Citizens Coal Council’s work on the issue of coal processing focuses on the toxic byproduct that is coal slurry/sludge. The information below provides more background on coal slurry.
WHAT IS COAL SLURRY?
Coal slurry (also known as sludge) is the toxic solid/liquid by-product of the mining and processing of coal. Strip mines (see: strip mining) and mountaintop removal (see: mountaintop removal) generate enormous quantities of “overburden” (rocks and soil), which is then used to create dams, usually in valleys or hollows between two mountains. When the coal leaves the mine, it is “dirty”, that is, mined material consists not only of coal, but also of silt, dust, and other non-combustible material. The coal must be processed (or washed) and between 20-50% of the mined material received must be rejected and impounded (National Research Council, 2002; coalimpoundment.org). The area behind the dam is then filled with millions of gallons of noxious slurry. Slurry is made up of a large list of hazardous chemicals, either leached from the coal during the washing process, or added to the water in order to facilitate the washing of coal.
WHAT IS A COAL SLUDGE IMPOUNDMENT?
The chemical agents added to water that is used to process coal are largely undisclosed as manufacturers of these agents assert that the chemical composition is a “trade secret”, thus keeping concerned citizens from knowing what chemicals are used in the process (Sludge Safety Project). When the slurry is dumped behind the dam, the larger particles to left to settle at the bottom of the pond, and the water on top is frequently re-used in the washing process.
Sometimes more settling ponds are constructed to capture runoff excess, and runoff from these ponds is dumped into a local waterway (Earth Science Applied to Coal Impoundment Monitoring). What makes coal slurry impoundments hazardous is the lack of regulation or monitoring of their structural integrity. Several disasters have occurred when the dam holding the billions of gallons of toxic sludge fails.
Risk in modern dams lie in undermining, seepage, and weakness in the walls of the dam. Most of these slurry impoundments are in the eastern United States, and put in risk homes, water supplies, ecosystems, and even the lives of people living downstream. Several large-scale disasters have occurred when the slurry impoundments failed. In 1972, 3 dams in West Virginia failed, dumping 130 millions gallons of slurry in the Buffalo Creek Flood, killing 125 people, injuring over 1,100 more and leaving over 4,000 people homeless. More recently, on October 11, 2000, a Martin County, Kentucky sludge impoundment broke into the mine below just after midnight. An estimated 306 million gallons of slurry poured into the mine and out of the mine’s openings, dumping into the Tug Fork River. The following morning, one of the creeks fed by the Tug Fork went from a 10 foot-wide stream to a 100-yard wide span of thick sludge. The spill was 30 times larger than the Exxon-Valdez oil spill in 1989.
Citizens Coal Council 125 West Pike St. Suite 2 Canonsburg, PA 15317