2016-08-25_REPORT - C2009087

• Permit No: C2009087
• IBM Index Class Name: REPORT
• Doc Date: 8/25/2016
• From: DRMS
• To: Peabody Sage Creek Mining, LLC
• Annual Report Year: 2015
• Permit Index Doc Type: Hydrology Report
• Email Name: JLE
• Email Name: DIH
• Media Type: D
• Archive: No

Peabody Sage Creek Mining, LLC
Page 5
8/25/2016
No exceedances were report for NPDES Pond 002.
Upper Grassy Creek:
Four sites are monitored on Upper Grassy Creek that also
fall within the Yampa Segment 13i; sites YSGF5, SSG1,
SSG2 and NPDES Pond 003. The following
exceedances were noted on Table 15 of the AHR:
• NPDES Pond 003, Total Rec. Iron in October of
2014.
• SSG1, Total Rec. Iron in June of 2015.
• SSG1, Total Mercury in April through June of
2015.
• SSG2, Total Rec. Iron in June of 2015.
• SSG2, Total Mercury in April through
September 2015.
• SSLG5, Total Rec. Iron in May and June of
2015.
• YSGF5 Total Rec. Iron in June of 2015.
• YSGF5, Total Mercury in April and September
2015.
According to the AHR, the Iron excursions are a result of
high suspended solids and that a temporary modification
(expires December 31, 2018) of the Iron standard as
"current conditions". Given this, the AHR indicates
these excursions are not considered to be a standard
exceedance. It is unclear if the Mercury standard was
actually exceeded. The Method Detection Limit (MDL)
for Mercury is .2 ug/1 and the stream standard is .01 ug/l.
Given this, the MDL is higher than the standard.
-Lower Grassy Creek:
Lower Grassy Creek is on Segment 13j of the Yampa
River Basin. This segment is classified for Agriculture,
Aquatic Life (Warm 2), and Recreation N. One
monitoring site discharges into this segment, Site YSG5.
The following exceedance was noted on Table 17 of the
AHR:
• The Ammonia standard was exceeded in June of
2015.