2009-11-25_PERMIT FILE - C1982056A ‎(5)‎

• Permit No: C1982056A
• IBM Index Class Name: Permit File
• Doc Date: 11/25/2009
• Doc Name: Pages 2.05-65 to 2.05-122.1
• Section_Exhibit Name: 2.05 Operation and Reclamation Plans Part 2
• Media Type: D
• Archive: Yes

11. There will be some long -term settlement of both disposal areas. We recommend overbuild of
approximately 5 percent in the central portion of both fill areas in order to maintain long -term drainage. The
surface of the fill should be designed with a slope of 5 percent away from the head of the fill. The fills should
drain to ditches on both sides of the fill.
Given that these drainage features encompass the entire temporary clay stockpile, topsoil pile, and light -use road,
and that these disturbances represent only a small portion of the total excess overburden stockpile area, they should
provide effective drainage and sediment control for the proposed temporary activities. A temporary fueling station,
consisting of a fuel tank and lined secondary containment, will also be established at the stockpile location. The
stockpiled clay will be recovered and placed as cover material on the western slope of the Refuse Pile as soon as
ongoing refuse placement and grading bring this area to the final design elevation and grade. The light -use road
will be narrowed and ripped, stockpiled topsoil will be replaced on the associated disturbance areas, and all
disturbed areas will be reseeded with the permanent rangeland seed mix.
4) Subsurface and Surface Drainage - Small drainage ditches will be constructed downslope of the temporary
stockpiles to minimize water running over and down finished slopes of the CRDA. Also, it was recommended in
Exhibit 26A -1 that temporary drainage ditches be established along the eastern edge of the benches as they are
constructed, to prevent excessive surface runoff from flowing over the finished/compacted slope of the CRDA.
The specific recommendations for these temporary drainages are presented in Exhibit 26A -1.
Coal Refuse Disposal Area Expansion (MR07 -226 and TR09 -67)
With the existing CRDA nearing its design capacity, TCC completed an evaluation of required refuse disposal
requirements through the end of the Foidel Creek mine life. Included in this evaluation was an assessment of the
potential refuse disposal requirements for the nearby Sage Creek Project, in the event it proceeds to development
and full -scale production. The evaluation of .otential future refuse disposal requirements indicates that a maximum 3 rr^�`
of approximately 20.0 MM cubic ards o (additional capacity will be required to address reasonably foreseeable 9'
C C future needs. Based on the calculated refuse . isposal capacity requirement, TCC contracted with Northwest 0 _ . 7
-- Colorado Consultants (NWCC) to complete site geotechnical investigations and detailed design and phasing plans /OA
for phased construction of a 20.0 MM cubic yard CRDA Expansion, along with all associated structures and
facilities. The proposed CRDA Expansion is located immediately adjacent and to the east of the existing CRDA,
and the existing CRDA on the west, natural ridgelines to the east and south, and the engineered, benched refuse fill
toe on the north, effective bound and provide containment for refuse fills. Designs for the associated facilities
include required access, drainage control structures, and soil and cover material handling plans and stockpiles.
Site geotechnical investigations are required to provide foundation and soils information for design, permitting, and
construction of the Coal Refuse Disposal Area Expansion. The area proposed for the Refuse Pile Expansion is an
area of reclaimed mine spoils immediately adjacent and to the east of the existing CRDA, as shown on Maps 24,
Mine Facilities and Freshwater Systems, and EX26C -M1 Surface Facilities - Refuse Pile Expansion. Site
geotechnical investigations for the CRDA Expansion involved completion of five, 4 -inch hollow -stem auger
sample holes to depths of 20 -40 feet; excavation of seven shallow (ten to fifteen feet in depth) backhoe test pits;
and collection, examination, and testing of soil samples. There will be a total of no more than twelve auger holes
and test pits.
No new roads were built, sample locations were accessed overland using rubber -tired equipment, and access was
limited to periods when the ground was dry or frozen in order to minimize surface disturbance. In order to
minimize surface disturbance, soil removal was limited to the immediate area of each auger -hole or test pit, with
soil material being windrowed to the side of the disturbance area, and re- spread immediately following completion
of drilling /excavation/sampling and backfilling. Site runoff from the limited disturbance areas was addressed
through the use of alternative sediment controls consisting of straw wattles, placed ands staked immediately
downgradient of each disturbance area. Auger drilling is a dry drilling operation, so no mud pits were required, and
no discharge of drilling fluids occurred. Because the auger -holes and test pits were in reclaimed mine spoils on a
hillslope, the potential for intercepting any significant quantities of ground water was negligible. Air was not used
a circulation medium, so dust generation was not a concern.
TR09 -67 2.05 -97.2 05/16/09