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These wells were installed at a depth of 20' (twenty feet) into solid bedrock. The wells were drilled at 2.375" <br />diameter and cased with nominal 2" perforated HDPE plastic pipe to allow for any leakage and/or seepage to be <br />measured and/or collected. The pipe was grouted at the ground surface interface to prevent surface water inclusion. <br />A lockable cap has been installed. There was no groundwater detected at the time of installation. See the figure that <br />follows for an illustrative schematic of this installation: <br />Lockable Ca <br />2" DR-11 HDPE Pip <br />Non-Shrink Gro <br />Gracie Line- I V 2.375' Bore <br />Mineral Topsoils <br />Gravely, <br />UMEW. I <br />nconsolidated Soil 24V <br />Moderately <br />Weatherecl Bedrock °. <br />Weathered Be <br />Bedroc <br />Perforated, 3/16'° Dla„ <br />Spaced 4 Cotunns, III ?? <br />I" Annular Rows <br />Monitoring bell <br />Constructlon <br />The EPA currently is doing extensive monitoring of ground water sources (as stated earlier, The Big Five Tunnel <br />drainage is monitored, collected, and pumped to the Argo Tunnel Treatment Facility located in Idaho Springs). <br />As a part of normal mill operations, mill process water will be continuously monitored. A pH monitor and data <br />recorder will be installed at the tailings pump location within the mill. Should the pH reach a state outside of the <br />7.5-9 range that is necessary to precipitate the heavy metals, alann notification will be activated for the operations <br />personnel. The submittal notes on this Serfilco Model 432 monitor/recorder can be found attached in this Exhibit C. <br />If the pH falls outside of the 7.5-9 range, the operators are instructed to shut down the operation that delivers waste <br />to the impoundment. Once the source of the problem is corrected upstream in the process, waste can then be <br />continued to be discharged to the impoundment. <br />Page 7 of 37