2009-05-12_PERMIT FILE - C1980005 ‎(2)‎

• Permit No: C1980005
• IBM Index Class Name: Permit File
• Doc Date: 5/12/2009
• Section_Exhibit Name: Tab 12 Operation Plan
• Media Type: D
• Archive: No

state Rea.
rw~aff) x (slope adjustsent i`actor) x (Porrling Factor) x
(watershed shape adjustment factor) = Q10cfs.
11. Determine culvert size by using Quart 5 for roarrd
corrugated metal pipes with projecting entrances frcan the
Federal Highway AdminiGtration's "Hydraulic FY~gineering
C;rr~,lar No. 5." The culvert diameter is determined fr'CIIn
the ncmngraph aft.P.r' knaaing What the di c~-harr~e is aIYl the
ratio of allowable headwater to culvert diameter is for a
projecting headwall-type entrance.
12. Suitable protection against erosion or fill saturation
will be provided at the entrance where headwater is
anticipated.
13. Peabody requests a variance frrnn the QII12B Arles aryl
Regulations, Section 4.03.1(4)(e)vi, requirirq the
spacing of culverts at specified intervals. With the
topography, site conditions, and precipitation rates at
the Seneca II Mine site, Peabody's experience has been
that with properly desic~ed, installed, and maiTrhainad
culverts, excessive erosion will be controlled as well as
or better than goir-g to multiple culvert spacir-g which
will create more drainage channels aryl rmrltiply any
erosion potential.
14. See Table 12-6 for a list of culvert specifications.
15. See Appendix 12-2 for culvert sizing calculations.
16. Zhe design of all new culverts proposed to be wnstructed
during the next five year permit term will be designed to
safely pass the peak runoff from the 10-year, 24-hour
storm event. The peak flows will be determined using the
SIDIMOT II Co¢[g~utes Program. Proposed culvert
specifications and cxurtputer printouts aooor~any this
application in Table 12-6 and Appendix 12-2. F7diibit 7-7
depicts culvert locations.
4.03.1(6) Maintenance. Haul roads are inspected on a daily basis at
the Seneca II Mine. If upon inspection it is determined that
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12-35 Revised 10/02/89