Our recent story on Washington becoming the first state to ban toxic coal tar-based asphalt sealants had to be trimmed, so I’m following up with this important information: The U.S. Environmental Protection Agency has conducted tests showing the coal tar-based sealants release far more toxic chemicals than the alternative, asphalt-based sealant. This is significant because much of the research that thrust the coal tar-based sealants into the spotlight was done by the U.S. Geological Survey. EPA, though, is the agency —— U.S. Environmental Protection Agency, whose rules allow the use of the coal tar sealants, has conducted research but has not released the results. In the tests, researchers measured toxic chemicals in runoff from parking lots sealed with coal tar sealants, asphalt sealants and with no sealants. “We found out that the coal tar- based sealant had the highest concentration of (chemicals) in the runoff, which was not really surprising,” said Amy Rowe, then a postdoctoral student who worked on the research with EPA. “But the asphalt-based sealants were so low. “We thought it would be lower, but not as low as it turned out to be.” Rowe said the agency is giving the research “a rigorous review.” EPA scientist Thomas O’Connor wrote in an e-mail that release of the study “is not imminent.”
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Forest collaboratives formed in the wake of the Pacific Northwest’s “Timber Wars” have become major power players operating largely out of the public eye
Gary "Chris" Twombley was put on administrative leave in December 2023
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