2017-11-06_PERMIT FILE - C1980007

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 11/6/2017
• Section_Exhibit Name: Exhibit 66 Mine Water Control Plan
• Media Type: D
• Archive: No

EXECUTIVE SUMMARY & ENGINEER'S CERTIFICATION
Exhibit 66 was prepared to update the Mine Water Control Plan at West Elk Mine to reflect the
construction of a new sedimentation pond (Pond MB -5E) and associated work on ditches and
culverts necessary to direct water to the new pond, a new refuse pile east of the current one
draining to the RPE pond (RPE East Expansion), and construction of a new haul road west of
the refuse pile East Expansion. Pond MB -5E replaced MB -5, and will serve the drainage areas
that formerly reported to Ponds MB -1 (converted to freshwater storage, FW -2), MB -213
(filled/decommissioned and converted to a coal stockpile), and MB -5 (replaced by MB -5E). This
exhibit updates the one produced in August 2009 to present the proposed changes associated
with construction of the new haul road, RPE east expansion, and pond MB -5E and associated
drainage re-routing. That revision updated the November 2008 revision, which presented an
updated SEDCAD+ analysis of the mine's surface water collection and treatment system, based
on field inspections of the existing ditches and culverts, and also reflected proposed repairs to
be constructed from Fall 2008 through Summer 2009. The current analysis was based on
previous analyses provided by West Elk Mine, field confirmation of site conditions by West Elk
Mine, and designs for the RPE East Expansion conducted by Barr Engineering. Barr's April
2010 SEDCAD results for the RPE East Expansion were provided by West Elk Mine, and
incorporated into the permit tables. Survey information from the previous design analyses was
accepted, but not checked.
The current analysis includes the watersheds and drainage networks reporting to Ponds MB -3
and MB -5E, the cleanwater diversions at MB -5E, and road ditches draining to lower Sylvester
Gulch associated with construction of the haul road accessing the RPE East Expansion.
Materials submitted in 2008 remain current for the NSSA Pond and Pond SG -1; cleanwater
diversion outfalls not located near MB -5E and the RPE expansion; and outfalls to natural
drainages within Sylvester Gulch upstream of the new haul road outfalls. Updated site maps
and drainage network diagrams for MB -3 and MB -5E are included. No changes have been
made to existing previously approved Small Area Exemption demonstrations, or to Pond MB -4.
With consideration to applicable drainage principles and generally accepted engineering
standards and procedures, the analysis submitted provides for the drainage and stormwater
flow from the subject site areas to be in accordance with applicable requirements, and to the
best of my knowledge, represents good standard engineering practice. The drawings presented
herein are for permitting purposes only (not for construction).
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Peter E. Kowalewski, PE