_PERMIT FILE - C1981008A ‎(13)‎

• Permit No: C1981008A
• IBM Index Class Name: PERMIT FILE
• Doc Name: Sedimentation Pond 004
• Section_Exhibit Name: Tab 13 Attachment D
• Media Type: D
• Archive: Yes

INTRODUCTION
Sediment Pond 004 is an earthen embankment structure constructed by
Peabody Coal Company in the mid-1970's as a temporary sediment structure
to control runoff and sediment from the disturbed areas of Nucla Mine.
In 1986, Sedimentation Pond 004 was redesigned and subsequently approved
by CMLRD. The remedial work was completed in November, 1987. Sediment
Pond 004 is located in Section 31 of Township 46 North, Range 15 West,
northwest of the town of Nucla (see Exhibit 13-14A) .
SITE DESCRIPTION
LAND USE
Sediment Pond 004 has a 6.3-acre watershed that is tributary to Tuttle
Draw. This watershed is classified as approximately 100 percent
reclaimed.
EMBANKMENT
The existing embankment is a homogeneous earth fill compacted in lifts
to design specifications. The top width of the embankment is
approximately 12-feet wide with upstream and downstream slopes of
approximately 3h:ly, respectively. The existing spillway consists of a
12-inch diameter drop inlet corrugated metal pipe with a 5/8-inch
diameter hole located at the 100 percent sediment storage level .
DESIGN ANALYSIS
GENERAL
Sedimentation Pond 004 was evaluated and constructed to meet or exceed
the design and performance requirements of the Colorado Mined Land
Reclamation Division while utilizing as much of the existing structure
and topography as possible. Sedimentation Pond 004 was constructed to
adhere to the following specifications:
1. Provide storage for the runoff from the 10-year, 24-hour storm
event without experiencing any discharge through the emergency
spillway (0.19 ac-ft.) .
1