Agenda - Council - 06/25/2013 - Laserfiche WebLink

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Enterprise Park to Crooked Lake 115 kV Transmission Line March 2012 Environmental Assessment Indirect impacts could include sediment reaching surface waters during construction due to ground disturbance by excavation, grading, construction traffic, and dewatering of holes drilled for transmission structures. This could temporarily degrade water quality due to turbidity. These impacts will be avoided or minimized using appropriate sediment control practices and best management practices (BMPs) contained in MPCA's NPDES permit erosion control plan. As the Rum River is a Minnesota Wild and Scenic River, the Applicant will adhere to all rules under Minnesota Rules Chapter 6105. This includes avoiding or reducing impacts to the extent possible to the wooded swamp north of the road bridge. Sound water and soil conservation practices will be maintained during construction and operation of the Project to protect topsoil and adjacent water resources and minimize soil erosion. These practices may include: • Containing stockpiled material away from river banks and wetland boundaries. • Stockpiling and re -spreading topsoil. • Implementing erosion and sediment controls. • Locating structures and disturbed areas as far away from rivers and wetlands as practicable. • Reseeding and re -vegetating disturbed areas. Once the Project is completed, there will be no significant impact on surface water quality because wetland impacts will be minimized and mitigated per the various federal, state and local permits required to construct and operate the Project. Disturbed soil will be restored to previous conditions or better, and the amount of land area converted to an impervious surface will be minimal The Project should have no impact on the impairment status of the waters in the Project area. There is potential to increase turbidity due to increased sediment loading from construction activities; however, appropriate erosion and sediment control measures will be implemented to avoid or minimize such impacts. Potential impacts to riparian areas along the Route will be limited to ground disturbances due to pole placement. Due to the flexibility to avoid placing poles in sensitive areas, the anticipated impacts to the riparian areas along the Route are minimal Construction of the transmission line is not expected to alter existing water drainage patterns or floodplain elevations due to the small cross section per pole and their relatively wide spacing. Also, modifications at the existing Crooked Lake and Enterprise Park substations will not substantively change the size of impermeable surfaces. The small area of impermeable surfaces created by the pole structures and breaker station outbuildings or foundations will not cause an increase in susceptibility of flooding in the region. Temporary impacts to wetlands may occur if they need to be crossed during construction of the transmission line. No staging or stringing setup areas will be placed within or 47