Agenda - Council - 01/26/2021 - Laserfiche WebLink

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Riverstone South EAW Draft — December 2020 Site Plan (Figure 3, Appendix A), these slopes are proposed to be developed into residential lots and a street. The area of 12-14% slopes will be graded and recontoured as part of project construction. Development of the project area will disturb more than one acre of land and therefore will require application for coverage under the National Pollutant Discharge Elimination System/State Disposal System (NPDES/SDS) General Permit administered by the Minnesota Pollution Control Agency (MPCA) prior to initiation of earthwork. In compliance with the General NPDES Permit for construction activities, the project proponent and construction contractor will need to implement Best Management Practices (BMPs) to reduce erosion and sedimentation and stabilize exposed soils after construction. Erosion and sedimentation control BMPs related to stormwater runoff are discussed in greater detail within Item 11.b.ii. NOTE: For silica sand projects, the EA W must include a hydrogeologic investigation assessing the potential groundwater and surface water effects and geologic conditions that could create an increased risk of potentially significant effects on groundwater and surface water. Descriptions of water resources andpotential effects from the project in EA W Item 11 must be consistent with the geology, soils and topography/land forms and potential effects described in EA W Item 10. 11. Water Resources a. Describe surface water and groundwater features on or near the site in a. i. and a. ii. below. i. Surface water - lakes, streams, wetlands, intermittent channels, and county/judicial ditches. Include any special designations such as public waters, trout stream/lake, wildlife lakes, migratory waterfowl feeding/resting lake, and outstanding resource value water. Include water quality impairments or special designations listed on the current MPCA 303d Impaired Waters List that are within I mile of the project. Include DNR Public Waters Inventory number(s), if any. The project area does not include any surface waters, wetlands, streams, or channels. The site has sandy soils and drains overland toward the Mississippi River. The National Wetlands Inventory shows one PFOlA wetland onsite (Figure 8) and soils mapping shows the entire site mapped as non- hydric and predominantly non-hydric soils (Table 4, Figure 7). Kjolhaug Environmental Services (KES) reviewed the site in the field for wetlands on October 19, 2019 and determined that the site include no wetland. At that time, the site consisted mostly of cornfield and woodland. The woodland was dominated by oak and elm trees and did not contain any depressions dominated by hydrophytic plants. Aerial photographs of the cropland were reviewed for wetland signatures using guidance from the Minnesota Board of Water and Soil Resources (BWSR) and the U.S. Army Corps of Engineers (USAGE). The aerial photograph review found the cropland did not have any areas with enough wetland signatures to warrant a field review. Nevertheless, soils were sampled in two locations that showed some wetland signatures. Non-hydric sandy soils were found at both sample points and KES concluded that the site does not include any wetlands. The Lower Rum River Watershed Management Organization (LRRWMO) concurred with the no wetland determination on November 21, 2019 and the U.S. Army Corps of Engineers (USAGE) sent a letter concurring that the site does not include aquatic resources on June 15, 2020. Appendix B includes the site assessment for wetlands and concurrence with the no wetland determination from wetland agencies. The Mississippi River is a MN DNR public watercourse and is located about 666 10