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• the RDA had been filled approximately to elevation 7600. Three benches had been <br />constructed; the slope between the benches is 2.2 or 2.3 to 1 (H:V). Reno drainage <br />blankets (rock filled wire baskets) have been constructed along both sides of the <br />RDA to control surface drainage. The topography of the existing RDA is shown on <br />Fig. 1 based upon survey information provided by Basin Resources. <br />Our review of portions of the permit documents indicates the RDA was <br />planned with a maximum 2:1 (H:V) slope face with minimum 20 foot wide benches at <br />50-foot vertical intervals. Avery wide bench was planned about elevation 7850. We <br />believe this bench was included to follow existing topography rather than for stability <br />considerations. A sedimentation pond was constructed at the base of the RDA. An <br />internal drain was recommended at the centerline of the valley, splitting into two <br />drains to follow the two drainages which exist below the RDA. The planned top <br />• elevation of the RDA was about 7900. <br />Our understanding of the initial construction procedures is based primarily on <br />discussions with Mr. Joseph Febbraro of Febbraro Construction Company who <br />performed the initial sedimentation pond construction, stripping, drain construction <br />and coal refuse placement and compaction. We reviewed several photographs which <br />show initial drain construction and fill placement provided by Basin Resources; two <br />of the photographs are shown on Fig. 4. We also discussed the initial procedures <br />wkh Mr. Tom Augustine who was the mine operation manager for the previous <br />owners (CF&I and Wyoming Fuels). Our discussions with Mr. Augustine generally <br />confirmed the information from Mr. Febbraro. Following is our understanding of <br />initial construction procedures based upon these discussions. <br /> <br />6 <br />