2003-03-12_REVISION - M1977342 (2)

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Letter to Ms. Lurline Underbrink-Curran financial warranty, the amendment proposed to remove this azea from our permitted boundary. This change does not impact Henderson's financial warranty. POST-MINING LAND USE AND TREE/SHRUB STOCKING RATE Henderson has proposed to change the post-mining land use to "rangeland" from "open forest". This change has been proposed only to bring Henderson's post mining land use into line with the use classifications recognized by the Division. It is our belief that rangeland is the post-mining land use that most closely matches the "open forest" use in the current permit. In addition, rangeland is consistent with county zoning for the property. The change to rangeland does not, in itself, change our proposed reclamation activities or the financial warranty. I understand your concerns relating to the proposed stocking rate for trees and shrubs included in the amendment. In response, Henderson has requested that this portion of the amendment be deleted for all azeas of the mill, except the tailing deposition azea. We are convinced, based on our experience and available reclamation literature, that we would have close to a 100% failure rate for trees planted on the reclaimed tailing impoundment. It would not be beneficial or economically reasonable to require Henderson to plant seedlings on the reclaimed tailing impoundment given this expected high mortality rate. Instead, we propose to construct "islands" of thicker cover on the tailing impoundment as locations to plant trees and shrubs. This change will affect the financial warranty by reducing the costs associated with revegitation of the tailing impoundment. WET COVER RECLAMATION OF TAILING IMPOUNDMENT In the amendment, Henderson proposed an altemative wet-cover scenazio for the tailing impoundment. This alternative was proposed because it represents the current industry standazd for tailing impoundment reclamation. Experience at other reclaimed tailing impoundment sites, including some owned by Climax Molybdentun Company and located in Colorado, has shown that dry covers are only successful in very arid climates. Wet covers, on the other hand, have been more successful in climates like that in the Williams Fork Valley. Wet covers were a topic of the ICARD 2000 proceedings, and successful case histories of wet covers at Miramachi, New Brunswick, the Falconbridge mine, and from the Elliot Lake area of Toronto are available. In response to your specific concerns regarding a wet cover: 1. Soil rives to prevent leaching out of the pond. The tailing impoundment at Henderson leaks. It is not possible under either closure scenario -wet or dry cover - to eliminate the seepage and leaching though the tailings, regardless of available soil type. In fact, there is no closure option that will eliminate the seepage through the tailings. We believe, based on experience at Urad, that the water quality of the seepage would be better under wet closure. 2. Dam inlet/outlet structure and long term maintenance. Climax Molybdenum Co. owns the mill property and is responsible for long term maintenance, water treatment,