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6.4.7 Exhibit G -Water Information <br />Past drilling and logging of holes on this property by others reveal that the top of <br />the alluvial groundwater occurs at an average of 6-7 ft below natural ground <br />surface. Shale, at an average depth of 16 feet on this site, defines the bottom of <br />the alluvial aquifer. The mining operation is to be a dry operation, meaning that <br />dewatering trenches will be constructed at the toes of the pit slopes to prevent <br />accumulation of groundwater in the pit excavations. Water will flow through the <br />dewatering trenches to sumps located at the lowest point of the trench, where <br />pumps are to be set. The predicted maximum dewatering rate is 300 gallons per <br />minute. Mine dewatering water from cells within 100 feet of Boulder Creek, Cells <br />3 and 4, will be pumped from discharge points directly to Boulder Creek. <br />Mine dewatering water from the remaining cells, Cells 1, 2, 5 and 6, will be <br />routed to recharge trenches for infiltration back into the alluvial aquifer. Per the <br />Substitute Water Supply Plan submitted to the State Engineer, the trenches are <br />located at the same distances from the creek as the centroids of the cells, to <br />match in timing and amount the replacement of groundwater pumped from the <br />cells. <br />A complete search of all State Engineer's well records and a thorough search on <br />the ground and with aerial photography have shown that no alluvial wells exist <br />within 600 ft of the limits of mining. There are no nearby wells or significant <br />bodies of water that are expected to be adversely impacted by the operational <br />dewatering. Depletions to Boulder Creek will occur due to water taken with the <br />mined product, usage for dust control (0.1 acre-feet/month), and evaporative <br />loss. Impacts to Boulder Creek are addressed and compensated for by the <br />Substitute Water Supply Plan. Replacement water will come from a fully <br />consumable lease agreement with the City of Louisville or the City of Lafayette <br />via Coal Creek. Please refer to the Substitute Water Supply Plan submitted to <br />the State Engineer's Office for further detail. <br />A hydraulic barrier will be constructed adjacent to the Plumb and Dailey Ditch for <br />the purpose of hydraulically isolating the ditch from dewatering operations. An <br />agreement to mine within 200 ft of the ditch is currently being negotiated. If an <br />agreement cannot be reached, ASCI will provide a geotechnical slope stability <br />analysis and hydraulic analysis. <br />An NPDES permit application for sand and gravel operations is currently in place <br />and will protect Boulder Creek from excess sedimentation. A well permit and <br />Substitute Water Supply Plan approval have been applied for with the State <br />Engineer's Office. <br />Turnpike Mining Resource M-2004-AM-1 <br />Regular 112 application <br />