2016-12-01_PERMIT FILE - C1980007 ‎(6)‎

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 12/1/2016
• Doc Name: Hydrologic Characterization of the South of the Divide
• Section_Exhibit Name: Exhibit 71
• Media Type: D
• Archive: No

2016 Recommended Modifications to the West Elk Mine Hydrologic Monitoring Network 1
1.0 INTRODUCTION
MCC owns and operates the WEM, located south of the North Fork of the Gunnison River near
Somerset, Colorado. The WEM has operated under several Federal coal leases including; C-
1362 (issued in 1967), COC -56447 (issued in 1995), and COC -67232 (issued in 2007), where
current and/or future mining may occur. The coal exploration program for the WEM property
was initiated during the late 1960's and continued through the 1970's. The preliminary permits
for the WEM were issued in 1981. Prior to the mine's development, the initial hydrologic
baseline monitoring began in 1977. Construction of surface facilities, coal handling facilities,
and portals for the WEM began in 1981. The initial room and pillar coal production for the "F"
Seam began in 1982 in the northwestern mine area. Beginning in 1991, MCC began longwall
mining development of the `B" Seam in the Northwest Panel area (aka Jumbo Mountain area).
Mining was completed in the Northwest Panel area (Panels 1 to 11) in August 1997. The
Gribble Gulch hydrologic monitoring sites are underlain by the Northwest Panel area.
Hydrologic monitoring in Gribble Gulch began in 1977 and continues to the present. Hydrologic
monitoring in Raven Gulch began in 2005 and continues to the present. There are no plans for
future mining in the Raven Gulch area (MCC, 2016).
HydroGeo has conducted the hydrology monitoring program for MCC since November 2001.
MCC recently retained HydroGeo to review the water quality and flow data collected from the
existing hydrologic monitoring sites and to make recommendations on reducing the number of
monitoring sites in areas that have not been actively mined for more than ten years and where no
future mining is planned, specifically, the Gribble Gulch and Raven Gulch areas. The
hydrologic monitoring sites in the Gribble Gulch and Raven Gulch areas (Map 1) that have
shown no adverse trends in water quantity (flow) and/or water quality since active mining
operations in the area ceased were selected as candidates for possible elimination from the MCC
WEM hydrologic monitoring network.
Seep E-14-1, located in Upper Box Canyon, is also recommended for removal from the network
because there has been no flow during the period of record, and the site was permanently
covered by a drill pad in 2006.
In addition to the recommendations for the spring and seep and surface water monitoring sites in
the Gribble Gulch and Raven Gulch areas, HydroGeo also recommends that the 14 compromised
and/or damaged wells that are no longer functional be eliminated from the monitoring network.
The WEM hydrologic monitoring network, including the sites recommended for removal is
presented on Map 1.
August 2016 HydroGeo, Inc.