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Middle Sandstone- wells near mine workings (TR-4, TR-7A, 81-01, 83-01, 83-02). During the yeazs of active mining in Mines 5 and 6, water levels in Middle Sandstone monitoring wells neazest the mine workings fluctuated in response to mine dewatering and subsidence. Between 1995, when mining ceased, and 2001, when the temporary cessation monitoring plan became effective, the water levels in these wells recovered to pre-mining levels. The Middle Sandstone is monitored in well TR-7a as part of the temporary cessation plan. This well showed continued recovery of the Middle Sandstone's pontentiometric surface in 2001 and 2002. Water quality in the Middle Sandstone wells has shown no impact from mining. The changes in the potentiometric surface and the water quality indicate hydrologic impacts in the Middle Sandstone have been minimized within the permit azea. Twentymile Sandstone Water level monitoring data reported through the 2002 annual hydrology report had shown no change in the piezometric levels in the Twentymile Sandstone that could be attributable to mining activities. The water quality data for the two Twentymile Sandstone wells, No. 9 Mine Well and We11259, showed no adverse impact or trend. Williams Fork Alluvium Ground water levels in the alluvium have remained fairly regulaz, with normal seasonal fluctuations apparently related to changes in river levels. Ground water levels in the alluvium are plotted in Figure 22 in Section 2.04.7 of the permit application package. Annual hydrology reports through 2002 indicate no depletion has occurred and suggest that mining appears to not have affected Williams Fork River alluvial water quality. In 2002 Colorado experienced a significant drought. Low water elevation in the Williams Fork River is recorded in the lower water elevation measured in the AVF-5 Well in June 2002 and should not be indicitive of mining impact. Compliance with the Basic Standards for Ground Water (Regulation 41 of the Colorado Water Quality Control Commission) Section 4.05.13(1) of the Regulations requires the establishment of one or more ground water points of compliance (wells) for an operation which has the potential to negatively impact the quality of ground water. The mine monitors the Middle Sandstone in well TR-7a and the Williams Fork alluvium in well AVF-5. The TR- 7a well is within the expected bedrock flowpath of mine leachate, should the mine discharge leachate to bedrock units. The AVF-5 well is within the expected alluvial flowpath of leachate, should the mine discharge leachate to Williams Fork River alluvium. AVF-5 is also within the expected flow path of pumped mine water, should mine water adversely impact the alluvial water. Both wells meet the qualifications of a compliance point, as those qualifications are listed in Section 24