2010-04-26_PERMIT FILE - C1980007A ‎(3)‎

• Permit No: C1980007A
• IBM Index Class Name: Permit File
• Doc Date: 4/26/2010
• Doc Name: Refuse Pile Expansion East
• Section_Exhibit Name: Exhibit 82 Refuse Pile Expansion East
• Media Type: D
• Archive: Yes

of the Colorado Discharge Permit System (CDPS) General Permit for Coal Mining Facilities
(CDPHE, 2008).
Adequate storage for runoff from both the existing RPE and the RPE East is provided by raising the
top of the existing spillway headwall in the manhole located at the head of the discharge standpipe
serving the pond. The headwall will be raised six inches to an elevation of 6106.0 to store the runoff
from the 10 -year, 24 -hour storm. Larger storms will overtop the headwall and discharge through the
existing primary and spillway outlet pipe. The pond area has sufficient capacity to store runoff from
the probable maximum precipitation (PMP) event (5 inch rainfall) without overtopping its
embankments.
•
Revised April 19, 2010 P P
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P:\Mpls \06 CO\26 \06261003 MCC Refuse Pile Site Review & Permit \WorkFiles\Permit Application \Text \2010- 04- 19_RPE East Permit Application.doc13