PERMFILE52521

• Permit No: C1981008A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: NH1 TAB 13 ATTACHMENT B SEDIMENTATION POND 001
• Media Type: D
• Archive: Yes

• stage-discharge relationship of the principal spillway was calculated
using SEDIMOT II, while the stage-discharge relationship of the
emergency spillway was calculated as a broad crested wier using the
Bernoulli equation. Table 5 is a summary of the spillway data.
Principal Spillway
•
•
Emergency Spillway
TABLE 5
Spillway Data Summary
Sediment Pond 001
Type
Barrel Diameter
Riser Diameter .
Length of Barrel .
Vertical Head Drop .
Entrance Loss Coef.
Bend Loss Coef.
Wier Coef.
Orifice Coef.
Manning Coef.
Drop Inlet (CMP)
6.000-inch
12.000-inch
110.000-ft
2.000-ft
1.000
0.500
3.100
0.600
0.025
Type .
Bottom Width .
Depth
Sideslope
Manning Coef.
Spillway Slope .
Spillway Length. .
Exit Channel Slope .
Exit Channel Length. .
Trapezoidal Channel
15.000-ft
2.000-ft
3h:ly
0.035
0.000 %
27.000-ft
16.000 %
60.000
The entrance to the emergency spillway is located more than one foot
above the principal spillway. There will be no flow through the
emergency spillway as a result of the runoff from a 10-year, 24-hour
precipitation event or less.
REMEDIAL COMPLIANCE PLAN
The present storage capacity and spillway configuration of Sediment Pond
001 are inadequate. As a result of this, Peabody proposes the following
remedial actions be taken pending CMLRD approval:
1. Excavate the ponding area to provide the storage capacity
shown in Table 4.
2. Construction of principal and emergency spillways as shown on
Exhibit 13-11.
9