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Melanie Lawrence <br />January 2, 2007 <br />Page 2 <br />As part of the mining operation, a concrete batch plant will be installed onsite in 2007. <br />The batch plant will utilize water from a new proposed well which will be constructed adjacent to <br />the batch plant. Depletions to the South Platte River resulting from pumping the batch plant <br />well will be replaced under this SWSP. <br />The proposed replacement source is fully consumable water leased from the City of <br />Longmont. <br />The final reclamation of the pit includes backfilling or lining of all exposed groundwater <br />within the permit boundary. The applicant has bonded for lining and backfilling of the pit as part <br />of their permitting process through the Division of Minerals and Geology. <br />Depletions <br />This plan describes the projected uses for 2007. According to the information submitted, <br />no water surface was exposed within the permit boundary prior to January 1, 1981. <br />The anticipated consumptive use for 2007 consists of 40.04 acre-feet of evaporation loss <br />from an exposed area of 13.5 acres, 17.66 acre-feet lost in product (4% moisture of 600,000 tons <br />of raw material), 5.0 acre-feet of water used for dust control and 12.42 acre-feet used for concrete <br />hatching (total 75.22 acre-feet). At some point during 2007, Platte Sand and Gravel anticipates <br />backfilling some of the currently exposed pit with overburden material, thereby reducing the <br />exposed ground water surface area to 5 to 7 acres. This SWSP currently assumes that the entire <br />13.5 acres will be exposed for the entire plan period. <br />The depletions from evaporation and operational losses were lagged to the stream using a <br />Glover analysis and assuming a distance to the stream of 2,900 feet, distance to the impermeable <br />boundary of 16,100 feet, permeability of 1,043 fUday, saturated thickness of 20 feet and specific <br />yield of 0.2. The depletions from the batch plant well were also lagged to the stream using a <br />Glover analysis and assuming a distance to the stream of 1,642 feet, distance to the impermeable <br />boundary of 12,592 feet, transmissivity of 178,800 gpd/ft and specific yield of 0.2. The Applicant <br />has provided a monthly schedule of lagged actual depletions to the river system, together with a <br />schedule of replacement requirements. This SWSP accounts for actual depletions determined to <br />accrue to the steam system during this plan period. <br />Replacements <br />The proposed source of replacement for this pit is fully consumable wastewater <br />treatment plant effluent or reservoir releases from a lease with the City of Longmont. The City <br />of Longmont wastewater treatment plant is located approximately 20 miles upstream of this <br />existing mining operation. A 0.5 percent per mile transit loss (10.0 percent overall loss) has <br />been accounted for in the replacements for April through October and a 0.25 percent per mile <br />transit loss (5.0 percent overall loss) has been accounted for in the replacements for November <br />through March. The monthly depletions and replacement requirements are found on the table <br />below: <br />