2009-06-12_ENFORCEMENT - M1977211 (2)

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before the Board at the April, 2009 Board meeting. The Operator requested that the hearing be moved to the May 13, 2009 Board meeting. 11. The site is located in a geologically structurally complex zone where five faults are mapped near, and within, the mine boundary. The site geology consists primarily of Manitou limestone, with Saguache sandstone underlying, and Pikes Peak granite forming the base. Complex faulting resulted in the strata being uplifted and tilted at a steep angle. At the west boundary of the quarry the strata dips east at about 70 to 80 degrees. Erosion over many millennia has exposed the Manitou Limestone outcrop, which is the aggregate being mined. The CGS issued a report ("CGS Report") by Jon White, and TC Wait, on January 7, 2009, drafted at the Division's request and after CGS engineering geologists visited the site and reviewed the 1994 Mine Permit document, a 1986 slope stability evaluation by MSHA ("1986 Slope Stability Memo"), and a 2001 Decision Notice by the National Forest Service that permitted the removal of granite on forest lands above the quarry wall. The CGS Report states "[b]rittle deformation features are abundant within the Precambrian granite, sandstone, and limestone outcrops in the vicinity of the fault zone (e.g. slickensides, altered zones, fractures, and fault gouge), which indicate additional numerous, small unmapped fault and shear zones within the mine area." The CGS Report on p. 10 concludes that the quarry rockmass is inherently weak "caused by the abundant discontinuities related to the Rampart range fault zone."2 12. On May 8, 2001 the Division approved the Operator's Amendment #2 to permit number M-1977-211. Condition 41 of the approval for Amendment 42 ("the Condition") provided that the Operator would provide a geo-technical report when the underlying granite rock formation was exposed. The Condition states in part "No portion of the quarry high wall will be constructed (mined) to slope angles steeper than the granite east joint dip without prior approval by the Division." The Condition required the Operator to report to the Division "as soon as the granite is exposed, the east joint dip and bench high wall slope angle for each cliff (bench high wall) at approximately the north and central ridge location." The Operator was to report the dip and slope angle "at these two locations for each new bench high wall until the final granite portion of the high wall configuration is completed." 13. The Condition required the report to be prepared and signed by a registered geotechnical engineer or other qualified engineer, and was to include an analysis of the stability of the cliff (bench high wall) as it related to the overall stability of the amendment area quarry high wall. If the expert analysis revealed potential high wall stability problems, then the Operator was to propose a modification to the mining plan to eliminate the instability problem. 14. The Division testified and the Operator did not contest that granite was exposed and the Division did not get a report. The report required by the Condition was not z The causes of the slope failure and the resulting violations are discussed in a separate Board Order for MV-2009- 012. Continental Materials Pike View Quarry, M-1977-211 MV-2009-013 3