GENERAL36155

• Permit No: M1980244
• IBM Index Class Name: General Documents
• Doc Date: 4/30/1997
• Doc Name: CRESSON MINE HEAP LEACH PAD-STATUS OF LOW VOLUME SOLUTION COLLECTION SYSTEM FOR PHASE 2-CC&VG
• From: DMG
• To: BERHAN KEFFELEW
• Media Type: D
• Archive: No

•
Memo to Berhan Keffelew
CC&VG LVSCS ALR Response
page 4
CC&VG's stated purpose for the LVSCSs, as articulated by Mr.
Hardaway in his April 16, 1997 letter to Mr. Keffelew;
"The purpose of each (LVSCS) system is to pump pregnant
solution that may move through the uppermost liner due to an
imperfection in that liner, to convey that fluid out of the
LVSCS and, thus, away from the lower liner, and to thereby
control and minimize the fluid pressure that could otherwise
occur on that lower liner. By minimizing the fluid pressure
on a composite liner, the potential for flow to occur through
that liner, which, in the case of each LVSCS, is the lowermost
composite liner in the containment system, is also minimized.
Further, removal of solution prevents saturation of the LVSCS
and, thus, reduces the potential for a saturated zone to occur
throughout the entire thickness of the LVSCS gravel, which, if
it occurred, would transmit the pressure from the, overlying
column of pregnant solution to the lower composite liner."
(2) The Division will accept and review a permit revision
application from CC&VG, should it choose to submit one, which
proposes the following modifications to its existing ALR and
Response Actions specified within the approved Amendment
Number 6 application.
(a) CC&VG submits the revised ALR projection calc Tations
contained within its April 16, 1997 letter~~for the
purpose of amending its ALR trigger levels.
(b) CC&VG agrees to continue daily monitoring of saturated
levels within the PSA and daily inflow monitoring of both
Phase 1 and Phase 2 LVSCSs. The collected data shall be
submitted to the Division weekly by CC&VG.
(c) CC&VG proposes to amend its ALR Response Actions as
follows:
(1) CC&VG will maintain two operable pumps in each
LVSCS at all times. Each individual pump will be
capable of removing 112 of the maximum previously
monitored inflow to the respective LVSCS.
(2) An additional fully-operational standby pump, of
fluid pumping capacity equivalent or greater to the
largest required LVSCS pump(s), will be maintained
on site at all times. In the event of pump
failure, the Division wi1l,Eje notified within one
(1) day, and the effected pump(s) will be replaced