1992-04-13_PERMIT FILE - M1983141

• Permit No: M1983141
• IBM Index Class Name: Permit File
• Doc Date: 4/13/1992
• Doc Name: LIMITED IMPACT OPERATION 110 2 RECLAMATION PERMIT APPLICATION FORM
• Media Type: D
• Archive: No

1
' materials were removed prior to heat fusion seaming.
10. Sand bags were used to keep the geomembrane line in
t position during windy conditions prior to completely
filling the impoundment area with mill tailings.
' 11. Any necessary repairs to the polyethylene
geomembrane liner will be patched with similar liner
material, and will be repaired in the same manner used
during the initial installation.
' 12, When the tailings pond is expanded, the upper edge
of the geomembrane lining will be used to seam
' additional panels to the previously installed
polyethylene liner material.
' 13. During the construction of the tailings dam, the
granite bedrock was ripped and exposed along the entire
length of the tailings impoundment area. Because the
exposed bedrock would not permit gravity drainage, the
' excess water decantation line was placed in position
along the high side of the interior of the tailings pond
on top of the installed geomembrane liner. The
' geomembrane liner is sealed to the horizontal section of
the water decantation pipe where it passes through the
tailings dam, and several seep rings were attached to
the pipe to prevent tailings from piping along the
' decantation line.
A 30 mil polyethylene geomembrane was selected to
line the tailings impoundment area rather than the
originally proposed plastic liner composed of polyvinyl
chloride. The polyethylene liner has better ultraviolet
' light resistance characteristics than the polyvinyl
chloride liner material, and it will be less susceptible
to deterioration due to prolonged exposure to sunlight
and weathering. It also possesses good chemical
' resistance to acids and heavy metals and, because of its
high tensile strength, will be more puncture resistant
and less prone to environmental stress cracking than a
' liner composed of polyvinyl chloride. The geomembrane
liner was manufactured by Poly-America, Inc. , of Grand
Prairie, Texas, and installed under the direction and
' supervision of a field representative from Con-Tec
Lining, Inc. , of Bakersfield, California.
14. Two monitoring wells were drilled downgradient from
' the tailings pond by Ground Water Systems, Inc. , of
Boulder, Colorado. Accompanying this letter are copies
of the Colorado Division of Water Resources' Permits for
' those two monitoring wells. These two wells were spaced
135 feet apart and were drilled to a depth of 60 feet,
with the upper 20 feet encased in steel pipe to prevent
surface water migration from contaminating the wells.