2009-09-25_PERMIT FILE - M2009076 (43)

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Reclamation Feasibility Report - Virginia Canyon • Sixteen stream sites were sampled during a summer thunderstorm on August 17, 2000. Two draining mine adits were subsequently sampled the following day. There were no rain gauges in Virginia Canyon, but, based upon measurements in Idaho Springs, the thunderstorm was estimated to be approximately 1 inch. One of the stream samples was an opportunistic sample taken directly below a mine waste pile. Stream flow less than 1 cfs was measured using one-inch and four-inch Baski cutthroat flumes. Stream flow over 1 cfs was measured with a current meter. Field measurements included pH and electrical conductivity. Water samples were collected at each site in 250 ml pre-acidified HDPE bottles. Total recoverable metals and dissolved metals samples were collected. The dissolved metals samples were filtered through 0.45-micron filters in the field. The May 2000 water quality data is presented in Appendix 1. The August 2000 storm flow data is presented in Appendix 2. It should be noted that metals loading data in the appendices is reported in grams per day, whereas throughout the text, the data is presented in pounds per day. This was done to enable the reader to visualize the amounts better. To convert pounds to grams, multiply the number of pounds by 454. Conversely, to convert grams to pounds, divide the number of grams by 454. Water samples were collected by CSM three different times in 1999. The water samples were collected along with sediment samples to compare the chemistry of the two mediums. Water samples were collected in 1999 during spring run-off in May, during low-flow drainage in August, and after a 0.5 - 1 inch summer thunderstorm in August. Only dissolved metals samples were • collected. Flows were not measured. The pH, Eh, ionic conductivity, and water temperature were recorded. The water samples were filtered, then acidified for later analysis using the ICP-AES. The spring 1999 data is presented in Appendix 3. The 1999 low-flow data is presented in Appendix 4. The data following a summer thunderstorm is presented in Appendix 5. MINE WASTE SAMPLING Mining waste samples were collected at 74 different locations in Virginia Canyon. All the mine waste samples were waste rock. No mill tailings were observed in Virginia Canyon. Vegetated and unvegetated soils and alluvium were also collected at 5 locations. The vegetated soils included one near the headwaters and one near the two brothers mine. Alluvium samples were collected in a recent 16-foot high head-cut in Boomerang Gulch and a manganeous debris flow near the mouth of Robinson Gulch. One sample of a naturally denuded soil, near the Comstock Mine, was sampled. The locations of the sampling sites are shown on Figure 3. Waste rock and soil samples were collected from a minimum of ten and maximum of thirty locations at each site. Acid-washed plastic 100 ml beakers were used to remove the top two inches of material. The 10+ sub-samples from each site were composited in a 1-gallon re- closeable plastic bag. The composited samples were thoroughly mixed by inverting the plastic bag numerous times. The soil and waste rock samples were analyzed by two different methods. A portion of the composited sample was sent to Analytica Laboratory as a solid sample. Another portion of the composite sample was leached with deionized water, then the filtered leachate was sent to Analytica Laboratory. a