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TETRATECH RMC Mr. Larry Oehler February 9, 2005 Page 2 of 3 Mining Plan. Direction of mining will be south to north, and be mined wet with no de- watering with use of a drag-line. Once mining is completed in Phase 3A, the plant's process water will be discharged to the lake created by this mining. Previously deposited silt material from discharge areas within the slurry wall shall also be transported internally be truck and deposited in this created lake. Phase 3B mining shall be the easternmost IS+ acres of this phase. A 100'± wide area will initially be left unmined, then the remaining area of Phase 3B shall be de-watered and mined from east to west. Water pumped from this area shall be pumped and discharged into the lake created in Phase 3A in order to help maintain alluvial groundwater levels off-site to the west and south west. After mining of all but this 100'+ wide area, de-watering will cease and then this 100'+ wide area will be mined wet mined from south to north. Any remaining unmined areas of Phase 3A within 200' of structures, where restrictions have been satisfted to allow mining, shall then be mined at this time with Phase 3C. " Fill Placement id the West Fill Area: As described in the original application document for M-2004-044, Tucson South Resource Exhibit D -Mining Plan: "The area designated on the Mining and Reclamation Plan Maps (Refer to Exhibit C and F), as the `West Fill Area' will not be mined. This area will be used for overburden, topsoil and `mud lens' material storage. Any excess material not needed for reclamation and not sold, will be used as fill in the `West Fill Area'. The area will be graded not less than 2% and not greater than 25%. The f Il area will not infringe the Brantner or Brighton Ditch prescriptive or legal easement/right-of--way. The operator will provide adequate erosion control measures to ensure protection of the ditches. " As described in the Adequacy Review Response for M-2004-044, Tucson South Resource, dated November 22, 2004: "The West Fill Area will be disturbed and ftll placed in stages....The stages are identified on the Mining Plan Map numbered 1-6. Each stage will be filled to rough grade and be seeded with a temporary cover crop. " "Stockpiles in West fill area will not be greater than 30 feet high with 3:1 sideslopes. The topsoil grass screening berms will be graded with 4:1 sideslopes as shown on the detail. " "The existing topsoil in the Fill Area will be stripped and used to create the grass covered screening berms along the northern property line. At final reclamation the topsoil berms will be used for final grading the Fill Area. " Based on discussions at the MLRB Hearing on January 191°, we are providing the following language to clarify the process proposed for the West Fill Area: