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CashMineWaterMonitoring AdrianBrown <br />2.5 Surface Water <br />2.5.1 Occurrence <br />Surface water is limited at the site. The site drains steeply from the ridge crest to Gold Run to the south. <br />Cash Gulch runs immediately to the west of the mine and mine portals, while a small unnamed gulch <br />runs immediately to the east. All hillside drainages, and Gold Run, are generally dry, with flow only <br />occurring in limited reaches during or immediately after precipitation or snowmelt events. <br />2.5.2 Quality <br />Surface water quality at the site is not frequently sampled, due to the ephemeral nature of flow in the <br />streams. Two samples of ponded water were taken after runoff events in Cash Gulch, with the results <br />presented in Table 1. The quality is similaz to that chazacteristic of water from mineralized orebodies in <br />the district (based on quality of water observed in mine voids and portals). <br />2.6 Groundwater <br />2.6.1 Occurrence <br />Groundwater in the vicinity of the mine exists in a low permeability/low yield system typical of the <br />granitic rocks of the Front Range. Yield of wells completed in the bedrock in the area is small; typically <br />a few gallons per minute at most. The inflow to the Cash Mine, developed to 668 feet below ground <br />surface, is generally less than 2 gpm. <br />The groundwater table is shallow (approximately 50 feet below ground surface), due to the infiltration <br />equaling or exceeding the flow capacity of the bedrock system. The groundwater table is a muted <br />reflection of the ground surface, and intersects the ground surface in the deeper gulches and creeks. <br />Groundwater enters the system from infiltration of precipitation, estimated at 2" per year (10% of <br />precipitation). The piezometric surface in the bedrock in the vicinity of the mine has been estimated <br />from well water levels, mine water levels, mine inflow, and computed infiltration and is presented in <br />Plate 3. A section through the mine showing the results of modeling the current groundwater table and <br />subsurface flow regime is also included in Plate 8. <br />2.6.2 Quality <br />The quality of groundwater in the vicinity of the Cash Mine is variable. The general quality of <br />groundwater in the country rock is good, as reflected in the water quality samples taken from wells <br />upgradient of the mine. Average quality of the water taken from the deepest of the wells (MW-1) is <br />presented in Table 1. <br />Ambient groundwater quality in mineralized veins and fissures in the mining district is of substantially <br />lower quality, generally containing concentrations of sulfate and some metals, notably iron, manganese, <br />and zinc that are elevated above the country rock water. This is the water that is present in the orebody <br />veins, and is therefore typical of the quality of water that flows into the mines. An example of this water <br />quality is also provided in Table 1. <br />1601A-20061106 2 <br />