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encourage quicker settling of suspended solids within settling ponds 1-4. Flocculant may be used <br /> in settling ponds E, F, G, and H to the same affect. The use of flocculant expedites the `drop-out' <br /> of sediment in process waters within recirculation ponds. Due to the high clay content of glacial <br /> debris and alluvium mined on-site, it is imperative to use flocculant to facilitate settling and thus <br /> separation of fine low-density clay sediments from desirable cobbles, gravels, and high-density <br /> gold. Several nearby placer mines in the area use flocculants to improve water recycling in their <br /> operations. <br /> Flocculant used here is an anionic wet flocculant like Hyperfloc AF852 produced by Hychem, <br /> Inc. of California. This chemical is not harmful to fish or other animals unless it is dumped in <br /> full concentration directly into the South Platte River in large quantities. See Material Data <br /> Safety Sheets in Appendix 3. It is safer than many other chemicals used for flocculating dirty <br /> waters today and the City of Denver uses it in its drinking water plants. <br /> 5.1 System Design <br /> One 150 gallon tank of water can be found adjacent to the sluice box, wherever it is placed in the <br /> permit area. A 55 gallon steel drum of the Hyperfloc chemical is set up next to the 150 gallon <br /> water tank. Hyperfloc and water are pumped from both tanks using small pumps into a separate <br /> mixing tank as needed to allow the proper mixing concentration. Since the flow rate in the sluice <br /> is constant, this will be easy to accomplish. The mixing tank is a heavy duty plastic 100 gallon <br /> tank and a fixed mixer will accomplish the thorough mixing. A small valve and garden hose type <br /> pipe will allow the mixed solution to flow to the sluice box. The mixture then enters the slurry <br /> from the sluice where the flocculation of fine particles in the sluice tails pond takes place. This <br /> chemical is used in very small quantities and the majority of solids should and do settle very <br /> rapidly. <br /> One, at least, 55 gallon drum of Hyperfloc will be stored on-site at any one time. The Hyperfloc <br /> will be stored in the drum within 50 feet of the sluice so that it can be mixed and applied to the <br /> sluice tails within a short distance. Additional tanks of Hyperfloc will be stored in secondary <br /> containment on-site to be readily available for use when necessary. <br /> The 55 gallon steel drum, the 100 gallon mixing tank, and 150 gallon water tank will collectively <br /> be stored within secondary containment capable of holding 110% of the collective tank capacity. <br /> Alma Placer Mine / t.r,%IzwwLi and,s wia(mPIA{ <br /> December 2017 D-11 <br />