HYDRO29393

• Permit No: C1981019
• IBM Index Class Name: Hydrology
• Doc Date: 9/18/2001
• Doc Name: Letter on Concerns for Outfalls 005A, 006A & 001A
• From: DMG
• To: WQCD
• Permit Index Doc Type: DMR’s
• Media Type: D
• Archive: No

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STATE OF COLURP~DO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman S[., Room 215
Denver, Colorado 80203
Phone: [phone]
FAx: [phone]
September 18, 2001
DIVISION OF
MINERALS
GEOLOGY
R E C L A M A T I O N
MINING•SAF ETY
Ms. Carla Lenkey Rill ovens
Colorado Department of Public Health and Environment Governor

Water Quality Control Division Greg E. Walther
E.ecmive Director
4300 Cherry Creek Drive South Michael B. Long
Denver, Colorado 80222-1530 Division Direnor
Re: Colowyo Coal Co
References:
1) Colowyo Coal Company L.P. letter of April 6, 2001, Re: DMR Report for Colowyo Coal
Company L.P.; Colorado Waste Water Discharge Permit System Number CO-00045161;
Request for Alternate Limits
2) Colowyo Coal Company L.P. letter of June 14, 2001, Re: Colowyo Coal Company L.P.
(Colowyo); CDPS No. CO-0045161 First Quarter Follow Up Letter
3) Colowyo Coal Company L.P. letter of July 18, 2001, Re: Colowyo Coal Company L.P.
(Colowyo); CDPS No. CO-00045161 First Quarter Follow Up Letter for Outfalls OOIA and
OOSA
4) CARLA J Lenkey e-mail July 26, 2001 9:58 subject Colowyo Coal Company
5) Permit Application Package (Colorado Division of Minerals and Geology Permit C-81-019,
Colowyo Coal Company L.P., Colowyo Coal Mine)
6) Colorado Division of Minerals and Geology (Division) Monthly Inspection Records
Deaz Ms. Lenkey:
This letter is in response to reference 4) above. By this reference, you ask if the various outfalls
had capacity prior to the event that was up to a 10 year / 24 hour event. The outfalls are OOSA
(Stoker Coal Loadout Pond), 006A (Loadout Loop Pond) and OOlA (Streeter Pond) (reference
1).
The Streeter Pond (Outfal] OOIA)
This pond appears to have had capacity prior to the event.
This pond has a design capacity (reference 5, Exhibit 7, Tab 13, Appendix A, ]0-14-1998) of
0.84 acre feet of sediment storage and 10.16 acre feet of water storage at the stage of peak
discharge from a 10-year - 24 hour event. The peak discharge of such an event is demonstrated