Orono_Route_Permit_Application - Docket # W002/TL-11-223

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According to the Clean Water Act, Section 401 water quality certification is required for activities that may result in a discharge to waters of the United States. On non -tribal lands in Minnesota, such as the Orono Substation site and Proposed Route, the MPCA administers Section 401 water quality certification. If the USACE authorizes the Project under its GP/LOP permitting program as expected, the MPCA waives its Section 401 Water Quality Certification authority. Although the Orono Substation, and to a lesser degree the surrounding residential lots, have a greater elevation than the wetland areas, the entire Project is located within the 100 -year floodplain (FEMA, 1994) and is designated as Zone A. The 100 -year floodplain maps indicate areas with a one percent chance of being inundated by water in any given year. The Zone A designation for this area means that no flood base elevations have been designated. The crossing of the 100 -year floodplain occurs in upland areas as well as wetland areas. Although the Orono Substation and first 410 feet of proposed transmission line leaving the substation site is located within the 100 -year floodplain, the elevation (983) of this area is much greater than the surrounding wetlands areas (964). Mitigative Measures Xcel Energy will obtain a MnDNR License for Utility to Cross Protected Waters from the MnDNR Division of Waters because the proposed transmission line passes over, and across wetlands designated as state public waters (unnamed 27-916 W and 27-917 W), under Minn. Stat. 5 84.415. This license will include specific requirements for the PWI crossing. In addition to implementation of storm water BMPs and the Stormwater Pollution Prevention Plan ("SWPPP'� during construction, Xcel Energy will implement the requirements of the MnDNR license to cross the PWIs. In addition to the wetland delineation that was conducted at the existing Orono Substation site, Xcel Energy will conduct wetland delineation of the Proposed Route for the new transmission line. During construction, the most effective way to minimize impacts on wetland areas will be to span wetlands to the extent possible. In addition, crossing wetlands with equipment will be avoided except where necessary. Where wetlands must be crossed to pull in the new conductors and shield wires, workers may be required to walk or drive equipment across ice in the winter. These construction practices will help prevent soil erosion and ensure that construction vehicles and equipment fueling and lubricating will occur at a distance from wetlands. Xcel Energy will follow standard erosion control measures identified in the MPCA Stormwater BMP Manual, such as using silt fencing to minimize impacts on adjacent water resources. Impacts on wetlands will be minimized through appropriate construction practices. Construction crews will maintain sound water and soil conservation practices during construction and operation of the facilities to protect topsoil and adjacent water resources and minimize soil erosion. Practices may include containing excavated material, protecting exposed soil, and stabilizing restored soil. Crews will avoid major disturbance of individual wetlands and drainage systems during construction. This will be accomplished by strategically locating new access roads and spanning wetlands and drainage systems where possible. The Project design will incorporate spacing of structures to span wetlands and streams to the extent possible. However, it is possible that some transmission structures could be placed within wetlands; any necessary permits will be obtained after final design is completed and prior to starting construction. When it is not feasible to span the wetland, construction crews will use several methods to minimize impacts: Orono Project June 7, 2011 MPUC Docket No. E002/TL-11-223 57