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~~4nr March 30, 2007 Mr. Aiex Schatz Banks & Gesso 720 Kipling St., Suite 117 Lakewood, CO 80215 Dear Alex: Martin and Wood Water Consultants, lnc. 602 Park Point Ddve, Suite 275, Golden, CO 80901 Phone: (303) 526-2600 . Faz: (303) 526-2624 www.martinandwood.mm Re: Lafarge Sundance Gravel Pit Dewatering Effects Project Number: 536.4 This letter report presents the results of a ground water modeling study conducted on behalf of Lafarge for their proposed sand and gravel pits located within portions of Sections 9, 10, 14, 15, 22, and 23, Township 17 South, Range 65 West in EI Paso County, Colorado. This study was conducted to determine the effects of dewatering of the gravel pits on the surrounding area and nearby wells. Background Lafarge is planning to mine a gravel pit over approximately 15 years on property south of the Fountain adjacent to Fountain Creek. A map of the proposed gavel pit locations is presented as Figure 1. Lafarge is proposing to mine the site in phases. Each small mine cell will be dewatered, and Lafarge will remove the gravel with dry mining techniques in Phases 1 and 2. Two large areas (Cells 5 and 6) will be mined after constructing slurcy walls around the proposed cells. Generally, the smaller cells with be mined from north to south. After each pit is mined, it will either be completed and converted to a reservoir or filled in with native material as subsequent cells are mined. The cells shown are for modeling purposes and may change when mining occurs. As is required for a gravel pit-mining permit from the DRMS, the effects of dewatering wells within 600 feet must be determined. Banks and Gesso, LLC, has provided us with a map locating these wells (Banks and Gesso Exhibit C-1). These wells, identified by their Exhibit C-1 well number, are also presented in Figure 1 of this report. Geology The proposed gravel pit is located within the Fountain Creek alluvium. Martin and Wood utilized United States Geological Survey Water-Supply Paper 1583 (Jenkins, 1964), geologic (lithologic) boring logs provided by Lafarge, and Colorado State Engineer records of wells in the vicinity to interpolate the geology of the alluvium near the mining area.