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We will establish a stormwater detention "pond"on the eastern boundary of the amendment <br /> area; because during and after mining, the amendment area will be slightly lower than the <br /> Phase 1 area to its east. The majority of the time, there will not be water in the "pond," but in <br /> the case of a storm event, the "pond"will be of an adequate size to hold any excess water from <br /> sheet run-off. Stormwater detention ponds should be able to hold 900 cubic feet of water per <br /> acre. We are mining 83 acres, so the pond will be constructed to hold at least 74,700 cubic <br /> feet. The pond will not be lined, to allow for percolation of stormwater into the soil. We will <br /> maintain the pond after mining is completed. <br /> We have a similar detention pond on the currently permitted area, which is part of our <br /> Stormwater Management Plan, and which has worked well for detaining water in the rare storm <br /> events. From our experience in this area, we have found that the surface topsoil and <br /> overburden are very permeable. Our experience with large storm events for the past ten years <br /> of operation has been that sheet run-off is minimal. Much of the rain water penetrates directly <br /> into the soil it initially contacts during storm events. If there is any excess sheet flow, it follows <br /> the contours of the area to the detention pond, where it remains until soaking into the ground. <br /> In regards to the fiber optic cable along the western edge of the amendment area, we will <br /> maintain a minimum of a 2:1 set-back. In other words, for every 1 foot of depth of excavation, <br /> we will stay 2 feet distance from the cable. We will flag it prior to any mining operations in the <br /> area to ensure that it not be affected in any way. <br /> If you have any questions, or need more details on the reclamation, please call me. <br /> Si9Rrermpi <br /> y, <br /> Lynn E.Regulatiance <br /> cc: R. A. Everist, Andesite Rock Company <br /> Kim Ogle, Weld County Planning <br /> t..fn/C•vlrec;llrucsv-OPirJ10G <br />