ENFORCE33118

• Permit No: C1981047
• IBM Index Class Name: Enforcement
• Doc Date: 4/14/1989
• Doc Name: BLUE RIBBON MINE PORTAL BENCH FACIAL SLUMP PN C-81-047
• From: MLRD
• To: MATT HAYES
• Violation No.: CV1989008
• Media Type: D
• Archive: No

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STATE OF COLORADO
Roy Romer, Governor
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DEPARTMENT OF NATURAL RESOURCES
MINED LAND RECLAMATION DIVISION
FRED R. BANTA, Dlreetor
DATE: April 14, 1989
T0: Matt Hayes ,._
FROM: Jim Pendleton
RE: Blue Ribbo ine Po Bench Facial Slump
( No. C-81-047)
Jeff Clayton and I met Jim Stover at the Blue Ribbon Mine to complete an
examination of the recent slump observed on the face of the reclaimed portal
bench. I refer you to our inspection report of April 12, 1989 for detailed
observations regarding the observed site conditions. In brief, my examination
led me to believe that the slump occurred because of saturation of the
surficial soil cover placed on the bench face. The deeper refuse is not
saturated and does not appear to have participated in the slump. The top
surface of the reclaimed mine bench was observed to be dry and well drained,
not evidencing any of the ponding which plagued it in prior years. At n{y
request, Jim Stover completed several shallow test holes, in each case
determining that the soil on the top of the bench was unsaturated. Piezometer
P-4, which is located at the crest of the facial slope shows the water table
in the deeper refuse to stand 26 feet beneath the top surface of the bench.
While at the site I encouraged Jim Stover to submit a repair plan, required as
an abatement in the recently issued NOV, which included a discussion of the
above topics. I also indicated that we would accept a repair similar to the
one completed far last year's analogous facial slump. That repair appears to
have stabilized the area affected by the slump which occurred in the spring of
1988. I also encouraged him to propose the installation of a pair of
piezometers in the area of the 1989 facial slump. One piezometer would be
installed with an isolated completion in the deeper refuse (approximately 20
feet in depth). The second piezometer would be completed in the surficial
cover of the bench (approximately 5 feet in depth). Hopefully, this pair of
piezometers would allow determination of the degree of saturation existing
within the refuse versus the surficial cover in the affected facial area of
the reclaimed bench.
cc: Susan Mowry
5259F/scg
215 Centennial Building, 1313 Sherman Street Denver, Colorado 80203-2273 Tel. [phone]