In 2006, the city of Austin, Texas, banned the use of coal tar sealants on asphalt parking lots and driveways.
Three years later, Springfield’s Environmental Advisory Board recommended the city do the same. After a year of presentations from folks on both sides of the issue, City Council voted to ban the use on city-owned lots but stopped short of a citywide ban.
The debate continues. And the city should reconsider a ban in light of more information.
In 2010, we recommended that Council resolve the issue and not drag the debate out for too long. We believed that it could be a quagmire that had the potential to preoccupy council members for months. It did.
But more research, including a report done for the city by local scientists at Missouri State University, has shown that this is a problem that won’t go away — especially if it gets into our waterways.
Coal tar, a byproduct of steel manufacturing, has been sprayed on parking lots and driveways in Springfield and throughout the eastern portion of the country for decades. It is what provides that shiny black surface that allows yellow and white striping to stand out and look sharp.
The companies that manufacture coal tar sealant claim it also provides the best protection and extends the life of the asphalt, but that is questionable. The city’s lots, which have not been sealed with coal tar for years, have not experienced any additional wear. And none of the Missouri Department of Transportation’s miles of asphalt roads are sealed.
So, why does it matter?
Coal tar contains polycyclic aromatic hydrocarbons —PAHs —that are classified as a Class 1 human carcinogen (at least, that’s what it says on the tar coal sealant’s material safety data sheet). When they get into the water system, which occurs when the material breaks down, fish and other wildlife die.
Opponents of a ban, primarily representatives of the industry that produces coal tar — a profitable side business for the steel manufacturing industry, say that the original research by the U.S. Geological Survey done in 2005 for Austin is flawed and more tests are needed, or that there is no evidence that tar coal sealants are the primary contributors to PAHs in waterways.
A study completed in October by Robert T. Pavlowsky with the Ozarks Environmental and Water Resources Institute at MSU did more tests and came to some pretty convincing conclusions that the majority of PAHs in city waterways are coming from coal tar sealants. And the most affected streams flow directly into Lake Springfield.
When Springfield first considered a ban, many skeptics were hoping that a report by the U.S. Environmental Protection Agency would resolve the issue, either by declaring that coal tar sealant was not the culprit or banning its use.
The EPA did neither.
In 2011 the agency completed its report and found that runoff from coal tar-sealed surfaces is about 100 times more potent in PAHs than the alternative asphalt-based sealant, and that the most cost-effective way for communities to deal with the pollution is to ban coal tar sealants. But the EPA did not issue a ban.
That puts the ball right back in the city’s court if the city believes the research it paid for.
Pavlowsky’s report claims, “Large commercial and residential parking lots are a major sources of PAHs to streams and ponds in Springfield.” Of the 49 locations tested, 46 percent are in the toxic range, and 42 percent are borderline.
It is important that the city continue to consider the impact of a ban on business, but it is also time to consider the impact on the entire community — and those communities downstream.
Copyright Springfield News-Leader. Reprinted with permission.