2005-07-19_REVISION - M1977403HR

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~~M P G consulting scientists and engineers TO: FROM: DATE: SUBJECT: ~~~, JU( T g Z~QS Divi;idn ~;r?0a F1e1y MFG PROJECT: 180715 Bill Lyle, Idarado Mining Company Jason Andrews and Sherro Worthington June 16, 2005 Acid-Base Accounting Test Results -Pandora Soil Repository Geochemical chazacterization (acid-base accounting) tests were conducted for Idazado Mining Company (IMC) on materials excavated from the Idarado Legacy "Pandora Area" Development Property and placed in the repository at the Pandora Mill site in Telluride, Colorado. Materials placed in the repository consist of native alluvial/colluvial soils intermixed with mine and mill-related beneficiation materials (primarily tailing with minor amounts of development or waste rock materials and concrete debris) generated in 2004 from excavation of underground utilities in the Pandora Area and from demolition of the foundation ruins at the Gold Run Mill area. As shown on Figure 1, the repository is located on the existing Pandora Mill development rock pile, north of Highway 145 and west of Marshall Creek, adjacent to the Pandora Mill facility. The repository was approximately 300 feet long, 120 feet wide at the time the soil samples were collected on September 21, 2004. Based on the approximate area of the repository (Figure 1) surveyed by Foley Associates, Inc. in February 2005, the repository contained an estimated 40,000 cubic yards of materials. From June to October 2004, IMC removed underground utilities in the Pandora Area of the Idarado Legacy Development Property in accordance with the MFG Inc. Management Plan for Miscellaneous Mill-related Wastes prepared for and approved by San Miguel County. Common with many historic mining community developments throughout the western United States tailing had typically been used in the past as bedding materials for many of the underground utility lines in the Pandora area. The utility removal involved the excavation of overlying and adjacent native soil materials and tailing bedding materials for the utility lines, and transport of the mixed soiUtailing materials to the repository. The utility lines were typically buried at depths ranging from approximately six to ten feet below Bound surface, and were typically bedded with tailing materials from approximately six inches beneath to approximately 12 inches above the lines. As such, the majority of the material volume excavated from the utility trenches and placed in the repository consisted of native soils overlying or adjacent to the utility lines. Several of the utility lines consisted of transits (asbestos-cement) pipe. All transits pipe was managed and handled by licensed and trained asbestos abatement personnel with the pipe being poly-wrapped, labeled, transported and disposed in accordance with local, state and federal requirements at an off-site licensed facility. Materials consisting of native soil, remnant mill waste or development rock, and concrete debris from excavation and demolition of the Gold Run Mill foundation ruins and roadway surfaces were also placed in the repository. MFG, Inc. 3801 Aummation Way, Suite /00 Fort Collins, CO 80515 Phone: 970-223-9600 Far: 970-223-717! MEMORANDUM P9100JISUti~iga~ion~ABA mamg-Final.doc