REP23718

• Permit No: C1982056
• IBM Index Class Name: Report
• Doc Date: 10/14/2003
• Doc Name: 3rd Quarter 2003 Refuse Pile Report
• From: Northwest Colorado Consultants Inc
• To: Twentymile Coal Company
• Permit Index Doc Type: Waste Pile/Fill Report
• Media Type: D
• Archive: No

Geotechnical I Environmental Engineering • Materials Testing
IlEli~'d H ~®
October 9, 2003
OCT 14 2003
Twentymile Coal Company
29515 RCR #27
Diuisian of Minclals and Geo!c; Oak Creek, CO 80467
A[[n: Mr. Rick Mills
Job Number: 99-3983
Subject: Quarterly Observation Report, Refuse Pile.
Foidel Creek Mine, Routt County, Colorado.
Ladies & Gentlemen;
As requested, NWCC, Inc. (Northwest Colorado Consultants, Inc.) has prepared this letter outlining our
observations made during the third quarter of 2003 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 September 18, 2003 to
provide our quarterly observations. Our firm also visited the subject site twice during this quarter to test
the compaction of the refuse materials that had been placed and compacted.
A[ the time of our site visit on July 23, 2003, we conducted ten (10) compaction tests (#235 to #244) across
Areas 1 and 2 %: of the refuse pile. Nine of the ten tests taken met the compaction specifications.
However, one test (#241) did not meet the compaction specifications. We advised Dave Wallace of RAG
that they should moisten and recompact the refuse materials in this area prior [o placing any additional fill
materials. We visited the project site a second time during this quarter, September 9, 2003, to test the
portion of the refuse pile in which the failing test was recorded during our last visit and to test the
additional materials that had been placed in Areas 1 and 2 '/~ since our last visit. All of the tests (241 A,
245, 246, and 247), met the minimum compaction requirement of 90% of the maximum standard Proctor
density. Copies of [he compaction test results and daily reports are attached. 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 values have been
determined in accordance with ASTM D698/AASHTO T99.
We also visited the site on September 18, 2003, to conduct our quarterly inspection. Mr. Rick Mills and
Dave Wallace of RAG/Twentymile Coal Company were not available at the time of our site visit. At the
time of our visit, it appeared that the majority of the refuse materials (waste coal) that were being produced
werti'being stockpiled in the north end of Area 2. At the time of this visit, we also noted that the contractor
was in the process of moving the materials that had been previously stockpiled at the extreme south end of
the pile'[o~Area 2 '/,. ~ At the time of our visit, we did not observe any signs of adverse drainage conditions
on the pile. As noted in our previous report, we still observed a slight amount of groundwater seepage
coming from [he east face of the lower bench of Area 1 at the toe and several hundred feet north of the
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