_GENERAL DOCUMENTS - C1981017 ‎(165)‎

• Permit No: C1981017
• IBM Index Class Name: GENERAL DOCUMENTS
• Doc Name: Bid Documents ‎(IMP)‎
• Permit Index Doc Type: General Correspondence
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources pilor,t7wp
1313 Sherman St., Room 215
Denver,Colorado 80203
Phone:[phone]
FAX:[phone]
DEPARTMENT OF
MEMO NATURAL
RESOURCES
November 11, 1994 Roy Romer
Governor
TO: Maintenance File James S.Lochhead
Executive Director
FROM: Steven Renner Michael B Long
Division Director
RE: Coal Stockpile Drainage and Maintenance Requirement
A large erosional gully has developed at the upper coal stockpile
area as a result of uncontrolled discharge from this area to the
road ditch below the area. The apparent cause of this erosion is
either a failure of a pre-existing berm, or the failure to install
a berm to direct runoff away from the stockpile area outslope.
Approximate measurements of the erosional feature are: 20 feet in
length, 5 feet in width and 4 feet in depth. Due to the size,
relative stability and presence of weedy growth on the sides of the
gully, I assume that it has been in place for several years.
Map IV-C-I does not indicates where the drainage from the upper
coal storage area (B bed coal stockpile) is directed. However, the
drainage from the conveyor which feeds stockpile reports to the
road ditch immediately below the stockpile, and into a 24 inch cmp
which then drains into the Redwood Tank Pond and the Bus Garage
Pond ) . This appears to be confirmed by permit text at App II-b-7
att. 4, page 4 of 11, which indicates that the drainage from the
"#1 stockpile area" is directed into the road ditch. This text
indicates that the capacities of the pond system discussed above is
adequate to contain the runoff from the stockpile area and from the
conveyor right of way. A portion of the area toward the east is
contained by a small non-discharging berm. However, the majority
of this approximately 5 acre area appears to drain through the
gully to the road ditch which drains to the above mentioned pond
system.
The subject of maintenance activities at the stockpile area will be
to ensure that the drainage is either passed safely from the
stockpile to the conveyance system or contained at the site. This
may be accomplished by either building a berm to allow water to
accumulate at the stockpile area, construct a berm and discharge
pipe to the road ditch or erection of a silt fence to contain as
much of the coal fines as possible on the site prior to the water
discharging to the road drainage system.
Site conditions were re-evaluated on November 9, 1994, after