Friday, March 16, 2012

U.S. Dioxin and Furan standards for WTE Plants

Response to query by construction and buildings organization:
The US emission standards for municipal waste combustion plants (WTE plants) are the same as in E.U, Japan, Singapore, etc. With regard to dioxin/furans, there is some confusion because EPA expressed the standard as TOTAL nanograms of dioxins per standard cubic meter of stack gas while the rest of the world express it as TOXIC EQUIVALENT (TEQ) nanograms. In the 2003 thesis of P. Deriziotis (www.wtert.org, Publications, Theses) you can read that there are 200 dioxin compounds but only a few are toxic. The WHO and also EPA have developed the same toxic factors so that TOTAL ng can be converted to TEQ ng. For WTE plants, the conversion factor is about 100 so that the 13 ng total standard of EPA corresponds to 0.13 ng TEQ of other OECD nations, where the standard is 0.1 ng TEQ.
WTERT have been monitoring the US WTEs and current dioxin emissions are less than 0.1 ng TEQ which for the 28 million tons of MSW combusted in the US correspond to less than 10 grams TEQ of dioxins per year. EPA now reports that the major source of dioxins is "backyard barrel burning" estimated at over 500 TEQ grams per year. Other major sources are forest fires and the 4th of July fireworks. It is a real pity that some environmental groups perpetuate the "high dioxins" myth, thus contributing to the fact that the U.S. is the world's No. 1 landfiller.

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