A dam wall burst releasing more than a billion gallons of coal ash in East Tennessee just before Christmas on December 22. The gray sludge apparently now covers over 300 acres and has destroyed three homes. Interestingly the spill has been blamed on cold weather and above-normal rains (see MSNBC news report).
In the US and Australia coal ash, also known as fly ash, is captured at power stations and generally stored as a sludge while in many parts of the developing world it escapes through the chimney and contributes significantly to air pollution. Linfen, China, is considered one of the most polluted places in the world because of this coal industry emission (see the Blacksmith Institute 2006 Annual Report).
Captured coal ash can be used in pre-mixed concrete, for road stabilization and has agricultural applications. But at least in Australia, its classification as a waste means its use is subject to all sorts of regulatory controls beyond those for claimed equivalent virgin materials meaning too much ends up in unnecessarily in overflowing sludge dams rather than being recycled.**
A challenge for our society is to better utilization industry by-products like coal ash and better prepare for cold weather including through ensuring appropriate infrastructure for the storage of substances like coal ash.
In the meantime, I extend my sincere commiserations to the residents of Roane County in Tennessee.
**Ash Utilisation – an Australian Perspective. Craig Heidrich. 2003 International Ash Utlization Symposium, Center for Applied Energy Research, University of Kentucky. http://www.flyash.info/2003/03heid.pdf
Photograph courtesy of the Tennessee Valley Authority via Environmental News Service
Kingston Ash Slide Update web page, http://www.tva.gov/