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TETRA TECH RMC Mr. Larry Oehler <br />Adequacy Response M-2004-044 <br />November 22, 2004 <br />Page 10 of 20 <br />The Mining Plan Maps have been revised to indicate the location of the perimeter <br />screening berms; two (2) along the northern property line and one (1) along State <br />Highway 7 outside the 100 year floodplain. A detail has been added to show the <br />cover vegetation, height and sideslopes. These berms will be established during <br />the initial stages of mining and remain for the life of the mine. At reclamation of <br />the West Fill Area, the topsoil material used for the northern property line berms <br />will be used for final cover of the Wes[ Fill Area and seeded to the Disturbed <br />Area seed mix outlined on the revised Reclamation Plan Maps. The screening <br />berm along State Highway 7 will be established at the initial stages of mining and <br />used for creation of reservoir sideslopes during reclamation of Phase 3. <br />6. Your plan includes the regulatory requirement that topsoil will be segregated <br />from other spoil. At A. I.'s adjoining Tucson Resource Mine, topsoil has not <br />been segregated from other overburden material What is your plan to insure <br />that pit operating personnel segregate topsoil from other materials. <br />The Mining Plan Maps have been revised with labels to identify the material for <br />each stockpile. <br />7. Your plan for re-vegetation of upland areas includes a seed mix more suited to <br />areas of higher precipitation and sandy soils. Please consider changing your <br />seed mix to the mix recommended by the Natural Resource Conservation <br />Service. Their letter of comment was forwarded to Tetra Tech. <br />The Upland and Disturbed Areas Seed Mix on the reclamation plan has been <br />revised to reflect that requested by the Natural Resource Conservation Service <br />(NRCS). <br />8. Your seeding rates for the pond bank slopes, upland areas and other disturbed <br />areas are too low; however, since you may be changing the mix and seeding <br />rates in response to item 7 above, final review of this issue will be after the <br />Division receives your response to item (7) seven. <br />The Upland and Disturbed Areas Seed Mix on the reclamation plan has been <br />revised to reflect that requested by the Natural Resource Conservation Service <br />(NRCS). <br />9. Your mining Phase 2 includes the construction of a slurry wall The <br />Construction Materials Rules at 3.1.6(2) states "Earth Dams, if necessary to <br />impound water, may be constructed if the formation of such impoundments will <br />not damage adjoining property... " The City of Brighton is concerned about the <br />impact of the proposed operation on the Morgan Smith Natural Area, which <br />lies between Phase 2 and the South Platte River. The natural area has a large <br />eommuniry of cottonwood trees. Groundwater, which is needed by the trees, <br />FI:U919_019_OIVvILRB\DMG Response\lst Adequacy Response to DMG 11-5-04.doc <br />