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. ,. <br />After the spoil aquifer has been fully recharged, a mound of <br />ground water will begin to develop in the spoils. Eventually <br />the spoil aquifer will begin to discharge water to the bedrock <br />aquifers, stream alluvium, and ultimately to Stollsteimer Creek. <br />The rate of spoil water discharge will be a function of the <br />recharge rate (infiltration and deep percolation rates) of the <br />reclaimed spoils. The estimated recharge rate for the 13 acres <br />of reclaimed spoils over the East Pit spoil aquifer is 1 gallon <br />per minute (gpm). Therefore, the rate of discharge from the <br />spoil aquifer will be less than 1 gpm for the East Pit. A <br />calculation of the discharge rate for the spoils aquifer <br />developed in the Barren Ridge Area has also been estimated to <br />be less than 1 gpm. Given a mean value for spoil water quality <br />of approximately 5,000 mg/1 for TDS (data from other surface <br />mines in the state), a mean value for alluvial water quality of <br />approximately 650 mg/1 for TDS, an estimated flow rate within <br />the alluvial aquifer of 55,555 gpm across the alluvial valley <br />floor, and a flow rate from the two spoils aquifer of 2 gpm, <br />the total degradation which would result from the two spoil <br />aquifers will be 0.03 percent or an increase of 0.18 mg/1 TDS. <br />These estimates are based on average or linear flow situations, <br />whereas under actual field conditions, the increased TDS levels <br />would be concentrated in the area of the greatest amount of <br />spoil material. However, it is believed that the <br />above-projected estimates are close to the potential actual <br />field conditions and, with the projected increases in TDS <br />levels as low as those given here, the potential impacts would <br />be negligible. These projected TDS levels are similar to those <br />derived from a study done on the Barren Ridge Area by Piteau <br />Associates. This study concluded that both the water quality <br />and water quantity in Stollsteimer Creek would be impacted by <br />less than one percent (Piteau Report, September 15, 1983, <br />Exhibit 38, Federal Lease permit revision application). <br />The above information is sufficient to show that potential <br />changes to water quantity or quality will be negligible and, <br />thus, there will be no material damage on site or off site to <br />the water recharging the AVE. <br />X. Operations on Prime Farmland <br />A. The Division has made a negative determination for the presence of <br />prime farmlands within the approved permit areas. The decision was <br />based on the fact that there are no prime farmland mapping units <br />(see Exhibit 19, Volume IV, of the approved permit application), <br />and the land has not been historically used as cropland. <br />Contact with Mr. Hancynn of the U.S. Soil Conservation Service in <br />Pagosa Springs by Mariah Associates, Inc. also verified that no <br />prime farmland exists on the Revision No. 1 area (page 5, Soils <br />Baseline Report by Mariah Associates, August 1983). The existing <br />and proposed operations are in compliance with this section. <br />6873E <br />_lg_ <br />