ENFORCE31647

• Permit No: M1988112
• IBM Index Class Name: Enforcement
• Doc Date: 5/27/1992
• Doc Name: NOV & ORDER
• Media Type: D
• Archive: No

Battle Mountain Gold
NOPV Abatement Requirements
page 3

(6> Cyanide Detection, Interception, Containment and Remedial Tre~tment:
BMG originally proposed the construction of a heap leach at t e San Luis
mine. In 1988, BMG amended its permit application to delete he heap
leach and implement a contained vat processing system. This mended
process was designed to yield detoxified tailings for disposa within the
tailings area. BMG replaced the originally proposed heap lea h double
liner system with leak detection with a composite liner syste without
leak detection. This amendment was approved by the Division elying upon
BMG's representation that tailings Cyanide levels would note teed 3.8
ppm WAD Cyanide and 4.4 ppm total Cyanide.
In the absence of a leak detection system, migrating leakage rom the
tailings disposal ponds would only be detected by the five gr and water
monitoring wells (M-5, M-6, M-7, M-8 and M-9) located in the icinity of
the tailings area. Since the inception of the approved monit ring
program, only monitoring well M-9 has intercepted ground water. The
analytical results from samples collected from well M-9 have n t detected
any Cyanide occurrence.
The Division directs BMG to reevaluate its approved program fo ground
water monitoring, sampling and analysis for the tailings dispo al area.
At a minimum the Division believes that an expanded monitoring program,
including additional ground water monitoring wells, should be 'mplemented
to ensure continuous penetration of the ground water table. F rther, the
Division believes that all tailings area monitoring facilities should be
sampled monthly and the analytical results reported expedition ly to the
Division. This evaluation report shall be submitted to the Di~ision as a
technical revision prior to May 29, 1992.
Further, BMG shall develop and submit a tailings effluent leak ge
interception, containment and treatment plan, to be implemente in the
event of contaminant migration from the tailings area. This c ntingency
response plan should specify methods to remedy contamination o ground
water, surface water and soil. This plan shall be submitted t the
Division as a technical revision prior to June 15, 1992.
Status: Satisfied - BMG has committed to development of remed~al plan
in letter of April 16, 1992.
- The requirements for monitoring plan modi ication
were only advanced by the Division on April 21, 1992.
- BMG verbally committed to modify the moni oring plan
on April 22, 1992.
<7) Modification of Ore Processing Methodology:
BMG's preliminary suspicions of altered metallic ore content, nd the
coincidental failure of the designed processing Cyanide recove y circuit,