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area.No existing overburden or topsoil berms are found on the site. However, estimates on <br /> overburden and topsoil availability is highly variable due to the inconsistent thickness of the <br /> gravel deposit and overlying strata above the gold-bearing gravels and underlying bedrock. <br /> Estimates were based on the NRCS soils report and pre-law observable operations. <br /> 5. Flocculant Use <br /> The Box Creek Placer may use biodegradable flocculant at times to improve the recycling <br /> process of wash water used in gold-bearing gravel processing to encourage quicker settling of <br /> suspended solids within on-site settling ponds. Flocculant is used in water recirculation systems <br /> in mining operations that involve significant material washing. The use of flocculant expedites <br /> the `drop-out' of sediment in process waters within recirculation ponds. Due to the high clay <br /> content of glacial debris and alluvium mined on-site, it is imperative to use flocculant to facilitate <br /> settling and thus separation of fine low-density clay sediments from desirable cobbles, gravels, <br /> and high-density gold. Several nearby placer mines in the Fairplay area use flocculants to <br /> improve water recycling in their operations. <br /> Flocculant to be used here is an anionic wet flocculant like Hyperfloc AF852 produced by <br /> Hychem, Inc. of California. This chemical is not harmful to fish or other animals unless it is <br /> dumped in full concentration directly into the Arkansas River and its tributaries in large <br /> quantities. See Material Data Safety Sheets in Appendix 3. It is safer than many other chemicals <br /> used for flocculating dirty waters today and the City of Denver uses it in its drinking water <br /> plants. <br /> 5.1 System Design <br /> One 150 gallon tank of water will be placed adjacent to the sluice box. A 55-gallon steel drum of <br /> the Hyperfloc chemical is set up next to the 150 gallon water tank. Hyperfloc and water are <br /> pumped from both tanks using small pumps into a separate mixing tank, as needed,to allow the <br /> proper mixing concentration. Since the flow rate in the sluice is constant, this will be easy to <br /> accomplish. The mixing tank is a heavy duty plastic 100 gallon tank and a fixed mixer will be <br /> used to homogenize the solution. A small valve and garden hose type pipe will allow the mixed <br /> solution to flow to the sluice box. The solution then enters the slurry from the sluice where the <br /> Box Creek Placer Mine Greg Lew"i and As wtm Pt l d <br /> September 2018 D-11 <br />