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this specified azea, the Stollsteimer Creek alluvial water is of such small volume that it is not currently used and is unlikely to be used in the future. The Basic Standazds have no water quality standazds for the Limited Use and Quality classification; therefore, the mine is in compliance with the Basic standazds for Ground Water. Protection of Ground Water Recharge Capacity -The area disturbed by mining at Chimney Rock comprises less than 1 % of the length of the outcrop belt on the northeastern margin of the San Juan Basin where ground water is recharged. This disturbed azea is too small to have reduced the regional ground water rechazge below the approximate premising rechazge rate. On a local scale, the disturbed area does not significantly divert ground water flows to surface water flows {via spoil springs), and surface water infiltration has not been impaired. Therefore, the approximate premising ground water recharge rate has been preserved locally. Impacts to Surface Water -The Chimney Rock Mine is on Segment 6 of the Piedra River Sub- basin ofthe San Juan River Basin. The mine's NPDES discharge pemut CO-850034 was temunated on 11/4/97 following reclamation of all sediment control ponds in the mine permit azea. Waters in Stollsteimer Creek recently complied with the instream numeric standazds where the creek passes through the Chimney Rock Mine permit azea, as shown by 2001 and 2002 monitoring data from sites S-1(upstream from mine disturbance), S-2 (at the former mine site), and S-3 (downstream from mine disturbance). The samples were analyzed for 19 pazameters. The results were submitted in the bond release application. The data show no degradation of water quality in Stollsteimer Creek. The Chimney Rock Mine has never been found in violation of loading of Stollsteimer Creek with dissolved solids, NPDES limitations, or instream numeric standazds. Sustained stream flows, and the compliance with NPDES discharge limitations and instream standazds, indicate Kaiser has prevented material damage to the surface water hydrologic balance outside the permit. The rangeland and pastureland post-mining land use in the permit area has not been impaired by changes to the hydrologic balance caused by Kaiser, if any. The changes were the minimum that can be expected from a surface mining operation. Future surface water pollution caused by Kaiser's mining operation, if any, should not significantly exceed the current level because the future discharge rate of spoil leachate into the Stollsteimer Creek alluvium will be a small percentage of the creek's flow, thus allowing adequate dilution. Page 12 of the PHC in the mining permit application predicts that at Stollsteimer Creek's historical low-flow of 1.78 cfs, the predicted 25 gpm of leachate dischazge into the creek would increase the creek's TDS by 14 mg/1, from 557 mg/1 to 571 mg/1. The increase would be a small fraction of 14 mg/1 during imgation season when streamflow typically is an order of magnitude lazger than during low-flow. Impacts to Alluvial Valley Floors (AVFs) -Lands in the Stollsteimer Creek AVF received fmal bond release in SL-4. Sustained stream flows in Stollsteimer Creek since Kaiser's operations began indicate Kaiser has not depleted the supply of water to the AVF. Although post-mining electroconductivity values of surface and alluvial waters in Stollsteimer Creek exceed the material damage suspect levels for alluvial valley floors, the post-mining values do not exceed the baseline values (see following table). 13