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impacts to water in bedrock aquifers for the following three reasons: 1) there was no disturbance of bedrock in the bond release area (previously disturbed colluvial materials were used to construct the pad and elevated portions of the access road); 2) the azea was used for office, bathhouse, electric substation, coal transfer and loadout, and railroad track support facilities. As coal materials were contained in structures until train loadout, leachates or contaminated discharges were minimized (no dischazge permit exceedences were experienced in surface runoff discharges), and 3) the bond release area is not within a significant rechazge zone of bedrock aquifers. There may have been some peculation of precipitation through the relatively porous gravel-surfaced pad and roadways, but the lack of contaminants indicate little adverse impact to adjacent valley colluvial or Oak Creek alluvial deposits. All of these conditions (geologic setting, lack of contaminants, etc.) indicate the permittee minimized hydrologic impacts within the bond release area, and has prevented material damage to ground water outside the permit area, down- gradient from the bond release area. Aquifer recharge has not been diminished (infiltration of meteoric waters into the ground surface has not been reduced), and the permittee has not caused adverse impacts to ground water that impair the postmining land use. The improbability of adverse impacts to ground water indicates the operation is in compliance with the Basic Standazds for Ground Water (Colorado Water Quality Control Regulation 41.S.C.6). Findings with regard to Surface Water Impacts: The only surface water feature in the bond release area is Oak Creek, a perennial stream. Oak Creek, with the exception of a culvert crossing, was not disturbed by P & M's operations. Surface runoff collection ditches routed runoff from the pad and roadway to former sedimentation ponds a short distance north of the bond release area. P & M has conducted long-term monitoring at a flume at the outlet of the Tipple Pond farthest downstream (CDPS outfall 001). The ponds held water only a few weeks each yeaz following springtime snow melt and large rain storms. There were no exceedences of dischazge limitations at outfa11001 for at least 5 years. These discharge limitations were based on which chemical constituents were likely to be present in discharge effluent, and did not include all of the constituents for which there are instream standards in Oak Creek. It is unlikely, however, that the influent would have contained these other constituents in significant amounts during operations, and there is no potential for them now that operations have ceased and all coal-handling facilities have been removed. It is reasonable to conclude that operations in the bond release area aze in compliance with the instream standards. The ponds were determined to be no longer required on August 20, 2003. Findings with regard to Impacts to Alluvial Valley Floors (AVFs): Oak Creek does not meet the regulatory definition of an AVF within the permit area. Oak Creek has, however, been designated an AVF immediately north of the permit area, approximately one mile downstream from the bond release area. Mining operations at the Edna Mine did not disturb the alluvium of the Oak Creek AVF. The previously described absence of adverse hydrologic impacts to Oak Creek surface water and alluvium indicate the essential hydrologic functions have been preserved by maintaining the geologic, hydrologic, and biologic characteristics that support those functions. 9