PERMFILE122701

• Permit No: C1981010
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: POSTMINING LAND USE
• Section_Exhibit Name: APPENDIX O
• Media Type: D
• Archive: No

i
378-7 Pond
_ Table 1. Acceptable PVC Pip e for Use in Earth Dame 1
Schedule for standard Maximum depth of
Nominal Pipe Size dimensio n ratio (SDR) fill over pipe
(in.) (ft.)
8, 10,
12 Schedule 40, SDR 26, SDR 21 10
Schedule 80, SDR 17 15
'Polyvinyl chloride pipe, PVC 1120 or PVC 1220 conforming to ASTH D-1785 or
ASTM D-2241.
Table 2a. Minimum Gages for Corrugated Hetal Pipe
' (2-2/3 in. z'1/2 in. corru¢ationa)
Steel Aluminuml
Minimum Ga a Hinimum thickness (i
Pi e.Diameter (in.) Pipe Diameter (in
Fill height 21 aad 21 and
(f t.) less 24 30 36 42 48 less 24 30
1-15 16 16 16 14 12 10 0.06 0.06 0.075
15-20 16 16 14 14 12 10 0.06 0.075 0.105
20-25 16 16 14 12 10 10 0.075 0.105 0.135
1Riveted or helical fabrication.
• Table 2b. Hinimum Cages for Corrugated Steel Pipe
' (3 in. x 1 in. corrurtations)
•
Height of Soil Cover Minimum Gage
Over Pipe Pi a Diameter
(feet) in.)
42 and less 48
0-20 16 16
20-25 16 14
Table 3. TSinimum Spillway Capacity
£ffectlvelheight of Minimum design storm2
Drainage Area Dam Storage Frequency Minimum Duration
(acre) (ft.) (acre-ft) (yr) (hr)
20 or less...... 20 or less Less than 50 10 24
20 or less...... Hors than 20 Less than 50 25 24
Hors than 20. ... 20 or less Less than 50 25 24
All others ....................... .............. 50 24
?As defined under Scope.
Select rainfall distribution based on climatological region.
SCS,Colorado, April 1980