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foundations are broken and buried in place, they will require at least two feet of depth of replaced material on top, 6 to 8 inches of ~vhiclt must be soil, and the remainder to be waste rock. Some of such rock spreading could cover available soils. An alternative to burying the foundations in place, especially given the volume of other debris to be disposed of, will be to doze out a disposal pit onsite, then place broken concrete and other debris in i[, and then cover it with rock and soil. The disposal pit is most efficient if centrally located behveen buildings, and adequate if sized at about 100 feet square by 10 feet deep. It may accept metal, wood and concrete, all being inert materials. This is cheaper by far than hauling all metal and wood from superstructures to a distant disposal site. A few items must be removed from the site, such as waste oil (estimated 1 l0 gallons) and non-PCB transformers. The excess excavated material front the pit may be used to backfill the shafts, then the pit site may be graded level again, topsoiled and seeded. It is this method I estimated costs for, as you will see in the enclosed packet. Shaft closure will consist of backfilling waste rock. Vent shafts will require truck and loader work to bring sufficient material front the waste pad, but all debris from the shaft sites may be back£Iled a[ each respective site. It was not clear if your recent letter meant to state that closure itself would be by blasting the concrete collar at a depth of 50 feet, or if that would only be to dispose of the collar at that depth after backfilling up to that point. I discourage closure by dumping only blasted concrete down the hole, due to the possibility of material bridging, which maybe reasonably shown to be unstable and produce voids and settling. At present, my estimate includes complete backfilling (as your earlier application materials specified), and since I regard such method as adequate, 1 will approve such method. If you want to use a different method, please provide details of such. There is no credit given for salvage value of certain equipment or structures onsite, though earlier discussions included such credit. The main reasons for not giving salvage value credit at this time are stated in Hard Rock and Metals Rules 4.3.9 and 4.12, and portions of Sections 117(3) and l 18(4) of CRS 34-32-101 et seg. Such credit may be given, but only after the operator has petitioned the Board for approval and if a first lien to the State can be documented. [tt addition, since this is for a revocation contingency often long after mining has terminated, provision must be made to ensure that equipment and fixtures can be protected and maintained in good condition. Therefore, at this time, I cannot grant such credit, though it may be applied for by you at any later tune, by following the steps outlined in the above-cited Rules and statutes. The proofs of additional filings have been reviewed, and appear to include all materials relevant to this application to-date. Please ensure that such filings continue to be made. There are tto further items outstanding at this point. The decision date is still set at 9/1/99, at which time all adequacy items must be addressed. Please note that the reclamation costs are tentative; you should contact me about any mistakes or omissions you find. If you have any questions about this letter or the estimate, you may contact me at the Division's Durango field office: 484 Turner Dr., Bldg. F-101, Durango CO 81301; tel 970/247- 5193 or fax 970/247-5104. Sincerely, Bob Oswald Environmental Protection Specialist encl: reclamation cost estimate packet. a:\van4 ad2 recl est/rco