REP52856 - Laserfiche WebLink

Home Browse Search

Ground Water Monitoring Site TR-4, a e 3 of 3 WR-1, level and quality ,West Ridge (base) 4.6-141 1, 30-51, Appendix B, Ground Water Elevations, page 3 of 3; Ground Water Monitoring Site WR-1, a e 3 of 3 slo a stabili round water 215W and L, level, Moffat, NW 4.6-145 1, Appendix D, Moffat Area 218 W and L, level, Moffat, NE 4.6-145 Wells, page 3 of 3 8925 and L, level and quality ,Moffat, SW 4.6-146 Trout Creek Sandstone TCS-1 uali ,annual) , 3` eriod 4.6-148 56, A endix F, Pa e 1 of 1 S rin and See Surve Western edge, West Ridge, May or after snow melt 4.6-145 53, Appendix C, Exhibit 1 ' See Table 4.6-54, page 4.6-144 of the PAP for pazameters and frequency (partial monthly, April through October, complete 3/yeaz). Review of Predicted Probable Hydrologic Consequences No direct disturbance of the quantity of water in Trout or Oak Creeks was anticipated to occur (PAP page 2.5-96). Post-mining contributions to flows in Trout and Oak Creeks from the permit area will be unchanged from that which now exists (PAP page 2.5-98). The quantity of water discharged from the mine site after reclamation was predicted to nearly remain unchanged from pre-mining conditions after reestablishment of hydrologic regimes (PAP 4.6-61 a). Such appeazs to be the case. With regazd to the Trout Creek drainage, spring and seep flows increase with snow melt and then taper off, indicating that backfilled azeas have become spoil aquifers in equilibrium with charge and discharge cycles. As revegetation of reclaimed becomes more and more representative of pre-mining vegetative cover, and as reclaimed surfaces are similar in topography to pre-mining conditions, surface runoff likely approaches pre-mining levels. The difference at this time is that surface runoff is collected and directed to sedimentation ponds, with point dischazges. For most of the site, these point dischazges are representative ofpre-mining drainage discharges, and the ponds have been permitted as permanent features. As the ponds are generally full, inflow is equivalent to discharge. Any infiltration of precipitation over and above pre-mining conditions is likely recovered in the spoil spring discharges. Disturbed areas of the Oak Creek drainage have been reclaimed to the requirements of the reclamation plan, and sedimentation ponds have been removed. There is no post-mining condition that would deplete runoff from these azeas from pre-mining conditions. Flows in Oak Page 5