REP47560

• Permit No: C1980007
• IBM Index Class Name: Report
• Doc Date: 5/1/1989
• Doc Name: ANNUAL HYDROLOGY REPORT MT GUNNISON NO 1 MINE WATER YEAR 1988
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

•
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HYDROLOGIC MONITORING ACTIVITIES

The hydrologic monitoring program at the
Mt. Gunnison No. 1 Mine was initiated in 1974
with the completion of several groundwater
observation wells. This preliminary monitoring
network was expanded considerably and in 1981,
with the approval of the Mt. Gunnison No. 1
Mine, Mining and Reclamation plan (M and
R Plan), became the "approved" hydrology moni-
toring program. fn 1984, the hydrology monitoring
program was revised, with the approval of the
Colorado Mined Land Reclamation Division
(CMLRD), to more efficiently monitor possible
effects from mining and provide data for future
permitting.
In 1987, the hydrology monitoring program
was revised again, based on anticipated annual
coal production figures that have been down-
wardly revised. Under the revised program, base-
line monitoring in areas that would not be mined
for at least several years has been reduced. Con-
sequently, the program focuses more closely on
coordinating hydrology monitoring with areas
being mined to look for possible mining impacts.
Sampling periods and parameters were also
revised. Beginning with the 1988 water year
(1 October 1987 through 30 September 1988),
sampling is conducted three times per year instead
of quarterly. These three sample periods cor-
respond to the start of spring runoff, the peak of
spring runoff, and the fall low flow. Sample
parameters include pH, conductivity, temperature,
total iron, total manganese, total dissolved solids,
and total suspended solids. Because this revised
monitoring plan was approved by the CMLRD
during the 3rd quarter of 1987, the 1988 water
year was the first year affected by the revision.
This report reflects those changes.
The 198$ Annual Hydrology Report contains the
following:
Data from continuous flow monitor-
ing at five stream gauging stations;
Data from continuous flow monitor-
ing, in cooperation with the U. S.
Geological Survey (USGS), at the
reconstructed Minnesota Creek Gaug-
ing Station site and at the USGS
gauge on the North Fork of the
Gunnison River near Somerset.;
Data from seasonal water quality
sampling at two surface water quality
monitoring stations: The North Fork
Gunnison Rivcr above Sylvester
Gulch and the North Fork Gunnison
River below the mine;
Data from seasonal measurements of
pH, temperature, dissolved oxygen,
turbidity, and conductivity at the six
stream gauging stations in the Min-
nesota Creek Basin and Sylvester
Gulch;
• Data from seasonal measurements of
discharge and water quality sampling
on seven springs issuing from of
below the "F'-seam wal;
• Data from seasonal water level and
water quality measurements on 19
wells; and
Data from measurements of mine
water discharges, and mapping of
inflow locations.
SURFACE WATER
MOI~IITORING
WECC's surface water monitoring program
includes nine monitoring locations (Table 1). The
locations of these monitoring stations are shown
on Exhibit I. Under the revised monitoring pro-
gram, flumes located on Horse Creek, South ~
Prong, and East Fork of Minnesota Creek below S~
Beaver Reservoir have been removed and will no
longer be monitored until they are reestablished
the summer before mining impacts can be ex-
pected in those drainages. Daily flow estimates
(including mean, maximum, and minimum flows)
for the five WECC gauges are summarized in
Appendix A