket protecting the slope front (e.g., straw, coconut fiber) can be used. erosion and providing favorable conditions for revegetation. 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 arc 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 arc 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 November 2010 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 RECP-I EC -6 Rolled Erosion Control Products (RECP) Turf Reinforcement Mat (TRM): A rolled erosion control product composed of non -degradable synthetic fibers, filaments, nets, wire mesh, andor other elements, processed into a permanent, three- dimensional matrix of sufficient thickness. TRMs, which may be supplemented with degradable components, arc designed to impart immediate erosion protection, enhance vegetation establishment and provide long-term functionality by permanently reinforcing vegetation during and after maturation. Note: TRMs arc 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, unreinforccd 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. RECP-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC -6 Table RECP-l. ECTC Standard Specification for Temporary Rolled Erosion Control Products (Adapted from Erosion Control Technology Council 2005) Product Description Slope Applications* Channel Applications* Minimum Tensile Strength' Expected Longevity Maximum Gradient C Factor ' Max. Shear Stress Mulch Control Nets 5:1 (H:V) <0.10 (a: 5:1 0.25 lbs/ft2 ( l2 Pa) 5 lbs/ft (0.073 kN/m) Up to 12 months Netless Rolled Erosion Control Blankets 4:1 (H:V) <0.1() (a 4:1 0.5 lbs/ft- (24 Pa) 5 lbs/ft (0.073 kN/m) Single -net Erosion Control Blankets & 3:1 (H:V) Open Weave Textiles <0.15 tit 3:1 1.5 lbs/ft- (72 Pa) 50 lbs/ft ((1.73 kN/m) Double -net Erosion Control Blankets 2.1 (H.V) <0.70 (a 2:1 1.75 lbs/ft- (54 Pa) 75 lbs/ft (1.09 kN/m) Mulch Control Nets 5:1 (ITV) <0.10 (a: 5: I 0.25 lbs/ft2 (12 Pa) 25 lbs/ft (0.36 kN/m) 24 months i Erosion Control Blankets & Open Weave Textiles (slowly degrading) 1.5:1 (H:V) <0.25 (a 1.5:1 2.00 lbs/fr (96 Pa) 100 lbs/ft (1.45 kN/m) 24 months Erosion Control Blankets & Open Weave Textiles 1:1 (H:V) 41,25 a 1:1 2.25 lbs/ft- (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 (instruction B,14Ps for more in!orn ation on the C {actor.) Minimum Average Roll Values, Machine direction using ECTC Mod. ASTM D 5035. 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. 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. ' The permissible shear stress levels established for each performance category arc based on historical experience with products characterized by Manning's roughness coefficients in the range of 0.01 - 0.05. Acceptable large-scale test methods may include ASTM D 6459, or other independent testing deemed acceptable by the engineer. ° 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. November 20 I 0 Urban Drainage and Flood Control District RECP-3 Urban Storm Drainage Criteria Manual Volume 3 EC -6 Rolled Erosion Control Products (RECP) Table RECP-2. ECTC Standard Specification for Permanent' 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 0.5:1 (H:V) Maximum Shear Stress" 6.0 lbs/ft2 (288 Pa) Minimum Tensile Strength'' 125 lbs/ft (1.82 kN/m) 11.5: I (H:V) 8.0 lbs/ft2 (384 Pa) 150 Ibs/ft (2.19 kN/m) 0.5:1 (H:V) 10.0 lbs/ft2 (480 Pa) 175 lbs/ft (2.55 kN/m) 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 .AST\1 I) 681 (Supersedes Mod. .A [\1 I) 5035 for RECPs) 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/f0 or greater. ' 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. 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 arc 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 arc 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 RECP-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC -6 Staking patterns arc 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 arc 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 arc 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 arc 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, arc 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. November 20 I0 Urban Drainage and Flood Control District RECP-5 Urban Storm Drainage Criteria Manual Volume 3 EC -6 Rolled Erosion Control Products (RECP) UNDISTURBED SOIL PERIMETER ANCHOR TRENCH, TYP. JOINT ANCHOR TRENCH, TYP. TYPE OF ECU AS INDICATED IN PLAN VIEW. INSTALL IN ALL DISTURBED AREAS OF STREAMS AND DRAINAGE CHANNELS TO DEPTH D ABOVE CHANNEL INVERT. ECB SHALL GENERALLY BE ORIENTED PARALLEL TO FLOW DIRECTION (I. E. LONG DIMENSIONS OF BLANKET PARALLEL TO ELOWLINES) STAKING PATTERN SHALL MATCH ECB AND/OR CHANNEL TYPE. TOP OF CHANNEL BANK ECB-1. PIPE OUTLET TO DRAINAGEWAY JOINT ANCHOR TRENCH, TYP. 6" TOPSOIL TYPE OF ECB, INDICATED IN PLAN VIEW ECB SHALL EXTEND TO THE TOP OF THE CHANNEL PERIMETER ANCHOR TRENCH. TYP. COMPACTED SU BG RADE STAKING PATTERN PER MANUFACTURER SPEC. OR PATTERN BASED ON ECB AND/OR CHANNEL TYPE (SEE STAKING PATTERN DETAIL) ECB-2. SMALL DITCH OR DRAINAGEWAY ANCHOR DETAILS GEOTEX FABRIC -I TILE OR MAT, TYP. - 3" MIN, TYP 6 MIN, TYP. COMPACTED BACKFILL, PERIMETER `"- SINGLE EDGE 'I` STAKE, TYP. TYP. ANCHOR TRENCH JOINT ANCHOR TWO EDGES OF TWO ADJACENT ROLLS TRENCH INTERMEDIATE LOOP FROM MIDDLE OF ROLL ANCHOR TRENCH FLOW OVERLAPPING JOINT 1 2" MIN. WOOD --I STAKE I- 3" MIN. DETAIL RECP-6 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 November 2000 Rolled Erosion Control Products (RECP) EC -6 STAGGER OVERLAPS DIVERSION DITCH TYPICALLY AT TOP OF SLOPE PERIMETER ANCHOR TRENCH OR JOINT, TYP. STRAW 4,1-3.1 SLOPES ECB-3. OVERLAPPING JOINT STAKING PATTERN PER MANUFACTURER SPEC. OR PATTERN BASED ON ECB AND/OR SLOPE TYPE (SEE STAKING PATTERN DETAIL) PERIMETER ANCHOR TRENCH OUTSIDE OF DRAINAGEWAY ROLL WIDTH W, TYP. Y2W 0 0 - Yz W 0 0 2 STRAW -COCONUT COCONUT OR EXCELSIOR STAKING PATTERNS BY ECB TYPE 3 6' - --I I- 3/2 W 0 o Y2 0 W— - Y2 W 3,1 -2.1 SLOPES W 0 0 0 0 2.1 AND STEEPER SLOPES Yz W 2' LOW FLOW CHANNEL HIGH FLOW CHANNEL STAKING PATTERNS BY SLOPE OR CHANNEL TYPE November 20 I0 Urban Drainage and Flood Control District RECP-7 Urban Storm Drainage Criteria Manual Volume 3 EC -6 Rolled Erosion Control Products (RECP) EROSION CONTROL RI ANKFT INSTAL I ATION NOTES 1. SEE PLAN VIEW FOR: -LOCATION OF ECB. - TYPE OF ECB (STRAW, STRAW -COCONUT, COCONUT. OR EXCELSIOR). - AREA, A, IN SQUARE YARDS OF EACH TYPE OF ECB. 2. 100% NATURAL AND BIODEGRADABLE MATERIALS ARE PREFERRED FOR RECPs, ALTHOUGH SOME JURISDICTIONS MAY ALLOW OTHER MATERIALS IN SOME APPLICATIONS. 3 IN AREAS WHERE EGOS ARE SHOWN ON THE PLANS, THE PERMITTEE SHALL PLACE TOPSOIL AND PERFORM FINAL GRADING, SURFACE PREPARATION, AND SEEDING AND MULCHING. SUBGRADE SHALL BE SMOOTH AND MOIST PRIOR TO EGO INSTALLATION AND THE ECB SHALL BE IN FULL CONTACT WITH SUBGRADE. NO GAPS OR VOIDS SHALL EXIST UNDER THE BLANKET. 4. PERIMETER ANCHOR TRENCH SHALL BE USED ALONG THE OUTSIDE PERIMETER OF ALL BLANKET AREAS. 5 JOINT ANCHOR TRENCH SHALL BE USED TO JOIN ROLLS OF ECBs TOGETHER (LONGITUDINALLY AND TRANSVERSELY) FOR ALL ECBs EXCEPT STRAW WHICH MAY USE AN OVERLAPPING JOINT. 6 INTERMEDIATE ANCHOR TRENCH SHALL BE USED AT SPACING OF ONE-HALF ROLL LENGTH FOR COCONUT AND EXCELSIOR ECBs. 7. OVERLAPPING JOINT DETAIL SHALL BE USED TO JOIN ROLLS OF ECBs TOGETHER FOR ECBs ON SLOPES. 8. MATERIAL SPECIFICATIONS OF ECBs SHALL CONFORM TO TABLE ECB- 1. 9. ANY AREAS OF SEEDING AND MULCHING DISTURBED IN THE PROCESS OF INSTALLING EGOS SHALL BE RESEEDED AND MULCHED. 10. DETAILS ON DESIGN PLANS FOR MAJOR DRAINAGEWAY STABILIZATION WILL GOVERN IF DIFFERENT FROM THOSE SHOWN HERE. TABLE ECB-1. ECB MATERIAL SPECIFICAT ONS TYPE COCONUT CONTENT STRAW CONTENT EXCELSIOR CONTENT RECOMMENDED NETTING.* STRAW - 100% - DOUBLE/ NATURAL STRAW— COCONUT 30% MIN 70% MAX _ DOUBLE/ NATURAL COCONUT 100% — — DOUBLE/ NATURAL EXCELSIOR _ _ 100% DOUBLE/ NATURAL 'STRAW ECBs MAY ONLY BE USED OUTSIDE OF STREAMS PND DRAINAGE CHANNEL. •'ALTERNATE NETT NG MAY BE ACCEPTABLE IN SOME JURISDICTIONS RECP-M Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Rolled Erosion Control Products (RECP) EC -6 EROSION CONTROL RI ANKFT MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPS IN EFFECTIVE OPERATING CONDITION INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY, 3 WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. ECBs SHALL BE LEFT IN PLACE TO EVENTUALLY BIODEGRADE, UNLESS REQUESTED TO BE REMOVED BY THE LOCAL JURISDICTION. 5. ANY ECB PULLED OUT, TORN, OR OTHERWISE DAMAGED SHALL BE REPAIRED OR REINSTALLED. ANY SUBGRADE AREAS BELOW THE GEOTEXTILE THAT HAVE ERODED TO CREATED A VOID UNDER THE BLANKET, OR THAT REMAIN DEVOID OF GRASS SHALL BE REPAIRED, RESEEDED AND MULCHED AND THE ECB REINSTALLED. NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAILS ADAPTED FROM DOUGLAS COUNTY, COLORADO AND TOWN OF PARKER COLORADO. NOT AVAILABLE IN AUTOCAD) November 20 I tl Urban Drainage and Flood Control District RECP-9 Urban Storm Drainage Criteria Manual Volume 3 Concrete Washout Area (CWA) MM -1 Description Concrete waste management involves designating and properly managing a specific arca of the construction site as a concrete washout area. A concrete washout area can be created using one of several approaches designed to receive wash water from washing of tools and concrete mixer chutes, liquid concrete waste from dump trucks, mobile batch mixers, or pump trucks. Three basic approaches arc available: excavation of a pit in the ground, use of an above ground storage area, or use of prefabricated haul - away concrete washout containers. Surface discharges of concrete washout water from construction sites are prohibited Appropriate Uses Photograph CWA-1. I sample of concrete washout area. Note gravel tracking pad for access and sign. Concrete washout areas must be designated on all sites that will generate concrete wash water or liquid concrete waste from onsite concrete mixing or concrete delivery. Because pH is a pollutant of concern for washout activities, when unlined pits are used for concrete washout, the soil must have adequate buffering capacity to result in protection of state groundwater standards; otherwise. a liner/containment must be used. The following management practices arc recommended to prevent an impact from unlined pits to groundwater: • The use of the washout site should be temporary (less than I year), and • The washout site should be not be located in an arca where shallow groundwater may be present, such as near natural drainages, springs, or wetlands. Design and Installation Concrete washout activities must be conducted in a manner that does not contribute pollutants to surface waters or stormwater runoff Concrete washout areas may be lined or unlined excavated pits in the ground, commercially manufactured prefabricated washout containers, or aboveground holding areas constructed of berms, sandbags or straw bales with a plastic liner. Although unlined washout areas may be used, lined pits may be required to protect groundwater under certain conditions. Do not locate an unlined washout area within 400 feet of any natural drainage pathway or waterbody or within 1,000 feet of any wells or drinking water sources. Even for lined concrete washouts, it is advisable to locate the facility away from waterbodies and drainage paths. If site constraints make these Concrete Washout Area Functions Erosion Control No Sediment Control No Site/Material Management Yes November 20 I (I Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 CWA-I courtesy of (U( )T. MM -1 Concrete Washout Area (CWA) setbacks infeasible or if highly permeable soils exist in the area, then the pit must be installed with an impermeable liner (16 mil minimum thickness) or surface storage alternatives using prefabricated concrete washout devices or a lined aboveground storage area should be used. Design details with notes arc provided in Detail CWA-1 for pits and CWA-2 for aboveground storage areas. Pre -fabricated concrete washout container information can be obtained from vendors. Maintenance and Removal A key consideration for concrete washout areas is to ensure that adequate signage is in place identifying the location of the washout arca. Part of inspecting and maintaining washout areas is ensuring that adequate signage is provided and in good repair and that the washout arca is being used, as opposed to washout in non -designated areas of the site. Remove concrete waste in the washout arca, as needed to maintain BMP function (typically when filled to about two-thirds of its capacity). Collect concrete waste and deliver offsite to a designated disposal location. 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. If the wash water is allowed to evaporate and the concrete hardens, it may be recycled. Photograph CWA-2. Prefabricated concrete washout. Photo Photograph CWA-3. I'arthen concrete washout. Photo courtesy of CI CWA-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Concrete Washout Area (CWA) MM -1 12" TYP. >4 CONCRETE WASHOUT AREA PLAN UNDISTURBED OR COMPACTED SOIL >3 CONCRETE WASHOUT L�SIGN COMPACTED BERM AROUND THE PERIMETER I3' MIN. >311 8 X 8 MIN. SECTION A VEHICLE TRACKING CONTROL (SEE VTC DETAIL) OR OTHER STABLE SURFACE 2% SLOPE VEHICLE TRACKING CONTROL (SEE VTC - DETAIL ) CWA-1. CONCRETE WASHOUT AREA CWA INSTALLATION NOTES 1. SEE PLAN VIEW FOR: -CWA INSTALLATION LOCATION. 2. DO NOT LOCATE AN UNLINED CWA WITHIN 400' OF ANY NATURAL DRAINAGE PATHWAY OR WATERBODY. DO NOT LOCATE WITHIN 1,000' OF ANY WELLS OR DRINKING WATER SOURCES. IF SITE CONSTRAINTS MAKE THIS INFEASIBLE, OR IF HIGHLY PERMEABLE SOILS EXIST ON SITE, THE CWA MUST BE INSTALLED WITH AN IMPERMEABLE LINER (16 MIL MIN. THICKNESS) OR SURFACE STORAGE ALTERNATIVES USING PREFABRICATED CONCRETE WASHOUT DEVICES OR A LINED ABOVE GROUND STORAGE ARE SHOULD BE USED. 3. THE CWA SHALL BE INSTALLED PRIOR TO CONCRETE PLACEMENT ON SITE. 4. CWA SHALL INCLUDE A FLAT SUBSURFACE PIT THAT IS AT LEAST B. BY B' SLOPES LEADING OUT OF THE SUBSURFACE PIT SHALL BE 3.1 OR FLATTER. THE PIT SHALL BE AT LEAST 3' DEEP. 5 BERM SURROUNDING SIDES AND BACK OF THE CWA SHALL HAVE MINIMUM HEIGHT OF 1'. 6. VEHICLE TRACKING PAD SHALL BE SLOPED 2% TOWARDS THE CWA. 7 SIGNS SHALL BE PLACED AT THE CONSTRUCTION ENTRANCE, AT THE CWA, AND ELSEWHERE AS NECESSARY TO CLEARLY INDICATE THE LOCATION OF THE CWA TO OPERATORS OF CONCRETE TRUCKS AND PUMP RIGS. 8. USE EXCAVATED MATERIAL FOR PERIMETER BERM CONSTRUCTION. November 20 I0 Urban Drainage and Flood Control District CWA-3 Urban Storm Drainage Criteria Manual Volume 3 MM -1 Concrete Washout Area (CWA) CWA MAINTENANCE NOTES 1. INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY, 3 WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. THE CWA SHALL BE REPAIRED, CLEANED, OR ENLARGED AS NECESSARY TO MAINTAIN CAPACITY FOR CONCRETE WASTE. CONCRETE MATERIALS, ACCUMULATED IN PIT, SHALL BE REMOVED ONCE THE MATERIALS HAVE REACHED A DEPTH OF 2.. 5. CONCRETE WASHOUT WATER, WASTED PIECES OF CONCRETE AND ALL OTHER DEBRIS IN THE SUBSURFACE PIT SHALL BE TRANSPORTED FROM THE JOB SITE IN A WATER - TIGHT CONTAINER AND DISPOSED OF PROPERLY. 6 THE CWA SHALL REMAIN IN PLACE UNTIL ALL CONCRETE FOR THE PROJECT IS PLACED. 7 WHEN THE CWA IS REMOVED, COVER THE DISTURBED AREA WITH TOP SOIL, SEED AND MULCH OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAIL ADAPTED FROM DOUGLAS COUNTY, COLORADO AND THE CITY OF PARKER, COLORADO, NOT AVAILABLE IN AUTOCAD). NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. CWA-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC -2 Description A sediment control log is a linear roll made of natural materials such as straw, coconut fiber, or other fibrous material trenched into the ground and held with a wooden stake. Sediment control logs are also often referred to as "straw wattles." They arc 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. Photographs SCL-1 and SCL-2. Sediment control logs used as I ) a perimeter control around a soil stockpile: and 2) as a"I-hook perimeter control at the comer of a co 1stIncIion site. Design and Installation Sediment control logs should be installed along the contour to avoid concentrating flows. The maximum allowable tributary drainage area per 1011 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: I. 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 Ycs Site/Material Management No November 2010 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 SCL-1 SC -2 Sediment Control Log (SCL) Although sediment control logs initially allow runoff to flow through the BMP, they can quickly become a barrier and should be installed is if they arc impermeable. Design details and notes for sediment control logs arc provided in Detail SCL-I. Sediment logs must be properly trenched and staked into the ground 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, 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 recommended when used in perimeter control, inlet protection and check dam applications. SCL-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC -2 1Y4 x 1Yi" x 18" (MIN) WOODEN STAKE 9" DIAMETER (MIN) SEDIMENT CONTROL LOG --- Y3DIAM. FLOW OF SCL (TYP.) SEDIMENT CONTROL LOG COMPACTED EXCAVATED TRENCH SOIL FLOW SECTION A 2" OVERLAP (MIN.) Co 9" DIAMETER (MIN) SEDIMENT CONTROL LOG NOTE- LARGER DIAMETER SEDIMENT CONTROL LOGS MAY NEED TO BE EMBEDDED DEEPER. CENTER STAKE IN CONTROL LOC 9" DIAMETER (MIN) SEDIMENT CONTROI LOG Y3 DIAM. SCL (TYP.) 1 J�" x 11" x 18" (MIN) WOODEN STAKE SEDIMENT CONTROL LOG JOINTS SCL-1. SEDIMENT CONTROL LOG November 20 I (I Urban Drainage and Flood Control District SCL-3 Urban Storm Drainage Criteria Manual Volume 3 SC -2 Sediment Control Log (SCL) COMPACTED EXCAVA-ED TRENCH SCI_ FLOW 1" V E MIN. CEN-EP, STAKE IN CCNTRC_ LOG 9" DIAME"CR (E./ N) SFr MFNT CON-RO. 1O. PLACE _OG AGAINST BACK C= CURE Y� DIAM. SC_ (-YP.) SCL-2. SEDIMENT CONTROL LOG AT BACK OF CURB CENTER STAKE it IN CONTRC_ LOG z., , 9" DIAMETER (VIN) SEDIMENT CONTROL LOG 6" MN. Y., DIAM. SOL (T"P.; F LOW TREE LAWN ( 'YE CAL) L PLACE CONTROL LOG AGAINST SIOEWA_K SIDEWALK CURE SCL-3. SEDIMENT CONTROL LOG AT SIDEWALK WITH TREE LAWN STAKING A" 4 MAX. ON CFNIFR (TYP.) I VERTICAL SPACING VARIF S N .AG I ON S_OPE \ r:ON i l\,IOUs SOT AT PER ME -ER C= CONS -RUCTION SITE SCL-4. SEDIMENT CONTROL LOGS TO CONTROL SLOPE LENGTH SCL-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC -2 SEDIMENT CONTROL 100 INSTAI I ATION NOTES 1. SEE PLAN VIEW FOR LOCATION AND LENGTH OF SEDIMENT CONTROL LOGS. 2 SEDIMENT CONTROL LOGS THAT ACT AS A PERIMETER CONTROL SHALL BE INSTALLED PRIOR TO ANY UPGRADIENT LAND -DISTURBING ACTIVITIES. 3 SEDIMENT CONTROL LOGS SHALL CONSIST OF STRAW, COMPOST, EXCELSIOR OR COCONUT FIBER, AND SHALL BE FREE OF ANY NOXIOUS WEED SEEDS OR DEFECTS INCLUDING RIPS, HOLES AND OBVIOUS WEAR 4. SEDIMENT CONTROL LOGS MAY BE USED AS SMALL CHECK DAMS IN DITCHES AND SWALES. HOWEVER. THEY SHOULD NOT BE USED IN PERENNIAL STREAMS OR HIGH VELOCITY DRAINAGE WAYS. 5 IT IS RECOMMENDED THAT SEDIMENT CONTROL LOGS BE TRENCHED INTO THE GROUND TO A DEPTH OF APPROXIMATELY Y,T OF THE DIAMETER OF THE LOG. IF TRENCHING TO THIS DEPTH IS NOT FEASIBLE AND/OR DESIRABLE (SHORT TERM INSTALLATION WITH DESIRE NOT TO DAMAGE LANDSCAPE) A LESSER TRENCHING DEPTH MAY BE ACCEPTABLE WITH MORE ROBUST STAKING 6 THE UPHILL SIDE OF THE SEDIMENT CONTROL LOG SHALL BE BACKEILLED WITH SOIL THAT IS FREE OF ROCKS AND DEBRIS. THE SOIL SHALL BE TIGHTLY COMPACTED INTO THE SHAPE OF A RIGHT TRIANGLE USING A SHOVEL OR WEIGHTED LAWN ROLLER. 7 FOLLOW MANUFACTURERS' GUIDANCE FOR STAKING. IF MANUFACTURERS' INSTRUCTIONS DO NOT SPECIFY SPACING. STAKES SHALL BE PLACED ON 4' CENTERS AND EMBEDDED A MINIMUM OF 6" INTO THE GROUND. 3" OF THE STAKE SHALL PROTRUDE FROM THE TOP OF THE LOG. STAKES THAT ARE BROKEN PRIOR TO INSTALLATION SHALL BE REPLACED. SEDIMENT CONTROL IOG MAINTENANCE NOTES 1 INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREQUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE. 4. SEDIMENT ACCUMULATED UPSTREAM OF SEDIMENT CONTROL LOG SHALL BE REMOVED AS NEEDED TO MAINTAIN FUNCTIONALITY OF THE BMP, TYPICALLY WHEN DEPTH OF ACCUMULATED SEDIMENTS IS APPROXIMATELY )5 OF THE HEIGHT OF THE SEDIMENT CONTROL LOG. 5. SEDIMENT CONTROL LOG SHALL BE REMOVED AT THE END OF CONSTRUCTION. IF DISTURBED AREAS EXIST AFTER REMOVAL, THEY SHALL BE COVERED WITH TOP SOIL, SEEDED AND MULCHED OR OTHERWISE STABILIZED IN A MANNER APPROVED BY THE LOCAL JURISDICTION. (DETAILS ADAPTED FROM TOWN OF PARKER. COLORADO. JEFFERSON COUNTY, COLORADO, DOUGLAS COUNTY. COLORADO, AND CITY OF AURORA, COLORADO, NOT AVAILABLE IN AUTOCAD) NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. November 20 I tl Urban Drainage and Flood Control District SCL-5 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 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: Photograph ITC -I. A vehicle tracking control pad constricted with properly siied rock reduces off -site sediment tracking. • 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 arc 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 arc 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 November 20 I0 Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual Volume 3 VTC-I SM-4 Vehicle Tracking Control (VTC) 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 arc 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. Photograph VTC-2. A vehicle tracking control pad with wheel wash fitcility- Photo courtcsv of Torn Gore_ 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. VTC-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 SIDEWALK OR OTHER PAVED SURFACE PUBLIC ROADWAY INSTALL ROCK FLUSH WITH OR BELOW TOP OF PAVEMENT COMPACTED SUBGRADE 50 FOOT (MIN.) 20 FOOT (WIDTH CAN BE LESS IF CONST. VEHICLES ARE PHYSICALLY CONFINED ON BOTH SIDES) 9" (MIN ) UNLESS OTHERWISE SPECIFIED BY LOCAL JURISDICTION, USE CDOT SECT. #703. AASHTO #3 COARSE AGGREGATE OR 6" MINUS ROCK NON -WOVEN GEOTEXTILE FABRIC BETWEEN SOIL AND ROCK UNLESS OTHERWISE SPECIFIED BY LOCAL JURISDICTION, USE CDOT SECT. #703, AASHTO #3 COARSE AGGREGATE OR 6" MINUS ROCK r 9" (MIN.) SECTION A NON -WOVEN GEOTEXTILE FABRIC VTC-1. AGGREGATE VEHICLE TRACKING CONTROL November 20 I0 Urban Drainage and Flood Control District VTC-3 Urban Storm Drainage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) PUBLIC ROADWAY NOTE: WASH WATER MAY NOT CONTAIN CHEMICALS OR SOAPS WITHOUT OBTAINING A SEPARATE PERMIT DITCH TO CARRY WASH WATER TO SEDIMENT TRAP OR BASIN WASH RACK 6'7" MIN REINFORCED CONCRETE RACK__ (MAY SUBSTITUTE STEEL CATTLE GUARD FOR CONCRETE RACK) DRAIN SPACE SECTION A VTC-2. AGGREGATE VEHICLE TRACKING CONTROL WITH WASH RACK VTC-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 EXISTING PAVED ROADWAY 18" MIN OCO e4' `LO,L\O SS \ TRM END OVERLAP WITH J4:1 e ,1�.,,0 SPIKES OR STAKES O \ G \ CONSTRUCTION MATS, WOVEN c o d.Q(<,‘' OR TURF REINFORCEMENT STRAP C'�E,o,�� MAT (TRM) CONNECTORS 4 DISTURBED AREA, CONSTRUCTION SITE. STABILIZED STORAGE AREA OR STAGING AREA SPIKES OR STAKES RESTRICT CONST. VEHICLE ACCESS TO SIDES OF MAT CONSTRUCTION MAT END OVERLAP INTERLOCK WITH STRAP CONNECTORS 20' OR AS REQUIRED TO ACCOMMODATE ANTICIPATED TRAFFIC (WIDTH CAN BE LESS IF CONST. VEHICLES ARE PHYSICALLY CONFINED ON 80TH SIDES) VTC-3. VEHICLE TRACKING CONTROL W/ CONSTRUCTION MAT OR TURF REINFORCEMENT MAT (TRM) November 20 I0 Urban Drainage and Flood Control District VTC-5 Urban Storm Drainage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) STABILIZED CONSTRUCTION ENTRANCE/EXIT INSTALLATION NOTES 1. SEE PLAN VIEW FOR -LOCATION OF CONSTRUCTION ENTRANCE(S)/EXIT(S). -TYPE OF CONSTRUCTION ENTRANCE(S)/EXITS(S) (WITH/WITHOUT WHEEL WASH, CONSTRUCTION MAT OR TRM). 2 CONSTRUCTION MAT OR TRM STABILIZED CONSTRUCTION ENTRANCES ARE ONLY TO BE USED ON SHORT DURATION PROJECTS (TYPICALLY RANGING FROM A WEEK TO A MONTH) WHERE THERE WILL BE LIMITED VEHICULAR ACCESS. 3. A STABILIZED CONSTRUCTION ENTRANCE/EXIT SHALL BE LOCATED AT ALL ACCESS POINTS WHERE VEHICLES ACCESS THE CONSTRUCTION SITE FROM PAVED RIGHT-OF-WAYS. 4 STABILIZED CONSTRUCTION ENTRANCE/EXIT SHALL BE INSTALLED PRIOR TO ANY LAND DISTURBING ACTIVITIES. 5 A NON —WOVEN GEOTEXTILE FABRIC SHALL BE PLACED UNDER THE STABILIZED CONSTRUCTION ENTRANCE/EXIT PRIOR TO THE PLACEMENT OF ROCK. 6. UNLESS OTHERWISE SPECIFIED BY LOCAL JURISDICTION, ROCK SHALL CONSIST OF DOT SECT. #703, AASHTO #3 COARSE AGGREGATE OR 6" (MINUS) ROCK. STABILIZED CONSTRUCTION ENTRANCE/EXIT MAINTENANCE NOTES 1 INSPECT BMPs EACH WORKDAY, AND MAINTAIN THEM IN EFFECTIVE OPERATING CONDITION. MAINTENANCE OF BMPs SHOULD BE PROACTIVE, NOT REACTIVE. INSPECT BMPs AS SOON AS POSSIBLE (AND ALWAYS WITHIN 24 HOURS) FOLLOWING A STORM THAT CAUSES SURFACE EROSION, AND PERFORM NECESSARY MAINTENANCE. 2. FREOUENT OBSERVATIONS AND MAINTENANCE ARE NECESSARY TO MAINTAIN BMPs IN EFFECTIVE OPERATING CONDITION. INSPECTIONS AND CORRECTIVE MEASURES SHOULD BE DOCUMENTED THOROUGHLY. 3. WHERE BMPs HAVE FAILED, REPAIR OR REPLACEMENT SHOULD BE INITIATED UPON DISCOVERY OF THE FAILURE 4. ROCK SHALL BE REAPPLIED OR REGRADED AS NECESSARY TO THE STABILIZED ENTRANCE/EXIT TO MAINTAIN A CONSISTENT DEPTH. 5 SEDIMENT TRACKED ONTO PAVED ROADS IS TO BE REMOVED THROUGHOUT THE DAY AND AT THE END OF THE DAY BY SHOVELING OR SWEEPING. SEDIMENT MAY NOT BE WASHED DOWN STORM SEWER DRAINS. NOTE: MANY JURISDICTIONS HAVE BMP DETAILS THAT VARY FROM UDFCD STANDARD DETAILS. CONSULT WITH LOCAL JURISDICTIONS AS TO WHICH DETAIL SHOULD BE USED WHEN DIFFERENCES ARE NOTED. (DETAILS ADAPTED FROM CBI' OF BROOMFIELD. COLORADO. NOT AVAILABLE IN AUTOCAD) VTC-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 DRAINAGE CRITERIA MANUAL (V. 3) CONSTRUCTION BEST MANAGEMENT PRACTICES 1s, (44 Is, SILT FENCE INSTALLATION -NTS- POST ANCHORED TO FABRIC NOTE EROSION CONTROL MEASURES SHALL BE MAINTAINED UNTIL I ANDSCAPING IS COMP! [TED, OR AS DIRECTED BY LOCAL JURISDICTION 2 1/2H (12" MIN) z - N ty FABRIC MATERIAL (ANCHORED IN TRENCH) 4'x4" TRENCH COMPACTED BACKFILL r FLOW SECTION -NTS- DETAILS PROVIDED TO DISTRICT BY THE CITY OF BROOMFIELD, COLORADO Figure C5 -10 —Silt Fence Erosion Barrier 2007-10 C-63 Urban Drainage and Flood Control District Hello