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1 1 1 1 1 investigations. Several proposed ground water and surface water monitoring station locations aze proposed for the site. The surface water and ground water quality sampling program is designed to address future regulatory requirements and to provide baseline water quality data for future water quality compliance activities. Surface water and ground water constituents proposed to be evaluated are listed in Tables lA and 1B and 2A and 2B. Al[ sampling and analysis for water quality will conform to standazd EPA and USGS approved methodologies. Methodology Water monitoring sites will be established upstream or updip and downstream or downdip of the surface mine, the proposed underground mine workings, and any large support facilities, such as the preparation plant or the refuse disposal area(s) as justified by the resource. Small intermittent drainages and aquifers at limited extent may only be monitored downstream or downdip. All impacted drainages will have surface water sites and alluvial wells. There will be at least one set of updip wells and one set of downdip wells for each portal complex except for areas where the aquifers outcrop downdip. Locations of surface monitoring points and well locations are detailed on Figure 1. Surface Water Hydrology The project area is drained by several ephemeral and intermittent streams. Because the majority of the proposed project is an underground operation, the only areas where there may be direct potential impact to the surface water regime would be near the proposed surface facilities. Indirect impacts may result due to subsidence. Since subsidence studies are proposed for the site, a concurrent surface flow monitoring task will be undertaken in the area defined as being potentially impacted by mine subsidence. The surface water sampling and gauging stations have been strategically located so that the surface water quality and the surface water hydrology have been defined before mining has been initiated. Studies will be completed to define the existing physical and hydrologic characteristics of the surface watersheds draining the project area. To adequately characterize baseline surface water hydrologic conditions several specific steps will be followed: Surface drainage definition including stream designatio^ as intermittent, ephemeral, perennial; drainage area delineation; drainage area size; average slope; stream sinuosity. 2. Flow analysis including runoff, peak flow, (2, 10, 25 and 100 year storm), low Flow and flow duration curves. 3. Sedimentation potential, if sediment yield ratios are available, otherwise an erodibiliry analysis based on weighted K factors will be completed. 4. Surface water quality. 5. Surface water rights. 8