HYDRO21985

• Permit No: M1977424
• IBM Index Class Name: Hydrology
• Doc Date: 2/10/2000
• Doc Name: CDPHE CONCURRENCE ON LOGAN WASH MINE CLOSURE
• From: HARDING LAWSON ASSOCIATES
• To: DMG
• Media Type: D
• Archive: No

Xerding Lawson Assiielstes
February 9, 2000
Mr. Don Holmer
Colorado Departrnent of Public Health and Environment
4300 Cherry Creek Drive South
Denver, CO 80246-1530

RE: Concurrence au Occidental Oil Shale, Inc. Logan Wash Mine Closure, DeBeque, Colorado
Deaz Mr. Holmer:
Glenn Springs Holdings, Inc. (GSHI), subsidiary and property manager of Occidental Oil Shale, Inc (OOSI)
requests the concurrence of the Colorado Departrnent of Public Health and Environment (CDPHE) in the
closure of retorts and the termination of the surface-water monitoring program at the Logan Wash Mine site.
GSHI is in the process of closing the Logan Wash Mine, an inactive oil shale facility located approximately
12 miles northeast of DeBeque, Colorado. Hazding Lawson Associates (fD..A), the environmental consultant
for GSHI, is conducting closure activities. As part of the mine's closure, GSHI intends to shut-in the
underground oil shale retorts that are currently draining to an evaporation pond (Pond 1). The portals and
surrounding disturbed acreage will be sealed and all disturbed acreage will be reclaimed.
The Colorado Division of Minerals and Geology (DMG), the permitting agency for the mine, has approved
the Proposed Closure Plan for the Logan Wash Mine Retorts -Technical Revision No. 2. As part of the
technical revision, HLA has installed a compliance well at the head of Logan Wash, downgradient of the
mine. HLA intends to sample the well according to the schedule agreed upon in the DMG letter of October
25, 1999. In addition, DMG has approved all reclamation plans associated with the mine's closure.
CDPHE has been involved with monitoring activities at the Logan Wash Mine including the administration of
NPDES permit CO-0029947. This permit involves two sample sites or outfalls; outfall OOl, located
approximately 450. feet (ft) below the main mine water discharge pipe, and outfall 002, located at the mine
water discharge pipe at the Research Mine portal. Ou[fall 001 has not shown flow since 1991 and therefore
has not been sampled.
In addition to the NPDES monitoring program, CDPHE required surface water monitoring at 5 surface water
sites associated with the mine in 1997. T'he purpose of the surface-water monitoring program was to monitor
water quality downstream of planned discharge from the Logan Wash Mine evaporation/holdingyond. The
monitoring program was to be conducted for a period of two years. However, the planned discharge from the
evaporation pond was never implemented and GSHI has no future plans to discharge water from the pond.
The water that remains in the pond after the retorts are shut-in will be managed on-site using enhanced
evaporation techniques. Five surface-water sites have been sampled from 1997 to the present and include
sites P-1 (pipeline station), Pond-1 (evaporation pond), RC-1 (Roan Creek upstream of Logan Wash), [JN-I
Engineering and 743 Horimn Coun, Suite 7368 Grano Jungion, CO 87506 [phone]
Environmental Services ASubnJury of NaNing Anoriaru • Ofim Nmiom.:dr