2014-05-28_REPORT - C1982056 ‎(4)‎

• Permit No: C1982056
• IBM Index Class Name: Report
• Doc Date: 5/28/2014
• From: Twentymile Coal Company
• To: DRMS
• Annual Report Year: 2013
• Permit Index Doc Type: Hydrology Report
• Email Name: JDM
• Email Name: DIH
• Media Type: D
• Archive: No

2013 ANNUAL HYDROLOGY REPORT
1.0 INTRODUCTION
The following Annual Hydrology Report (AHR) presents 2013 hydrologic monitoring data from the Twentymile
Coal, LLC's (TC's) Foidel Creek Mine located near Oak Creek, Colorado. Hydrologic monitoring locations and
specific data results are discussed below. This AHR fulfills the reporting requirements under the Colorado State
Division of Reclamation Mining and Safety (DRMS) Permit No. C -82 -056. Unless otherwise indicated, all
references to "2013" in this report refer to the 2013 Water Year (October 1, 2012
through September 30, 2013). Monitoring results for prior water years are presented in previous AHRs,
although selected historical data from prior years are summarized in some of the tables and figures for
comparison with 2013 data.
Following Section 2.0's discussion of Site Location and Background, this AHR provides Section 3.0 on the TC
2013 Hydrologic Monitoring Program, which in turn is divided into nine subsections:
3.1) Bedrock Groundwater monitoring,
3.2) Alluvial groundwater monitoring,
3.3) Surface water monitoring,
3.4) Spoil springs monitoring,
3.5) Natural springs monitoring,
3.6) Mine water discharge sites monitoring,
3.7) CDPS discharge sites monitoring, and
3.8) Mine inflow study.
3.9) Water Balance
Next follows Section 4.0, discussing Subsidence impacts for local creeks (Fish, Foidel, and Middle Creeks), and
lastly Section 5.0, Summary and Conclusions. Tables and Figures are provided in appendices located at the back
of this AHR.
2.0 SITE LOCATION AND BACKGROUND
The TC Foidel Creek Mine site is located approximately 20 miles southwest of Steamboat Springs, Colorado, at
the south end of Twentymile Park (see Figure 1). This is an active underground coal mining operation, having
affected a cumulative total of roughly 15,200 acres in south Routt County through 2013. The total Life -Of -Mine
permit area encompasses approximately 22,530 acreas. The primary TC surface facilities cover about 800 acres,
including discharge ponds and railroad loadout areas. The Foidel Creek Mine portals and surface facility areas
are bordered on the south and south west by strip mine spoils from the former Colorado Yampa Coal Company
(CYCC). Trench and berm rockfall mitigation structures, located north of the primary TC facilities along Routt
County Road 27 beneath the Twentymile Sandstone cliffs, covers approximately 30 acres. The coal refuse pile at