GENERAL40372

• Permit No: C1981025
• IBM Index Class Name: General Documents
• Doc Date: 1/25/1989
• Doc Name: NORTH THOMPSON CREEK MINE C-025-81 MINE STATUS
• From: MLRD
• To: JIM STEVENS
• Permit Index Doc Type: GENERAL CORRESPONDENCE
• Media Type: D
• Archive: No

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STATE OF COLORADO
Roy Romer, Govei
DEPARTMENT OF NATURAL RESOURCES
MINED LAND RECLAMATION DIVISION
FRED R. BANTA, Director
DATE: January 25, 1989
T0: Jim Stevens
FROM: Candy Thompson
RE: North Thompson Creek Mine, C-025-81, Mine Status
The mine renewal is complete with the permit issued and the bond in place. A
tracking of the Dond is in the permit application. The entire mine site has
been reclaimed with the exception of the No. 1 mine portal area and prime farm
land at the truck dump area. There are approximately two acres of prime
farmland that were taken out of production by the truck dump haul road and
dump area. The landowner (Anschutz) wants the road and truck dump pad left in
for access and hay storage. However, both OSM and our regulations require
that the prime farmland be replaced. Bond has been kept to replace the prime
farmland as needed.
Tne No. 1 portals were sealed but leakage occurred soon after backfilling. A
pond and ditch system was installed to treat the high iron leakage. Treatment
was done with sodium hydroxide. The operator is unofficially proposing to try
to reseal the portals to curtail or greatly diminish the leakage.
A meeting was held with the Colorado Department of Health (Pat Nelson and
Sandy Marik) to discuss the possibility of a low amount of leakage being
allowed to drain directly to the North Thompson Creek without treatment. This
is of course supposing that the proposed portal sealing would be much more
effective than the existing seals. A repermitting of effluent limits could be
accomplished by allowing for the leakage from the portals to be put directly
into North Thompson Creek based on receiving stream standards. The problem is
that the existing Q7 ,10 flow is so low that very little leakage could occur
before the iron levels are exceeded. The Q7 ,10 appears to be too low for the
stream segment based upon observation during low flow years. The operator is
researching if there is other monitoring data exist, to allow for revision of
the low flow on the stream. If resealing of the portals is pursued, a plan
will need to be given by technical revision to determine how storage and/or
treatment of the drawdown water will be handled.
The No. 3 mine was developed in a different seam which exhibits no acid
properties. The Colorado Department of Health has issued an NPDES direct
discharge permit for the mine water. To date, no water quality problems of
import have been noted with this discharge. However, the levels of TDS should
be watched for elevation.
21 S Centennial Building, 1313 Sherman Street Denver, Colorado 80203-2273 Tel. [phone]