2004-02-27_REVISION - M1977424 - Laserfiche WebLink

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Logan Wash Mine TR No. 4 1 Portal provides access to the lower and intermediate levels of the mine, including access to the lower bulkheads of the retorts. The L-1 Portal has never discharged mine water on the surface. However, the L-1 Drift and Portal corridors contain buried drainage pipes that convey both, retort water from Retorts 4, 5, 6, 7, and 8, and mine water from other areas in the mine. Work conducted in the summer of 2003 included full replacement of this drainage plumbing system with 2-inch diameter HDPE pipe. The retort drainage pipes are now all HDPE pipe from the retort bulkheads to the toe of the Lower Dump. In addition to replacing the retort drain pipe, the new pipe was relocated in a trench excavated around the north side of the Lower Dump and down Dry Gulch to the valve at the toe of the Lower Dump. This realignment results in a more stable location for retort drain pipe for the long term scenario. Mine water continues to enter a French drain that was originally constructed in the floor of the L- 1Drift, and drain from the portal in a buried steel pipe. The pipe enters a valve in the vault on the Lower Bench. During the summer of 2003, a new drain line from the vault was constructed. The new drain line, consisting of 2-inch diameter HDPE, extends north in a buried trench with the retort drain pipe line on the Lower Bench. At the intersection with Dry Gulch, the mine water pipe daylights and discharges into Dry Gulch. Under NPDES Permit COG600452, this discharge must be monitored in the case that it flows on the surface at an old metal flume in Dry Gulch at the southern property boundary with BLM land. This is unlikely as the old discharge point was at least 500 ft closer to the boundary and was never observed flowing on the surface at the property boundary. Proposed Reclamation Because drainage from the L-1 Portal is conveyed by buried pipes and no other drainage discharges from the portal, the L-1 Portal will be sealed with an earth plug. The existing steel door will be demolished and disposed of in the mine. A 35-ft earth plug consisting of waste-rock material will be placed in the drift to the top of the drift's back between the portal collar and the existing steel door threshold. On the surface, the earth plug material will be extended to at least 3-ft above the portal back elevation. The plug will be contoured to blend with the surrounding outcrop face and Lower Bench surface. The surface of the earth plug will be revegetated as part of the Lower Bench revegetation effort. Current Status The L-1 Portal was reclaimed as described above during the fall of 2003. 7.0 Evaporation Pond Reclamation The evaporation pond, also referred to as Pond 1, is located on BLM land approximately one- quartermile south of the Logan Wash Road, 1.5 miles east of County Road 45 and Logan Wash Road intersection. The 3.5-acre pond receives retort water discharge from the L-1 Portal retort Western Water & Land, Inc. 14