Orono Substation Expansion - Enviromental Assessment (1)

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v 1 During the construction phase of the Project,there is the potential for temporary impacts to ' wetlands as a result of ground disturbance related to grading,construction traffic,substation construction,and placement of the transmission line structures. Although minimal grading of areas around pole locations is expected,the substation site will be graded. Potential impacts to wetlands will be limited to the area where the structures and line will be constructed and operated (Xcel Energy,2011a). Based on a review of NWI data,approximately 1.0 and 3.3acres of wetlands are located within the 75-foot-wide anticipated rights-of way of the Baker Park Reserve Route Alternative and the Xcel Energy Proposed Routes respectively (Xcel Energy,personal communication,November 21,2011). Permanent impacts to wetlands would occur where structures must be located within wetland boundaries. Xcel Energy has designed the replacement substation to avoid direct impacts to wetlands. Depending on the delineated location of wetlands and the final location of the ROW,up to five structures could potentially be placed in wetlands for both routes (Figure B-2). Each structure would result in approximately 50 square feet of permanent wetland impacts per structure or up to 250 square feet total (0.006 acres). The Project may require wetland and water resource approvals from the U.S.Army Corps of Engineers (USAGE),MnDNR,Hennepin County and the Minnehaha Creek Watershed District. Wetlands crossed by the Project may be jurisdictional to the USACE under Section 404 of the Clean Water Act. Once a route is finalized and permitting requirement are determined,Xcel Energy will submit the Minnesota Local/State/Federal Application Form for Water/Wetland Projects to the USACE's St.Paul District,MnDNR and,if needed, the Hennepin County Soil and Water Conservation District. Xcel Energy has stated that they anticipate that authorization for the Project from MnDNR would come,if granted,under the USACE's General Permit/Letter of Permission permitting program (Xcel Energy,2011a). As part of the permitting process,Xcel Energy will be required to submit sufficient materials for the USAGE to make its jurisdictional determination for impacted wetlands. The joint application will also be subject to MnDNR,Hennepin County Soil and Water Conservation District,and Minnehaha Creek Watershed District review and regulation under the Minnesota Wetland Conservation Act. A license from the MnDNR is required to cross public water wetlands. Under the Clean Water Act,Section 401 water quality certification is required for activities that may result in a discharge to waters of the United State. MPCA administers Section 401 water quality certification on non-tribal lands in Minnesota. If the USAGE authorizes the Project under its General Permit/Letter of Permission permitting program, the MPCA waives its Section 401 Water Quality Certification authority(Xcel Energy,2011a). The Project is located within the 100year floodplains of Lake Katrina and Painter Creek mapped P PP by the Federal Emergency Management Agency (FEMA,2011). Although the Project would install several transmission structures in a 100 year floodplain,the function of the floodplain would not be affected. Mitigation Measures The Project will require a MnDNR License for Utility to Cross Protected Waters from the MnDNR Division of Waters because the Project passes over and across wetlands designated as state public waters (unnamed 27-916 W and 27-917 W). The MnDNR license to cross Protected Waters would outline mitigation measures. Environmental Assessment PUC Docket E002/IL-11-223 Page 48