2010-10-01_REVISION - C1981008 ‎(11)‎

• Permit No: C1981008
• IBM Index Class Name: REVISION
• Doc Date: 10/1/2010
• Doc Name: Proposed Decision & Findings of Compliance
• From: DRMS
• To: Western Fuels-Colorado, LLC
• Type & Sequence: PR6
• Email Name: MLT
• Email Name: SB1
• Media Type: D
• Archive: No

also uses straw dikes, silt fences, small V-ditches, riprap, mulches, check dams,
vegetative sediment filters, temporary cover crops and sediment traps that will reduce
overland flow velocity, reduce runoff volume, or trap sediment. The complete
sediment and water control plan is presented in Section 2.05.3(3) Mine Facilities of
the permit application package.
With the Midterm Permit Review of November, 2005, WFC was requested to update
the permit application with the design information for all surface water control
structures and provide one map which depicts all culverts, ponds, and ditch locations
on site. In 2006 prepared Technical Revision No. 54 (TR-54) to include a complete
inventory of all surface water control structures and a complete new list of culverts,
collection ditches and diversions for the permit area. TR-54 was approved in July
2007 and included new Map 2.05.3(3)-1, Surface Water Hydrology (Surface Water
Features and Controls),
The updated information with TR-54 incorporates the latest topography for the site
and essentially all designs east of 2700 Road show the post-mining topography
design, while the area west of 2700 Road uses the worst case drainage scenarios so
that the structures are conservatively designed. Collection ditches, culverts, and
diversion design parameters are described in Section 2.05.3(3) Mine Facilities pages
2.05.3(3)-8 through 10 and detailed design information is given in Attachment
2.05.3(3)-1 Collection/Diversion Ditches and Culverts Design Parameters. As of the
Midterm Review inventory of 2006 completed for TR-54, there are no surface water
control structures of any kind at the New Horizon #1 site.
C. Stream Channel Diversions
There are no stream channel diversions proposed for the New Horizon Mine.
Calamity Draw flows undisturbed parallel to the NH Mine 2 southern boundary, with
Tuttle Draw doing the same along the northern boundary.
D. Sedimentation Ponds
WFC uses sediment ponds to prevent additional contributions of sediment to
streamflow or runoff outside the permit area due to mining disturbances. Existing
and proposed sediment pond locations are shown on Map 2.05.3(3)-1. Sediment
pond design, construction and maintenance are described in Section 2.05.3(3) Mine
Facilities pages 2.05.3(3)-10 through 25 of the permit application package. The pond
designs and runoff calculations for the permit area ponds are shown in the following
attachments: Pond 007 Attachment 2.05.3(3)-2; Pond 008 Attachment 2.05.3(3)-4;
Pond 009 Attachment 2.05.3(3)-5; Ponds 10 & 13 Attachment 2.05.3(3)-6; Pond 011
Attachment 2.05.3(3)-14; Pond 012 Attachment 2.05.3(3)-12 and 13; Pond 014
Attachment 2.05.3(3)-11; and Pond 015 Attachment 2.05.3(3)-20.
Pond 010 has an approved design but WFC has not built this pond at currently does
not intend to construct it. Pond 016 is an additional pond proposed for the western
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