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Mr. Andy Rodriguez, P.E. <br />July 31, 2008 <br />Page 2 <br />for dust control and 12.28 acre-feet for concrete batching at this site the well will provide 1.67 <br />acre-feet of water for dust control at the adjacent Parker-Dersham Resource site. <br />The applicant has bonded for lining and backfilling of the pit through the Division of <br />Reclamation Mining and Safety. <br />Depletions <br />Currently 7.6 acres of ground water surface is exposed at the Baseline Resource pit <br />(WDID 0203017) (7.18 acres in the settling ponds and 0.42 acres in dewatering trench). <br />Consumptive use from the operation of this site consists of 12.43 acre-feet of water lost in <br />product (4% moisture of 422,500 tons of raw material), 1.66 acre-feet for on-site dust control, <br />12.28 acre-feet used in the production of 100,000 tons of concrete and 22.38 acre-feet of <br />evaporation from the 7.6 acres of lake surface exposed after December 31, 1980. The total <br />consumption at this site from mining operations is 48.74 acre-feet. <br />The depletions from the mining operation were lagged to the stream using the SDF <br />method. The construction of the slurry wall affects the timing of the lagged impacts on the <br />South Platte River. The applicant previously prepared a numeric model to account for this <br />affect. According to the model, the SDF for the Batch Plant production well (concrete <br />production and dust suppression) was estimated to be 176 days and the SDF for the <br />evaporation loss and water lost in product was estimated to be 205 days. <br />Replacements <br />The proposed source of replacement for this pit is fully consumable effluent leased from <br />the City of Aurora and nontributary ground water pumped from an existing Laramie-Fox Hills <br />aquifer well. <br />The applicant has entered into a long term lease agreement with the City of Aurora <br />("Aurora") whereby Aurora will deliver up to 49 acre-feet of fully consumable water to the South <br />Platte River at the confluence of the South Platte River & Sand Creek, just north of Metro <br />Wastewater Treatment Plant. The confluence is located approximately 20 miles upstream of <br />the Baseline Resource Pit. A 0.25 percent per mile transit loss for November through March <br />(5.0 percent overall loss) and a 0.5 percent per mile transit loss for April through October (10.0 <br />percent overall loss) has been accounted for in the replacement schedule. <br />In addition to replacing depletions resulting from this mining operation, the City of Aurora <br />effluent will also be used by the Applicant to replace 20.9 acre-feet of depletions resulting from <br />operation of the Bestway Concrete Well No. 1, in accordance with the C.R.S. 37-92-308(4) <br />SWSP approved for Bestway Concrete. Since the City of Aurora effluent is being used as a <br />replacement source for both plans, the applicant's accounting for each SWSP must specify the <br />total amount of effluent released and the amount associated with each SWSP. <br />The nontributary Laramie-Fox Hills aquifer water will be withdrawn by an existing well <br />pursuant to permit no. 64750-F. Additional information regarding the well is shown below: