GENERAL40803

• Permit No: C1981037
• IBM Index Class Name: General Documents
• Doc Date: 12/10/1992
• Doc Name: CITIZENS REQUEST FOR INSPECTION DATES 11 15 1992 GEC MINE C-81-037
• From: DMG
• To: THE CORLEY CO
• Permit Index Doc Type: GENERAL CORRESPONDENCE
• Media Type: D
• Archive: No

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STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
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Department of Natural Resources ~~o
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1313 Sherman St., Room 215
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Denver, CO 80203 a,
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Phone:[phone] re~a
FAX: [phone]
Ray Romer
Governor
December 10, 1992 Micnae~R.long
Division Director
Dr. W.D. Corley
The Corley Company
P.O. Box 1821
Colorado Springs, CO 80901
RE: Citizen's Request for Inspection Dated November 15, 1992,
G.E.C. Mine, C-81-037
Dear Dr. Corley:
The Division inspected the G.E.C. West Pit with you on December 3,
1992 to review the issues outlined on the November 15, 1992
Citizens' Request for Inspection. The letter specifically identified
two concerns: The southern extension of the berm on the eastern side
of the diversion ditch and sediment removal from the pond.
During the inspection, the West Pit drainage channel was measured
6" upstream of the southernmost extension of the berm. The channel
was a trapezoidal shape with a 10' bottom width and an 18.8' top
width. Measurements were taken at 3' intervals from west to east from
the bottom of the channel to the tape elevation (10", 13", 7.5", 11",
and 14", such that the mean depth was 0.84'). The shallowest depth
between the top of a sand bar and the low point on the extension of
the berm was 4"-6", taken from a visual sighting from the sand bar to
the low point between the West Pit drainage channel and the unnamed
creek diversion. A hydraulic analysis of a 10-year 24-hour event in
the West Pit was performed in the office. A 10-year 24-hour event for
the West Pit above this point is 15.5 cfs. This discharge results in
a flow depth of 0.231' in the previously described channel.
Therefore, the channel can currently handle the flow, but further
deposition may change the situation. Therefore, the inspection report
requested that Harrison extend the berm to provide a margin of safety
(page 4 of 4).
The Division acknowledges that sediment removal within the pond has
not been completed. The April 22, 1992 Compliance Agreement called
for sediment removal by June 30, 1992. The Division performed some
measurements during the July 16, 1992 inspection, and notified
Harrison Western that more work was required. Storms in August
resulted in significant sediment deposition from Overburden Stockpile
No. 2, the West Pit and the Unnamed Creek. Harrison Western did
3-4 days of work on sediment removal starting November 5, 1992. They
apparently had some difficulty cleaning the sediment with the
equipment they had and they ran out of time.