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Logan Wash Mine Annual Report <br />Permit No.: M-1977-424 <br />5.1 Mine Maintenance <br />During the reporting period, OOSI inspected the Logan Wash Mine site on a weekly to monthly <br />basis during April through December. The upper mine facilities are usually not accessible from <br />December through March due to deep snowpack and poor road conditions. Inspections focused <br />on mine roads, headwalls, portal closures, bench surfaces, dump faces, constructed storm <br />drainage and rip-rap channels, and the plant irrigation system, when deployed. Mine water <br />discharge rates and Evaporation Pond water levels were periodically monitored and recorded <br />(Section 3.2). No snow removal was conducted during the 2009-2010 winter. Road maintenance <br />activities included grading of the running surface and constructing and maintaining runoff ditches <br />and waterdips is typically conducted in the spring and summer months or after major storm <br />events. <br />5.2 Evaporation Pond Maintenance <br />Maintenance of the Evaporation Pond included inspection of (1) discharge rates to the pond from <br />the mine retort plumbing system, (2) the leak detection vault, (3) wildlife security fence, (4) storm <br />drainage ditches, and (5) general conditions of the pond, liner, and egress ladders. <br />5.2.1 Evaporation Pond Leak Detection System <br />In December 2009 and January 2010, inspections of the Evaporation Pond leak detection vault <br />indicated that the vault was receiving water from the leak detection system as the vault <br />progressively showed more water in the sump. <br />On January 13, 2010, the water in the sump was several inches above the level of the three leak <br />collection system pipes and the water was pumped out of the sump and into the pond. On January <br />27, 2010, an automated sump pump and pressure transducer were installed in the sump and the <br />sump was pumped down after water inflow reached a depth of approximately 2 feet in the sump. <br />This resulted in a pump cycle period of about 4 hours. Total inflow from the 3 detection pipes <br />was measured at 0.25 gallons per minute (gpm). Water samples were collected on January 27 and <br />confirmation samples were collected on February 11, 2010. The confirmation sampling consisted <br />of sampling the vault and the pond. Both sampling events indicated that the vault water was very <br />similar composition to the pond water. On February 5, 2010, the DRMS, U.S. Bureau of Land <br />Management and the Colorado Department of Public Health and Environment were notified of <br />these observations and that a possible leak was present in the pond liner. These regulatory <br />agencies were kept informed of leak detection monitoring findings at least once every two weeks <br />after this date. <br />The following mitigation procedures were proposed by OOSI: <br />1. Pump the detection vault. Maintain current automated pumping system to reduce head <br />in the pond's underlying detection system. <br />2. Conduct confirmation sampling. Sampling will be conducted the week of February 8, <br />2010 to confirm the previously reported results for the vault and to assess concentrations <br />in the pond itself. <br />3. Locate the leak in the liner. Work will begin to locate the leak once snow and ice have <br />melted from the pond and air temperatures are sufficient to make the liner more pliable. <br />A full survey of the pond will be conducted. The presence of salt precipitate on the liner <br />surface may inhibit locating the leak. Other measures may be required as work <br />progresses. <br />Western Water & Land, Inc.