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Jeff Clark Page 2 <br /> Bromley Lakes SWSP <br /> February 10, 2016 <br /> The City of Brighton obtained a storage water right in the Ken Mitchell Lakes (which includes Cells 1, 2 <br /> and 3) in case no. 1998CW018 (2006CW222). Figure 2 (enclosed) shows the various portions of the site <br /> and the area of exposed ground water. <br /> Cell No. 1 was previously mined by RMCC under Bromley Lakes DRMS permit no. M1987-049. Mining of <br /> additional acreage will occur within the existing Cell No. 1 slurry wall under DRMS permit no. M2015-041 <br /> and will add approximately 225 acre-feet of water storage to Cell No. 1. For the proposed mining <br /> operations, water within the liner boundary is classified as trapped native ground water. Since the <br /> proposed mining operations occur within the boundary of the existing Cell No. 1 slurry wall there are no <br /> depletions associated with the water removed in the product. However any water removed from within <br /> the lined area is required to be replaced by the operator, unless it is discharged directly back to the <br /> river without consumption. Water to wash the product mined under is obtained from within the lined <br /> area of Cell No. 1, and is being replaced under this SWSP. <br /> Depletions will result from: <br /> • evaporative losses of exposed ground water: (a) Bromley Lakes Cell 2, (b) Bromley Lakes <br /> Lot 2 <br /> • water used to wash product - obtained from Bromley Lakes Cell 1 <br /> • water lost with mined product -Bromley Lakes Lot 2 <br /> • dewatering activity to facilitate mining - Bromley Lakes Lot 2 <br /> The proposed replacement sources are consumptive use credits from 5 Fulton Ditch shares <br /> owned by the Applicant, fully consumable water in storage, and water leased from the City of <br /> Brighton. <br /> In accordance with the letter dated April 30, 2010 from the Colorado Division of Reclamation, <br /> Mining, and Safety ("DRMS"), all sand and gravel mining operators must comply with the <br /> requirements of the Colorado Reclamation Act and the Mineral Rules and Regulations for the <br /> protection of water resources. The April 30, 2010 letter from DRMS required that you provide <br /> information to DRMS to demonstrate you can replace long term injurious stream depletions that <br /> result from mining related exposure of ground water. The DRMS letter identified four approaches to <br /> satisfy this requirement. <br /> In accordance with approach nos. 1 and 3, you have indicated that a bond has been obtained <br /> for $4,169,240 that can cover the cost of lining at the Bromley Lakes site to prevent the exposure of <br /> ground water. <br /> Depletions <br /> SWSP depletions are from evaporation of exposed ground water, dewatering, water used to <br /> wash mined product, and water lost in mined product. Tables 1A and 1B (attached) summarize <br /> projected depletions from January through December 2016. The exposed ground water will vary <br /> based upon hydrologic conditions and the amount of backfill. For the period of this SWSP, the area of <br /> exposed ground water is not expected to exceed 29.2 acres in Bromley Cell 2 and 2 acres in Bromley <br /> Lot 2. This gross evaporation rate at this location based upon evaporation atlases in NOAA Technical <br /> Report NWS 33 is 44.5 inches per year. Using the effective precipitation of 10 inches per year the <br /> projected net evaporative loss is 84 acre-feet for Bromley Cell 2 and 5.8 acre-feet for Bromley Lot 2. <br /> Actual evaporation from exposed ground water will be accounted for based upon the actual exposed <br /> ground water areas. <br />