2016-08-31_REVISION - M1991037 - Laserfiche WebLink

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To DRMS Den Page 5 of 10 2016-08-31 16:05.58(GMT) 13032008630 From. Greg Le\mcki The 55-gallon steel drum, the 100 gallon mixing tank and 150-gallon water tank will all sit inside a metal stock tank of a minimum of 10 feet diameter and 2 feet tall, which is more than enough to contain 110°=0 of all tanks being.ruptured. A standard 55-gallon drum spill kit will be placed on site to be rapidly employed in case a spill of the flocculent were to occur.All employees`,will be trailed to check for spills of the flocculent and trained in the use of the spill kit. In addition, DRMS, CDPHE and Park County Department of Health will be immediately notified if any spill occurs from the flocculent. The expected wet chemical use with water will be at the ratio of 0.75-gallon liquid chemical per hour for the expected flow rate of 1400 gallons per minute. This was determined from a laboratory test conducted by Hyc hem on the actual dirty water at the Alma Placer. Therefore, since the gold operation uses a process flow rate of 1400 gallons per minute for an expected 10-hour day, the chemical will be used at the average rate of 7.5 gallons per day. See enclosed data from Hychem. The flocculent will allow all solids to settle out in the initial area of the sluice tails pond. This pond is excavated in native material, and has shown itself to not drain to the surrounding area. As the pond is used. silt and fines will build up within the pond, further reducing its permeability. Sluice Tails Pond Cleanout Using the laboratory test result of 3.4%solids in the dirty water, this means that,for a total flow of 185 cubic feel/minute, the solids are 6.3 cubic feet per minute. Assuming that the settled solids have 40°'o water by weight,this means that 8.8 cubic feet/minute of'-muck"will be produced from the sluice. For 10 hours of operation, this is 5,280 cubic feet per day, or 196 cubic yards. Cleanout of the pond wi It may not be needed since the pond area will he reclaimed by the deposition of sluice tails, however_ some quantity of fines may be used for reclamation or backfilling purposes elsewhere, and these calculations provide an estimate of how much material could be provided. Any muck extracted will be allowed to drain for a few days and the semi-dry material will be hauled to various locations on site for possible use as substitute topsoil in the reclamation. Much of the water will drain rapidly from the muck as it is placed on the bank along the pond. The dry solids removed from the pond are expected to be approximately 116 cubic yards. Water Transmission The sluice pond is not lined with a synthetic liner.The pond has been excavated in native material which has a significant proportion of fines within it. The ground water table(which is the alluvial aquifer of the river)is at least 100 feet below the sluice pond bottom Sluicing operations into the pond Nvill decrease the permeability of the pond even further,as silt and tine build up in the bottom.Water will leave this pond in two mays:recycling to the sluice itself,and evaporation.Infiltration will be negligible. 1 t is also known that the ponds cannot be receiving spring water to any si,91ilicant degree since:the water table is at least 100 feet below the bottom of the ponds. Any overflow from the sluice ponds will be contained on site by the existing site berms.