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3.0 HYDROLOGY AND MINE DEVELOPMENT <br />This monitoring period from October 1, 2001 to September 30, 2002 has provided the <br />hydrologic information necessary to assess the adequacy of monitoring program, the adequacy <br />of the mitigative measures designed to protect the hydrology, and identify and quantify impacts <br />that may have occurred during this period. <br />3.1 Mining Related Hydrologic Impacts <br />The only impacts identified to date include: <br />• Withdrawal of water for the mine from the lagoon adjacent to the White River thus slightly <br />reducing the flow in the White River. BME has legal right to this water. <br />• Discharge of storm water from ponds SS-1, RP2/3 and RP4 into Red Wash and DP-1 into <br />Scullion Gulch, White River tributaries. Discharges contained lower TSS than typical <br />receiving stream flows during storm events. <br />• Decline in piezometric level in wells in close proximity to mine workings. Holes that were <br />mined through typically turned dry. <br />• Subsidence in Red Wash resulting in ponding of surface water. The ponds quickly fill with <br />Gay and silt with Red Wash maintaining its original channel. <br />• Subsidence in Scullion Gulch with no surface hydrologic consequences observed to date. <br />Not enough precipitation has occurred to truly test the system. Runoff was rarely observed <br />in the impacted sections of Scullion Gulch prior to mining. <br />3.2 Comparison of Projected Impacts with Observed Impacts <br />The comparisons of the projected impacts (probable hydrologic consequences) with the <br />observed impacts are discussed in the following. <br />The water withdrawal rate from the lagoon at the White River this reporting year was estimated <br />at 158,503,473 gallons or 486 acre-feet. This compares with an expected withdrawal rate of <br />552 acre-feet per year at full production. <br />The deGine in piezometric levels in bedrock zones "upper sandstone fades", "siltstone/coal <br />fades", and "lower sandstone fades" was anticipated as probable impacts as the result of <br />13 <br />