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JRN-10-1997 11 37 `J~RR COMPRNIES INC. • 66~ 6743 P.02 <br />Marra Companies, Inc. <br />i 2180 South 88th Street. Bloomfield. CO 80020 (303)6666657 Fu Number <br />Friday 10 January 1997 <br />Christina Kamnikar <br />Colorado Division of Minerals 8~ Geology <br />1313 Sherman Street, #215 <br />Denver, Colorado 80203 <br />Delivered this date to FAX #[303] 832-8106 [DMG] <br />Dear Christina: <br />As we discussed on the 3rd, attached is across-section diagram of t e area of <br />excavation that must occur on the southern portion of the Dakolios it before <br />concurrent grading can commence. The area is necessary to allow eq ipment to <br />manuver to perform grading on the initial pit wall which runs 1100.Ot eet along <br />the southern boundary [refer to the 1996 aerial photograph]. The a erage pit <br />floor depth is expected to be 15.0± feet [since the floor raises as xcavation <br />progesses to the north. <br />Extraction will occur with scrapers advancing ahead of the pit floor app oximately <br />250.0± feet, resulting in an effective slope of 6h:1v. As extraction ad antes to <br />the north the resulting pit floor will eventulally extend 250.Ot feet from the <br />southern wall. As represented in the Diagram #2, this is the maximu extent of <br />pit walls at which time concurrent cut and fill grading can and will oc r. Upon <br />grading of the southern wall, grading of the east and west pit walls ill occur <br />concurrently at 100 feet intervals per 100 foot advances in extraction n rthward. <br />Groundwater depth is expected to occur at 5.0± feet from the surfs ,for an <br />effective depth of 10.0± feet. As indicated in Diagram #1, this will res It in 4.73 <br />million cubic feet of water. At 7.48 gallons per cubic foot, the total olume of <br />water necessary to be dewatered is 25 percent of that volume (refer to age 3 of <br />determinations made by Allen Sorenson for M82-015 Siegrist Pit (aka Del <br />Camino Pit) on 7/31/95]. <br />Utilizing Mr. Sorenson's estimate of dewatering at $230.00 per millio gallons, <br />the value for this operation is $ 2.034.37. Cost for cut and fill rading of <br />18,437.5 cu. yds. of material at $0.40lcu.yd. _ $ 7.375.00. Total a timate to <br />establish concurrent grading is $ 9,409.37 in a i " n to you total of <br />$89,550.00. <br />Next, I utilized rental rates verified by an appraisal by Uniwest Eqt <br />[see attached correspondence from Rick Sekich of 9 January 1997]. <br />Co. <br />are <br />