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Mr. Dustin Czapla <br /> Page 2 of 7 <br /> South Pit <br /> • Remove and replace a portion of the east slope on the South Pit area that has <br /> been moving over the past few years. The upper diversion ditch will be re- <br /> established and lined with a Geosynthetic Clay Liner (GCL) to minimize <br /> infiltration along its alignment and divert water across the slope. <br /> North Pit <br /> • Re-establish the east diversion ditch of the north pit to convey runoff into the <br /> existing diversion ditch further south. The ditch will be regraded and lined with a <br /> GCL to minimize infiltration along its alignment and divert water across the slope. <br /> A short section of the North Pit diversion ditch will be moved into the slope to <br /> improve safe access along the maintenance road. <br /> Sediment Control Pond Improvements <br /> • Improvements to the sediment control pond, which include lowering the water <br /> level, replacing the sediment pond valves and risers, and lining the upstream face <br /> of the sediment control dam to limit seepage into the embankment. <br /> Sand Filtration (Water Treatment) Plant Demolition <br /> • The sand filtration (water treatment) plant located near the toe of the sediment <br /> control pond embankment will be demolished and disposed of, placing recovered <br /> material in approved storage areas, and plugging the pipes from the sediment <br /> dam. Approaches to demolish and remove plant will be made and reviewed by the <br /> Engineer of Record, due to pipe penetration associated with the embankment. <br /> LPL Advancement <br /> HMC is continuing to advance the evaluation of alternatives that can be implemented at <br /> the Pitch Reclamation Project (Figure 1 and Figure 2) to reduce uranium load to the <br /> Colorado Discharge Permit System (CDPS) permit (No. C00022756) compliance point <br /> Outfall 001A (also known as SW-33) and establish the Lowest Practical Level (LPL) for <br /> uranium. Field testing from 2015 through 2018 involved the injection of a mixture of <br /> phosphate and conservative tracer into the historical Pinnacle underground mine <br /> workings and the Indian Rock Dump. This program was successful at treating uranium by <br /> precipitation as low-solubility phosphate-based minerals. In addition, an intermediate- <br /> scale field implementation engineered treatment cell (ETC) was installed in 2018 to <br /> intercept surface water routed from the Chester Fault Springs (Figure 2). <br /> The phosphate injection program and ETC installation were completed using existing and <br /> recently completed injection/monitoring wells and limited surface disturbances as <br /> approved in previous technical revisions (TR-6, TR-7, TR-8, and TR-9) to the DRMS <br /> reclamation permit No. M-1977-004HR. <br /> Building on the success of the 2015 through 2018 pilot and field tests, and in the interest <br /> of continued evaluation of potential alternatives to address the other uranium source <br /> loads, the following field activities are planned: <br /> HOMESTAKE MINING COMPANY V 1 1 2 MARSHALL STREET, SARGENTS, COLORADO 81 248 <br />