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//~ Kennecott ~ .Energy •Co(owyo CoalConr~aayL.P.. FOR: Steve Hinkemeyer West Pit Fi11 Inspection Certification • July 14, 1999 On June 29, 1999, I inspected the area designated as the West Pit Excess Spoil Fill. The purpose of this inspection was to determine if there were any hazards to the stability of the Excess Spoil Fill. I inspected the Surface Rock Drain bordering the 3:1 slope on the East and North Sides, the 3:1 slope itself ,the vegetative efforts on the fill surface, and the contour ditches which run across the fill. This inspection meets the requirements of CMDG Rule 4.09.1 (lla). During the inspection the surface rock drain seemed stable and no springs or seeps were noted except at the toe of the slope where the designed Under Drain surfaces into the West Pit Pond. The collection ditches at the approximate elevations of 6950 and 7150 were stable and functioning as designed. The re- established 7050 contour ditch was vegetated and functioning as expected. During the Quarter approximately 3,000,000 LCY of material was placed in the excess spoil fill. This material was placed on the 7375, 7425, and 7450 dumps and included approximately 150,000 LCY of reclamation grade backfill on the outslopes. Final grading, topsoiling and seeding is still required to finalize these dumps. During the quarter the West Pit Excess Spoil Fill expansion, as submitted to the CDMG, was used for dump room. This expansion was constructed as designed and took approximately 2,500,000 of the 3,000,000 LCY of fill placed in the West Pit Excess Spoil Fill. As noted above the Under Drain was running approximately 10 gpm, in addition a small seep <3gpm was examined from the designed West Hillside Drain. No other conditions were noted that may present a hazard to the West Pit Excess Spoil Fill. I am a Mining Engineer, registered in the State of Colorado, and am experienced in the construction of rock or earthen fills for the purpose of mining activities. To the best of my knowledge, based on my professional expertise, the West Pit Excess Spoil Fill appears stable and constructed according to pages Ia-2 through Ia-4, Exhibit 19Ib, and other applicable --requirements of Permit C-81-019 as submitted to the Colorado Division of Minerals and Geology. Bri n Keith Briggs Colorado Registered Profession Engineer # 31 • Memorandum Filc. d ~miscl\dm¢\wpins299.wpd