2013-02-01_REPORT - C1981018 (2)

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The only impacts identified to date include: 3.0 HYDROLOGY AND MINE DEVELOPMENT This monitoring period from October 1, 2011 to September 30, 2012 provided the hydrologic information necessary to assess the adequacy of monitoring program, the adequacy of the mitigating measures designed to protect the hydrology, and identify and quantify impacts that may have occurred during this period. 3.1 Mining Related Hydrologic Impacts • Withdrawal of water for the mine from the lagoon adjacent to the White River thus slightly reducing the flow in the White River. BME has legal right to this water. Discharge of storm water from pond DP -1 into Scullion Gulch, a White River tributary. Discharges contained lower TSS than typical receiving stream flows during storm events. • Decline in piezometric level in wells in close proximity to mine workings. Holes that were mined through have turned dry. • Subsidence in Red Wash resulting in ponding of surface water. The ponds quickly fill with clay and silt with Red Wash maintaining its original channel. • Subsidence in Scullion Gulch resulted in no surface hydrologic consequences observed to date. Not enough precipitation has occurred to truly test the system. Runoff was rarely observed in the impacted sections of Scullion Gulch prior to mining. 3.2 Comparison of Projected Impacts with Observed Impacts The comparisons of the projected impacts (probable hydrologic consequences) with the observed impacts are discussed in the following. The water withdrawal rate from the lagoon at the White River this reporting year was estimated at 119,281,000 gallons or 366 acre -feet. This compares with a projected withdrawal rate of 552 acre -feet per year at full production. The decline in piezometric levels in bedrock zones "upper sandstone facies ", "siltstone /coal facies ", and "lower sandstone facies" was anticipated as probable impacts as the result of 14