REP18929

• Permit No: C1982056
• IBM Index Class Name: Report
• Doc Date: 10/10/2001
• Doc Name: QUARTERLY OFSERVATION REPORT REFUSE PILE
• From: NORTHWEST COLO CONSULTANTS INC
• To: TWENTYMILE COAL CO
• Permit Index Doc Type: Waste Pile/Fill Report
• Media Type: D
• Archive: No

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Geotechnical /Environmental EnQineerinQ • Materials
October 5, 2001 O
Twentymile Coal Company
29515 RCR #27
Oak Creek, CO 80467
Attn: Mr. Rick Mills
]ob Number: 99-3983
Subject: Quarterly Observation Report, Refuse Pile,
Foidel Creek Mine, Routt County, Colorado.
Gentlemen:
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As requested, NWCC, Inc. (Northwest Colorado Consultants, Inc.) has prepared this letter outlining our
observations made during the third quarter of 2001 at the Refuse Pile, which is located at the Foidel Creek
Mine in Routt County, Colorado. During this quarter, we visited the project site on August 16 and
September 27 to test the compaction of the materials being placed and compacted, as well as to provide our
quarterly observations.
At the time of our site visit on August 16, 2001, we met with Mr. Rick Mills, Gary Buchan and Dave
Wallace of Twentymile Coal Company and Dave Zehner of Precision Excavating to observe the conditions
at the Refuse Pile, as well as discuss the placement of the clay cover material over the east face of Area 1.
At the time of our visit, we observed that the majority of the refuse materials (waste coal) were being
stockpiled and placed in Area I and that the client was spreading and compacting the fill materials in Area
2. We also observed that the client had removed all of the previously stockpiled materials from the south
end of the refuse pile and had exposed the underlying, natural clays. During this visit, we again observed
some seepage and standing water along the tce of the embankment at the north end of the refuse pile. We
recommended that the areas in which the standing water was observed be regraded so that the seepage is
not allowed to pond at the toe of the slope. it should be noted that the east face of the refuse pile was dry
and we did not observe any seepage or wet areas along this face of the embankment at the time of our visit.
We were informed that the State Inspector in a letter dated August 9, 2001 had approved the east face of
Area I for placement of the clay cover materials in this area. We were advised that Precision Excavating
would start the placement of the clay cover materials within the next week.
At the time of our site visit on September 27, 2001, we conducted five (5) compaction tests (#201 to #205)
across the portion of the refuse pile in which the compacted lift had been placed in Area 2. A copy of the
compaction test results and daily report are also attached. Based on the compaction test results, it appears
that the fill materials are being placed and compacted in general accordance with the project specifications.
It should be noted that the abbreviations given in the Nuclear Density Test Results (Proctor Data) are as
follows: Maximum DD =Maximum Dry Density and OMC =Optimum Moisture Content. Both of these
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2580 Copper Ridge Drive, P.O. Box 775226 • Steamboat Springs, CO 80477