Agenda - Council - 04/13/2021 - Laserfiche WebLink

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Riverstone South EAW January 2021 pollutants, such as phosphorus, was also achievable. Although nutrient removal efficiency varies with site conditions, well -designed wet ponds and constructed wetland treatment systems are effective in removing sediment and associated pollutants, such as trace metals, nutrients and hydrocarbons. Stormwater basins also remove or treat oxygen -demanding substances, bacteria and dissolved nutrients. Stormwater and Erosion Control BMPs Because project construction will disturb more than one acre of land, the project proponent will be required to apply to the MPCA for coverage under the National Pollutant Discharge Elimination System/State Disposal System (NPDES/SDS) General Permit prior to initiating earthwork on the site. BMPs will be employed during construction to reduce erosion and sediment loading of stormwater runoff. Inspection of BMPs will be required after each rainfall exceeding 0.5 inches in 24 hours, and on a routine basis every 7 days. The NPDES permit will also require perimeter sediment control maintenance and sediment removal. BMPs to be implemented during construction include: 1. Construction of temporary sediment basins in the locations proposed for stormwater ponding, and development of these basins for permanent use following construction. 2. Installation of silt fence and other perimeter erosion controls prior to initiation of earthwork and maintenance of these controls until viable turf or ground cover is established on exposed areas. 3. Periodic street cleaning and installation of a rock construction entrance to reduce tracking of dirt onto public streets. 4. Stabilization of exposed soils within the time limits specified in the General NPDES permit. 5. Energy dissipation, such as riprap, installed at storm sewer outfalls. 6. Use of cover crops, native seed mixes, sod, and landscaping to stabilize exposed surface soils after final grading. Erosion control plans will be reviewed and accepted by the City of Ramsey and the LRRWMO prior to project construction. Potential adverse effects from construction -related sediment and erosion on water quality will be minimized by implementation of the above BMPs during and after construction. iii. Water Appropriation. Describe if the project proposes to appropriate surface or groundwater (including dewatering). Describe the source, quantity, duration, use and purpose of the water use and if a DNR water appropriation permit is required. Describe any well abandonment. If connecting to an existing municipal water supply, identify the wells to be used as a water source and any effects on, or required expansion of municipal water infrastructure. Discuss environmental effects from water appropriation, including an assessment of the water resources available for appropriation. Identify any measures to avoid, minimize, or mitigate environmental effects from the water appropriation. Surface/Groundwater Appropriations and Dewatering Project construction may require temporary dewatering and groundwater appropriation to facilitate installation of sanitary sewer and excavation to construct the 3.5-acre deep pond. The project will not involve installation of new water wells. Project construction will require a MN DNR water 16