REP35632

• Permit No: C1980007
• IBM Index Class Name: Report
• Doc Date: 4/28/1988
• Doc Name: 1987 ANNUAL HYDROLOGY REPORT
• Annual Report Year: 1987
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

1
' Annual Hydrology Report
April 28, 1988
Page 19
i
A ~mpar
son of 1987 monitoring data with previous years shows no significant
trends or changes which can be associated with mining activity. Most springs
aze responsive to spring runoff, but flow rates are sporadic and many times do
' not correlate well with other seasonal parameters such as snowpack,
precipitation, or streamflow.
' 2.3 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 Mt. Gunnison No. 1 Mine. Continuous monitoring of
strea,T flows and periodic monitoring of spring dischazge rates are performed to
provide the long term data base from which possible impacts of mining can be
' assessed.
2.3.1 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 discharges at the Mt. Gunnison No. 1 Mine.
Baseline characterization was performed downstream of the mine using data from
the USGS stream gaging station on the North Fork near Somerset and from the West
' Elk Coal Co. water quality monitoring station on the North Fork below the mine
for sample data prior to the stazt of construction 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 Reclamation Plan for the Mt. Gunnison No. 1 Mine and in the First
Annual Hydrology Report.
2.3.2 Comparison of Baseline Water Quality with Operational Data
Of the ten parameters selected for baseline characterization, seasonal trends
t are apparent for TDS, TSS, and total iron. The other parameters do not exhibit
seasonal variation. Total dissolved solids are least concentrated in the North
Fork during the period between about May and July, probably because high-TDS
ground water is diluted by snow runoff. Total iron is most concentrated during
' this period of time. Total suspended solids aze most concentrated from April to
July.
A comparison of baseline water quality data in the North Fork of the Gunnison
' River to 1987 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.
any chances in the North fork of the Gunnison There does not
River quality appear to be
that can be
attributed to affects of mining for water year 1987.
1
1