2012-06-08_PERMIT FILE - C2009087A ‎(12)‎

• Permit No: C2009087A
• IBM Index Class Name: Permit File
• Doc Date: 6/8/2012
• Doc Name: DRAINAGE AND SEDIMENT CONTROL PLAN
• Section_Exhibit Name: Exhibit 2.05.3-E2 Drainage and Sediment Control Plan
• Media Type: D
• Archive: Yes

Peabody Sage Creek Mine - Drainage and Sediment Control Plan
4.3 Culverts
Culverts were designed to safely pass the peak flow from the 10 -year, 24 -hour storm event.
Some select locations have culverts installed at a larger diameter or in multiples to ensure
additional safety from larger runoff events Rule 4.03.1(4)(e)(i) stipulates that culverts with
an end area greater than 35 square feet shall be designed to safely pass the 20 -year event;
there is site - specific 25 -year event data and it results in a more conservative design, thereby
increasing the safety factor. The culvert sub - routine in SEDCAD4 was used to size the
culverts; however, SEDCAD4 can only size a single diameter pipe at a location - it does not
have the ability to design multiples of smaller diameter pipes. Table 2.05.3- E2 -10, Culvert
Conversions - Single Culvert to Multiple Culverts, summarizes design multiples.
Operational culvert locations are shown on Map 2.05.3 M4, Drainage and Sediment
Control Plan; postmine culvert locations are shown on Map 2.05.4 M1, Sage Creek
Postmining Topography. Culvert design demonstrations are included in Appendix 2.05.3 -
E2.A, Sediment Pond 002, 10 year /24 hour SEDCAD Demonstration and Appendix 2.05.3 -
E2.H, Postmine Channel and Culvert Designs, respectively. Minimum culvert dimensions
for operational culverts are summarized in Table 2.05.3- E2 -11, Operational Culvert
Schedule, while postmine culvert dimensions are summarized in Table 2.05.3- E2 -12,
Postmine Culvert Schedule.
TABLE 2.05.3 -E2 -10
Culvert Conversions - Single Culvert to Multiple Culverts
Design Size
Multiples
feet
inches
x -sec.
area
(s q. in.
60 -inch
48 -inch
36 -inch
10
120
11309.7
4.0
(4)
6.3
(7)
11.1
(11)
9
108
9160.9
3.2
(4)
5.1
(5)
9.0
(9)
8
98
7238.2
2.6
(3)
4.0
(4)
7.1
(7)
7
84
5541.8
2.0
(2)
3.1
(3)
5.4
(6)
6
72
4071.5
1.4
(2)
2.3
(3)
4.0
(4)
5
60
2827.4
1.0
(1)
1.6
(2)
2.8
(3)
4
48
1809.6
1.0
(1)
1.8
(2)
3
36
1017.9
1.0
(1)
Note: assume headwater depth
is the same for multiples
as used for design size.
5.0 STOCK TANK DESIGNS
Twenty -one stock tanks were designed and constructed for the previously reclaimed surface
mine area as part of the reclamation activities for the closed Seneca II Mine. The
construction occurred in conjunction with the construction of various postmine channels. As
part of the Seneca II Mine bond release evaluation activities Seneca Coal Company
determined that several of the stock tanks could be reclaimed - 13 stock tanks were
subsequently approved as permanent postmine structures by CDRMS.
TR -0)' 2.05.3 -E2.22 Revised 04/12
4