Laserfiche WebLink
Technical Revision No. 80 <br />Angus[ 19, 1998 <br />Page 5 <br />to relation to the annual variability irr soil moisture related to d~ererrces in precipi[ation <br />/infiltration. U~ fortunately, no quantitative soil water moisture or related slope stability <br />monitoring data exists with which to objectively verify WWE's conceptual evaluation. <br />A landslide has now developed at the Bear Mine, and appears to be associated with a new <br />water discharge. This discharge location is consistent with hydrologic projections <br />provided with this revision application. The landslide and discharge may be a result of <br />water storage in the West Elk Mine NW Panels. Provide a detailed analysis regarding the <br />earrse of the landslide. <br />The analysis completed by WWE was an objective, quantitative evaluation of the probable <br />hydrologic consequences of detaining water in the NW Panels sealed sump. WWE's <br />analysis was based on sound scientific principles and actual data collected by MCC at the <br />West Elk Mine. WWE clearly stated their assumptions, and used high and low ranges for <br />the relevant parameters. The analytical methods were reviewed with the Division in <br />advance. Messrs. Rold and Dunrud, renowned experts in geology and geohydrology, have <br />also reviewed the PHC and concur with WWE's analyses. <br />MCC has accumulated a great deal of soil moisture and slope stability data from its own <br />mine site located in relative close proximity to the east of the Bear Mine site and have <br />applied these data to the analysis of the Bear Mine slope stability situation. The Bear Coal <br />Company has apparently done no mine site slope stability monitoring, had poor in-mine <br />geologic conditions documentation, and did very little monitoring or sampling of mine <br />inflows or surface flows on the mine site. The Bear Mine has little, if any, site specific data <br />on which to base allegations presented in previous correspondence from Mr. Stover on <br />behalf of Bear Coal Company. MCC, WWE, and Mayo have utilized all known available <br />data to complete the analyses for the PHC. <br />Detailed analyses regarding the cause of the landslide at the Bear No. 3 Mine and the <br />Edwards Portal spring were previously provided to the Division in response to NOV CV- <br />97-022. Please refer to MCC's July 24, 1998, letter and information packet. <br />Box Canvon Probable Hvdroloeic Consequences <br />No remaining issues in this section. <br />Cumulative Hvdroloeic Impact Analysis and other Surface Water Oualiri Issues <br />42. Additional information is requested regarding the discharge scenarios from the West E!k <br />Mine, to the North Fork of the Gunnison River. This information will be used to define the <br />maximum discharge allowable from the West Elk Mine, relative to river flow scenarios and <br />to develop a current Cumulative Hydrologic Impact Study (CH/S) for the North Fork of the <br />Gunrrtson River. The main emphasis of the CHIS is err analysis of salinity, expressed as <br />Tote/ Dissolved Solids (TDS) relative to downstream uses such as irrigation. The CHIS <br />