APPCOR11788

• Permit No: C1981071
• IBM Index Class Name: Application Correspondence
• Doc Date: 3/4/1986
• Doc Name: AREA 9 10 POSTMINE TOPOGRAPHY FN C-81-071
• From: MLRD
• To: COLO YAMPA COAL CO
• Media Type: D
• Archive: No

Richard D. Lamm
Governor

DEPARTMENT OF NATURAL RESOURCES
David H. Getches, Executive Director
MINED LAND RECLAMATION DIVISION
DAVID C. SHELTON, Director
March 4, 1986
Mr. Richard Mills
Colorado Yampa Coal Company
29588 Routt County Road No. 27
Oak Creek, Colorado 80467
Re: Area 9/10 Postmine Topography - File No. C-81-071
Dear Mr. Mills:
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999
We are concerned that the recently submitted Area 9/10 postmine topographic
mapping and cross sections indicate that backfilling and grading was not
conducted in compliance with the approved plan. Evaluation of submitted cross
sections and comparison of proposed and surveyed topography indicate a
material deficit in upper portions of the regraded slope and in general, it
appears that efforts were not taken to insure the redistribution of spoil in
conformance with the plan.
Slope profiles deviate significantly in some cases with respect to posits
and extent of convex, straight and concave slope segments. Grade reversals
which did not exist in the original condition or the proposed topography are
apparent along the upper portion of the slope in some areas.
Page 78-10(a) of the permit indicates that a portion of the three million
cubic yards of prelaw spoil in Area 51 was to have been transported upslope
for use in backfilling the final pit. This operation was never implemented.
In view of the fact that the regraded configuration does not match that
approved in the reclamation plan, Colorado Yampa Coal Company (CYCC) will need
to complete additional backfilling and grading or will need to submit
documentation which confirms that the existing regraded slopes conform with
approximate original contour requirements. Specifically, the demonstration
will require that CYCC evaluate the land configuration and drainage pattern
and show that the topography is at least as effective as that approved, in
terms of mass stability and surface erosion. The effect of alterations in
slope shape, length, gradient, and drainage pattern will need to be evaluated
with respect to surface stabilization and long term geomorphic stability.
423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. [phone]