WOODSTOCK – The paving industry closely is watching McHenry County as its officials consider a ban on toxic asphalt sealants commonly used on driveways.
The black, coal tar-based sealant is used on everything from commercial parking lots and residential driveways to playgrounds.
Government research suggests that the sealant is the source of a growing contamination problem, an assertion that industry groups deny.
Coal tar-based sealcoats contain high concentrations of polycyclic aromatic hydrocarbons, called PAHs, which have been linked to cancer and are toxic to fish and other aquatic life, according to the U.S. Geological Survey.
A ban needlessly would hobble local businesses, said Anne LeHuray, executive director of the Pavement Coatings Technology Council, an industry trade group based in Alexandria, Va.
“The only impact of [a ban] would be to hurt small businesses, resulting in lost jobs and tax revenue,” LeHuray told the county’s Groundwater Protection Task Force last week. “The science says that the sealers are not the source of your problem.”
Others countered that the possible health risks and potential environmental cleanup costs associated with coal tar-based sealcoats warrant new regulations.
A ban “could be a very useful tool,” said Judy Crane, a research scientist with the Minnesota Pollution Control Agency who has studied PAH contamination of stormwater pond sediments in Minnesota.
High concentrations of PAHs were discovered in runoff from driveways in Lake in the Hills and in sediment samples from Woods Creek Lake in Lake in the Hills, according to USGS research.
Studies found almost 90 percent of driveways in Lake in the Hills were sealcoated.
No other areas of McHenry County were tested, but other towns here and across the country could have similar issues, said Cassandra McKinney, the county’s water resources manager.
“We should be concerned when the PAH levels are getting that high,” Crane said.
Once applied to a surface, the sealcoat doesn’t stay there forever.
“We know there is a lot of PAHs in coal tar sealant, and we know [the sealant] wears off,” said Bob Newport of the U.S. Environmental Protection Agency. “It gets tracked into the house or blown by the wind into the grass or carried off with the stormwater. ... All of those outcomes are really unfavorable for the environment.”
Asphalt-based sealants contain much lower concentrations of PAHs compared with coal tar-based sealants. But that doesn’t mean suburban driveways sealed with a coal tar-based product should be torn up.
“You don’t have to get into a moon suit to walk down your driveway,” Crane said. “But you probably should consider using an asphalt-based sealcoat in the future or not sealcoating at all.”
Bans and restrictions are being considered at almost every level of government after USGS studies found that these sealants were contaminating waterways.
U.S. Rep. Lloyd Doggett, D-Texas, is drafting legislation that would regulate sealcoats containing coal tar nationwide.
Earlier this month, Washington became the first state in the nation to ban coal-tar based sealcoats, according to news reports.
Several municipal governments across the country also have bans or restrictions.
McHenry County’s Groundwater Protection Task Force has come up with a draft ban on the sealants, but a countywide ban is unlikely.
The McHenry County State’s Attorney’s Office wrote in a letter that the county doesn’t have the legal authority under state law to enforce such a ban.
Task force members have talked with many of the top experts on coal tar sealants.
The group’s meetings are closely being followed by local municipal officials, including Crystal Lake Director of Public Works Victor Ramirez and Lake in the Hills Village Administrator Gerald Sagona.
Meetings also have attracted members of environmental groups and representatives from major companies in the industry. Many are concerned about the bans.
Alternative products, such as asphalt-based sealcoats, don’t work as well or aren’t nearly as cost-effective as coal tar-based sealcoats, said Jeff Lax of Bonsal American, a leading manufacturer of packaged building materials and pavement maintenance products.
“We have seen a very small demand for asphalt-based sealers,” he said. “We’ve seen a spike in the last couple of years, but it’s maybe 1 percent of our total sealcoat production volume.”
Additional county task force meetings already have been scheduled. In the meantime, officials are looking at a variety of strategies.
“The county will continue to meet with concerned municipalities to explore options for addressing coal tar-based sealants through education, advocacy, and possibly statewide legislation,” McKinney said.