INSPEC18303

• Permit No: M1980244
• IBM Index Class Name: Inspection
• Doc Name: MINERALS PROGRAM INSPECTION REPORT
• Inspection Date: 11/5/1994
• Media Type: D
• Archive: No

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(Page 2)
NINE ID f OR PROSPECTING ID ~ H-80-244
INSPECTION DATE 11-5-94
INSPECTOR'S INITIALS CS
OBSERVATIONS
A monitoring inspection of the Phase 1 leach pad construction was conducted.
The geomembrane contractors deployed several textured VLDPE panels comprising the upper liner
in the pregnant solution storage area during the morning. Strong wind goats that began in
the late morning did not allow any further deployment this day. It was noted that the free
ends (above the lower anchor trench) of several geomembrane panels previously deployed on the
south aide of the pad were being lifted and blown by the wind. The CQA monitor directed the
geomembrane contractor to stabilize the free ends by placing Band bags. It is critical, in
order to prevent geomembrane damage, that all geomembrane deployed be securely held with Band
bags or other means up to the point that the drain cover fill ie applied.
The steepest elope within the pregnant solution storage area on the north aide of the pad was
measured with an Abney level to be 16°, or about 6.8° leas than the maximum allowable elope
of 2.5:1.
The access/haul road constructed on drain cover fill above the lower anchor trench on the
south side of the pad was inspected. The low area in the curve above the anchor trench,
noted in the 10/29/94 inspection report as a PB, had been brought up to grade. The road was
found to be at the 5' minimum thickness or greater throughout its length.
The earthworks contractor was pushing drain cover fill onto the composite liner on the south
side of the pad during the afternoon. This operation ie typically done at night when there
are fewer problems with wrinkles in the VLDPE, however, the specifications do allow spreading
of drain cover fill at other times at the discretion of the manager. Spreading of drain
cover fill this day was in locations near the free ends of geomembrane panels, so that
wrinkles could be worked out toward the free ends. It is the Division's view that drain
cover spreading onto the liner should only be allowed during times when the liner is
contracted and tight, such as at night or during the early morning, or in areas where
wrinkles can be easily propagated to a free end, such as was the case this day.
The earthworks contractor was stockpiling soil liner fill at the top of hill no.l, just north
of the Phase 1 pad. A laborer was observed to be removing oversize rocks from the fill in
the stockpile location.
The geomembrane contractors worked on patching and repair work in several Locations during
the afternoon. Destructive peel and shear testing of coupons cut from test welds was
observed at the beginning of the afternoon shift.
The geomembrane contractor initiated the tying-in of smooth to textured VLDPE at the lower
anchor trench. It was observed that the tie-in was a fusion weld, perpendicular to the
slope, and located below the lower anchor trench. This tie-in method results in smooth VLDPE
in direct contact with the upper geotextile in the Leak collection system. Such direct
contact ie unacceptable, see PB 1. The unacceptable tie-in occurred at the low end of panels
SH-160, SM-162, SM-164, and SM-165. There are a number of ways that an acceptable tie-in
could be accomplished. One preferred method is illustrated in a conceptual diagram attached
to this report. Whatever the method used to tie-in the smooth VLDPE to the textured VLDPE,
the critical considerations are: 1)The composite liner (defined as geomembrane in intimate
contact with soil liner) must be continuous throughout the entire pad; 2) Only a textured
VLDPE surface may be in contact with geotextile.
Another critical consideration for upper geomembrane deployment at the lower anchor trench
interface, is that the transition from soil liner subgrade to geotextile subgrade be smooth,
and that the soil liner subgrade at the transition be compacted and free of loose atones or
other detritus.
cc: Berhan Keffelew
I & E Contact Address Carl Mount
^ CE
NAME John Hardaway ^ BL
OPERATOR Crio ole Creek & Victor Gold Co. ^ FS
STREET P.O. Box 191 ^ HW
CITY/STATE/2IP Victor. CO 80860 ^ HMWMD (CH)
^ SE
^ WQCD (CH)
^ OTHER