2019-03-11_REPORT - C2009087 ‎(2)‎

• Permit No: C2009087
• IBM Index Class Name: Report
• Doc Date: 3/11/2019
• Doc Name: Annual Hydrology Report
• From: Peabody Sage Creek Mining, LLC
• To: DRMS
• Annual Report Year: 2018
• Permit Index Doc Type: Hydrology Report
• Email Name: TNL
• Media Type: D
• Archive: No

Introduction
The information assembled in this 2018 Annual Hydrology Report (AHR)
includes data collected from approved monitoring sites established at
the Peabody Sage Creek Mine (PSCM), State Permit No. C-2009-087.
Locations of monitoring sites associated with the PSCM can be found by
referring to Map 2.04.7-M1, Hydrology, provided in Volume 4A of the PSCM
Permit Application Package (PAP). Locations of monitoring sites
associated with the Seneca II Mine can be found by referring to Exhibit
7-2, Hydrology Monitoring Site Location Map, provided in the Seneca II
PAP. In addition, NPDES ponds, surface water sites, monitor wells and
spoil springs are depicted on Figure 1, Appendix A. A general site map
of PSCM and Seneca Coal Company monitoring sites is provided in Figure
2. All references to 2018, or to "this year", will be for Water Year
2018 (October 1, 2017 through September 30, 2018) unless otherwise
noted. All tables referred to in the following text can be found in
Appendix A. In addition, a table of contents for Appendix A is given at
the beginning of that appendix.
The PSCM mining permit was approved by the CDRMS in May 2010. Excavation
of the portal area began in June 2011. A large portion of the reclaimed
Seneca II Mine (State Permit No. C-80-005) has been incorporated in the
PSCM permit area. The last of the coal at the Seneca II Mine was removed
in August 1999. Many of the hydrology monitoring sites used by the
Seneca II Mine continue to be used for the PSCM. Therefore, when
discussing historic data, the Seneca II Mine (or, Seneca) name will be
used. PSCM will be used when discussing current data.
Field conductivity and pH meters are calibrated prior to each day's use.
The conductivity meter is calibrated using a potassium chloride solution
with an electrical conductivity in the 1000 to 4000 umbos/cm range. The
pH meter is calibrated using NBS traceable buffers with pH values of 7
and 10. Prior to October 1, 1989, all field conductivity values
collected at Seneca II monitoring sites were not corrected for
temperature (i.e., 25° C). Field conductivity data starting on October
1, 1989 were temperature corrected to 25° C. The formula for correcting
1