REP43775

• Permit No: C1992081
• IBM Index Class Name: Report
• Doc Date: 2/11/1997
• Doc Name: H-G LOADOUT C-92-081 1995 ANNUAL HYDROLOGY REPORT
• From: DMG
• To: JOE DUDASH
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

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999
STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Depanmen; of Natural Rc~nurces
131 3 Shermnn til., Ruum 21 S {I~

Denver, Culurazio 80203 ~
~

Phone: [phone] II
FAX: [phone]
DEPARTMENT' OF
NATURAL
RESOURCES
DATE: February 11, 1997
Roy Romer
Governor
TO: Joe Dudash
lames 5. Lochhead
Executive Director
FROM: Susan Burgmaier nlichael B. Long
Division Duenor
RE: H-G Loadout(C-92-081)
1995 Annual Hydrology Report
I have completed a review of the 1995 Annual Hydrology Report (AHR) for the H-G Loadout. In
addition to reviewing the 1995 AHR, I reviewed the permit application package sections pertaining
to baseline information, monitoring requirements, probable hydrologic consequences (PHCj, and the
mitigation and hydrologic reclamation plan. Following are my comments regarding the review.
Seneca Coal Company conducted the required surface and ground water monitoring as
described in the approved permit application package, with no apparent exceptions.
The site is located on, and drains to Dry Creek which is tributazy to the Yampa River.
The PHC section of the permit application package predicts that the operation will not
measurably impact the water quality of Dry Creek, nor will the operation pose any
threat to existing water use potential of Dry Creek and the Dry Creek alluvial aquifer.
Seneca Coal Company's monitoring, through the 1995 water yeaz, shows that alluvial
water quality is consistent with monitoring results reported by H-G Coal Company
from 1987 through 1992.
Water levels reported by Seneca Coal Company for the alluvial wells also is consistent
with levels reported by H-G Coal Company for the period of record.
With a few exceptions, surface water quality is also consistent with data over the
period of record. The exceptions aze:
Total Dissolved Solids (TDS) at site HGSD3, which is the "new"
downstream site, reached an al)-time high of 5870 mg/l on April 6,
1995. The previous high was 5656 mg/I in November 1986.
Sulfate also reached its highest point, again at site HGSD3, on April 6,
1995. The reported value of 3750 mg/I exceeds the previous high of
3688 mg/1 reported in August 1992.
On the same date, TDS and Sulfate at the upstream site (HGSD1) were
2800 mg/l and 1660 mg/1, respectively.
Seneca Coal Company dewatered Pond 001 three times during the Spring of 1995, on
March 2, May 9, and May 22. None of these dewatering periods directly coincides
with the increased TDS and Sulfate on Dry Creek in April. The March 2 dewatering
effort produced an average flow of 94.7 gpm, for 26 hours, with a reported TDS of