HYDRO24998

• Permit No: C1981019
• IBM Index Class Name: Hydrology
• Doc Date: 10/8/1998
• Doc Name: REQUEST FOR ALTERNATE LIMITS DUE TO A STORM EVENT SECOND QUARTER 1998
• From: CDOH
• To: COLOWYO MINE CO
• Permit Index Doc Type: DMR’s
• Media Type: D
• Archive: No

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STATE OF COLUI~UU
Roy Romer, Governor
Patti Shwayder, Executive Director
Dedicated to protecting and improving the health. and environment o! the people of Colorado
4300 Cherry Creek Dr. 5.
Denver, Colorado 80246-1530
Phone [phone]
Located in Glendale, Colorado
h «p://www.cdphestate.co. us
October 5. 1998
Laboratory and Radiation Services Division
8100 Lowry Blvd.
Denver CCl A0220-6928
17031 692J090
J.D. Harmon
Colowyo Mine Company L. P.
Colowyo Mine
5731 State Highway 13
Meeker, Colorado 81641
RECEIVED
OCT 8 1998
DIV. OF MINERALS
8 GEOLOGY
RE: Request for Alternate Limits due to a-Stone Event, Second Quarter 1998
CDPS Permit No. COG-850017, Moffat County
Dear Mr. Harmon,
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Colorado Department
of Public Health
and Fltvitonmrnt
This is in response to a letter from Kimberley A. Wolf dated August 11, 1998 in which she reported a
noncompliance with effluent limits at outfalls 001 A, 002A, 004A, 007A, 009A, and 010A due to a storm
event. Her letter described a rain event that occurred on June 17 8 18, 1998 during which an accumulation
of precipitation was recorded at various rain gauges at Colowyo Coal Company that resulted in discharges
at the various outfalls referenced above. Ms. Wolf claimed altemate limits of less than or equal to a 10-
year/24-hour precipitation event for all outfalls. The recorded rainfall for June 17 818, 1998 qualifies as a
storm event of less than or equal to a 10-year/24-hour precipitation event for all referenced outfalls, except
outfall 009A. All outfalls, except outfall 009A, are exempt from effluent limits for Total Suspended Solids
and Total Iron. Because discharged occurred seven days after the rain event at outfall 009A, this outfall
does not qualify for the alternate limits. The self monitoring data you provided on your Discharge
Monitoring Report is shown below:
Reported Permit
Period Outfall Parameter Results Conditions
2098 001A TSS (mg/I) 161 (30 day avg) 35 (30 day avg)
2Q98 001A TSS (mg/I) 296 (daily mx) 70 (daily mx)
2Q98 002A TSS (mg/I) 92 (30 day avg) 35 (30 day avg)
2098 002A TSS (mg/I) 92 (daily mx) 70 (daily mx)
2098 004A TSS (mg/I) 74 (30 day avg) 35 (30 day avg)
2098 004A TSS (mg/I) 74 (daily mx) 70 (daily mx)
2Q98 007A TSS (mgll) 284 (30 day avg) 35 (30 day avg)
2Q98 007A TSS (mgll) 488 (daily mx) 70 (daily mx)
2Q98 007A Iron, Total (mg/I) 7.98 (30 day avg) 3.5 (30 day avg)
2098 007A Iron, Total (mg/I) .14.2 (daily mx) 7.0 (daily mx)
2Q98 008A TSS (mg/I) 49 (30 day avg) 35 (30 day avg)
2Q98 010A TSS (mg/I) 76 (30 day avg) 35 (30 day avg)
2098 010A TSS (mg/I) 76 (daily mx) 70 (daily mx)
For the above reported values, Colowyo Coal Company L. P. has shown that discharge occurred within 24-
hours of the precipitation event and the condition of the ponds before the event could contain a 10-yearl24-
hourprecipitation event. Thus, Colowyo Coal Company qualifies for the alternate limits waiving TSS and