HYDRO27114

• Permit No: C1980007
• IBM Index Class Name: Hydrology
• Doc Date: 1/30/1997
• Doc Name: Mine water inflows - request for bypass
• From: CDOH
• To: MOUNTAIN COAL CO
• Permit Index Doc Type: NPDES
• Media Type: D
• Archive: No

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Roy Romer, Governor
Patti Shwayder, Executive Director
III IIIIIIIIIIIII III
999
STATE OF COLORADO
Dedicated to protecting and improving the health and environment o(the people olColorado
4700 Cherry Creek Dr. 5. Laboratory Building
Denver, Colorado 80222-1530 4270 E. 11th Avenue
Phone [phone] Denver, Colorado 80210-3716 ~ _
[phone] ~~=r,~c~~t ~-r
January 28, 1997
JAN 3 01997
Ms. Kathleen G. Welt
Mountain Coal Company
P.O. Box 591
Somerset, CO 81434
DiviSi00 OI mune(c~a a x.,eoio0y
Re: Your Letter dated January 27, 1997, Request for Bypass -
Mountain Coal Company -West Elk Mine
CDPS Permit No. CO-0038776; Gunnison County, Colorado
Dear Ms. Welt:
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Colorado Deparunent
of Public Health
and Environment
The WQCD received the above-referenced letter on January 27, 1997, via facsimile. In the letter, MCC proposes
temporarily bypassing treatment ponds to directly discharge water collected from behind the "sealed" fault area
and piped to the surface. From the letter and this morning's telephone conversation, 1 understand that MCC
believes that the bypassed mine water will meet the TSS and other effluent limitations imposed at the permitted
outfalls.
The WQCD approves of the short-term bypass as long as the following conditions are met:
• The mine water is sampled from behind the seal for all tote same parameters required at MB- I's Outfall 002
and the results indicate the discharge will comply with all effluent limitations prior to discharge. Please
remember that 30-day average limitations must be met.
• MCC advises the WQCD when the bypass is initiated and terminated, and provides updates daily for the
fast three days and weekly thereafter.
• The bypassed water is sampled twice daily at the pipe outlet, independently from any other discharges. This
effluent must meet all the same effluent limitations specified for outfalls 002 and 004 independently of the
others and should not be reported together with pond MB-1 or any other discharges. If at any time effluent
limitations are not met, the bypassed discharge must cease as soon as practical without temperattrre-
shocking the fish; and the WQCD must be notified.
• Since the mine water is 88°F behind the seal and 77°-80°F at the mine portal, MCC must initiate and
discontinue the bypass flows in a staged manner to prevent temperature-shocking the fish in the receiving
stream. The maximum allowed rate of instream temperature change is 0.5 °F per hour, up to a maximum
total temperature change of 2°F, as measured comparing temperatures 100 feet upstream to 100 feet
downstream of the bypass discharge. Please measure instream temperatures each half hour until MCC is
discharging from the bypass at maximtun flow rates, then MCC may conduct twice daily sampling, if there
is no danger of exceeding the aforementioned criteria. If at any time these temperature conditions are not
met, the bypassed discharge must be decreased as soon as possible without temperature-shocking the fish by
not exceeding the maximum allowed rate of instream temperature change of 0.5 ° F per hour. Approval is
based upon MCC's discharges through outfalls 002, 004, and the bypass comprising no more than 3% of the
total stream flow.