ENFORCE29281

• Permit No: M1988112
• IBM Index Class Name: Enforcement
• Doc Date: 4/21/1992
• From: MLRD
• To: ANDREW J DOUCHANE
• Media Type: D
• Archive: No

Battle Mountain Gold
NOPV Abatement Requirements
page 3
(6) Cyanide Detection, Interception, Containment and Remedial Treatment:
BMG originally proposed the construction of a heap leach at the San Luis
mine. In 1988, BMG amended its permit application to delete the heap
leach and implement a contained vat processing system. This amended
process was designed to yield detoxified tailings for disposal within the
tailings area. BMG replaced the originally proposed heap leach double
liner system with leak detection with a single liner system without leak
detection. This amendment was approved by the Division relyin~ upon
BMG's representation that tailings Cyanide levels would not ex eed 3.8
ppm WAD Cyanide and 4.4 ppm total Cyanide.
In the absence of a leak detection system, migrating leakage f#om the
tailings disposal ponds would only be detected by the five gro nd water
monitoring wells (M-5, M-6, M-7, M-8 and M-9) located in the v~cinity of
the tailings area. Since the inception of the approved monito~Ying
program, only monitoring well M-9 has intercepted ground water, The
analytical results from samples collected from well M-9 have nit detected
any Cyanide occurrence.
The Division directs BMG to reevaluate its approved program fod ground
water monitoring, sampling and analysis for the tailings dispo al area.
At a minimum the Division believes that all existing ground wa er
monitoring wells should be deepened or redrilled to ensure con inuous
penetration of the ground water table. Further, the Division believes
that all tailings area monitoring facilities should be sampled monthly ^ ;
and the analytical results reported expeditiously to the Division. This /X\
evaluation report,~as a technical revision prior to May 29, 199$.
Further, BMG shall develop and submit a tailings effluent leak ge
interception, containment and treatment plan for impacted grou~d water,
surface water and soil. This plan shall be submitted to the D vision as
a technical revision prior to June 15, 1992.
Status: Unresolved - BMG has committed to development of reme~ial plan
in letter of April 16, 1992.
- The requirements for monitoring plan timer~dment were
only advanced by the Division on April 211, 1992.
(7) Amendment of Ore Processing Methodology:
BMG's preliminary suspicions of altered metallic ore content, end the
coincidental failure of the designed processing cyanide recoveriy circuit,
are indications that the ore processing methodology currently tieing
applied by BMG may require significant modification. If BMG d termines
it necessary to modify its ore processing methodology, BMG shall submit
appropriate permit revision applications to the Division. Appdopriate
permit amendments, supported by comprehensive analytical results and