_GENERAL DOCUMENTS - C1981017 ‎(146)‎

• Permit No: C1981017
• IBM Index Class Name: GENERAL DOCUMENTS
• Doc Name: Bid Documents ‎(IMP)‎
• Permit Index Doc Type: General Correspondence
• Media Type: D
• Archive: No

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DEPARTMENT OF NATURAL RESOURCES
* * David H.Getches,Executive Director
# 1 MINED LAND RECLAMATION DIVISION
876 D"IDC.SHELTON, Director
Richard D.Lamm
Govemor
May 17, 1984
Mr. Doug Bowman
Mid-Continent Resources, Inc.
P.O. Box 158
Carbondale, Colorado 81623
RE: Remedial Analyses for Coal Basin Waste Piles - File No. C-017-81
Dear Mr. Bowman:
The Division has completed a review of the submittal made by Mid-Continent
Resources, Inc. in response to a violation issued for failure to properly
place material within the processing waste and rock tunnel development waste
piles at the Coal Basin Mines. This submittal was prepared by Geo-Hydro
Consultants, Inc. The consultant tested compaction at both structures and
performed field examinations to determine whether the structures were being
built in conformance with the approved plans.
Coal Refuse Disposal Structure
Compaction testing was performed by Chen and Associates, under Geo-Hydro's
supervision. The investigation determined that, while a majority of the pile
had been built properly, "... some coal waste material was dumped over the
crest of the existing facilities slopes." The high moisture content of that
material resulted in mudslide-type slumps occurring. Geo-Hydro states that no
end-dumping or pushing of the refuse material over the crest of the structure
should be allowed. Further, they recommend that the facial problems be
corrected by grading the loose slump material down the pile face and
recompacting it in a facial zone. The foundation should be properly prepared
and material placed and compacted in lifts not exceeding 12" in thickness.
This construction should be supervised by an experienced engineer and
compaction periodically tested utilizing sand-cone methods.
This remedial technique will be acceptable, providing that the structure
conforms to the originally approved design footprint. If the applicant needs
to expand the pile in order to accomplish the required recompaction, an
appropriate revision, including stability analysis, will be required. The
applicant's strict adherence with the inspection and reporting requirements of
Rule 4.10 will be required.
423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel.[phone]