Laserfiche WebLink
Technical Revtston No. 80 <br />August 19, 1998 <br />SeeaaEe of Mine W ater to Off-Site Areas <br />Page 3 <br />12. The Division reiterates its correern regarding discharge of water to the NW Panels sealed <br />sump and its potential for adverse impacts to off-site locations. Anew discharge of mine <br />water is now occurring at the Bear Mine, and [his discharge corresponds with hydrologic <br />projections previously provided by MCC regarding the possibility for such discharges. <br />Please refer to MCC's letter to the Division dated July 24, 1998, which provides <br />information and documentation to refute the allegations ofNOV CV-97-022. <br />13. The Division continues to be concer~red that the practice of lumping mine inflow water to <br />the NW Panels sealed sump may create adverse impacts to off-site areas. The it formation <br />presented in MCC's September 22, 1997 letter, and the information presented irr J. E. <br />Stover ce Associates letter dated October 10, 1997 appear to be contradictory. The <br />Division recommends that all parties meet !o resolve these significant issuer. <br />See response to #12, above. <br />14. The Division commends MCC on its :rse of aquifer test data to calculate hydraulic <br />conductivity values for the B-Seam as opposed to a conceptual-level analysis as was <br />previously presented in the original TR-80 submittal. Please calculate and provide <br />seepage velocities based on the calculated hydraulic conductivity values presented orr page <br />1! and Table 2 of your September 22, /997 response letter. Specifically, provide an <br />estimate of [ravel time for groundwater flow through the unmirred coal block between the <br />NW Panels sealed sump and Bear Mirre B-seam workings. Also if feasible, consider the <br />effects of secondary porosity. <br />MCC acknowledges the exts[ence oja fault at the western extent of Third West Panel of the <br />Bear Mine. Please consider the effects of secondary porosity and provide [he Divisiar with <br />any available information of the effects that [his may have on groundwater flow and on <br />communication between the West Elk Mine workings and the Bear Mine workings. <br />To reiterate from numerous previous responses, since the slug tests account for the in-situ <br />characteristics of the geologic formation, primary and secondary porosity should both be <br />accounted for in the permeability values. In the absence of large faults or fractures, the <br />permeability values derived from the slug tests are the most appropriate values. MCC's <br />Geologist inspected both the West Elk Mine and the Bear No. 3 Mine and did not note <br />significant faults or fractures in the unmined coal block between the mines. The possible <br />exception being the fault encountered in the Bear No. 3 Mine at the western end of the <br />Third West Panel. However, this fault was not detected in the West Elk Mine where it <br />would have projected through longwall panel 7NW. Beaz reported no measurable inflows <br />from this known area of secondary porosity, but halted the expansion of Third West into a <br />small coal lease area located to the west of the fault, reportedly due to poor mining <br />conditions, including water (per D. Bear to MCC staff). <br />