HYDRO29173

• Permit No: C1981041
• IBM Index Class Name: Hydrology
• Doc Date: 10/4/1985
• Doc Name: POWDERHORN COAL INFLOW REPORT ROADSIDE MINE
• From: MLRD
• To: THOMAS D GILLIS
• Permit Index Doc Type: CORRESPONDENCE
• Media Type: D
• Archive: No

Richard D. Lamm
Governor
•
DEPARTMENT OF NATURAL RESOURCES
David H. Getches, Executive Director
MINED LAND RECLAMATION DI\
DAVID C. SHELTO N, Director
DATE: October 4, 1985
T0: Thomas D. Gillis, Esq.
FROM: Steven G. Renner
RE: Powderhorn Coal Inflow Report, Roadside Mine
As per your request, I have reviewed the inflow report for the Roadside Mine.
Water typically flows into the workings from the coal itself. Inflow from the
coal appears to account for the majority of the inflows. I observed that the
active face of the mine will be wet, while coal adjacent to a recent cut is
quickly dewatered, usually in a matter of days. The wet coal generally seems
to flow as small seeps (less than 1 gallon/minute) or as a wetted line sloping
forward (toward the face) from bottom to top.
Where roof bolts have penetrated the shale unit overlying the coal, small
amounts of water flow into the mine. These points generally flow less than 1
gallon per minute, but are quite numerous. This source probably accounts for
20% or less of mine inflows.
The floor also contributes flow into the mine. This sandstone (Rollins
Sandstone Member?) in places appears to contribute substantial amounts of
water. For the mine as a whole, about 10% to 20% of the inflow is from the
floor.
Finally, the contact between Quarternary gravels and the Mesaverde Fm. is the
source of more inflows. This contact is responsible for most of the 30 g/m at
the North Decline. This is because the decline fan housing which penetrates
the gravels and upper Mesaverde, provides a conduit for flow into the mine.
Condensation at the fan reportedly accounts for some of the water at the
decline area, also.
As for~uality of the water, it is high in total dissolved solids, and
acceptable in iron and manganese levels. The pH is fairly basic, varying from
8.08 to 8.77. These four parameters are the only ones, besides total
suspended solids, measured. Based on this limited information, the water is
of poor quality (very hard) for drinking, but could probably be discharged to
the surface system without adverse effects.
An annual average of two hundred twenty-two gallons/minute of inflow were
measured in the mine during 1984 (116.7 million gallons/year). Annual
consumption at the mine, which includes discharges to the surface system from
points 001 and 002, is 106.7 million gallons/year. The difference between
inflow and outflow (consumption) is 10.0 million gallons/year (19 g/m). This
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