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CDPHE-designated engineered control suitable for the mine would be a sedimentation <br />basin in order to abate total dissolved and total suspended solids which can be created <br />as a result of active mining. The metals constituents are regulated but have been found <br />to not be affected by active mining practices, therefore there is no 'metal treatment <br />component' to the permitted discharge. If the metals were found to be affected by the <br />mining practice then appropriate treatment and controls would have been prescribed <br />by the permit. The regulations require that the mine not exceed state standards for the <br />protection of surface water, and to monitor their point source discharge effluent on a <br />quarterly basis for the perpetuity of their CDPS permit life cycle. Results of the permit <br />discharge have never been out of compliance (the exception being timely paperwork <br />filing requirements). The status of the permit, the mine site compliance and public <br />water quality records is available via the EPA Water Discharge Permit system database <br />(EPA, 2009). <br />Compliance with the CDPS permit and the site-stormwater permit (COR-04025) assures <br />compliance with the mine site retaining a water quality 'balance' with the hydrologic <br />setting as a whole. The underground mine disturbances would be captured by the point <br />source discharge. The mine has to actively pump water from its lower workings in order <br />to continue mining. This water is a direct reflection of all possible disturbances created <br />as a result of mining. The discharge is monitored on a routine basis as described by <br />State of Colorado regulation. As per the CDPHE CDPS permit conditions, there will not <br />be any disturbance to the hydrologic setting. The surface mine disturbances are held in <br />check with the stormwater permit. The permit contains a stormwater plan - approved <br />by CDPHE which outlines the surface management practices put in place at the mine to <br />control all surface nonpoint sources of pollution including sediment and any chemical <br />spills. The spills are held in check by the spill prevention plan which is part of the <br />stormwater plant. The combination of these two permits (the CDPS and Stormwater) <br />effectively holds the mine in compliance to control all water quality disturbances. <br />j) Compliance with applicable water laws = The proposed milling activities described within this <br />amendment are nonconsumptive. Water used by the mill will be obtained from mine-sources <br />underground and will be re-circulated back into the system. Water decanted from the subgrade <br />ore repository will be routed back into the ball mill. <br />k) Description of how encountered acid or toxic producing materials will be handled and disposed <br />of = the deposition of 'surface' materials was already provided within the Technical Revision <br />No. 1 documentation (Castle, H., 1999) and approved by DRMS (DMG, 1999) however in order <br />to address concerns surrounding the proposed underground subgrade repository, the Mount <br />Sneffels Mining Company has adopted a conservative approach to manage the milled materials <br />(refer to Section 2. 'Tailings and Milling Plan' within this Exhibit for a complete discussion). In <br />summary, management of encountered acid or toxic producing materials will be addressed in a <br />8