Laserfiche WebLink
„ iii iiiiiiiiiiiiiiii , <br />FINANCIAL WARRANTY REQUIREMENT RE-EVALUATION <br />SAN LUIS PROJECT M-88-I l2 <br />December 22, 1999 <br />TASKS AND COST ESTIMATES FOR REMAINING RECLAMATION OBLIGATIONS: <br />WEST PIT WATER MANAGEMENT PROGRAM <br />ASSUMPTIONS <br />In order to clean up the West pit backfill, the operator needs to withdraw, and process, 10 pore <br />volumes of water from the aquifer. <br />1 pore volume equals 180,700,000 gallons <br />10 pore volumes equal 1,807,000,000 gallons <br />2 processes and 1 alternative have been evaluated since they aze the only approved operations. <br />A) Nano-filtration process -Cost equals $9.43/1000 gallons treated. 7 month operation. <br />B) Evaporation system - $10,810.00/month for 5 months <br />The West pit water level will be pumped down 15 feet (to a msl of 8580feet) at 4~)0 gpm for 70 <br />days. Thereafter, the aquifer will be pumped at the steady state rate which is estimated at 100 <br />gpm. Since the water level has already been lowered 3 feet (to 8592 msl), it should only take 56 <br />days, and 32,256,000 gallons, to lower the water level another 12 feet (at 400 gpm). <br />32,256,000 gallons of water will be pumped during the first 56 days. 144,000 gallons/day will be <br />pumped thereafter. <br />The operator has already removed 44,201,933 gallons of water from the backfill aquifer up to <br />December 1, 1999 (this does not include the volume of water that has exited the West pit into the <br />alluvial aquifer). <br />It will take approximately 33 years to pump and treat 10 pore volumes of water. This is based on <br />1,807,000,000 minus what has already been pumped, minus 32,256,000 gallons which will be <br />pumped during the first 56 days; divided by 144,000 gallons (daily pump rate). <br />WATER MANAGEMENT TREATMENT AND ESTIMATED COSTS <br />First year's treatment starting January 1, 2000 <br />1) 56 days at 400 gpm equals 32,256,000 gallons at $9.43/1000 gallons = $304,174 <br />2) 156 days at 100 gpm equals 22,464,000,000 gallons at $9.43/1000 gallons = $2l 1,836 <br />3) 5 months evaporation system at $10,810.00/month = $54,050 <br />4) Total = $570,060 <br />