GENERAL46113

• Permit No: C1982057
• IBM Index Class Name: General Documents
• Doc Date: 7/3/2006
• Doc Name: Proposed Decision & Findings of Compliance for RN4
• Permit Index Doc Type: Findings
• Media Type: D
• Archive: No

SG9 is located upstream from Pond 017, and above any mine related discharges in
the south extension area. Monitoring was conducted from 1997 through 1998, and
reinitiated in 2000, with monitoring conducted June and September.
SG7 (upstream of 006 Gulch confluence and downstream of 016 Gulch confluence)
is monitored monthly for flow and field parameters, and triannually for the
parameters noted in Appendix 15-1 of the permit application package. The total
dissolved solids (TDS) plot provided for this site in the 2003 AHR indicates an
increasing trend. The PHC predicts an irrigation season average TDS value of
1787 mg/1. For 2003, the observed value was 1110 mg/1,
FG1 (Hubberson Gulch downstream of 006 Gulch confluence) is equipped with a
continuous flow recorder and water quality samples are obtained triannually for the
parameters listed in Appendix 15-1, The TDS plot in the 2003 AHR indicates an
increasing trend. The PHC predicts an irrigation season average TDS value of
2193 mg/I for this site, while a value of 1480 mg/1 was reported in the 2003 AHR.
SG9, SG16 and SG17 were added to the monitoring program within PR-02. SG16
and SG17 were the baseline sites for Ponds 016 and 017, respectively, These sites
have been replaced by Colorado Discharge Permit System (NPDES) monitoring
sites located at the Pond 016 and 017 outfalls.
Dry Creek
One site is monitored on Dry Creek, downstream of mining (SGS). Flow and field
parameters are measured monthly, and water quality samples for the parameters
listed in Appendix 15-1 are taken triannually. The TDS plot included in the 2003
AHR indicates an increasing trend. The Seneca II-W PHC predicts an average
irrigation season TDS value of 2451 mg/1 at this site, while a value of 1825 mg/l
was observed in 2003. The ephemeral drainage tributary to Dry Creek, which
drains the "D" Pit reclamation area in [he northern portion of the original permit
area, is monitored at the Pond 005 outfall NPDES site.
Sage Creek
SCC monitors one NPDES site on Sage Creek, at the Pond 009 outfall. Flow and
field parameters are recorded monthly upstream, and triannual samples are taken
for the parameters listed in Appendix 15-1. In addition, SCC monitors an NPDES
site at the Pond 015 outfall, located on a south tributary of Sage Creek.
Seneca Coal Company has installed a sediment control system to divert, convey
and/or treat surface water runoff in and around the mine site. The sediment control
system includes seven sedimentation ponds (Ponds 005, 006, 009, 015, 016, 016A
and 017). A more complete discussion of this system is contained in Section III.C.
of this document.
Seneca II-W Findings Document 40 July 3, 2006
Permit Renewal No. S