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City of Orono <br />Surface Water Management Plan February 2019 16 <br />information regarding TMDL requirements and tracking can be found in the City’s SWPPP at the link <br />provided above. <br />OUTSTANDING RESOURCE VALUE WATERS <br />Coverage under the MPCAs MS4 General Permit authorizes Orono to discharge stormwater into <br />Minnesota’s waters through its Municipal Separate Storm Sewer System (MS4). The permit does not <br />allow new and expanded discharges to restricted waters as defined by Minnesota rules (7050.0180) <br />unless prudent and feasible alternatives to the new and expanded discharge do not exist. The only rule- <br />listed restricted waters that exist in Orono are the two Scientific and Natural Areas (SNA): Wolsfeld <br />Woods and Wood Rill. <br />NPDES CONSTRUCTION ACTIVITY PERMIT <br />In compliance with the provisions of the Clean Water Act, the MPCA issues a general NPDES permit to <br />authorize the discharge of stormwater from construction activity. The Construction Activity Permit does <br />not allow new or expanded discharges to Outstanding Resource Value Waters nor does it allow <br />discharges to waters identified as impaired unless certain conditions are met. For projects that have a <br />discharge point on the project that is within one mile of, and flows to, an impaired water, the permit <br />requires additional water quality treatment and also requires that a portion of this treatment occur through <br />infiltration. According to the permit, certain site conditions such as lack of separation to seasonally <br />saturated groundwater, proximity to bedrock, poor soils, and contaminated soils can eliminate the <br />infiltration requirement. The permit does not include language that eliminates the infiltration requirement <br />for industrial sites and drinking water source protection areas, though the Minnesota Stormwater Manual <br />(produced by the MPCA) supports exemptions in these two cases, as well, and the Minnesota Department <br />of Health guidance for infiltration supports an approach that is protective of drinking water supplies. <br />NPDES INDUSTRIAL ACTIVITY STORMWATER PERMIT <br />The Minnesota Pollution Control Agency (MPCA) issues a general NPDES permit that authorizes the <br />discharge of stormwater for certain industrial activities. This permit covers a multitude of industrial <br />facilities where the exposure of chemicals and other pollutants creates the potential for contaminated <br />runoff to enter surface and groundwater resources. Much like the MS4 permit and the Construction <br />Activity Permit, Industrial Stormwater Permit holders must develop a Stormwater Pollution Prevention <br />Plan, or SWPPP, that describes control measures to prevent pollutant discharges. As a means of avoiding <br />the permit requirements, industrial facilities can certify a “No Exposure” condition, whereby all <br />significant industrial materials and activities are protected from rain, snow, snow-melt and runoff through <br />a storm resistant shelter. <br />3.2 LOCAL REGULATION <br />Local regulation occurs through the cooperative efforts of Orono and the Minnehaha Creek Watershed <br />District (MCWD).Table 3.1 describes the mechanisms by which this local regulation is applied. <br />Table 3.1: Regulatory Mechanisms <br />Official <br />Control Responsibility Mechanism <br />Erosion and <br />Sediment <br />Control <br />City, MCWD <br />·NPDES MS4 Permit – Orono Stormwater Pollution <br />Prevention Program (SWPPP) <br />·NPDES Construction Permit <br />·NPDES Multi-Sector Permit <br />·Orono City Code: Chapter 79 – Construction Site <br />Runoff Control. Building Permits incorporate Chapter <br />79 requirements. <br />·MCWD Erosion Control Rule