2010-11-17_REVISION - C1981008 (3)

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03/18/2009 12:29 9702475104 DMG DURANGO OFFICE PAGE 07/21 Elivircmmcntal ScicntistR and Enpincers, L)..C: August 12, 2008 Mr. Ross Gnbka Western. Fuels Colorado T 'LC Box 628 Nucla Colorado 81424 Subject: REVISED Subsoil Suitability Study New Horizon, Mine Walsh Project No, 7873 -010 Dew Mr. Gubka: Walsh Envirotuncn.W Scientists & Engineers, T.f C ('Wal.8h) has performed a limited soil investigation and iJSpectiort of operations at the New I-Iprixon Mine in. Nucla, Colorado. Work was conducted under contract to Western Fuels— Colorado T.,i.0 (WFC). This letter describes investigation tecliniques, results, and their implication to mine operations and iR a revision( of the original soil' itivcstigation dated Mareb. 20, 2008. Revisions are based on comments received from the Division of Rcc`1FMati01l, Mining, and Safety (DRM.8) in a letter dated May 28 2008. Batkgrnttnd The New Horizon Minc mines coal under a DRMS permit, The permit defines soil li u,dli.nq procedures that have been followed by WFC. Prior to February 2008, the permit did not rocoE(ltize any soil within the permit boundary as bcillg ` pri.n,e farmland" as defined in the DRMS regulations and by the National Resource Conservation Service (MRCS). Soil handling was consistent with the permit and the NRCS ruling prior to permit issuance that there were no prime farmland soils within flit permit area. in February 2008, the Nii(S delcrminad that some of the soil with(t, the permit boundary qualified as prime fartnlan.d. Some of that prime farmland had bccn m.inod an,d reclaimed, some had been mined but had not yet beet, fully reclaimed, and some of the material has not yet been tttinod, WPC has chosen to take steps to ensure that the unreelaimed mined area that has been reclassified as prime farmland is repLaccd with soil. and subsoil that is suitable to restore prime .farmland characteristics, Miffing Operations Coal is mined by stripping topsoil in one or two hfls, mechanically stripping subsoil and weathered Dakota Formation bedrock overburden, blasting remaining bedrock overburden, and mining coal, The mining pit is backfilled first with the intcrburJan and blasted overburden follOwcd by placement ofthe wcathcred bedrock overburden, and finally the soil lift(s), The working face of the !.nine reveals 10 to 30 feet of wcai:llerod > andstonp and shale bedrock that has decomposed and .is mostly .friable (sec photos). This material is called "Bench. 1" or "overburden unit 1" material in the permit and by WFC. It grades imperceptibly into the overlying, soil, and contains we'sletn S1npe D1vlsh me Xa= Grunt, Avont,e . Gmxi Junction, Co100(10 RJSO1 -7790 . Phone (970) 241-4636 , FAX (970) 241.4312 , WolsheaV.tam corpurnfe Office.: 4888 PtAr1 Ecst t::11> 1c, suite, 7 os . R0t11110r, Colorado 803111 -2475 . P110m (308) 443.3:$2 . PAX (303) 443 -0367 (Revised Nov tow Attachment 2,05.4(2)(d) -4 -2