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

•
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2.0 Hydrologic Data /nrerpreranon and lmpacr Assessment for the Permir and Adjacent Areas
mining. The water in the wells were muddy
and acidification of the solutions prior to
filtration preferentially leached out
manganese.
2.3.4 "E" Seam
The "E" Seam is located below the inactive
(mining) °F" Seam and above the active
"B" Seam. Well SOM-23-H-2, historically
dry, has enough moisture on the casing wall
to preclude an accurate water level measure-
ment. It is located approximately a mile
south of the nearest mining activity. What-
ever the cause of the changed condition, no
hypothesis of impact to this well from min-
ing activity has been developed.
2.3.5 "B" Seam
Well SOM-C-72-H was "lost" due to
undermining in WY 1994. Active mining
occurred in the "B" Seam near the well's
location during the monitoring period, and
this loss was anticipated. Well SOM-129-H,
the replacement for sealed well SOM-127-H,
has not been in place long enough to
identify any specific trends as a result of
mining activity. It is located relatively close
to areas mined, and the depths of water in
the well validate a low permeability of the B
Seam.
Full-suite chemical analyses were run on
wells SOM-C-72-H, SOM-129-H and IMB-
12. Well SOM-C-72-H is a moderately
alkaline, saline sodium chloride water of
low hardness. All SOM-C-72-H samples
exceed the secondary drinking water
standard for chloride. The 4/22/94 sample
exhibited dissolved iron concentrations of
0.31 mg/1, and exceeded the secondary
drinking water standard in groundwater of
0.3 mg/l. All other parameters were well
below groundwater standards.
R1.2I0/l0A/OS/OS/95(9.18am)
21
Well SOM-129-H is a sligh[ly alkaline,
excessively saline (TDS is approximately
2300 mg/I) sodium bicarbonate water of low
hardness. One of the nine samples
(5/18/94) exhibited cadmium at <0.025
mg/1, exceeding the cadmium groundwater
drinking water standard of 0.005 mg/I. As
analytical interferences elevated the
detection limit, this reading establishes no
precedent on high cadmium levels. Two
samples (10/12/93 and 8!18/94) showed
concentrations of iron 1.1 to 3 times higher
than the secondary drinking water standard
for groundwater of 0.3 mg/I.
JMB-12 monitors an alkaline, saline (TDS is
approximately 1300 mg/I) sodium
bicarbonate water of moderate hardness (274
mg/l). Iron and manganese concentrations
regularly exceed the secondary drinking
water groundwater standards. The salinity,
high concentrations of sodium, and periodic
exceedances of groundwater standards would
preclude the B seam from use as an
untreated drinking water source. Its depth
in the mine's locale and the availability of
better quality, more easily accessed water
also would limit its use within the
foreseeable future.
2.3.6 Rollins Sandstone
Well SOM 128-H was set to monitor water
levels in the Rollins Sandstone, a formation
below the "B" Seam. The water levels
measured in SOM-128-H appear to represent
the piezometric surface approached in WY
1992 and peaked in WY 1993.
Consideration is being given to raise the
upper baseline limit to 6583.2, the level
reached on May 2, 1993. No sustained floor
flows have been encountered during mining
of the "F" or the "B" seams. Mirting
activities, in both the "F" and the "B"
seams, are thought to have had no impact on
groundwater in the Rollins Sandstone to
date. Anew monitoring well LP-1 was