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As described in the hydrologic section, the sandstone which underlies most of the spoil <br />has no identifiable permeability. Consequently, no water will flow into the sandstone <br />from the spoil or into the spoil from the sandstone. There is no groundwater in the base <br />of the spoil as discussed in previous material and demonstrated by drilling data. <br />Surficial waters and infiltrate that exist along the drainage will be discharged via the <br />underdrain. Since construction of the underdrain, mine personnel have observed that the <br />underdrain is functioning as designed. Small flows have been observed in wet and spring <br />runoff periods. <br />Permanently Reclaimed Spoil Area <br />The permanently reclaimed spoil area is approximately 8.56acres. The location of this <br />area is shown on Map 5-10. As described earlier, this area consists of box cut spoil, <br />blasted sandstone, and overburden material (primarily alluvial terrace sands and gravels) <br />excavated to access the North Pit and the SouthPit prior to achieving the steady-state pit. <br />As the spoil filled a segment of the original Carbon Junction Canyon drainage channel, <br />CDRMSrequired OEI to design and construct the spoil area as if it was an engineered <br />fill, meeting all the requisite performance standards. The final configuration of the <br />permanently reclaimed spoil area blends into the adjacent slopes of the permit area and <br />provides complimentary topography for the adjacent golf course. Slopes are 3:1 (h:v) or <br />less and drain toward Carbon Junction Canyon. Spoil placement was in four foot lifts <br />which were compacted to specified tolerances. Attainment of adequate compaction and <br />the grade and slopes involved will ensure that saturation and slope failure will not occur <br />(See Stability Study, Appendix 5-6). A designed underdrain was placed prior to spoil <br />deposition(Appendix 5-2). <br />One ephemeral seep has been located southeast of the Permanently Reclaimed Spoils <br />Area and northwest of the South Pit, adjacent to the pit access road. Inspection of the <br />seep in October 1997 revealed that the seep issues from a sandstone layer below the level <br />of the South Pit and above the level of the Permanently Reclaimed Spoils Area. Flow <br />from this seep enters the road drainage ditch and renters the ground approximately 250 <br />feet below the seep. Native hydrophytic vegetation has grown around the seep and ditch <br />and mitigates any acidic content of the seep prior to reentry into the ground. <br />Explosives and Blasting <br />There are no explosives used or stored on-site. As the mine is permanently reclaimed, <br />there is no anticipated need for explosives at the site. Should such a need arise, OEI will <br />revise and update the blasting informationprior to any use of explosives. <br />Abridged Permit Document 5-5Permit Renewal RN04 4/2014 <br />