Federal Standards Needed for Refilling Mines with Coal Ash

Federal Standards Needed for Refilling Mines with Coal Ash

by ENS, WASHINGTON, DC

3rd March 2006

Coal combustion in the United States leaves behind enough coal ash residue to fill a million railroad coal cars each year, and the volume continues to grow along with rising energy demands and improved pollution control measures.

Filling mines with those residues is a viable way to dispose of these materials, provided they are placed so as to avoid adverse health and environmental effects, says a new congressionally mandated report from the National Academies' National Research Council. Enforceable federal standards are needed to guide the placement of coal ash in mines to minimize health and environmental risks, the report says.

The residues left after coal is burned to generate power - called coal ash - consist of noncombustible coal matter and material trapped by pollution control devices.

Most of this ash is disposed of in landfills and surface impoundments, but it is increasingly being used in mine reclamation. In addition, about 38 percent of the residues are currently used to make cement, wall board, and other products.

The report encourages the continued use of some residues in industrial applications as a way to reduce the amount requiring disposal.

"Because the amount of coal combustion residues is large and increasing, we should pursue productive uses for them," said Perry Hagenstein, chair of the committee that wrote the report and president of the Institute for Forest Analysis, Planning, and Policy in Wayland, Massachusetts.

"When such uses are not feasible, putting residues in mines as part of reclamation provides an alternative to landfills and surface impoundments, although potential health and environmental risks must be addressed," he said.

The residues provide filler for mine reclamation efforts that restore land use conditions at a site, and putting these residues in mines lessens the need for new landfills. The residues may also neutralize acid mine drainage, lessening the potential for some contaminants from mines to enter the environment, the committee said.

Little is known about the potential for minefilling to adversely impact groundwater and surface water over long time periods. Because information from minefilling sites is limited, the committee assessed potential risks by examining data on adverse environmental effects from surface impoundments and landfill sites.

They found that adverse environmental impacts can occur when coal ash containing toxic chemicals has contact with water or when the residues are not properly covered. The report recommends that minefills be designed so that movement of water through residues is minimized.

The committee recommends improved characterization of mine sites and of the residues before they are placed into mines - testing the potential for hazardous chemicals to leach into the environment, and developing a clear understanding of groundwater flow patterns in mine sites.

The report also recommends a stronger monitoring program for mine sites where coal residues have been placed.

Under the federal Surface Mining Control and Reclamation Act, states are responsible for regulating the management of coal combustion residues during mine reclamation. While general enough to cover putting residues in mines, the Act does not specifically regulate the practice, leading some states to say they lack the power for more explicit regulation.

The committee recommended development of enforceable federal standards that would give the states such authority, while allowing sufficient flexibility for adapting requirements to local conditions.