2009-07-30_REVISION - C1982056

• Permit No: C1982056
• IBM Index Class Name: REVISION
• Doc Date: 7/30/2009
• Doc Name: Letter Application and Public Notice
• From: Twentymile Coal Company
• To: DRMS
• Type & Sequence: TR69
• Email Name: JHB
• Media Type: D
• Archive: No

Peabody
Twentymile Coal
July 24, 2009
Mrs. Janet Binns, Environmental Protection Specialist
Colorado Division of Reclamation, Mining, and Safety
1313 Sherman Street, Room 215
Denver, Colorado 80203
[phone] X8107
29515 Routt County Road 27
Oak Creek, CO 80467
970.879.3800
RFrr'INIE®
JUL b Q Ljn9
Division u -%_,awation,
Mining and Safety
RE: Twentymile Coal Company - Foidel Creek Mine (Permit No. C-82-056), Technical
Revision (TR09-69) for the 6-Right Thickener Underflow Borehole and Pipeline Project
Dear Mrs Binns:
Twentymile Coal Company (TCC) requests CDRMS approval of a Technical Revision to our existing
approved Permit for construction, operation, and reclamation of a new thickener underflow borehole,
pipeline, and associated ancillary equipment and facilities at the 6-Right (6RT) location. The new
thickener underflow installation is needed to provide for transfer and discharge underground of
thickener underflow slurry in the Eastern Mining District, in addition to the existing thickener
underflow discharge in the Southwestern Mining District.
The 6RT Thickener Underflow Borehole installation will be located southeast of the intersection of
Routt County Roads 27 (RCR27) and 33 (RCR33), on the north side of Foidel Creek and the
Twentymile Mine railroad spur. The Thickener Underflow Borehole will extend approximately 540
feet from the surface into the sealed Eastern Mining District (EMD) mine workings. An existing light-
use road extends approximately 250 feet from RCR33 to this location. A pad and required drainage
structures will be constructed. A buried thickener underflow pipeline will be installed between the
existing washplant facilities and the new Thickener Underflow Borehole.
Installation of the Thickener Underflow Borehole will involve placement of construction erosion
controls (silt fence and/or straw wattles), removal and windrowing of soil materials from the pad area
and road margins, grading to establish a level drill pad and improve the existing light-use road,
placement of gravel as surfacing for the light-use road, excavation of a temporary cuttings pit on the
drill pad, drilling and casing of the borehole, and installation of an access manhole. On completion of
drilling and casing operations, the cuttings pit will be allowed to dry-out, material excavated from the
pit will be replaced and graded, and the pad surface will be graveled to control erosion and sediment
and provide an all-weather operating surface. The completed Thickener Underflow Borehole
installation will include the light-use road, a soil material stockpile (pad and road); a 70 x 70 foot pad;
the 6-inch cased borehole, a 14-inch cemented surface casing, and a covered 8-foot diameter CMP
culvert manhole with lightening protection.
Pipeline installation will involve removal and windrowing of soil materials; trenching in most areas;
placement of suitable bedding materials; placement, connection, and pressure testing of the pipelines;
backfilling and compaction of suitable fill materials around and over the pipelines; backfilling and
compaction of the trench; regrading; replacement of soil materials; and revegetation of all disturbed