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 Darer /nrerprcrarion and /mpacr Asseumrnr for Permit Area and Adjacrnl Arens
Work on the preparation of the phase IV
area was not begun during 1988 as planned
because of lower refuse production. Preparation of
the area or at least a portion of the area, to
receive refuse material is anticipated to begin
during 1989. Phase 1V wnsists of a portion of the
hillside area and the south underdrain, as well as
an alternate access road. This area is permitted
and bonded at present.
ASSESSMENT OF SPRINGS
in August 1981. Both stations were 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 Recla-
mation Plan for the Mt. Gunnison No. 1 Mine
and in the first annual hydrology report.
COMPARISON OF BASELINE
WATER QUALITY WITH
OPERATIONAL DATA
A comparison of 1988 monitoring data with
previous years shows no significant trends or
changes which can be associated with mining
activity. Most springs are responsive to spring
runoff, but flow rates are sporadic and many times
do not correlate well with other seasonal para-
meters such as snowpack, precipitation, or stream-
now.
ASSESSMENT OF SURFACE
WATER AND AVF'S
Efforts were made in previous annual reports
to characterize baseline river water quality to
evaluate potential changes in surface water quality
due to mining activities at the M[. Gunnison
No. 1 Mine. Continuous monitoring of stream
^ows and periodic monitoring of spring discharge
rates are performed to provide the long term data
base from which possible impacts of mining can
be assessed.
BASELINE CHARACTERIZATION OF
WATER QUALITY AND STREAMFLOW
A baseline characterization of North Fork
water quality was performed in previous annual
reports to evaluate the potential changes in North
Fork water quality that could result from dis-
charges at the Mt. Gunnison No. 1 Mine. Baseline
characterization was performed downstream of the
mine using data from the USGS stream gauging
station on the North Fork near Somerset and
from the West Elk Coal Co. water quality moni-
toring station on the North Fork below the mine
for sample data prior to the start of construction
Of the ten parameters selected for baseline
characterization, seasonal trends are apparent for
TDS, TSS, and total iron. The other parameters
do not exhibit seasonal variation. Total dissolved
solids are leas[ concentrated in the North Fork
during the period between about May and July,
probably because high-TDS ground water is
diluted by snow runotf. Total iron is most con-
centrated during this period of time. Total sus-
pended solids are most concentrated from April
to July.
A comparison of baseline water quality data
in the North Fork of the Gunnison River to 1988
monitoring data shows no significant changes in
water quality in the North Fork. Slightly higher
results can be related to higher than previous fall
precipitation and are not a result of mining.
There does not appear to be any changes in the
North Fork of the Gunnison River quality that
can be attributed to affects of mining for water
year 1988.
MINE WATER MANAGEMENT AND
IMPACT ASSESSMENT
The discussion of the mine water system and
hydrologic impact assessment is organized by the
tour sources of water:
• North Fork water
• sanitary wastewater
• mine water, and
• runoff from disturbed areas.
Use and discharge of water from these sources is
studied for its potential to affect the North Fork.
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