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-29- The mine plan calls for holding all water in the ponds (up to a 10 year 24 hour precipitation event). Water will be discharged from the ponds within 36 hours. This holding time is designed to allow for the water to settle sufficiently to meet NPDES effluent parameters. During times of snowmelt and heavy rainstorms, the quantity of water in Deep Creek will be somewhat diminished. The quantity of water intercepted by the ponds, however, should be a small percentage of the flow of the creek, since the ratio of disturbance to the entire drainage basin is small. If the ditch and pond system is built as designed, impacts on the quality of Deep Creek water should be minimal during mining. Again, the ditches will divert all surface flow through disturbed land to the ponds, which are designed to hold runoff from 10 year 24 hour precipitation event. Therefore, in a normal year, all overland flow through the disturbed areas of Deep Canyon will be contained in these sediment ponds, where the water will either infiltrate into the underlying alluvial/colluvial materials, be lost to evaporation, or be discharged into the creek after settling. After mining, quantity impacts to Deep Creek should be alleviated with time. The pond and ditch system will be removed from the canyon after effective vegetative cover has been established. After this occurs, pre-mining overland flow amounts should be approximated, however, increased infiltration at the backfilled pits and overburden stockpile should be expected. Deep Creek will probably experience an increase in total dissolved solids after mining due to increased exposure to fractured overburden, however, no other quality effects are expected to impact the surface water system. Deep Creek is a minor tributary of Stollsteimer Creek, and, as such, diminished quantity and quality of flow in Deep Creek should have no significant impact on Stollsteimer Creek. Dilution of Deep Creek water by Stollsteimer Creek below their confluence should neutralize any adverse effects. During periods of low flow, dilution would be expected to be less, but Deep Creek, an ephemeral drainage, should not have flow during those periods. Therefore, cumulative surface water impacts to the Stollsteimer system will be negligible during mining, and shortly after mining should be expected to be insignificant. X. Climatological Information and Air Resources - Rules 2.04.8, 2.05.4(2)(h), 2.05.6(1), and 4.17 Baseline information presented in Section 2.04.8 (Volume I) and an adequate air emissions permit in Exhibit 16R2 of the permit application. The existing and proposed operations are in compliance with the requirements of this section.