REP01431

• Permit No: C1980007
• IBM Index Class Name: Report
• Doc Date: 5/5/1995
• Doc Name: 1994 ANNUAL HYDROLOGY REPORT
• Annual Report Year: 1994
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

•

1.0 HYDROLOGIC MONITORING ACTIVITIES
1.1 INTRODUCTION
The hydrologic monitoring program for the
West Elk Mine began in 1974 with the
completion of several groundwater
observation wells. This preliminary
monitoring network was expanded consider-
ably and in 1981, with the approval of the
West Elk Mine Mitring and Reclamation
plan (M and R Plan), became the "ap-
proved" hydrology monitoring program.
Pond MB-6 was eliminated through the
expansion and relocation of Pond MB-2 and
was redesignated MB-2R during WY 1994.
A number of additional monitoring activities
were started as explained in the various
sections of this report.
Surface water, springs, and groundwater are
considered separately even though they are
intertwined. The report discusses the
interrelationships that are significant or
could be expected.
The program was revised in 1984, 1987,
1989, 1993, and 1994. The 1984 and 1987
revisions were made to more efficiently
monitor possible effects from mining and
provide data for future permitting. The
1989 revision incorporated provisions for
collecting "B" seam baseline data and
monitoring for potential mining impacts in
anticipation of the 1990 opening of the "B"
Seam. Modifications in 1993 evolved in
conjunction with the Jumbo Mountain
expansion (PR-5) and MCC initiated a
revision in 1994 in response to Division
adequacy review of the 1990, 1991 and
1992 AHRs. This revision (TR-71) was
only recently approved. All revisions were
approved by the Office of Mined Land
Reclamation (OMLR). No changes in
monitoring procedures occurred during
Water Xear (WY) 1994 (October 1, 1993,
through September 30, 1994). Monitoring
of nineteen additional springs, one well, and
one surface station was initiated in WY 1994
to establish baseline information for the
Jumbo Mountain expansion area.
The sampling "seasons" or "windows" are
established as presented on Table 18 of the
M and R Plan. These "seasons" include
collection of samples on the rising limb of
the hydrograph (April 3 to May 13),
hydrograph peak (April 21 to June 26), and
full low flow (July 10 to October 8).
RI ?10/IOAi05/OS/95(8:04am)
1.2 SURFACE WATER
MONITORING
A baseline characterization of North Fork
water quality was performed to evaluate the
potential changes in North Fork water quali-
ty that could result from discharges at the
West Elk Mine. Baseline characterization
was performed downstream of the mine
before the start of construction in August
1981. Data sources were the USGS stream
gauging station on the North Fork near
Somerset above the mine facilities, and the
Mountain Coal Company's water quality
monitoring station on the North Fork below
the mine. The MCC station is downstream
of the surface facilities area and downstream
of all discharge points. Baseline data and
analysis of these data are provided in the
Mining and Reclamation Plan for the West
Elk Mine and in the first annual hydrology
report.
Mountain Coal Company's (MCC) WY
1994 surface water monitoring program
required eight surface water monitoring
locations (Table 1.2-1). Flow
measurements were taken and water samples
were analyzed for seven of eight stations
(there is no flow measuring capability at the
North Fork Gunnison Lower station). Water
quality was analyzed at the Lower Station on
the North Fork of the Gunnison River. Of
3 REVISED Februan 6. 199"1