ENFORCE21415

• Permit No: C1980007
• IBM Index Class Name: Enforcement
• Doc Date: 1/9/1998
• Doc Name: FAX COVER SHEET
• From: WRIGHT WATER ENGINEERS INC
• To: DMG
• Violation No.: CV1997022
• Media Type: D
• Archive: No

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MEMORANDUM
TO: Susan McCannon
Dave Berry
Colorado Division of Minerals and Geology
Vie FAX: [phone]
ce: Kirk Mueller, Esq., ARCO Coal
FROM: Wright Water Engineers, Inc. Via FAX: 293-x098
Kathy Wclt, Mountain Coal Company
DATE: January 9, 1998 Via FAX: [phone]
RE: Notes from Meeting at Colorado Division of Minerals and Geology (CDMG) on
December 18, 1997
Attending the meeting were: Kathy Welt, Mountain Coal Company (MCC); Kirk Mueller, ARCO I
Coal; John Rold, Wright Water Engineers, Inc. (WWE); Dave Jubenville, WWE; Jonathan Kelly,
WWE; Steve Brown, AG; Jim Pendleton, CDMG; Dave Berry, CDMG; Susan McCannon, CDMG, ~j
and Bntce Stover, CDMG. The meeting began shortly after 10:00 am at CDMG and concluded Z
around noon. y
The following key points were discussed during the meeting: W
W
• Kirk began the meeting by stating that the purpose of the meeting was to discuss the technical Z
aspects of the Bear landslide. Water from the "Bear Slide Spring" was to be discussed only in Z
terms of how the water related to the landslide. MCC is currently conducting water quality and W
isotope analyses to characterize and "fingerprint" the spring water.
W
• Rold began the [echnical discussion by stating that during his investigations in September, before Q
~
the landslide, he noted evidence of active slides. On the panorama photograph, Rold noted the ~
raveling slopes at the base of the hillside, where the slope was steeper than the angle of repose. F
2
• Pendleton asked Rold about evidence of larger, older slides on the hillside. Rold responded that CS
he did not see evidence of deep failures in the bedrock and coal seams.
~
• Rold proceeded to the past-landslide photographs to show the arcuate nature of the land mass.
Other key points were the lack of toe movement and the strip of land that was intact and had not
moved between the larger slide and the small slump at the spring.
• Pendleton asked if the hillside was dilating. Both Rold and Jubenville agreed that that was a
good term to describe the movement.
• Pendleton then asked if the spring was new. Rold responded that the small slump recently
exposed the spring, but there is evidence (i.e., well AAl and coal reclaim tunnel) that the water
has been emerging near that location for some time. McCannon asked .where the water
historically went Rold responded that the water likely percolated down through the colluvium
and adjacent coal pile into the alluvium.
• Pendleton asked if there were any other locations in the vicinity of the landslide where water has
been observed other than the spring- MCC and WWE responded that no other water has bern
observed. Berry concurred drat he did not observe water at any other location. ~
• Pendleton asked what the flow rate of the spring was. Berry noted that he measured 10 gpm and
felt that he caught 90% of the flow. MCC has subsequently measured 28 gpm and 20 gpm at a
~ location downgndient where the flow was gathered and duected into an AD5 pipe.