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Adelaide Landing Residential Development EAW, Hugo January 31, 2017 3) If the wastewater discharge is to surface water, identify the wastewater treatment methods and identify discharge points and proposed effluent limitations to mitigate impacts. Discuss any effects to surface or groundwater from wastewater discharges. Wastewater discharge is not to surface water. No effects are anticipated to surface or groundwater as treatment will to a publicly owned treatment facility. ii. Stormwater - Describe the quantity and quality of stormwater runoff at the site prior to and post construction. Include the routes and receiving water bodies for runoff from the site (major downstream water bodies as well as the immediate receiving waters). Discuss any environmental effects from stormwater discharges. Describe stormwater pollution prevention plans including temporary and permanent runoff controls and potential BMP site locations to manage or treat stormwater runoff. Identify specific erosion control, sedimentation control or stabilization measures to address soil limitations during and after project construction. The development must comply with stormwater management, wetland conservation, floodplain, shoreland, erosion control, and public waters requirements administered by: the City of Hugo, the RCWD, the Board of Water and Soil Resources (Wetland Conservation Act), the Federal Emergency Management Agency (FEMA), the Department of Natural Resources (DNR), and the MPCA through the National Pollutant Discharge Elimination System (NPDES) General Construction Permit. The City of Hugo Comprehensive Stormwater Management Plan (CSMP) is available on the City's website. The site is located in the Clearwater Creek Drainage Area (subwatershed 11.1 and 11.2) as shown in the City of Hugo's (CSMP) and is tributary to Rice Creek. Hugo is also a mandatory small MS4 (Municipal Separate Storm Sewer System) city, and is required by federal and state law to obtain and implement a NPDES Stormwater permit administered by the MPCA. MS4s are required to develop and implement a stormwater pollution prevention plan program (SWPPP), and submit an annual report to the MPCA. Stormwater management, including water quality, rate and volume control will be provided in accordance with Rice Creek Watershed District and city of Hugo requirements. A stormwater management report detailing the modeling results will be provided with the preliminary plan submittal to the City of Hugo. Pre -Construction Site Runoff Existing site runoff from the project area likely contains pesticides, herbicides, and fertilizer residues due to the presence of agricultural fields. There is also likely a minor amount of runoff that flows to the site from TH 61 and 130t1i Street North. However, because of existing drainages on the site, runoff primarily drains away from the site to the north. It is expected that a portion of the runoff infiltrates into the site's soils, but the majority of runoff likely leaves the site via overland flow through existing drainage swales and ditches. Post -Construction Site Runoff The change in land use will decrease the amount of agricultural chemicals and suspended solids, and increase other components typical of urban runoff. It is expected that the volume of runoff will increase during significant storm events as a result of the increase in impervious surface area. It is anticipated that only extreme conditions such as those occurring in connection with 17