REV12246

• Permit No: C1996083
• IBM Index Class Name: Revision
• Doc Date: 10/25/2001
• Doc Name: Request for Assistance ‎(Memo)‎
• From: Byron Walker
• To: Joe Dudash
• Type & Sequence: TR22
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203 DIVISION O F
Phone: [phone]Vt 1 N E RA L $
FAX: [phone] &
GEOLOGY
Interoffice MEMORANDUM R E C L A M A T I O N
MINING•SAFETY
8i11 Owens
to: Joe Dudash cnvemor
from: Byron G. Walker.,G~/"~ Greg E. Walther
subject: Request for Assistance, Technical Revision No. 22, Bowie No. 2 Mine, PermitPC1r1VP D1feCOf
Michael B. Long
No. C-96-083, Bowie Resources Limited Division Director
date: October 25, 2001
By your memorandum of October 12, 2001, same subject, (memo) you ask for me to review the
submittal and see if the geotechnical report (Geotechnical Data Report Bruce Park Dam, GEI
Consultants, Inc.)(report) is sound and if the seismic monitoring plan (plan) (revised pages 2.05-
113 and 2.05-114, both annotated TR-22 09/01) is adequate for.its intended purpose and
consistent with our regulations. Materials of my review consisted of the report, your memo, the
plan (submitted under the application), e-mail from Dudash to Norfleet, Oct 11, 2001, a-mail
from Norfleet to Dudash, Oct 17, 2001, e-mail from Gorham to Dudash, October 19, 2001 and
USFS letter, Oct 19, 2001, 2820-4, (letter).
In summary, I find that the report is deficient and the monitoring plan is inadequate and not in
compliance with our regulations. Further, these items do not fulfill the requirements of
Stipulation 9, or the USFS stipulation to the Iron Point Federal Coal Lease [Section 15, (f)(B)] as
stated in their letter.
The intent of Stipulation 9 is to ensure the safety and integrity of the Terror Creek Reservoir dam
(Bruce Pazk dam). The stipulation specifically addresses threats from seismic activity and
subsidence. [Rules 2.05.6(3)(ii), 2.05.6(6)](seismic impacts being a subsidence related
phenomena (Rules 2.05.6(6)(b)(i)(B) and (C), 2.05.6(6)(e)(i)(D)].
The geotechnical report is good as faz as it goes, but, in my opinion, it does not go far enough.
Adequacy and completeness of such a report is a function of its purpose. The geotechnical report
(investigation) is not an end in itself, but provides information for engineering analyses of the
stability and integrity of the dams [Rule 2.05.3(4)(ii)(B)]. The "soundness" of the report is thus
dependent upon the input requirements of engineering analyses. I have not seen such engineering
analyses. Strength parameters of construction materials aze required to make such analyses. The
report only provides two sets of strength pazameters, and both of these aze in the upper (new)
embankment fill of the Bruce Park Dam. A representative number of strength pazameters are
required from all the material horizons of the structure and the foundation materials. The
applicant proposes to raise the dams. A general and detailed plan is required [Rule 2.05.3(4)].
The reservoir (impoundment) needs to be in compliance with Rule 4.05.9 in its entirety [Rule
4.05.9(16)]. Thus the geotechnical investigation needs to be expanded accordingly. The Bruce