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i ~ ~=~ '~, _3a_ ,~ u ~ -'a ~ Similarly, Empire Energy Corporation will not impact the quality of ground water in the Twentymile sandstone, given the over and underlying separation from the present mine workings in the "F" and °P° seams. The ground water quality of the Middle and first White sandstones have a higher probability of being contaminated by mine water from the Eagle No. 5 and No. 9 Mines, respectively. As discussed previously, there is a demonstrated connection between these aquifers and the underlying mine workings. Monitoring will detect water quality changes that occur. Some mine waters may enter the surface water/alluvial system through discharges from springs, seeps or at outcrops or subcrops of coals and the affected overlying and underlying strata. However, given the primary permeability of the coals and their associated roof and floor strata, the quantities of degraded ground water discharges through these strata are anticipated to be negligible, and would be diluted by the greater quantity of higher quality water in the stream/alluvial systems. There is potential for surface water/alluvial ground water contamination by the Eagle No. 9 Mine given the large alluvial water bearing body overlying the mine. The greatest potential for surface water/alluvial system contamination by mine waters is through springs associated with secondary permeability tones in the coal and overlying strata (ie. fault zones, fracture zones and zones of subsidence). Spring flow rates in these types of zones are generally greater and these zones tend to control flow direction and points of spring discharges. Mine water discharges from both springs and seeps to the stream/alluvial system are predicted by the applicant to be minor given the few springs identified overlying the mine. The Division has required additional spring flow, water level and ground water quality monitoring to assess the impacts to the Eagle No. 9 Mine, and to verify the applicants predictions. In contrast, the Eagle No. 5 Mine is overlain by stream/alluvial system of the Williams Fork and Yampa Rivers which are smaller than the Big Bottom/Yampa River stream/alluvial system affected by the Eagle No. 9 Mine. The stream/alluvial system overlying the Eagle No. 5 Mine has already been undermined and is not as important to agriculture as the Big Bottom stream/alluvial system overlying the Eagle No. 9 Mine. The contribution of the Eagle No. 5 Mine waters through affected strata to the Williams fork and Yampa Rivers will be minor after the closure of the mine. Surface Water The applicant has provided a discussion of the probable hydrologic consequences of the proposed operation to the surface water hydrologic system. This discussion focuses upon two primary effects of mining that would occur during the mining operations: 1) Depletion of flow in stream/alluvial systems located above or adjacent to the underground workings; and 2) Discharge of water from the underground workings to Surface water systems.