HYDRO30516

• Permit No: C1981019
• IBM Index Class Name: Hydrology
• Doc Date: 9/19/2001
• Doc Name: Letter on Information from 1Q2001 Reports
• From: DMG
• To: WQCD
• Permit Index Doc Type: DMR’s
• Media Type: D
• Archive: No

III IIIIIIIIIIIIIIII
f 999
STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
September 19, 2001
Ms. Carla Lenkey
Colorado Department of Public Health and Environment
Water Quality Control Division
4300 Cherry Creek Drive South
Denver, Colorado 80222-1530
Re: Colowyo Coal Co
Reference:
DIVISION OF
MINERALS
Sc
GEOLOGY
RECLAMATION
MINING•SAFETY
Bill Owens
Governor
Greg E. Walther
Executive Dvetlor
Michael B. Long
Division DIteUOr
1) Colorado Division of Minerals and Geology letter of September 18, 2001, same subject.
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 OOlA and
OOSA
Deaz Ms. Lenkey:
This letter is in response to our telephone conversation of this morning. Your clarification was
for an assessment of the state of repairs and conditions of the ponds at the time of exceedences
reported in the lit Quarter 2001 Discharge Monitoring Reports. Such state of repairs or
conditions aze measured against the approved pond designs in the Colorado Division of Minerals
and Geology (Division) Permit Application Package for Permit C-81-019.
The sedimentation ponds at Colowyo Coal Company, L.P. Colowyo Coal Mine (Colowyo) aze
now operated as treatment ponds (passive, automatic dewatering) in lieu of the former
containment mode. As such, if the pond contains water to the level of the drawdown weep holes,
any water (in any amount) entering the pond will simultaneously initiate a discharge. Initially,
runoff into the pond will displace the cleaz water (if any) that was retained in the pond. After
displacement, the pond is designed to hold new runoff water long enough for any discharges to
meet settleable solids limitations.
The Streeter Pond (Outfall OOIA)
The condition and state of repair of this pond was marginal.