Orono_Route_Permit_Application - Docket # W002/TL-11-223

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than the surrounding wetland areas, the entire Project is located within the 100 -year floodplain (FEMA, 1994), and within the Minnehaha Creek Watershed District ("MCWD"). The MnDNR Public Waters Inventory ("PWI") identifies lakes, wetlands, and watercourses over which the MnDNR has regulatory jurisdiction. The statutory definition "public waters" and "public waters wetlands" can be found in Minn. Stat. § 103G.005, subd. 15 and 15a. A MnDNR License for utility to Cross Protected Waters is required for designated PWI crossings. Two wetland areas are crossed by the Project (see Appendix B-6) which are designated as "unnamed (27-916 W)" and "unnamed (27-917 W), and require a MnDNR license. (MnDNR, 2010d). These are discussed below in Section 6.5.3. Potential groundwater impacts associated with overhead electric transmission lines are typically associated with the construction of the lines and structure placement. Examples of potential impacts include the clearing of rights-of-way leading to erosion into nearby streams and wetlands, vibrations from construction equipment resulting in sedimentation being released into shallow aquifers and the drilling of foundations for towers into shallow aquifers. Groundwater impacts are not anticipated during the construction of the Project. Aquifers in the area of the Project are not typically considered to be shallow in nature, therefore, sedimentation as a result of construction activities is not expected to occur. Potential impacts on water quality resulting from ground disturbance (e.g., excavating, grading and traffic) are limited to the construction phase of the Project substation replacement and new transmission structures and lines, when sediment could possibly reach surface waters. Mitigative Measures No significant impacts to water quality are anticipated from the Project. Xcel Energy will apply erosion control measures and BMPs to minimize the potential for discharge to surface waters. Implementation of BMPs to prevent water quality impacts and the construction, restoration, and maintenance of the transmission line are discussed in Sections 5.1.4, 5.1.5 and 5.1.6. A National Pollutant Discharge Elimination System ("NPDES") stormwater permit will identify additional mitigation measures, if necessary. In addition, standard erosion control measures identified in the MPCA Stormwater BMP Manual will be followed. During construction, Xcel Energy will control construction activities to minimize and prevent material discharge to surface waters and groundwater. If materials do enter surface waters or groundwater, they will be promptly removed and properly disposed of to the extent feasible. Disturbed surface soils will be stabilized at the completion of the construction process to minimize the potential for subsequent effects on surface water and groundwater quality. 6.5.3 Wetlands Large wetland complexes and small isolated wetlands are located in and around the Project site. A summary of wetlands within and near the Project is located in Table 13 and shown in Appendix B-6. Some of these wetlands are adjacent to the various lakes that lie near the proposed Project. For the proposed transmission line off of Xcel Energy property, the U.S. Fish and Wildlife Service ("USFWS") National Wetlands Inventory ("NWI") was reviewed to assess which wetlands may be present within the requested transmission line route width for the Project (see Appendix B-6). The Orono Project June 7, 2011 MPUC Docket No. E002/TL-11-223 54