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Describe any steep slopes or highly erodible soils and identify them on the site map. <br />Describe any erosion and sedimentation control measures to be used during and <br />after project construction. <br /> <br />The nature of the Site is unique, in that the gravel resources to be mined are located only <br />in long narrow ridges (eskers). It is anticipated that these ridges will be excavated and <br />removed to a depth below the water table. Peat will be removed from the flat areas below <br />the ridges to a depth below the water table as shown in the Final Contours map. Based on <br />the topographic contours of the Site, surface water runoff from the western portion of the <br />Site will flow to the east and remain on site either in open water areas or wetlands. <br />Surface water runoff from the eastern portion of the Site will also remain on site and flow <br />into the low areas or wetlands. <br /> <br />Surface water runoff and erosion controls are proposed to control surface water discharge <br />off site. The proposed controls will include installation of silt fence/hay bales, rip-rap <br />placement in drainageways, and phased topsoil replacement and seeding of completed <br />phases. The silt fence/hay bales and rip-rap will be placed in areas deemed necessary <br />during mining operations. Since most of the Site will remain undisturbed during the <br />mining operations and the site will be lower than the surrounding area, only minimal, if <br />any, off site surface water run off is anticipated. <br /> <br />17. Water quality: surface water runoff <br /> <br />ae <br /> <br />Compare the quantity and quality of site runoff before and after the project. <br />Describe permanent controls to manage or treat runoff. Describe any storm water <br />pollution prevention plans. <br /> <br />Surface water runoff and proposed controls have been discussed in the preceding item. <br />As noted in Items 9 and 10, the majority of the Site is grassland/wetland and will be <br />excavated to create deeper water wetland types and open water areas. Currently, no <br />surface water runoff or sedimentation controls are employed at the Site with the <br />exception of the ditch abandoned in 1965. <br /> <br />The proposed mining operation will change the existing topography and may temporarily <br />decrease the quantity of runoff through the Site to some extent by creating additional <br />depressions and deepening the existing wetland basins. It is anticipated that most of the <br />run off will flow into topographic depressions, open water or wetlands on the Site and <br />eventually infiltrate to the shallow groundwater aquifer. The engineered erosion and <br />sedimentation controls identified in Item 16 will be based on runoff from the mining <br />area. Preparation of a SWPPP will be required to manage storm water run off. <br />Specifically, the SWPPP will describe site conditions and operations, including outdoor <br />storage of materials and a description of spill response procedures. If recycled asphalt is <br />used and stored at the Site, drainage from the piles will be prevented from entering any <br />surface waters. If applicable, monitoring of surface water quality may also be proposed <br />or required. Best Management Practices (BMPs) identified in the SWPPP will be <br />implemented as part of routine operations at the Site. <br /> <br />10 <br /> <br /> <br />