2018-10-22_REVISION - M2008078 (14)

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A portable sanitary facility is located adjacent to the scale house. Soils contaminated by any spills from the sanitary facility will be immediately collected, removed from the site, and landfilled. An above grade self-contained dual wall fuel tank is located on the north side of Phase 9 between the crush plant and screen plant. A fuel cleanup spill kit is located within the fuel tank area to treat any spills that may occur during refueling activities. Any soils contaminated by fuel will be removed from the site and landfilled. C. Erosion and Sediment Controls The structural practices that will be in place during mining will include sediment settling ponds, grading and temporary soil berms to direct drainage, ditches to convey stormwater flows, and sediment control logs. Sediment settling ponds and ditches shall be a minimum of 3 feet deep. Site grading shall be done to direct stormwater flows to the specified sediment settling ponds or infiltration areas as needed. Temporary soil berms shall be placed as necessary to contain stormwater flows onsite and direct flows to the sediment settling ponds or specified infiltration areas. Temporary soil berms shall be constructed of a height sufficient to contain and/or direct flows without the flows overtopping the berms, and shall be compacted to a minimum of 90% of the standard proctor maximum dry density of the material used for the berms. Temporary soil berms shall be seeded, mulched, and tackified to control erosion if they are in place for longer than 1 year. Sediment control logs shall be installed per the details shown on the site maps. Infiltration areas shall be cleaned of sediment if sediment depths exceed 6 inches to ensure stormwater flows will continue to infiltrate into the soils. The non-structural practices include seeding, mulching, and tackifying of the topsoil and overburden stockpiles if they are undisturbed for longer than 1 year according to seed mix in Appendix B. Final reclamation seed mix will be used in the areas that require it based on the DRMS reclamation plan. Sediment from the excavation of sand and gravel in the active mining area that enters stormwater flows will be filtered from these flows using the sediment settling ponds located as discussed above. The stormwater will then be discharged from the last of the ponds once sediment has settled out from the stormwater. The stormwater will be conveyed in a farm ditch (Discharge Point 001) along the north property boundary east to the Arkansas River. Stormwater flows around the temporary overburden and topsoil stockpiles, and the sand stockpile in Phase 17 will be directed as necessary through sediment control logs to limit sediment transport, then flow to the northeast along historic drainage patterns and collect in the undisturbed Phase 13 area, where they will infiltrate into the ground. No offsite discharges will occur from the areas around these stockpiles. Stormwater flows around the product stockpiles in the wash plant area will be directed as necessary through sediment control logs to limit sediment transport, then to the northeast into a pipe under the pit access road (combining with the wash plant discharge) and then through Phases 12 and 11 to the sediment ponds adjacent to the Phase 11 and Phase 8 borders. No offsite discharges will occur from the areas around these stockpiles. Any sediment that collects under the conveyor will be removed as necessary to limit sediment transport by stormwater flows. The temporary ditch crossing backfill will be compacted, and stabilization rock will be placed at the entrance and exit of the culvert to limit erosion/sediment transport within the ditch. The 4