Agenda - Planning Commission - 05/04/2017 - Special

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Pearson Farm Residential Development EAW Draft — March XX, 2017 Background Wetlands in and near the project area are generally regulated by the Lower Rum River Watershed Management Organization (LRRWMO), which administers the Minnesota Wetland Conservation Act (WCA) in the project area; the U.S. Army Corps of Engineers (USACE), which administers Section 404 of the Federal Clean Water Act (CWA). The project area includes three delineated wetlands that are identified on Figure 6. Physical Effects and Alterations Construction of an emergency overflow from Wetland 2 is expected to result in physical effects that will eliminate the existing wetland hydrology of Wetland 3. Wetland 3 is a 1,738-square-foot Type 1 seasonally -flooded, farmed wetland that was dominated by stunted corn at the time of the wetland delineation. The proposed 1,738 square feet of wetland impact falls below the 2,500-square-foot de minimis exemption threshold, which applies to wetlands in a 50 to 80 percent area (e.g., Anoka County) under the Minnesota Wetland Conservation Act "except for type 3, 4, 5, or 8 wetland or white cedar and tamarack wetland, outside of the shoreland wetland protection zone and inside the 11-county metropolitan area." (MN Rules 8420.0420, Subp. 8(2)(b). The proposed wetland impact also falls below the 5,000-square-foot wetland sequencing/compensatory mitigation threshold administered by the U.S. Army Corps of Engineers under RGP-003-MN, General Condition 1. The other wetlands on the site will be avoided. LRRWMO Wetland Protection Standards will require establishment of native vegetation within a 16.5-foot-wide buffer strip around these wetlands. b) Other Surface Waters. Describe any anticipated physical effects or alterations to surface water features (lakes, streams, ponds, intermittent channels, county/judicial ditches) such as draining, filling, permanent inundation, dredging, diking, stream diversion, impoundment, aquatic plant removal and riparian alteration. Discuss direct and indirect environmental effects from physical modification of water features. Identi measures to avoid, minimize, or mitigate environmental effects to surface water features, including in -water Best Management Practices that are proposed to avoid or minimize turbidity/sedimentation while physically altering the water features. Discuss how the project will change the number or type of watercraft on any water body, including current and projected watercraft usage. The proposed project is not expected to affect other surface water features such as lakes, streams, ponds, intermittent channels, or county/judicial ditches. The Mississippi River is located approximately 1,400 feet southwest of the project and will not be affected by the project. The site does not include other surface waters and the proposed project will not affect any MN DNR pubic waters. Although the National Hydrography Dataset shows a flowline running southeast through Wetlands 2 and 3, across the northeastern part of the site, this flowline was not observed in the field during the wetland delineation. Field investigation of this area found that it was dominated by corn with areas of green bulrush and intermittent inundation. The area did not include a drainage channel. 12. Contamination / Hazardous Materials / Wastes a. Pre project site conditions - Describe existing contamination or potential environmental hazards on or in close proximity to the project site such as soil or ground water contamination, abandoned dumps, closed 17