2013-09-10_REPORT - C1980005

• Permit No: C1980005
• IBM Index Class Name: REPORT
• Doc Date: 9/10/2013
• Doc Name: 2012 Annual Hydrology Report Review
• From: DRMS
• To: Seneca Coal Company
• Annual Report Year: 2012
• Permit Index Doc Type: Hydrology Report
• Email Name: JDM
• Email Name: DIH
• Media Type: D
• Archive: No

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dissolved sulfate (mg /1), and total dissolved solids (mg /1). All
required parameters were analyzed.
18. Basic Standards for
CWQCC regulations 41.4
The Seneca II Mine did not generate significant amount of
Ground Water
and 41.5
Ieachates in 2012. Both groundwater wells exceeded the
manganese standard (0.2 mg /1) in 2012. As mentioned in the
above item number 8 above, in soils with a high pH a
standard of 10 mg /l would be more appropriate than the .2
mg /1. In 2012 neither of the Seneca II wells displayed a value
higher than 3.5 mg /1. The TDS trend at well SBAL68 is stable
and do to the recent addition of well SFAL72 to the
monitoring program, a trend cannot be determined at this
time.
19. Restoration of ground
CDRMS regulation
For the 2012 water year, water levels at all wells fell within
recharge to approximate
4.05.12(3)
their historic ranges. All alluvial wells displayed seasonal
pre- mining rate
water level fluctuations in response to periods of
precipitation recharge.
20. Prevention of adverse
CDRMS regulation
Compliance with the Basic Standards for ground water, as in
impacts to ground water
4.05.11(1)
item 10, indicates the permittee is preventing adverse
systems outside permit area
impacts to ground water quality outside the permit area.
Monitoring data indicate the permittee is preventing impacts
to water quantity outside the permit area. Hydrology reports
indicate that a water level at all wells fell within their historic
ranges, with the exception of well SFAL72. SFAL72 is new to
the monitoring program so long term data is not available.
All alluvial wells showed seasonal water level fluctuations in
response to periods of precipitation or lack thereof.
Overburden and coal well water levels are fluctuating in
response to the precipitation recharge and ground water flow
from the reclaimed mine pits.
21. Prevention of impacts to
CDRMS regulation
No material damage has occurred, as discussed in item 20,
ground water that adversely
4.05.11(2)
above.
impact post- mining land use
22. Minimize disturbance to
CDRMS regulation
The disturbance to the hydrologic balance within and
hydrologic balance within
4.05.1(1)
adjacent to the permit area caused by mining and
and adjacent to the permit
reclamation at the Seneca II Mine is the minimum that can be
area
expected from a reclaimed surface mine at this location. Use
of best management practices indicates minimization of
disturbance to the hydrologic balance.
23. Prevention of material
CDRMS regulation
Surface water — Predictions were made for the TDS increases
damage to the hydrologic
4.05.1(1)
to be observed on Fish Creek during the months of June and
balance outside the permit
July due to discharges from the Seneca II Mine. In June, an 76
area
mg /l increase was predicted between SSF11 and SSF13. In
July, a 74 mg /l increase was predicted between SSF11 and
SSF13. Based on the information provided there was a 50
mg /l increase in TDS in June and a 40 mg /l increase in July. It
appears that the run -off from Seneca II has little impact on
Fish Creek.