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chemicals. The process of mining and milling however may create (solubilize) <br />constituents of concern from the mined rock and put these constituents into <br />solution. In order to address this concern several items were accomplished <br />including; 1) designing the milling and subgrade repository features to occur in <br />areas that are physically separated from groundwater contact thereby <br />eliminating the source of possible constituents from contacting groundwater, 2) <br />implementing a sampling regiment to constantly test the subgrade ore materials <br />to determine if any acid- or toxic-forming materials occur. If in the event these <br />materials are located, then operations will cease until these materials are <br />appropriately managed as per the Mineral Rules. Finally, this amendment <br />supplies supporting evidence that the mined materials (ore, waste rock and <br />tailings [subgrade ore]) are not acid-forming and lend few constituents of <br />concern into solution. This supporting evidence is contained within Attachment <br />C.1. The overall results of these three approaches (1- separation of potential <br />source material from groundwater contact, 2 - monitoring of potential source <br />material to keep the process from generating any acid- or toxic-forming <br />materials from being improperly managed, and 3- supporting evidence that <br />indicates the mine materials are inert and not toxic-forming) indicate that the <br />proposed amendment activities will adhere to the 'standards and conditions <br />applicable to unclassified groundwater' as per the mineral rules. Furthermore, <br />as described within this amendment, the potential 'life cycle' of water <br />associated with the Ruby Trust is entirely contained and managed with the <br />underground workings and released at a singular discharge point that is <br />managed by the permitted discharge (CDPS permit). This permitted discharge <br />point represents the applicable 'point of compliance' for the hydrologic balance <br />maintained by the mine. <br />Potential Impacts to Surface water Quality: The potential impacts attributable to the <br />Ruby Trust mining practices to surface water were previously evaluated by the Colorado <br />Department of Public Health and the Environment as part of the issuance of the CDPS <br />permit. It was determined that the mine practices would be held responsible to <br />'control' certain elements and water quality characteristics (sheen, aesthetics, turbidity, <br />release of metals) in order to comply with State of Colorado water rules and regulations. <br />These regulated elements were summarized in Exhibit B (Table B.2). It was also <br />determined that the mine discharge could be controlled to meet State Surface Water <br />Quality standards with the simplest of engineered solutions - with the placement of a <br />sedimentation basin at the point of discharge (synonymous with the 'point of <br />compliance'). The point of compliance for this permit is AT THE PIPE DISCHARGE AT THE <br />PORTAL - meaning any detected/regulated element from the discharge has to be <br />controlled at this point and therefore is NOT released to Sneffels creek directly, <br />otherwise the system is out of compliance. This permit issued by CDPHE identified the <br />7