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FE8-10-2005 THU 12 16 PM FAX N0. P, 02/05 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 6e truck a,ad deposited in this created dake. Phase 3B mining shall be the easternmost 15± 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 urea will he mined wet mined from south to north. Any remaining unmined areas of Pltase 3A within 200' of structures, where. restrictions have been su[isfted to allow mining, shall then be mined at this time with Phase 3C " Fill Placement in the West Fill Area: As described in the original application Resource Exhibit D -Mining Plan: document for M-2004-044, Tucson South "7'he area designated on the Mining and Reclamation Plan Maps (Refer to Exhibit C and F), as the 'West Fill Area' will not he mined. This area will be used for overburden, topsoil and 'mud lens' materlad storage. Any excess material not needed for reclamation at:d not Solt! will be used as fill in the 'West Flll Area'. The area will be graded not less than 2% and not greater than 25%. The f:ll area will not infringe the 9rantnet 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 itt the Adequacy Review Response for M-2004-044, Tucson South Resource, dated November 22, 2004: "The West Fild Area will he disturbed and f Il placed in stages.... The stages are Identified on the Mining Plan Map numbered ]-ti. 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 sidesdopes. fhe 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 herms along the northern property line. At final reclamation the [opsniJ berms will be used for final grading the Fidl Area. " Based on discussions at the MLRB Bearing on January 19°i, we are providing the following language to clarify the process proposed for the West Fill Area: ~aa,a...a--_ -^.+~v:x -rxz- "fir ..-