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8. SWPPPSTORM SEWER POLLUTION PREVENTION PLAN (SWPPP) ARBOR GLEN contractor as 1. CONSTRUCTION ACTIVITY INFORMATION This SWPPP was prepared by personnel certified in the design of construction SWPPPs. Copies of certifications are available upon request. Project Name: Arbor Glen Project Location: Address : 9170 Great Plains Blvd City : Chanhassen State: Minnesota Zip Code: 55317 County Parcel ID Number (PID): 250242900 Project Type: Residential Commercial/Industrial Road Construction Residential/Road Constructionl Other Cumulative Impervious Surface Home buildinq BMPs 7. Pollution Prevention Management Measures Number of acres to be disturbed: Single family lots within the overall site will be disturbed on a lot by lot basis as lots are sold & homes are 6.6 (tenths of an acre) Pre -construction acres of impervious surface: constructed. Home construction shall disturb previously stabilized areas. Typically entire lots will be disturbed 0.0 (tenths of an acre) Post -construction acres of impervious surface: as finish grading is completed. Areas not to be disturbed are typically designated by the use of silt fence. 2.0 (tenths of an acre) Total new impervious surface acres: Topsoil shall be preserved by stockpiling with sediment control installed around the perimeter of the stockpile. 2.0 (tenths of an acre) Receiving Waters Individual lots under construction shall also install vehicle tracking measures such as rock entrance berm or • Petroleum Products: All onsite vehicles and equipment will be monitored for leaks and receive Name of Water Body Type Special Water? Impaired? Water? Lake Riley Lake No Yes Lake Susan Lake No Yes Wetland 1 Wetland No No Pond Pond No No 3. Temporary Erosion Prevention Practices (continued) Home buildinq BMPs 7. Pollution Prevention Management Measures Rock Entrance Berm to be installed. Single family lots within the overall site will be disturbed on a lot by lot basis as lots are sold & homes are • Paints: All containers will be tightly sealed and stored when not required for use. Excess paint will Methods to be used to promote infiltration and sediment removal on the site prior to discharge constructed. Home construction shall disturb previously stabilized areas. Typically entire lots will be disturbed Practices for storage of pesticides, herbicides, insecticides, fertilizers, treatment chemical, and landscape • The water quality volume that must be treated by the project's permanent stormwater management system as finish grading is completed. Areas not to be disturbed are typically designated by the use of silt fence. materials to described in Part III.C. shall be 1/2 inch of runoff from the new impervious surfaces created by the project. Topsoil shall be preserved by stockpiling with sediment control installed around the perimeter of the stockpile. — e See Part III.C.2 for more information on infiltration design and appropriate site conditions. If it is determined Individual lots under construction shall also install vehicle tracking measures such as rock entrance berm or • Petroleum Products: All onsite vehicles and equipment will be monitored for leaks and receive that site conditions are not appropriate for infiltration (e.g. lack of 3 ft. of separation to seasonally saturated other tracking control BMP to maintain clean streets. Home builders shall be responsible for erosion & sediment regular preventative maintenance to reduce the chance of leakage. Petroleum products will be ground water, proximity to bedrock, contaminated soils) the reasons should be documented in the Stormwater control installation, maintenance, SWPPP inspection and record keeping for lots under their construction. stored in a tightly sealed container, which is clearly labeled. Any asphalt substances used onsite Pollution Prevention Plan (SWPPP) for the project. Infiltration is not required in Hydrologic Soil Group D soils. Continue vertical construcflon will be applied according to the manufacturer's recommendations. Clay soils throughout the site resulted in volume reduction being achieved via filtration shelfs in three (3) of the Home Construction BMP Phasing infiltrating the ground. onsite ponds. Protect lot area through use of one or a combination of the following; silt fence, mulch, bio -rolls, rockFertilizers: • Fertilizers will be applied only in the minimum amounts as recommended by the infiltration areas. Rip -rap to provide provide energy dissipation and prevent erosion. entrance berm, sod buffers or other approved method. In areas within 5011 of surface waters redundant manufacturer. Once applied, the fertilizer will be worked into the soil to limit the exposure to Timelines to be implemented on site for completing the installation of the erosion prevention BMPs controls shall be installed if a 50ft buffer can not be maintained. stormwater. Dates of Construction Construction Start Date: Spring of 2017 Estimated Completion Date: Summer of 2017 2. General Construction Project Information Personnel & Training Provide a certified erosion control supervisor in good standing with who is knowledgeable & experienced in the application of erosion prevention & sediment control BMPs. Supervisor shall work with the project engineer to oversee implementation of the SWPPP & the installation, inspection & maintenance of the erosion control BMPs. Provide at lease one certified installer for each contractor or subcontractor that installs erosion control BMPs. Chain or Responsibility Owner / Developer & Contractor are copermitees for the National Pollutant Discharge Elemination System (NPDES) Construction Permit. Contractor is responsible to comply with all aspects of the NPDES Construction Permit at all times until the Notice of Termination (NOT) has been filed with the MPCA or transferred to a home builder or another contractor. Contractor will develop a chain of command with all operators on the site to ensure that the SWPPP will be implemented & stay in effect until construction is complete, the site has final stabilization & NOT has been submitted to the MPCA Describe the construction activity This +/- 6.6 acre development will consist of the land development of 21 single family detached homes, and 860 linear feet of streets. Other soil disturbing activities will include: home building, driveway construction, and lot landscaping. This project will be mass graded and constructed in 1 phase, grading will be completed in the spring of 2017, and utilities completed in the same spring or summer. Soil disturbing activities will include: Demolition of the existing structures, installation of a rock entrance berth, clearing and grubbing, installation of utilities/minor utilities(including private utilities-gas,cable,electric, etc..), the installation of silt fence and tree fence prior to grading, the installation of silt fence around the proposed ponding areas after the grading is complete, grading, re -spreading topsoil, and grading restoration which will consist of seeding and mulching all disturbed areas outside of the street row. Erosion blanket will also be installed on all 3:1 slopes or greater. Additional erosion blanket may be used throughout the site. See the Erosion & Sediment Control Plan for specific locations. 3. Temporary Erosion Prevention Practices Describe types of erosion prevention BMPs expected to be implemented Perimeter Control shall be established around the site & around the base of stockpiles if the stockpile will remain longer than 30 days. Perimeter control is typically established with silt fence which also deliniates areas not to be disturbed. Silt Fence locations are shown on the Grading & Erosion Control plans. Where possible 5011 buffers shall be maintained around surface waters & wetland. Dual perimeter controls shall be installed if work is to take place within 5011 of surface waters & wetlands. Erosion blanket will be installed on all 3:1 slopes. During construction a. Stabilization of all exposed areas must be initiated immediately to limit soil erosion but in no case laterthan seven (7) days after the construction activity in that portion of the site has temporarily or permanently ceased. Once grading is complete, temporary erosion BMPs shall be installed immediately (ie. bio -rolls, erosion blanket, ditch checks, etc). No later than seven (7) days, the permanent stabilization should be in place. b. Temporary sediment basin requirements described in Part III.8.1-5 must be used for common drainage locations that serve an area with five (5) or more acres disturbed at one time. This project is being constructed in 1 phase. The permanent dry sediment basins shall be constructed first and all on-site drainage shall be routed to the ponds. The site does not have any concentrated swales that will directly discharge off-site List anticipated BMP Quantities • Silt Fence (Before Construction) - 3,030 LF • Silt Fence (After Construction)- 305 LF • Erosion Blanket- 1,200 SY Prior to Grading - Silt and tree fence to locate grading limits and provide down gradient sediment control. install drainage protection on down gradient inlets. • Rip -rap will be used at all flared -end structures Rock Entrance Berm to be installed. Establish staging / material storage area & Install temporary sanitary Facilities& supply dumpsters • Paints: All containers will be tightly sealed and stored when not required for use. Excess paint will greater than 75 feet with a grade of 3:1 or steeper) Prevent & manage spills of stored substances not be discharged into the storm sewer system, but will be property disposed of in accordance with • Grading - Erosion blanket will be utilized on all 3:1 slopes. Biorolls will be used in rear yard swales. MnDot Install Rock entrance berm, maintain clean streets local regulations. seed mix #250 will be spread at a rate of 100 lbs./acre and fertilize with 20-0-10 at 100 lbs./acre. Only Home Construction — phosphorus free fertilizer shall be used. Manage & protect stockpiles Practices for storage and disposal of hazardous materials or toxic waste • Utility &Street Work - Inlet protection on all storm sewer catchbasins. Weekly street sweeping to prevent maintain rock entrance berm & p perimeter controls utilities t ll & tconnect ues install nsa trench,leaks, • All hazardous materials like oil, gasoline and paint must be properly stored. To prevent spills and off-site vehicle tracking. However weekly sweeping may not be adequate. Sweeping is required 24 hours DLS 09/12/16 secondary containment is necessary for hazardous materials. after discovery of track out. Continue vertical construcflon • A leak proof containment facility shall be used for fuel storage tanks to prevent any leakage from DLS 01/25/17 Keep streets clean at all times & maintain inlet protection infiltrating the ground. • Permanent BMPs - Sediment bays are to be installed at flared end sections draining into dry pond and Fine grad pads, Upon completion of fine grade pads & home construction soils disturbing activities, An effort will be made to store only enough products to do the required job. infiltration areas. Rip -rap to provide provide energy dissipation and prevent erosion. each lot shall be stabilized with sod, seed, mulch, hydromulch, hydroseed, straw matting or combination • All materials stored on site will be stored in a neat and orderly manner. DLS 04/21/17 there of. Monitor stabilized areas until final stabilization is achieved • All products will be kept in their original container, with the original labels still attached, unless they Additional Erosion Control Prevention Measures to be Implemented on Site Maintain clean streets are not re -sealable. • Erosion Blanket- This blanket will be installed as indicated on the erosion and sediment control plan. It will Perimeter & temporary erosion & sediment controls are to remain in place until all up gradient areas • Substances will not be mixed with one another unless recommended by the manufacturer. provide slope protection until the turf is established. For retaining wall construction the grading contractor will have been permanently stabilized. • Whenever possible all of a product will be used up before disposing of a container. install Erosion blanket on the temporary 1:1 slopes until the wall construction can be completed. Post Construction • Manufacturers' recommendations for proper disposal will be followed. • Bio -rolls - Bio -rolls will be installed in swale areas to help slow runoff and minimize erosion. Remove silt fence after once final vegetation stabilization is established • Seeding Restoration - Temporary/Permanent Stabilization (Seeding and Mulching) -Temporary seeding and Remove inlet protection The site superintendent will routinely inspect the site to ensure proper disposal of all on site materials mulch must be placed on all disturbed soil within 14 days, unless actively being worked on. All disturbed areas Remove all construction materials & debris from site will be restored with 4" to 6" of topsoil. The restoration shall begin within 72 hours of the grading completion. clean all drainage structures Collection storage and disposal of solid waste in compliance with Minn. R. ch. 7035 The seed mix shall be MNDot Mix No. 250 applied at a rate of 100 lbs/acro and fertilized with 20-0-10 at a rate Remove all temporary erosion & sediment control BMPs & stabilize areas left disturbed. of 100 lbs. per acre. The mulch shall be Type 1 and applied at a rate of 2 tons per acre, disc anchored (with disc blades set nearly straight) immediately after placement. File NOT for individual lot . Solid Waste - All trash and construction debris from the site will be collected and deposited in a dumpster. A dumpster will be required for each new home constructed. The dumpsters shall be • Sodding - Two types of sodding will be done with this project. The first will be for erosion control protection for emptied as necessary. No construction materials shall be buried on site. All solid waste must be the streets, after the installation of the curb and the minor utilities the contractor will install two rows of sod 5. Permanent Stormwater Management System disposed of in accordance with the MPCA disposal requirements (Part IV.F.1) behind the curb for a temporary erosion protection. The second type of sod will be for the yards once the house construction is complete. Will the project result in one acre or more of new impervious area? -YES Management of portable toilets to prevent tipping and disposal of sanitary wastes in accordance with 4. Temporary Sediment Control Practices Minn. R. ch. 7040: If Yes, • Portable on-site sanitary and septic waste shall adequately be provided and maintained throughout Methods of sediment control BMPs to be implemented on site • The water quality volume that must be treated by the project's permanent stormwater management system the duration of the project. • Sediment controls for temporary or permanent drainage ditches and sediment basins that are designed as described in Part III.C. shall be one (1) inch of runoff from the new impervious surfaces created by the • All sanitary sewer waste will be collected from the portable units as required by local regulations. part of a treatment system project. Where site conditions allow, at least % inch of the water quality volume must be infiltrated. See Part • Installation of check dams or other grade control practice to ensure sheet flow and prevent rills (for slope III.C.2 for more information on infiltration design and appropriate site conditions. If it is determined that site Spill prevention and response for fueling and equipment or vehicle maintenance: lengths greater than 75 feet with a grade of 3:1 or steeper). conditions are not appropriate for infiltration (e.g. lack of 3 ft. of separation to seasonally saturated ground Spill Control Practices - • Sediment control practices on all down gradient perimeters prior to land disturbing activities. • Storm drain inlet protection for all inlets. water, proximity to bedrock, contaminated soils) the reasons should be documented in the Stormwater • All spills will be cleaned up immediately after discovery, in accordance with the manufacturer's • Silt fencing or other sediment control surrounding temporary soil stockpiles. Pollution Prevention Plan (SWPPP) for the project. Infiltration is not required in Hydrologic Soil Group D recommended methods. • Minimize vehicle tracking of sediments (e.g., stone pads, concrete or steel wash racks, or equivalent soils. • The spill area will be kept well ventilated. systems). A copy of the Stormwaer Management Report is available through the owner or engineer upon request. • Spills of toxic or hazardous materials must be reported to the Minnesota Duty Officer • Street sweeping of tracked sediment 1-800-422-0798. Soil boring and water level map is included in the Stormwater Management Report. • A log of the spill type, location, date, and time will be created by the job superintendent. The spill prevention plan will be adjusted to include measures to prevent this type of spill from reoccurring. Methods to be used for down gradient perimeter control • Silt Fences- are designed as a temporary sediment barrier consisting of a filter fabric attached to support posts. This site has three applications for silt fence. These applications aro as follow: 1. the installation of silt fence along the grading limits to protect the wetlands from sediment during the grading and utility construction process, 2. the installation of silt fence around the created ponds and rain gardens after construction to control the sediment runoff until the turf is established and the development is completed, 3. the installation of silt fence surrounding temporary stockpiles. If down gradient BMPs are overloaded (based on frequent failure or excessive maintenance), additional up gradient BMPs shall be installed to eliminate the overloading. The inspector or contractor shall notify the design engineer to establish appropiate up gradient BMP's or elimate any point load sources. Methods to be used to contain Stockpiles Silt fence- will be used to provide perimeter control around stockpiles. Methods to be sued for storm drain inlet protection • Storm Drain Inlet Protection - Storm drain inlet protection is a sediment barrier placed around a storm sewer inlet. This structure traps sediment before it enters the storm sewer system. The utility contractor will be required to install inlet protection per the City's details. • Outlet Structures and Outlet Protection - There are wetlands located within & adjacent to this project, as a result outlet structures are proposed to transfer water from the storm water treatment pond to the wetland after treatment. These structures will serve to provide skimming and rate control. Rip -rap will be placed at the base of all aprons to provide erosion protection by protecting the downstream soils from turbulence and high discharge velocities. Methods to minimize vehicle tracking at construction exits and street sweeoina activites Temporary Rock Construction Entrance - A rock entrance berm is constructed of coarse clean rock installed at the proposed entrance point for all construction vehicles. A detail of the rock entrance berm is shown on the final grading plan. This stone pad provides a tire cleaning mechanism for all vehicles leaving the site. There is one entrance for this project. Please see the Erosion & Sediment Control Plan for location of rock entrance berm. Methods of dissipating velocity along stormwater conveyance channels/ outlets I NO. • Rip -rap will be used at all flared -end structures • Street Sweeping - Weekly street sweeping shall be taken place. However weekly sweeping may not be • Check Dams - Installation of check dams or other grade control practice to ensure sheet flow and prevent rills (for slopes adequate. Sweeping is required 24 hours after discovery of track out. greater than 75 feet with a grade of 3:1 or steeper) Methods to be used to minimize soil compaction and preserve top soil (unless infeasible) on site Methods to be used for stabilization of ditch and swale wetted perimeters • Topsoil will be stripped and stockpiled. Grading operations will be performed and held down 0.5'to allow for • Bio -rolls shall be used for stabilization of ditches and swales as shown on the Erosion Control Plan. topsoil respread. Methods to be used for energy dissipation at pipe outlets • Rip -rap will be used at flared -end structures for energy dissipation. See plan for quantities. Measures to be used if Dewatering is required on site • Dewatering shall be routed to the sedimentation ponds for treatment before leaving site. See Erosion Control Plan for direction on Dewatering methods. 6. Inspection and Maintenance Acflvites Identify individual responsible for installing, supervising, repairing, inspecting, and maintaining erosion prevention and sediment control BMPs on site The owner, North Oaks Company LLC, will be responsible for the operation and maintenance of the erosion and sediment control BMPs. He will select individuals who will be responsible for the inspections, maintenance, and repair activities, and for filling out the inspection and maintenance reports. Rapp Farm HOA will operate and maintain the stormwater ponds. The owner shall keep the SWPPP and all supporting documents for three years after the Notice of Termination (NOT). These documents include, but aren't limited to, the SWPPP Narrative, any amendments, inspection and maintenance records, any stormwater related permits, any permanent operation and maintenance agreements, and calculations for temporary and permanent stormwater management systems. Procedures to routinely inspect the construction site, including: 1. Description of record-keeping requirements and content A maintenance/inspection report will be made after each inspection. A copy of the report will be sent to the City. 2. Frequency of Inspections Once every seven (7) days during active construction and; Within 24 hours after a rainfall event greater than 0.5 inches in 24 hours, and within seven(7) days after that 3. Areas to be Inspected • The silt fence will be installed prior to any site grading. • Only about one half of the site will be exposed at any given time. The grading contractor will be finishing lots as the cuts and fills are achieved in accordance with the approved grading plan. • All erosion control measures will be inspected every week and following any storm event greater than 0.5" in a 24 hour period. • All erosion control measures will be maintained in good working order, maintenance and repairs will be initiated within a 24 hour period of the report. Monitoring of all repairs will be done. • Built up sediment will be removed from all silt fence when it has reached one-half of the fence height. • Silt fence will be inspected for depth of sediment, tears, and to see if the fabric is securely attached to the fence posts, and to see if the fence posts are firmly in the ground. • The pond and infiltration/filtration area will be monitored for depth of sediment, and the build up of sediment will be removed at the end of the project, if necessary. • The embankment around the ponds and infiltration/filtration areas will be inspected for any breaches or erosion scars, over compaction and any repairs needed, will be promptly made. • The seeding and mulching will be inspected for any bare spots, washouts, and for healthy growth. If site conditions result in a needed erosion or sediment control BMP that is not planned for, the inspector or contractor shall contact the design engineer at Sathre-Bergquist Inc. (952.476.6000) to determine an appropriate plan and BMP to stabilize the affected area. Containment and disposal of vehicle and equipment wash water and prohibiting engine decreasing on the site: • A defined and limited area of the site shall be used for external washing of construction vehicles. Washing runoff shall be contained and disposed of in accordance with MPCA. No engine degreasing allowed on-site. Storaae and disposal of concrete and other washout wastes so that wastes do not contact the around: A leak proof containment facility shall be used for all liquid and solid wastes generated by concrete washout operations. Liquid and solid wastes shall not come in contact with the ground and must be disposed of in accordance with the MPCA. 7. Final Stabilization Method of Final Stablilization Upon final grading of any given portion of the site, final stabilization must be implemented within 14 days of completion. a. Stabilization of all exposed areas must be initiated immediately to limit soil erosion but in no case later than seven (7) days after the construction activity in that portion of the site has temporarily or permanently ceased. Once grading is complete, temporary erosion BMPs shall be installed immediately (is. bio -rolls, erosion blanket, ditch checks, etc). No later than seven (7) days, the permanent stabilization should be in place. b. Temporary sediment basin requirements described in Part III.B.1-5 must be used for common drainage locations that serve an area with five (5) or more acres disturbed at one time. This project is being constructed in one phase. The permanent dry sediment basins shall be constructed first and all on-site drainage shall be routed to the ponds. The site does not have any concentrated swales that will directly discharge off-site Procedures for completing final stabilization: Final stabilization includes but is not limited to: seed & mulch as described above, Erosion blanket, bio -rolls, sod, and after grading silt fence. All perimeter and down gradient silt fence shall be inspected and repaired as necessary. DRAWING NAME I NO. BY I DATE REVISIONS USE (INCLUDING COPYING, DISTRIBUTION, AND/OR CONVEYANCE OF INFORMATION) OF THIS PRODUCT IS STRICTLY PROHIBITED WITHOUT SATHRE-BERGQUIST, INC.'s EXPRESS WRITTEN AUTHORIZATION. USE WITHOUT SAID AUTHORIZATION CONSTITUTES AN ILLEGITIMATE USE AND SHALL THEREBY INDEMNIFY SATHRE-BERGQUIST, INC. OF ALL RESPONSIBILITY. SATHRE-BERGQUIST, INC. RESERVES THE RIGHT TO HOLD ANY ILLEGITIMATE USER OR PARTY LEGALLY RESPONSIBLE FOR DAMAGES OR LOSSES RESULTING FROM ILLEGITIMATE USE. I HEREBY CERTIFY THAT THIS PLAN OR SPECIFICATION WAS PREPARED BY ME OR UNDER MY DIRECT SUPERVISION AND THAT I AM A DULY REGISTERED PROFESSIONAL ENGINEER UNDER THEF'o LAWS OF THE STATE OF MINNESOTA. ^ p -;v��// V 1 n A /�D?k?y`�v— ,JAL, .,,�. IC/r l� eEks suR� w N SATHRE-BERGQUIST, INC. CITY PROJECT NO. SWPPP ARBOR GLEN GOLF LAKE CONDOS, LLC FILE NO. 23605-001 EKLO BASE 09 DLS 07/26/16 WATERSHED REVISIONS — DRAWN BY 10 MDM 07/26/16 GRADING REVISIONS CHANHASSEN, MINNESOTA JW 11 DLS 09/12/16 WATERSHED DISTRICT REV. 1 ,.t CHECKED 8Y 12 DLS 01/25/17 FINAL PLAN SUBMITTAL o .,., 150 SOUTH BROADWAY WAYZATA, MN. 55391 (952) 4766000 m `� ptiFRs a P�2 DLS 13 MDM 04/07/17 REVISE SITE PLAN DATE 14 DLS 04/21/17 REVISE SITE PLAN Daniel Schmidt, P.E. Date: 01-11-17 Lie. No. 26147 04/08/15