2010-08-10_REVISION - C1981008 ‎(10)‎

• Permit No: C1981008
• IBM Index Class Name: Revision
• Doc Date: 8/10/2010
• Doc Name: Response 4 Revised Section 2.05.4‎(2)‎‎(d)‎
• From: Western Fuels-Colorado
• To: DRMS
• Type & Sequence: PR6
• Media Type: D
• Archive: No

AW
W�i�li
Environmental Scientists and Engineers, LLC
August 12, 2008
Mr. Ross Gubka
Western Fuels Colorado LLC
Box 628
Nucla Colorado 81424
Subject: REVISED Subsoil Suitability Study
New Horizon Mine
Walsh Project No. 7873 -010
Dear Mr. Gubka:
Walsh Environmental Scientists & Engineers, LLC (Walsh) has performed a limited soil investigation
and inspections of operations at the New Horizon Mine in Nucla, Colorado. Work was conducted
under contract to Western Fuels — Colorado LLC (WFC). This letter describes investigation
techniques, results, and their implication to mine operations and is a revision of the original soil
investigation dated March 20, 2008. Revisions are based on comments received from the Division of
Reclamation, Mining, and Safety (DBMS) in a letter dated May 28 2008.
Background
The New Horizon Mine mines coal under a DRMS permit. The permit defines soil handling
procedures that have been followed by WFC. Prior to February 2008, the permit did not recognize any
soil within the pertnit boundary as being grime 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 the permit
area. In February 2008, the NRCS determined that some of the soil within the permit boundary
qualified as prime farmland. Some of that prime farmland had been mined and reclaimed, some had
been mined but had not yet been fully reclaimed, and some of the material has not yet been trained.
WFC has chosen to take steps to ensure that the unreclaimed mined area that has been reclassified as
prime farmland is replaced with soil and subsoil that is suitable to restore prime farmland
characteristics.
Mining Operations
Coal is mined by stripping topsoil in one or two lifts, mechanically stripping subsoil and weathered
Dakota Formation bedrock overburden, blasting remaining bedrock overburden, and mining coal. The
mining pit is backfilled fast with the interburden and blasted overburden followed by placement of the
weathered bedrock overburden, and finally the soil lift(s).
The working face of the mine reveals 10 to 30 feet of weathered sandstone and shale bedrock that has
decomposed and is mostly friable (see 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
western Slope Division:
535 Grand Avenue . Grand Junction, Colorado 81501 -2790 . Phone [phone]. FAX [phone]. walshenv.cotn
Corporate Office:
4888 Pearl East Circle, Suite 108 . Boulder, Colorado 80301 -2475 . Phone [phone] . FAX [phone]
Revised PR 06 June 10 Attachment 2.05.4(2)(d) -1 -2