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sh <br />Bnvirorunartzl ScienGste <br />August 12, 2008 <br />Mr, Ross Gubka <br />Western Fuels Colorado LLC' <br />Box 628 <br />Nucla Colorado 81424 <br />Subject: REVISED Subsoil Suitability Study <br />New Horizon Maine <br />Walsh ProjectNo. 7873 -019 <br />Dear Mu Gubka.: <br />Walsh Environments] Scientists & Engineers, LLC (Walsh) has performed a limited soil investigation <br />and inspectiints of operations at the New Horizon Mine in Nucla, Colorado. Work was conducted <br />raider contract ttr Western Fttels — Colorado LLC ( WFC). This letter describes investigation <br />techniques, results, and their implication to mine operations and is a revision of the original soil <br />investigation claled March 2C1, 2908_ Revisions are based on comments received from the Division of <br />Reclamation, Mining, and Safety (DAMS) in a letter dated May 28 2008. <br />Background <br />The New Horizon Mine, mines coal under a DRA4S permit. The permit defines soil handling <br />proced Lit es that have been followed by WFC. Prior to February 2008, the permit did not recognize any <br />soil within the permit boundary as being "prime farmland" as defined in the DRMS regulations and by <br />the: National Resource Conservation Service (MRCS). Soil handling was con_sistenl with tile, permit <br />and the NRCS ruling prior to permit issuance that there were no prime farmland soils within the permit <br />area. In February 2008, the NRCS detennined that same of the soil within the permit boundary <br />qualified as prime farmland. Some of that prime farmland had been mined and reclaimed, some had <br />been mined but had cut yet been fully reclaimed, and some of the material has not yet been mined. <br />WFC has chosen to take steps to ensure that the unreclaimed mined area that has been reclassified as <br />prime farmland is replaced with soil and subsoil that is suitable to restore prince famuarrd <br />characteristics. <br />Mining Operations <br />Coal is mined by stripping topsail In one or two lifts. mechanically shipping subsoil and weathered <br />Dakota Formation bedrock overburden, blasting remaining bedrock overburden, and raining coal. The <br />mining pit is backfitled first with the iute-rburderr and blasted overburden followed by placement of the <br />weathered bedrock overburden, and finally the soil lift(s). <br />The working face of the mine, reveals 10 to 30 feet of weathered sandstone anti shale bedrock that has <br />decomposed and is mostly friable (see photos). This material is called "Bench 1 ° or "overburden unit <br />1 ' material in the permit amd by WFC. It grades imperceptibly into the overlying soil, and contains <br />Vis"tem slope llivisioa: <br />535 Grend Avenue . Grsnd )unction, Corovado 81501 27QCI . Phone (970)'341 -4636 . PAX 1970; 241 -4312 - rvalshemzcom <br />4SR9f rxte Pist Ce: <br />4RRR Pend Eest Cjx, .r ., Spite 103 nouldcq Col _ado 80301 -2495 P! we 303} 443- . FAX (503) 343 -0367 <br />Revised September 2010 (PR 06) Attachment 2.05.4(2)(d) -1 -2 <br />