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Date: Oct. 12, 2001
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New Federal Standards Needed for Storing Coal Waste

WASHINGTON -- The federal government should have clear authority to review the stability of basins designed to store liquid waste from coal processing plants, says a new report from the National Academies' National Research Council. Regulatory agencies also should work toward establishing a standard design to prevent the barriers between basins and underground mines from collapsing.

Congress requested this study after a coal waste impoundment in Inez, Ky., failed last year, releasing 250 million gallons of waste that flowed through an underground mine into nearby creeks and rivers, including some that supplied water to the local community.

"As a first step, better surveys and maps of mines are needed to ensure that a sufficient barrier exists between basins and nearby underground mines, and more careful evaluation is needed of the pathways that waste may follow if an uncontrolled release occurs," said Franklin Orr, chair of the committee that wrote the report, and Beal Professor and dean of the School of Earth Sciences, Stanford University, Stanford, Calif. "Contrary to common practice, storage basins also should be studied as thoroughly as the embankment structures that are built to retain the coal waste. And alternatives to coal waste impoundment should be looked at more closely."

Before coal mined in the eastern United States is burned at a power plant, it is washed to remove noncombustible materials, leaving a slurry composed mainly of fine coal, small particles of rock, and clay, all suspended in water. The slurry is usually disposed of by pumping it into an impoundment area where particles are allowed to settle. Most impoundments in Appalachia use the natural topography of a valley to form a storage basin, with a dam-like structure known as an embankment built near the head of the valley.

Because of extensive coal mining in the eastern United States, many impoundments are built near old underground mines, creating the potential for slurry from an impoundment to break into a mine or for water collecting in an old mine to enter a basin, causing it to overflow. The committee found that despite these risks, the regulation of basins is less rigorous than that of embankments. To remedy this, the Mine Safety and Health Administration and the Office of Surface Mining -- federal regulatory agencies -- should have clear authority to review the stability of basins. It was not evident to the committee whether specific legislation would be required to allow more detailed examination of basins or whether these issues can be handled by additional rulemaking under existing authority. The agencies also should stay aware of impoundment strategies and technologies used in other mining industries to ensure that the best available practices are applied to the construction and operation of coal waste storage basins.

In addition, a standard to set the minimum distance between basin and mine locations should be promulgated by MSHA and OSM to help prevent breakthroughs, the committee said. Some states have such design standards, but there is no federal standard.

For a width standard to be effective, however, the location of old mines must be known. Unfortunately, many old surveys and maps are inaccurate, inadequate, or have been lost or destroyed. MSHA should work with OSM and relevant state agencies to set standards for mine surveying and mapping so that proper measurements are taken, and the maps should be stored in a digital archive, the committee said.

When mine maps cannot be found for an impoundment site -- or if there is reason to doubt their accuracy -- remote sensing and geophysical technologies can be employed to search for abandoned underground mines. Research into these techniques should be funded further, the committee said, although drilling still is necessary to confirm the presence of a mine.

The length of the review process for both new and existing impoundment permits should be shortened from the more than two years it often takes now, the committee added. MSHA and OSM need to combine the currently fragmented and inefficient collection of reviews into a single, joint review process, with sufficient engineering staff on hand.

The two agencies also should establish a single, consistent system for assessing the risk of both existing and proposed embankments and basins, the committee said. This risk assessment should measure the likelihood and consequences of a failure. And the agencies should thoroughly evaluate and determine which measures need to be applied to reduce risk to acceptable levels, especially at impoundments that fall into the highest risk category.

Noting that there is a limit to risk tolerance, the committee said that if the risk of failure is high and measures to reduce it are impossible, unproven, or too expensive, then a substantial change in impoundment operations is warranted. This may include using alternative processing and disposal technologies, reinforcing barriers, or closing down the impoundment altogether. Furthermore, MSHA should issue guidelines for the design of bulkheads that seal nearby mine tunnels.

In addition, MSHA and OSM should consider requiring 24-hour monitoring of certain basins to provide timely warning of an impending failure, the committee said. The use of automated, round-the-clock surveillance instruments to do this should be evaluated further as well. And the coal industry should work with local emergency response officials to better communicate the risk of failure to the public and to coordinate evacuation plans to prepare for a flood caused by a release of slurry. An analysis of the chemical makeup of slurry also is needed so that local authorities know what contaminants may be in the water supply if a breakthrough occurs.

The committee found many of the alternatives to impoundments to be promising, but also costly and dependent on local geography. Examples of alternatives include reducing the volume of waste by recovering more of the fine coal particles in the slurry or removing the water. Fine coal particles also can be burned to generate power, although at a much higher cost than burning clean coal. And there are methods for disposing of slurry in places other than impoundments. For example, slurry can be sealed in underground mines that do not exit to the surface and are below or far above ground water.

Two major studies are needed to determine the feasibility of alternatives to impoundments, the committee said. First, a comprehensive study of the entire system of mining, preparing, transporting, and burning coal should be conducted to identify technologies that can be used in each step of the process to eliminate or reduce the need for slurry impoundments while meeting environmental and economic goals. Second, research is needed to determine the best options for disposing of slurry in places other than impoundments, along with the costs of doing so. In addition, tax breaks and other financial incentives should be explored as a way to encourage the development and implementation of alternatives.

The study was sponsored by the U.S. Department of Labor's Mine Safety and Health Administration. The National Research Council is a private, nonprofit institution that provides science policy advice under a congressional charter granted to the National Academy of Sciences. A committee roster follows.
Read the full text of Coal Waste Impoundments: Risks, Responses, and Alternatives for free on the Web, as well as more than 1,800 other publications from the National Academies. Printed copies are available for purchase from the National Academy Press Web site or by calling (202) 334-3313 or 1-800-624-6242. Reporters may obtain a pre-publication copy from the Office of News and Public Information (contacts listed above).

[This news release and the report are available at]

Division on Earth and Life Studies
Board on Earth Sciences and Resources

Committee on Coal Waste Impoundments

Franklin M. Orr Jr.* (chair)
Beal Professor and Dean
School of Earth Sciences
Stanford University
Stanford, Calif.

Gary A. Davis
Director, Center for Clean Products and Clean Technologies;
Senior Fellow, Energy, Environment, and Resources Center; and
Adjunct Professor of Environmental Law
University of Tennessee

Barbara A. Filas
Vice President
Mining and Environment
Knight Piesold Consulting

C. David Henry
Vice President of Operations
Beard Technologies Inc.

Norbert R. Morgenstern*
Professor of Civil Engineering (emeritus)
University of Alberta, and
Independent consultant
Edmonton, Alberta

David A. Newman
Appalachian Mining and Engineering Inc.
Lexington, Ky.

Raja V. Ramani
Anne B. and George H. Jr. Deike Chair in Mining Engineering and Professor of Mining and Geo-Environmental Engineering
Pennsylvania State University
University Park

Robert L. Shuster
Scientist Emeritus
U.S. Geological Survey,
Independent Consultant

Madan M. Singh
Engineers International Inc.
Scottsdale, Ariz.

Don W. Steeples
Dean A. McGee Professor of Applied Geophysics
Department of Geology
University of Kansas

Clinton L. Strachan
Senior Geotechnical Engineer
Shepherd Miller Inc.
Fort Collins, Colo.

Richard J. Sweigard
Chairman and Professor
Department of Mining Engineering
University of Kentucky

Jack Tisdale
Chief, Safety Division
Mine Safety and Health Administration (retired), and
Independent Consultant
Chesapeake, Va.

David R. Wunsch
State Geologist of New Hampshire
New Hampshire Department of Environmental Services


Tamara L. Dickinson
Study Director

* Member, National Academy of Engineering