1988-04-18_PERMIT FILE - C1981008A ‎(4)‎

• Permit No: C1981008A
• IBM Index Class Name: PERMIT FILE
• Doc Date: 4/18/1988
• Doc Name: Sedimentation Pond 007
• Section_Exhibit Name: Tab 13 Attachment G
• Media Type: D
• Archive: Yes

"Alternative B" (With Riprap):
Minimum Depth = 3.5 ft.
Side Slopes = 3:1
Slope = 1.4% to 33%
Maximum Velocity = 15 fps
Q = 67.1 cfs
n = 0.04
Shape = V-ditch
CONSTRUCTION PLAN
Site Work Prior to Embankment Construction
The embankment construction area will be dewatered as much as practicable to allow heavy
equipment to operate in the area. To accomplish this, a dewatering trench or trenches
will be excavated with a small backhoe. A pump will be set in the trench to lower the
local water table below the keyway. Before dewatering, Peabody will receive a
Construction Dewatering Wastewater Discharge Permit from the Colorado Department of
Health. This permit will allow Peabody to discharge this water down drainage away from
the construction activities. All dewatering will comply with the requirement of this
Discharge Permit.
Embankment Design and Construction
The embankment foundation area will be cleared of organic matter prior to construction.
The fill material will be free of sod, large roots, other large vegetation matter, frozen
soil, and coal processing wastes.
Material for both the keyway and the embankment will come from the ponding area within the
site. Topsoil from the construction area will be salvaged and stockpiled in a topsoil
stockpile.
The placing and spreading of fill material will proceed from the lowest point on the
embankment (keyway) in horizontal layers of such thickness as to allow for a minimum
compaction of 93 percent of standard proctor. Compaction tests will be run on
approximately every 2,500 cubic yards of material placed in the embankment. Results of
these tests will be kept on file at the mine engineering office and will be available for
inspection if requested. Both the upstream and downstream slopes of the embankment will
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