2001-01-24_REPORT - M1980244

• Permit No: M1980244
• IBM Index Class Name: REPORT
• Doc Date: 1/24/2001
• Doc Name: Memo RE: Review of As-Built Certification Report for the External Pond, Cresson Project
• From: James Dillie
• To: DRMS
• Media Type: D
• Archive: No

January 8, 2002
To: Berhan Keffelew
From: James Dillie i._ A
Re: Review of As-Built Certification Report for the External Pond, Cresson Project, M-1980-244
Per your request, I reviewed the certification report for the construction of the external pond at
the Cresson Project. The report was reviewed to ensure that the approved material and
construction specifications, as well,as material and construction testing, for the external pond
were complied with and to ensure that the structure was constructed in accordance with the
approved design plan. Following are my comments regarding the review:
1) It appears there is an unusual weather phenomenon at the mine site. The monitored
ambient night temperatures for the first month of monitoring appear to be higher than the
ambient daytime temperatures (see Appendix H-1). This occurred from 12-11-00 to 1-1-01.
Since this is a mountainous location, it seems that temperatures would decrease during the
night instead of the day when solar radiation would be warming things up. Also, it has been
my experience that the coldest time of the day is right before sunrise. However, I suppose
there are alot of unexplained weather phenomenons that occur in nature; and this may be
one of them. I would still like to hear CC&V's explanation. This is not a critical item. I just
want to be sure the monitoring equipment was functioning properly.
2)There appear to be a few non-destructive test summaries that need to be explained (see
Appendix J-9A &J-9B). On June 18, 2001 the seam connecting lower geomembrane
panels number 79 and 80 was pressure tested pursuant to specifications. Following
approved guidelines, the test lasted from 10:36 to 10:41. The pressure dropped to 24 psi
(from 30 psi) so the seam failed. The seam, apparently, was re-tested at 10:39; lasting for
5 minutes (10:44). The pressure only dropped 3 psi so the seam passed the test. My
question is, why did the re-test start before the initial test ended? This occurred again at
15:34— 15:39 and re-tested at 15:36— 15:41 where lower panel number 84 connected with
panel number 85 (June 18, 2001). As noted, the re-test initiated 3 minutes before the first
test ended (after the seam failed).
On June 25th, the seam between upper panels 87 and 89 was pressure tested for 5 minutes
between 14:07 and 14:12. The seam failed so it was re-tested at 14:09 (to 14:14). How
could it have been re-tested at 14:09 when the initial test didn't end until 14:12?
The other concern I have is there are no comments in the remark column indicating how
the seams were repaired (or if they needed to be repaired).
Other than the above noted items, it appears the operator complied with Rule 7 regarding the
design and construction of the external pond. Acceptance of the certification report can be
completed after receiving and reviewing CC&V's response to the above noted items if you do
not have any other problems.
cc: James Stevens