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HI. ISSUES TO BE CONSIDERED: Issues to be considered are based on the Pre-hearing Order for the 124`" Estates proposed operation dated November 28, 2001. 1. Will the sealing of the pil slop the natural flow of water to the numerous shallow wells in the area? (D. attd J. Billings) Division Response- -The applicant states that according to the Colorado Division of Water Resources, Office of the State Engineer, four wells are located within 600 feet of the site. Records show that three of the four wells are monitoring wells permitted to the Phillips Petroleum Company. The fourth well is located approximately 400 feet northwest of the proposed mining area and completed to a depth of 46 feet with water appearing at 29 feet below ground surface. In addition, the well owned by the Billings (Permit No. 140670) is located close to the northern boundary of the proposed mining area. State records show that this well was proposed for a depth of 180 fee[ into the Arapahoe Aquifer, but the applicant believes that the well was completed to a depth of 600 feet. The proposed mining operation will remove residual sand and gravel from the historic mine site to a depth of 8-14 feet in the alluvial aquifer. Two to four feet of claystone bedrock will then be ripped from the floor of the mine to create a clay liner. Due to the depth of the Billing's well, it is unlikely that the dewatering operations or lining of the pit will cause adverse impacts to deep wells. However, for all wells permitted or non-permitted, the applicant has committed to pay the landowners water bill from the South Adams Water and Sanitation District from that time through completion of the mine reclamation steps. According [o the applicant, most of these landowners were connected to the District's water supply due to contamination of the shallow groundwater from the Rocky Mountain Arsenal. By paying the water bills during the time of operation, the applicant will be directly compensating the well users for any losses due to decreased well capacity. In addition, the applicant has committed to pay far rehabilitation of shallow wells along 124th Avenue that lose efficiency during mine dewatering activities. 2. Will the quality of the deep (Arapahoe) aquifer be compromised by seepage of the presently contaminated skaf/ow aquifer (nitrates, DIMP or others)? (D. and J. Billings) Division Response- According to the applicant, in the mid 1990's a contaminant (DIMP) from the Rocky Mountain Arsenal was detected in shallow, unconsolidated groundwater at concentrations below drinking water standards. The applicant states that due to remedial efforts at the Arsenal, the distribution of this contaminant is now receding. The proposed mining operation will remove residual sand and gravel from the historic mine site until bedrock is reached. Two to 4 feet of claystone bedrock will be ripped from [he floor of the mine to create a clay liner. According to the applicant, bedrock in this area is very thick and i[ is improbable that the removal of 2 to 4 feet of bedrock would allow connection to a deeper confined aquifer. The Billings well is likely into the fringe of the Arapahoe Aquifer (at 180 feet) of into the Laramie Fox Hills Aquifer (at 600 feet). The deep consolidated aquifers will likely not be impacted by the mining operation or the clay lined reservoir which will sit on top of the bedrock. 3. Wilf /he additional mining and sea/ing of the pit effect long-term groundwater flows and water levels in the Henderson Ski Club lake? (Carlo Gaines and Tom Krueger) Carlo Gaines & Tom Krueger of the Henderson Water Ski Club withdrew their objection to the application.