REV12538

• Permit No: C1984062
• IBM Index Class Name: Revision
• Doc Date: 2/19/1991
• Doc Name: COLO YAMPA COAL CO MINE 3 SURFACE WATER QUALITY
• To: CYPRUS YAMPA VALLEY COAL CO
• Type & Sequence: TR6
• Media Type: D
• Archive: No

•
u
•

February 19, 1991
•
M. A. MiddletOrr
Cyprus Yampa Valley Coal Company
Colorado Yampa Coal Company - Mine No
• III IIIIIIIIIIIII III
3 Surface Water Quality
As you requested I have reviewed the surface water quality data in
the vicinity of Mine No. 3. The purpose of this review is to
demonstrate that runoff from reclaimed areas is not adversely
impacting surface water quality. To perform this review mean data
from surface water stations upstream of, within the area of and
downstream of Mine No. 3 were compared. The data indicate that there
has been no significant deterioraton of surface water quality due to
runoff from Mine No. 3.
Data from two stations upstream of Mine No. 3 were analysed. Since
Mine No. 3 is located at the confluence of Middle and Foidel Creeks,
Station 700 on Middle Creek and Station 900 on Foidel Creek were used
in the analysis. Station 29 is located on Middle Creek downstrean of
most of the actiivities related to Mine No. 3 and downstream of the
confluence of Foidel and Middle Creeks. Station 69 is located on
Trout Creek below its confluence with Middle Creek and is downstream
of all activities related to Mine No. 3.
Comparisons were made for mean data for Water Year 1990 and for all
available data. The means were calculated by using the detection
limit as the measured value thus calculating a very conservative
(high) mean. In general the mean concentrations for Station 29 fall
between the concentrations for the two upstream stations indicating a
normal mixing of the waters with minimal impact from the mining
activies. In general the mean concentrations for Station 69 are
lower than all of the upstream stations indicating virtually no
impact from Mine No. 3. The mean concentrations for only three
parameters at either Station 29 or 69 exceed a water quality
standard. These parameters were cadmium, mercury and silver. In all
cases the means included many values below the detection limit. In
the case of mercury and silver the exceedences were still within the
limits of the upstream values. The cadmium mean for all data for
Station 29 was calculated to be less than 1.07 ug/L while the
standard is 1.00 ug/L thus barely exceeding the standard; however,
this mean includes data that was below the old detection limit of S
ug/L. Also the 1990 data is subtantialy below the standard.
For a few other paramters the mean concentrations of the downstream
stations have values that are slighlty out of the range of the
upstream stations. These paramters include temperature, pH,
hardness, SAR, dissolved solids, suspended solids, major cation and
anions, metals, total ammmonia and ortho-phophate. in most cases
these out-of-range values are more environmentally favorable than the
upstream values. In the remaining cases the mean values are only
slightly out of the range, includes a number of below detection limit
values or are at the detection limit. None of these out-of-range
values represent a significant deterioration of water quality