Agenda - Environmental Policy Board - 10/15/2018

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• Any construction activities that MPCA determines will potentially contribute to a violation of a water quality standard or for significant contribution of pollutants to a water iesuuiee. Clearly, any construction on the Ramsey Town Center of any size will be subject to the provision of the Phase II construction permit, especially since the City's MS4 permit requires it to implement control measures addressing construction site runoff control. The SWPPP required for the general construction activity Permit must address the potential for discharge of sediment and/or other potential pollutants from the site, and must include the following elements: • Temporary erosion prevention and sediment control BMPs; • Permanent erosion prevention and sediment control BMPs; • A permanent storm water management system; and • Pollution prevention management measures. These elements must be incorporated into the final plans and specifications before applying for permit coverage. Special provisions are made within the General Permit language for discharges to Outstanding Resource Value Waters (ORVW), which includes the Mississippi River through the City of Ramsey, discharges to wetlands and discharges to scenic or recreational river segments, which include the Ramsey reach of the Mississippi River. Within these areas, additional protective BMPs are required. Since the ultimate discharge from Ramsey Town Center is the Mississippi River, these provisions will apply to the construction permits issued for the site. The Item 17 assessment of discharge found that discharge of any storm water from the Town Center downstream to the River will occur under wet conditions. The only feasible and economic alternative for surface water discharge from the site is to the River. Every effort will be made to retain and, if possible, infiltrate normal events on the Town Center site. Excess volumes of surface water runoff will be pre-treated before allowed to drain from the Center or its nearby/adjacent runoff treatment system. Because the Ramsey Town Center will not have any heavy industrial uses, it is not expected that the provisions of the Phase II NPDES program dealing with Industrial Activity will apply. However, if development conditions change before the site is finally built -out, and heavier industry is allowed on the site, these provisions could apply. Although there is no intent for heavy industry to occur in the Center, the City will monitor the permit requirements relative to land uses under which the permit conditions apply, and implement a control program if ever needed. Relationship to Mississippi River TMDL One water quality element of note in the mitigation plan is the need to reduce the negative impact of a discharge to an unpaired water" under the Total Maximum Daily Load (TMDL) program. The Mississippi River through the City of Ramsey has been listed on the MPCA recommended03d" list as impaired relative to fecal coliform, PCB and mercury. The PCB and mercury programs are regional in scale and are the subject of regional MPCA and USEPA remediation programs. The discharge of storm water high 17-17