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r ~ • • ~t4arch?7. /997 6. The grading on the lower bench will be done [o capture and prevent all flows from following [he asphalt en¢ance road. The Flows will be routed to the eazt on an abandoned bench road that intersects a rock cut on a cut face along the asphalt en¢ance road. All flows from the lower bench will be routed [o this gap and allowed to fall down the rock face to the entrance road. A small splash pad of large derrick stones will be placed adjacent to the entrance road to still the water falling over the gap and allow i[ to sheet flow onto the entrance road. 7. A small sediment pond (LB3) located below the rock gap will con¢o1 flows from Bazin H. This basin is relatively undisturbed and will not contribute much sediment. 8. There is a minor drainage ditch running along the entrance road to the mouth of the quarry. It is only good for conveying minor nuisance flows. No further improvements will be made to this ditch. Larger event flows will be allowed to sheet flow down the entrance road to the mouth of the quarry. An asphalt swale approximately I.5 feet in height will be constructed to capture and convey the Flows across the road into the lower sediment pond located at the mouth of the quarry. 9. The sediment pond at the mouth of the quarry will be regraded, vegetation removed and a small rock spillway installed. This pond was agreed to be ineffectual in terms of size. 10. Significant changes N the design flows have been achieved from the initial submittal. The increase in sediment pond size and a retook at basin characteristics hazed on the field trip justified modifying the model. We also changed the modeling program and used SEDCAD for the final computer runs. I I . The dimensions of the spillways and culverts proposed for each sediment pond are outlined in both the plan and the computer output that is attached. The details of the spillway would remain the same az the previous submittal. 12. The asphalt entrance road will have some minor ditch regrading to capture nuisance flows. The road will also be patched to remove cracks that could contribute to unstable slopes along the entrance road. Some grading and berming will also be done to repa¢ this unstable slope. We are N the process of preparing large scale plans to be used by Western Mobile for cons¢uction N the field. They will reflect the same items discussed above. If you have any questions, please do not hesitate to call.