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Reclamation Board for Coal Mining, and at that time the haul an'd' <br />access road embankments and road cuts were not constructed according <br />to the specifications set forth in Rule 4.03. Alternative <br />specifications may be authorized by the Division if the applicant can <br />demonstrate through appropriate geotechnical analysis that the <br />existing road embankments have a minimum safety factor of 1.25, and <br />that the road cuts have.a minimum safety factor of 1.5 or that a <br />lesser safety factor will not result in significant environmental harm <br />or harm to the public health or safety (4.03.1(3>(c)(i) and <br />(3)(d)(ix), and 4.03.2<3)(C)(i) and (3)(d)(ix)>. , <br />The operator has demonstrated that the haul road and access roads are <br />stable and will continue to meet the performance standard. The <br />demonstration was supplied in a report (Phase II - Geotechnical <br />Stability, by Merrick and Company) submitted in response to <br />stipulation No. 14 of the 1981 Orchard Valley Permit, and which.is <br />included with the Permit Application in Volume 6. The Division has <br />approved the alternative roatl specifications based on this <br />demonstration. <br />The property owner has requested that the benched areas remain and be <br />tied to an access road. The operator has committed to removing the <br />asphalt between Steven's Gulch and the crushing and screening level <br />and performing finish grading of the road. <br />In August 1986, the operator submitted a permit revision application <br />to construct new portal facilities in the East Roatcap Creek Valley. <br />This application proposed the construction of a new portal facility <br />and haul road, because the .existing portals at the Orchard Valley Mine <br />had been rendered unuseable by the underground coal mine fire. The <br />applicant proposed to upgrade an existing public access road to serve. <br />as a coal haul road to the proposed portal bench. <br />The geotechnical specifications are found in Volume 6, prepared by <br />Golder Associates, consultant to the operator. This appendix presents <br />the results of geotechnical investigations, stability analyses and <br />detailed engineering design for the portal bench cut and fill and the <br />accompanying haul road. The stability analyses are based upon <br />projected cut slope configurations and material mechanical properties <br />obtained from material sampling and laboratory analyses. <br />Stability analyses were completed for cross sections chosen at road <br />stations believed to represent potentially critical slope stability <br />situations along the proposed upgraded haul road. As a result of this <br />slope stability analysis, the operator amended its original proposed <br />road cut slope configurations to use a Hilfiker wall, or equivalent, <br />retention system. The retention system will be utilized as depicted <br />on Sheet 7 of 10 of the Golder Associates report, entitled "Haul Road <br />(1)," to reduce the unretained cut slope heights to a maximum of 30 <br />feet. The Hilfiker treatment will be applied between road design <br />stations 29+50' and 36+50'. Unretained cut slopes will not exceed a <br />maximum slope gradient of 1.25h:1.Ov (horizontal to vertical) unless <br />an appropriate slope stability monitoring program has been approved by <br />_2q_ <br />