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Memo to Dave Berry <br />Bowie No. 2 Geotechnical Adequacy Responses <br />page 2 <br />10. BRL added the location of the fault in question to Map No. 7, "Geology". The <br />presence of this fault within the near subcrop, shallower overburden <br />portions of the underground mine plan may have significant implications <br />for the distribution of ground surface subsidence. BRL chose not to <br />address my earlier adequacy comments regarding faulting implications at <br />the Bowie No. 1 Mine. However, the Bowie No. 2 Mine's subsidence <br />discussion, subsidence control plan, and monitoring program will need to <br />be amended to address the implications of this fault. A thorough aerial <br />photographic analysis of the permit and adjacent area might assist in <br />defining the location of potential faults. <br />25. BRL hired Morrison Knudsen (M-K) to address the geotechnical stability of <br />the proposed surface facility area of the Bowie No. 2 Mine. M-K, in turn, <br />subcontracted with Maxim Technologies, Inc. To complete a geotechnical <br />investigation of the site. Separate adequacy comments have been prepared <br />by the Division and forwarded under separate cover to BRL to expedite <br />finalization of this "Preliminary Geotechnical Study". In general the field <br />analysis and data collection was adequate. However, the study focused <br />upon the traditional operation life concern, to the relative exclusion of <br />the reclaimed configuration's geotechnical stability. The long term <br />geotechnical stability of the proposed reclaimed configuration of the <br />surface facilities will have to be thoroughly analyzed. <br />27. BRL states; "Slope stability analysis of the reclaimed slope will be <br />performed based on the in progress M-K geotechnical study and submitted <br />at a later date." The Division's primary responsibility regards the <br />geotechnical stability of the proposed reclaimed configuration. If the <br />Division cannot find that the mine site can be returned to a beneficial use <br />the permit cannot be approved. Therefore, permit issuance cannot occur <br />until BRL demonstrates that the mine site can be acceptably reclaimed. <br />No partial approval will be granted until this critical demonstration has <br />been completed. <br />59. BRL's response to this concern is acceptable. The drain material gradation <br />proposed would provide adequate protection to prevent clogging without <br />the use of a filter fabric. In the event that the proposed gradation cannot <br />