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33 <br />of the Purgatoire low flow is generally from mid- August through mid - April. Peak <br />flows occur from mid -April through July. Gravels removed from the riverbed will be <br />used as road base, riprap or bedding for underground rails. Excavation of gravels will <br />naturally alter the streambed. Every effort will be made to minimize disturbance. <br />The operator will either use rubber -tired or crawler loading equipment to remove <br />gravels from the upstream portion of the culverts. The amount of time for <br />maintenance activities will be dependent on the amount of gravel deposited. The <br />operator estimates 1 to 2 days will be necessary to facilitate cleaning. The volume of <br />gravel will be dependent upon the amount of deposition. <br />Normally, the operator will not stockpile the gravels removed from culvert <br />maintenance. They will be used for road base or ballast. If necessary, potential <br />stockpile areas at the New Elk will be located just east of the culverts being cleaned <br />and to the north of the scrap yard outside of the buffer zone to the river. The action <br />of cleaning the culverts is a mitigative action to comply with the surface mining rules <br />and regulations. <br />During 1981 and 1982 a new ventilation shaft was designed, permitted and <br />constructed in Apache Canyon (see Map 3, Mine Plan). A description of the facility <br />is presented in Exhibit 25, Apache Canyon Ventilation Shaft. All appropriate rules <br />and regulations concerning operation, maintenance and reclamation have been <br />included under this permit term. <br />During 2006 plans were submitted to MSHA for approval to re -enter the New Elk <br />underground mine to evaluate the feasibility of reopening the operation. As <br />determined by measuring water levels in the East Portal airshaft, the mine has <br />flooded to an elevation of 7220 feet. Prior to re -entry, a temporary vertical turbine <br />pumping system will be installed in the east portal airshaft to dewater the mine to an <br />elevation of 7180 feet (the elevation of the bottom of the airshaft and slope entries) <br />allowing entry into and exploration of the mine. Initial pumping capacity is planned <br />at 4,000 gpm. Location of the pumping system is shown on Map 11- Surface <br />Facilities and Roads East Portal. At this rate dewatering may take from 6 -9 months <br />dependent on actual quantities of water encountered. After dewatering to 7162 foot <br />elevation, pumping will continue to occur from pumps located underground and the <br />temporary system will be removed. <br />Prior to mine closure, mine water quality allowed discharge directly into the <br />Purgatoire River with no treatment. Since closure, mine water samples have been <br />periodically extracted from the East Portal airshaft and a borehole into the mine <br />workings (NEW -2 and NEW -4 of the hydrologic monitoring plan). Sample results <br />collected at these sites indicate that direct discharge can be resumed in compliance <br />with NPDES permit limitations. Additional samples will be collected at the pump <br />head and analyzed for the parameters listed in the NPDES permit renewal <br />application, page 10 items 26 and 28 (Exhibit 22 of the New Elk permit). No <br />discharge to the Purgatoire River will occur until confirmation of satisfactory test <br />results. <br />Section 2.05 TR -68 12/10/2014 <br />