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HomeMy WebLinkAboutFORT COLLINS JEEP - PDP - PDP170013 - SUBMITTAL DOCUMENTS - ROUND 3 - EROSION CONTROL LETTER/REPORTEROSION AND SEDIMENT CONTROL ASSOCIATED WITH CONSTRUCTION ACTIVITIES FOR FORT COLLINS JEEP DEALERSHIP CITY OF FORT COLLINS, COLORADO August 29, 2017 Job No. 16-018 Prepared for: COMMERCIAL BUILDING SERVICES 7561 South Grant Street Littleton, CO 80120 Prepared by: PARAGON ENGINEERING CONSULTANTS, INC. 7852 S. Elati, Suite 203 Littleton, CO 80120 303-794-8604 Attn: Wendell Ayers, President 2 EROSION AND SEDIMENT CONTROL NARRATIVE REPORT Name, address and telephone number Owner: Steve More Commercial Building Services 7651 S. Grant Street Suite A-4 Littleton, CO 80122 303-730-3001 steve@cbsconstruction.com Erosion Control Consultant: Paragon Engineering Consultants, Inc. 7852 S Elati, Suite 106 Littleton, CO 80120 Attn: Troy Denning, PE 303-794-8604 Current Developed Conditions The project consists of the re-development of an approximately 4.4-parcel with from former lumber yard to proposed car dealership. The site is located in the Southeast ¼ of Section 35, Township 7 North, Range 69 West of the 5th Principal Meridian., County of Larimer, State of Colorado. A Vicinity Map is contained within Appendix A. This site resides in the drainage basin for Fossil Creek (approximately ¾ of a mile southeast), which is ultimately tributary to Cache La Poudre River (5 miles east). Runoff from the site drains off-site to the east to South Mason Street and to the south to West Harmony Road, where it flows via street gutters towards the intersection of the two streets and enters the city storm sewer via a 10’ Type R Inlet. The existing site is 19% vegetated, with approximately 80% coverage in these areas. The vegetation consists of mature landscaping consisting of landscaped grass areas with trees and shrubs. The existing slopes within the parking area range from 1-2%, while the perimeter landscape areas along S. Mason St. and W Harmony Road range up to 3-4%. Soils on the site, according to USDA National Soil Conservation website, consist of Nunn clay loam – Hydrologic Soil Type C (94% of site) with a small area of Altvan-Satanta loams (6%) – Hydrologic Soil Type B, in the northeast corner of the site. When exposed, these fine-grained soils will be prone to sediment transport and channel cutting during storm events, but low slopes on site will mitigate major erosion events. Nature and Purpose of Construction 3 This project involves the remodeling of the existing main building on the site, with two additions and one removed area at the building, the removal and replacement of deteriorated asphalt paving and concrete areas from the parking area of the site. Alterations will be made to the two existing entrances to the site, and new areas of landscape will be incorporated into the parking lot and around the building. Approximately 4.0 acres may be disturbed during the redevelopment of this project. Rainfall Erodibility & Erosion and Sediment Control Methods According to the NRCS Soil Survey, the soils on the site are predominantly Nunn clay loam, (94.2%) and the remainder Altvan-Satanta loams (5.8%). Nunn clay loam is a fine clay loam that is hard, very friable, sticky and plastic. The cohesive properties and low slopes on site indicate this material will have a low erodibility. The Altvan-Satanta loam is fine sandy loam with fine pebbles. This material is not cohesive and also fine, which will lend itself to sediment transport during storm events. The area composed of this material is limited to a small area in the northeast corner of the site. The sediment control BMPs, silt fence, and rock berms in this area of the site must be specifically monitored for maintenance issues. The erosion control measures for the site are shown on the attached erosion control drawing. The NRCS Soil Survey report is included in Appendix A. Prior to Construction: Silt fence shall typically be installed down-slope of any proposed improvements, as Silt fence shall also be installed around any stockpiles kept on site. Construction fence will be added to the west side of the site. Potential Pollution Sources The Fort Collins Stormwater Criteria Manual identifies potential sources of pollution, listed on Table 1, for which at a minimum must be identified in the Erosion Control Report. Table 1 provides information regarding the specific potential pollution sources identified for this site. The table also provides the activities associated with these sources and BMPs selected to control contaminants from these sources from leaving the site in stormwater runoff. Specific details regarding BMP selection, implementation, inspection and maintenance are provided in the Stormwater Management Controls (SWMC) section, below. These sources should be updated as the project progresses. Additional pollution sources that are not included on this table should be added and delete sources that are no longer used on site. Handwritten changes are acceptable, date and initial changes that are made. 4 Table 1 Potential Pollution Sources Potential pollution source Potential with this project Activities associated with this pollution source BMPs selected to control source* Approximate location of pollution source on site** All disturbed and stored soils (includes stockpiles) Yes Clearing and grubbing, grading, utility installation, building construction, final stabilization Silt fence, inlet protection, vehicle tracking control, construction fencing, surface roughening, stabilized staging area, seeding/mulching, and street cleaning All disturbed areas of the site except paved surfaces Vehicle tracking of sediments Yes Clearing and grubbing, grading, utility installation, building construction, final stabilization Silt fence, inlet protection, vehicle tracking control, construction fencing, surface roughening, stabilized staging area, seeding/mulching, and street cleaning At site access point, which is limited to the north east entrance. Management of contaminated soils No No known contaminated soils exist on site. If contaminated soils are encountered, all activity shall be stopped until the situation can be assessed. The Superintendent will be contacted for further direction. Affected soils should be isolated from clean soils (placed on and covered with plastic, or placed in 55-gallon drums) whenever possible until a remediation plan can be implemented. Not applicable Loading and unloading operations Yes Delivery and staging of materials Vehicle tracking control, construction fencing, and stabilized staging area. Stabilized staging area Outdoor storage activities (including building materials, fertilizers, chemicals, etc.) Yes Delivery and staging of materials Stabilized staging area and street cleaning. Secondary containment ditches around storage areas. Provide and maintain spill control materials specified by chemical manufacturers (e.g. absorbents, sand) Stabilized staging area – only those products needed for use on the site 5 Table 1 Potential Pollution Sources Potential pollution source Potential with this project Activities associated with this pollution source BMPs selected to control source* Approximate location of pollution source on site** Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, paints, solvents, oils, grease, glues, joint compound, etc. Yes Vehicle and equipment use and storage, utility installation, final stabilization Stabilized staging area and street cleaning. Individual waste containment systems – such as children’s rigid pools, buckets, drums or other water tight vessel. Secondary containment ditches around storage areas. Provide and maintain spill control materials specified by chemical manufacturers (e.g. absorbents, sand) These items are generally kept in subcontractor vehicles or within the structure once constructed – only those products needed for use on the site will be on site at any one time. Extra product not used on site will be removed from the site by the subcontractor. On-site waste management practices (waste piles, liquid wastes, dumpsters, etc.) Yes Clearing and grubbing, grading, utility installation, building construction, final stabilization Dumpsters including regular trash removal, site management practices. Liquid wastes will be contained and removed from site and properly disposed by subcontractors generating such wastes. Dumpsters will be emptied by the appropriate subcontractor for disposal at a designated off-site disposal facility. Dumpsters will be placed on the site in amounts needed for anticipated waste generation. Waste piles that are unable to be transferred to available dumpsters on site will be removed from site and transported to designated off-site disposal facilities. Concrete truck/equipment washing, including the concrete truck chute and associated fixtures and 6 Table 1 Potential Pollution Sources Potential pollution source Potential with this project Activities associated with this pollution source BMPs selected to control source* Approximate location of pollution source on site** * See further discussion of appropriate BMPs in Stormwater Management Controls (SWMC) and Appendix B. ** For specific location of BMPs used on site see construction documents. 7 Stormwater Management Controls (SWMC) Silt fence is a sediment-trapping device installed prior to beginning earthwork activities. Silt fences will be installed inside the property boundary and at sensitive locations. The silt fence along the property boundaries shall remain in place until permanent vegetation has been established. A construction entrance with a vehicle tracking control pad will be provided at the proposed northeast access drive off existing S. Mason St. A stabilized staging area (SSA) will be constructed near the construction entrance to the northwest. The SSA will be used for storing construction materials, equipment and vehicles. Drip pans, cardboard, plywood or other absorbent materials must be placed beneath parked vehicles to control the release of hazardous materials from the SSA. Hazardous materials include but are not limited to gasoline, motor oil, hydraulic oil, and anti-freeze. The existing 10-foot inlet at the intersection of S. Mason St. and W. Harmony Drive (on S. Mason St.) shall be protected with inlet protection. Rock socks shall be installed along S. Mason St, and W. Harmony Rd, as allowed. All storm sewer inlets made operable during construction will have sediment-entrapment facilities installed to prevent sediment-laden runoff from entering the inlet. Contractor shall install the most effective method of inlet protection for the site conditions. Rock socks are constructed of gravel that has been wrapped by wire mesh or a geotextile to form an elongated cylindrical filter. They are used for perimeter protection (street flowlines, especially) or as part of inlet protection. A concrete washout shall be installed before any concrete mixing is done, and located near the SSA. A portable concrete washout consists of a shallow container that is designed to capture waste water and waste products resulting from the cleaning of concrete and masonry equipment. They are used to contain concrete and liquids from chutes of concrete mixers and hoppers that are rinsed out after delivery. The washout consolidates solids and allows for evaporation of liquids for easier disposal and to prevent runoff into storm sewers or waters on the site. The washout area shall be located near the SSA to control tracking of mud. 8 Dryland Vegetation Dryland vegetation construction is to be limited to small landscape areas newly created. If final landscape stabilization is delayed more than thirty days, temporary seeding and mulching for the establishment of stabilizing grasses shall be performed. Ultimately all landscape areas will be planted with landscape plants. Areas of sod disturbed in construction to be repaired. Refer to “L-1 Landscape Plan” from the “Fort Collins Jeep Dealership – Project Development Plan” set for sod, final vegetation, and soil amendment requirements associated with Fort Collins Municipal Code Sec. 12-130 through 12-132. Temporary and permanent seeding and mulching shall be performed according to the “Temporary and Permanent Seeding (TS/PS) EC-2” specification sheet, included in Appendix B of this report. Sequence of Construction Activities The construction schedule is as follows: Table 2 Construction Schedule Construction Activity Control Measures Timeline Mobilization Install construction entrance, vehicle tracking control, stabilized staging area, silt fence, inlet protection, and rock socks Spring 2017 Demolition Maintain and replace control measures as necessary to ensure proper operation. Specifically, but not limited to, replace damaged silt fence sections, clear inlet protection and silt fence of sediment and debris, maintain vehicle tracking control and stabilized staging area, and monitor seeding and mulching. Spring 2017 Site grading Seed and mulch all exposed soil areas. Control measure construction shall be ongoing as grading operations proceed; use on newly formed landscape areas if final landscape installation is delayed more than 30 days Summer 2017 9 Construction Activity Control Measures Timeline Building re-model Install concrete washout area Ongoing (refer to construction drawings) Paving and landscaping Maintain and replace control measures as necessary to ensure proper operation. Specifically, but not limited to, replace damaged silt fence sections, clear inlet protection and silt fence of sediment and debris, maintain vehicle tracking control and stabilized staging area, and monitor seeding and mulching. Ongoing (refer to construction drawings) De-mobilization Remove erosion control measures Winter 2018 Note: 1. Dates are approximate, assuming good weather and no unforeseen circumstances. 2. Refer to project schedule maintained by site superintendent for timelines and specific dates for all construction tasks. Maintenance The contractor shall make a thorough inspection of their stormwater management system at least once every 14 days and after any precipitation or snowmelt event that causes surface erosion. The construction site perimeter, disturbed areas, and areas used for materials storage that are exposed to precipitation shall be inspected for evidence of, or the potential for, pollutants entering the drainage system. Erosion and sediment control measures identified in the erosion control plan or SWMP shall be observed to ensure that they are operating correctly. Based on the results of the inspection, the description of potential pollution sources, and the pollution prevention and control measures that are identified in the erosion control plan or SWMP shall be revised and modified as appropriate as soon as practicable after such inspection. Modifications to control measures shall be implemented in a timely manner, but in no case more than 7 calendar days after the inspection. The operator shall keep a record of inspections. Any incidence of non-compliance, such as uncontrolled releases of mud or muddy water of measurable quantities of sediment found off the site, shall be recorded with a brief explanation as to the measures taken to prevent future violations, as well as any measure taken to clean up the sediment that has left the site. After adequate measures have been taken to correct any problems, or where a report does not identify any incidents of non-compliance, the report shall contain a signed certification 10 indicating that the site is in compliance. This record shall be made available to the Division upon request. In addition to the above, the following maintenance requirements shall be used for individual BMPs. Mulching - The key consideration is that the mulch needs to last long enough to achieve its erosion control objectives. Reapplication of mulch may be required to maintain effective soil stabilization over disturbed areas and slopes. After any rainfall event, the Contractor is responsible for maintaining all slopes to prevent erosion. Vehicle Tracking Control - Inspect routinely for damage and assess the effectiveness of the BMP. Remove aggregate, separate and dispose of sediment if construction entrance/exit is clogged with sediment. Inspect for damage and repair as needed. Silt Fence - Inspect silt fence at least once every 14 days and after rainfall events. Sediment shall be removed when the buildup reaches one third the height of the fence. Fence that has been damaged or washed-out shall be repaired or replaced in- kind. Inlet Protection - Inspect at least once every 14 days and after rainfall events. Inspect rock socks for displacement of the rock contents and/or damage to the surrounding fabric. Repair fabric and replace as needed. Geotextiles, Plastic Covers, & Erosion Control Blankets/Mats - These temporary controls shall be installed per the manufacturer specifications and inspected at least once every 14 days and after rainfall events to ensure their proper functioning. If washout or breakage occurs, re-install the material after repairing the damage to the slope or channel. APPENDIX A MAPS AND SOILS INFORMATION APPENDIX B EROSION CONTROL DETAILS APPENDIX C EROSION CONTROL ESCROW ESTIMATE Project: EROSION CONTROL BMPs Units Estimated Quantity Unit Price Total Price L.F. 1228 $2.50 $3,070.00 EA 7 $200.00 $1,400.00 EA 1 $500.00 $500.00 L.F. 120 $3.00 $360.00 EA 1 $2,400.00 $2,400.00 SY 200 $3.00 $600.00 Sub-Total: $7,730.00 1.5 x Sub-Total: $11,595.00 Amount of security: $11,595.00 Seeding and Mulching Area (Acres): 0.7 Total Acres x Price/acre: $6,300.00 Unit Price of Seeding per acre: $9,000.00 Sub-Total: $6,300.00 1.5 x Sub-Total: $9,450.00 Amount to Re-seed: $9,450.00 Minimum escrow amount: $3,000.00 Erosion Control Escrow: $11,595.00 Miniumum Escrow Amount Fort Collins Jeep Dealership Project “The amount of the security must be based on one and one-half times the estimate of the cost to install the approved measures, or one and one-half times the cost to re- vegetate the disturbed land to dry land grasses based upon unit cost determined by the City's Annual Revegetation and Stabilization Bid, whichever is greater. In no instance, will the amount of security be less than one thousand five hundred dollars ($1,500) for residential development or three thousand dollars ($3,000) for commercial development” Inlet Protection (IP) Concrete Washout (CW) (add all other BMPs for the site in this list) Final Escrow Amount Erosion and Sediment Control Escrow/Security Calculation for The City of Fort Collins BMP Amount Silt Fence (SF) Vehicle Tracking Control (VTC) Reseeding Amount Stabilized Staging Area (SSA) Rock Sock (RS) 8/29/2017 4:03 PM F:\Jobs\2016 Projects\16-018 Fort Collins Jeep\Engineering\Reports\Erosion Control Report\Compiled Report 2017-07-20\Example_Escrow.xls equipment (includes concrete and curing compounds) Yes Foundation construction and flat work Concrete washout areas, vehicle tracking control, and site management practices. A portable concrete wash out will provided and will be noted on the map. Concrete washout areas may be moved as needed to accommodate construction schedules. Dedicated asphalt and concrete batch plants No None planned for this site N/A Not applicable for this site. Non-industrial waste sources such as worker trash and portable toilets Yes All activities Dumpsters with lids, portable toilets secured to ground, site management practices. Individual units will be emptied and their contents properly disposed at off- site disposal facilities. Dumpsters and portable toilets will be placed on the site in amounts needed for anticipated waste generation. Their exact locations will be noted on the site map. Other areas or procedures where potential spills can occur No No other sources identified at this time N/A Not applicable for this site. Add additional detail to above categories if needed. will be on site at any one time. Extra product not used on site will be removed from the site by the subcontractor. Vehicle and equipment maintenance and fueling Yes Fueling and equipment repair for vehicles or equipment used in all phases of construction activity. Fueling will be performed by delivery vehicles which will provide necessary spill prevention or will be performed off-site. Fuel, greases and other maintenance fluids will be used and removed from site by the subcontractors. During fueling or maintenance operations items will be kept on mobile vehicles and not stored on site. Significant dust or particulate generating processes Yes Clearing and grubbing, grading, utility installation, building construction, final stabilization Wetting of soils. Refer to City of Fort Collins Odinance No. 44, 2016 “Fugitive Dust Ordinance”. Municipal Code Sec. 12-153. All disturbed areas of the site except paved surfaces.