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Dustin Czapla <br />Loesch Pit, M-1981-068, Garfield County, CO. <br />Technical Revision - Pit wall liner <br />Page 3 of 7 <br />Oct. 4, 2010 <br />For groundwater conditions during pit operations, the drainage ditch benefits the operation in <br />two ways: it intercepts groundwater that otherwise may have seeped into the pit, and it lowers <br />the water table adjacent to the pit. <br />For post-reclamation conditions, the water level in the drain dictates the maximum water level <br />in the reclaimed ponds under equilibrium conditions, e.g., when inflow into the ponds equals <br />losses from the ponds. The lowest elevation of the ditch is at the north end of the property, <br />where it flows back into the southern branch of the Colorado River (immediately north of <br />Phase IV). <br />For current operations, groundwater seepage has been handled with pumping and with lining <br />of portions of the pit walls. In places where a liner has been installed, it has typically been <br />covered with 8 to 10 feet or more of topsoil (a minimum of a dozer width at the top of the liner) <br />to keep the liner in place (Figure 3). The reclamation plan (1981) calls for final side slopes to <br />be 3H:1 V or flatter. Current practice has been to flatten slopes to typically 4 or 5H:1 V or flatter, <br />as can be seen in Photo 1, below. <br />PHOTO 1 <br />Current pump location in NW comer of operations. Note reclaimed pit walls. <br />wwTee RZWURCE CONSULTANTS, u.c