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1 <br />3.0 HYDROLOGY AND MINE DEVELOPMENT <br />Development of the Deserado Mine to commercial production has been somewhat slower than <br />originally anticipated. This slower growth period has allowed Western Fuels to gradually increase <br />activities at the mine. This monitoring period from October 1, 1991 to September 30, 1992 has <br />provided the hydrologic information necessary to assess the adequacy of monitoring program, the <br />adequacy of the mitigative measures designed to protect the hydrology, and identify and quantify <br />' impacts that may have occured during this period. <br />3.1 Mlning Related Hydrologlc Impacts <br />The only impacts identified to date include: <br />' • Withdrawal of water for the mine from the lagoon located in the White River alluvium <br />thus reducing the flow in the White River. <br />• Decline in piezometric level in upper sandstone facies at 2-12U as the result of <br />' subsidence above longwall panel #1. <br />• Decline in piezomeVic levels in monitor holes at the 2-7 location due to very near <br />' (<100') mining. <br />• Decline in piezometric level in 'lower sandstone facies° as the result of leaking <br />exploration holes (drilled in 1978) that were intercepted by mining, and possible effects <br />of longwall mining. <br />t • Subsidence in Red Wash resulting in ponding of surface water. The ponds quickly fill <br />with clay and silt with Red Wash maintaining its original channel. <br />' 3.2 Comparison of Protected Impacts Wlth Observed Impacts <br />' The comparisons of the projected impacts with the observed impacts are discussed in the following. <br />The water withdrawal rate from the lagoon in the White River Alluvium this reporting year (Oct 1, <br />1991 to Sept. 30, 1992) was estimated at 168.6 acre-feet. This compares with an expected <br />' withdrawal rate of 598 acre-feet per year at full production. Clean coal production during this <br />reporting period was 1,311,166 tons compared to projected lull production of 1.3 million tons per <br />year. <br />1 <br />1 <br />15 <br /> <br />