5.5. SR 04-04-2011 - Laserfiche WebLink

Home Browse Search

No new wells urill be installed onsite. Material extracted from the expansion area will be conveyed to an aggregate processing area in the adjacent existing mining operation to the south of the site. The existing mining facility operates a washplant. The well associated urith the washplant operates under DNR Vdater Appropriations Permit # 1972-0366-1. There is also a potable well located in the operations area which serves the scale building. The proposed additional mining area will not impact or require any changes to the existing permit. 14. Rater-related land use management district. Does any part of the project involve a shoreland zoning district, a delineated 100-year flood plain, or a state or federally designated wild or scenic river land use district? _Yes _X_No If yes, identify the district and discuss project compatibility with district land use restrictions. 1~. R'ater surface use. Will the project change the number or type of watercraft on any water body? _Yes _X_No If yes, indicate the current and projected watercraft usage and discuss any potential overcrowding or conflicts with other uses. 16. Erosion and sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to be moved. Describe any steep slopes or highly erodible soils and identify them on the site map. Describe any erosion and sedimentation control measures to be used during and after project construction. Approximately 21 acres will be graded and 800,000 cubic yards will be removed. The on-site soils are in general susceptible to erosion. Historically, they have been subjected to wind and water erosion, with between one-third and two-thirds of the original surface layer removed from erosion. Slopes on the subject property range from 2-15%, with the average slope at 10%. Mining will create steeper slopes with an excavation face of 1.5:1 (Horizontal to vertical). Erosion from the excavation slopes is inconsequential. Surface water drainage from active mining areas will be directed to low areas within the Plaisted mining operation. Collected surface water infiltrates into the underlying soils and/or evaporates and there is no site discharge. Surface water drainage will not be directed off-site. As part of restoration, excavated slopes will be graded and or backfilled to a maximum of 4:1 (25%). Reclamation grades over the subject parcel will range from 2% - 25%. Reclaimed slopes will be covered with topsoil and seeded to establish vegetation and stabilize the surface. Figures 4 and 5 indicate the excavation plan and the reclamation plan following completion of mining activities. 17. Water quality: surface water runoff a. Compare the quantity and quality of site runoff before and after the project. Describe permanent controls to manage or treat runoff: Describe any stormwater pollution prevention plans. Both the quantity and quality of site runoff will remain similar before and after construction. During active mining, the runoff from the subject property will be managed internally and will not drain off the site. The existing mining facility operates under a Minnesota NPDES permit for gravel musing facilities. The Storm Water Pollution Prevention Plan (SWPPP) for the existing site will be amended to include the subject property. The SWPPP includes best management practices including spill prevention, fuel storage, erosion control and eliminating site discharges of stormwater. b. Identify routes and receiving water bodies for runoff from the site; include major downstream water bodies as well as the immediate receiving waters. Estimate impact runoff on the quality of receiving waters. The site is located within the Elk River Watershed that ultimately drains to the Mississippi River. During active mining; stormwater will be handled internally. Sedimentation basins, diversion berms, silt fence and other appropriate controls are actively utilized to control sedimentation and treat stormwater. After final reclamation of the subject property and the existing mining facility, reclamation grades will direct water to the interior of site where it will percolate into ground. Elk River eventually flows into the Mississippi River located approximately 2.5 miles south of the site.