Mine Drainage Control—Design for
Reclamation and Neutralization
L. G. KOEHRSEN, Department Head
Stanley Consultants
Muscatine, Iowa
ALTEN F. GRANDT, General Manager
Land Use and Conservation Department
Peabody Coal Company
St. Louis, Missouri
INTRODUCTION
The Will Scarlet Mine owned and operated by Peabody Coal Company is
located in southern Illinois in the coal-rich Harrisburg-Marion area. The coal being
extracted by surface mining techniques includes the Davis and DeKoven seams
situated at a depth of 30 to 70 ft and generally yielding six ft of usable coal. At the
present time, approximately 65,000 tons of coal per month are being mined in the
Peabody operation. At current production rates, about 160 acres of land are being
strip mined each year. Several other companies are working or have mined in the
same general vicinity.
Peabody Coal purchased the Will Scarlet Mine in 1967. At that time, much of
the exposed spoil material contained large amounts of readily oxidizable pyritic
material which are converted to sulfuric acid and ferrous sulfate. These constituents,
mixing with ground and surface waters, present serious localized water pollution
problems.
Within the Peabody property, the problem is generally concentrated in an area
of slightly more than 2,000 acres at the south and southwest edge of the active coal
field. As the mining operation has moved to the west, the interval between the Davis
and DeKoven seams is smaller, thus reducing the volume of troublesome spoil. Also,
a concerted effort has been made to insure that material with a significant potential
for acid formation is covered with better spoil. The acid drainage abatement program
underway by Peabody is, therefore, largely centered in the previously stripped area.
The topography of the entire region is relatively flat. The strip mining
operations have affected natural drainage to the extent that there are presently a
number of closed basins draining to old open cut pits left when mining operations
were completed in a specific area. These pits have a general area tributary to them as
shown in Figure 1. Over the years since mining activities in these locations have been
suspended, final cut pits have filled with water nearly to the tops of the high walls.
Consequently, any heavy rainfall results in an outflow from the area and ultimately
into the major drainage course which is the South Fork of the Saline River. This
overflow is highly acidic as will later be illustrated quantitatively.
The control program which Peabody Coal is actively pursuing to eliminate acid
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