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Bu[/doP Mine Tui[inRs Pondr Evalunlion <br />2. Upper Pond Sediment Sample-Z: Poorly sorted tan to dazk brown soil and <br />weathered Creede Formation Sediments. Primarily medium grained with 3% - <br />5% volcanic rock fragments (up to 3 cm in diameter), approximately 30% clays, <br />and 15% organic material. <br />3. Lower Pond Sediment Sample-1: Light orange-brown medium grained sand. <br />Grains aze primarily quartz with minor feldspaz, mica, and rock fragments. <br />Matrix contains 1 % - 2% organics and less than 5% clay material. Coarser grained <br />materials aze lightly coated with iron and manganese oxyhydroxides. <br />4. Lower Pond Sediment Sample-2: Dazk orange-brown poorly sorted medium <br />grained sand with approximately 25% clay material and 3% - 7% organic <br />material. Coazse grained materials aze lightly coated with iron and manganese <br />oxyhydroxides. <br />5.4.2 Attenuation Test Methods <br />The procedures used for the attenuation tests consisted of adding the tailings pore water collected <br />at the Upper Pond to the soil materials at a 2:1 liquid:solid ratio. Although this ratio is higher <br />than a liquid solid ratio that would occur in natural conditions, it allowed an adequate amount of <br />water to be recovered from the materials after the tests for chemical analysis. The soil materials <br />and water were mixed in an Erlenmeyer flask and gently agitated by an automatic reciprocating <br />arm shaker for 24 hours. Electrical Conductivity and pH were measured in the laboratory. <br />Afterwards, water leachates were collected from the samples by pouring the supernatant through <br />a 0.45 µm filter and preserved with nitric acid. The collected waters were then sent to SVL <br />Laboratories (Kellogg, Idaho) for analysis of dissolved manganese, lead, antimony, and sulfate. <br />Six attenuation tests were performed in the flasks discussed above. Four flasks contained soils <br />from different locations azound the tailings impoundments (two from each impoundment), one <br />was a test duplicate with same soil as one of the four above, and the sixth flask contained tailings <br />pore water only to serve as a test rinsate. <br />5.4.3 Test Results <br />The analytical results from the attenuation tests are summarized in Table 5.5. These data show <br />. that manganese, lead, and antimony concentrations in the starting water were attenuated <br />significantly by reaction with the sediment and soil samples used in all of the test vessels. <br />Homesmke Mining Camparsy Shepherd dldltr. Inc. <br />a.ir~~uib~dry~x .~~ 33 ,~pnl 1 {. 799.- <br />