Control of Water at
Strip Mining Operations through Sound
Mining and Reclamation Practices
JAMES A. DEANE, Director
Forestry and Water Quality
Peabody Coal Company
St. Louis, Missouri
Water control at strip mine operations has two separate parts. The first is
handling the waste from the cleaning plant. The second is the handling of the
water at the active pit itself. The mining operation with proper planning will
have little or no effect on the receiving stream.
The fine coal waste or "slurry" can be handled by building settling ponds to
allow the suspended solids to settle out. The water can then overflow to the
stream. In most cases, however, the water flows to another pond or lake and is
pumped back to the cleaning plant. This type of closed circuit allows no water
from the cleaning plant to get into the adjacent streams.
The heavy coal waste or "gob" can be handled in two ways. It can be
pumped with the slurry or it can be hauled to a disposal area. The drainage from
gob" itself gives us most of our acid mine drainage since it is high in pyrites.
The "gob" that is pumped with the slurry does not contribute acia water to the
stream as long as the mine is active. The closed circuit system minimizes the
chance of acid water getting to the stream. Once the mining operation ceases,
these "gob piles" can contribute a great amount of acid water to the streams.
Several things have been tried to seal the refuse from air and moisture; both of
which are needed to cause sulfuric acid. Asphalt spraying was tried in Illinois, but
did not hold up over the winter. Allowing the refuse to Durn eliminates the water
problem but creates an air pollution problem. To date, the only sure known
method to eliminate this pollutant contributor is to cover it with a soil material.
This must be a well designed operation. The "gob pile" should be graded, terraced and covered with soil. When the refuse is covered, it should be planted to
establish a vegetative cover. This vegetative cover will minimize the erosion of
the soil covering. The cost of covering a "gob pile" varies from 800 to 2,000
dollars per acre. The cost depends on the size of the "gob pile" and the availability of the soil material used to cover it.
Heavy refuse that is hauled can be disposed of by depositing in piles on the
ground. The method is not very successful as the water running off this pile will
be acid; also, you still have the expense of covering it. If this method is used
diversion ditches should be dug around the disposal area. The best way to handle
the heavy refuse is to haul it back to the active pit. It is then covered during the
stripping operation. Should the haul to active pit be too long, the refuse should
be hauled to an abandoned pit that is close. Hauling to an abandoned pit will
place the refuse below drainage and no acid water will get to the streams. When
the pit is almost filled with refuse the surrounding spoil can be used to cover it.
Water encountered during the mining operation should be intercepted before it
enters the pit.   Diversion ditches above the hi-wall will handle run-off water.
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