REV13737

• Permit No: M1988112
• IBM Index Class Name: Revision
• Doc Date: 5/5/1994
• Doc Name: POTENTIAL FOR SEEPAGE FROM TAILING FACILITY BMRI SAN LUIS PROJECT FN M-88-112
• From: DMG
• To: LARRY OEHLER
• Type & Sequence: TR16
• Media Type: D
• Archive: No

• III IIIIIIIIIIIIIIII •
STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Dq~a rlmenl of Ndlwa Reso ura r.
I! I S Sherman 51., Ruom ! I S
Denver, Colorado N(12U 4
Phone: 1303) A6h 356:
FA%:0071832-AI U6
DATE: May 5, 1994
TO: Larry Oehler
FROM: Allen Sorenson ~~
r ~,,
RE: Potential for Seepage
Resources, Inc. (BMRI)
Introduction
~~~
DEPARTMENT OE
I~IATURAL
RESOURCES
Ruy Rnme~
G rvernnr
Ken $nlaea.
Cart ulivP D~q'Un~
Midrael B tool;
Dn~nwn Doer inr
from Tailing Facility, Battle Mountain
San Luis Project, File No. M-88-112
This memorandum is prepared in response to BMRI's letter dated November
30, 1993 which was a response to concerns raised by the Division in a
letter dated November 2, 1993, The five month time lag between receipt
of the BMRI letter and preparation of this memorandum is a result of
the Division awaiting additional data from BMRI in order to adequately
address all issues involved. The need for this data was expressed in
a letter from the Division to BMRI dated December 23, 1993. The
required data consists of drainage blanket permeability information and
soil liner permeability information, both sets of information were
represented to be forthcoming in the November 30, 1993 BMRI letter, as
well as additional information related to abatement item number 8,
specifically the analyses of the interstitial (liquid) component of the
AVR tailing. The need for interstitial fluid analysis was expressed in
a Posey to Oehler memo dated August 23, 1993. During a meeting
regarding abatement item number 8, held on September 17, 1993, BMRI
agreed to take additional AVR tailing samples, have the interstitial
fluids analyzed, and submit the results to the Division. To my
knowledge, the Division is still awaiting submittal of the requested
information. In addition, BMRI was required to provide monthly
monitoring data for embankment piezometers and monthly monitoring data
for flow rate to the collection pond; the data was to be supplied in
the annual report as a requirement of the terms of TR-016. This data
was not included in the annual report received during March of 1994.
Minimization of head on tailing facility liner
An integral component of the design of the San Luis Project tailing
facility is the installation of a high permeability drainage layer on
top of the composite liner which would serve to minimize hydrostatic
head developed on the liner, which in turn would minimize overall
seepage through the liner. As has been pointed out by BMRI, the
ability of a drainage layer to minimize head is dependent on the
relative difference in the permeabilities of the drainage medium and of