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Mr. Steve S. Shuey April 20, 1992 Page 2 The calculated service life projections for the R-0-M coal stockpile haul road are based upon the following assumptions: o Saturated subgrade conditions. o Anticipated traffic load of 35 trucks per day, three days per week, 52 weeks per year; 28 tons per fully loaded truck. ~VC~ does not anticipate a consistent and continuing long-term need to utilize the RAM coal stockpile at the design traffic load rate. The selected traffic design assumptions adequately address the current usage rate which is inflated above normal due to atypical mining conditions currently being encountered underground. COVCC is in the process of driving entries to connect the mine to a thick coal deposit in the western portion of the lease area. Seam thicknesses and coal qualities in this "linking" development are far belay conditions normally encountered at Orchard Valley. For this reason, the mine is seeing a temporary increase in the amount of material being generated as R-0-M coal. As the western development progresses into thicker, higher quality deposits, a dramatic decrease in the amount of RAM coal being generated will be evident. The traffic loading rate utilized in the bearing surface design therefore represents a worst case scenario intended to provide the mine with the flexibility to utilize this stockpile under extremely adverse conditions. The design service life of the road is also based upon the assumption of use exclusively under saturated subgrade conditions. This conservative assumption is intended to ensure the service life of the road is not exceeded before reevaluation of the road to assess remaining service life is completed. Q~VCC will commit to tracking utilization and reevaluating the road prior to the end of the design service life based upon this tracking. This assumption also eliminates the need to interpret whether or not saturated subgrade conditions exist while the road is being utilized. The proposed haul road is an existing structure initially developed in 1975 from fill material salvaged from the construction of the OVII~I benches. The road was subsequently used to access employee parking and equipment storage areas developed on the fill. Upon approval of minor revision 66, the road became, by definition, a haul road. As such, doc-im~estation addressing the design, location, and use of the road is proposed for inclusion in the permit docwnent under this revision. The initial geotechnical assessment of the road provided to the Division was not included as part of the permit doctimient other than by reference. COVCC proposes to incorporate the supplemental study of the road into the permit to fulfill the requirements of Rule 4.03.1.