Milwaukee Common Council Bans Coal Tar Sealants

Wisconsin’s largest city has banned the sale and use of coal-tar sealants with high levels of a potentially cancer-causing chemical compound, polycyclic aromatic hydrocarbons, also called PAHs.

A coal tar-based sealant is a liquid sprayed on parking lots, driveways and playgrounds. It often runs off into waterways through wastewater or industrial discharges, and runoff, as WPR previously reported.

A decade ago, Dane County was the first community in Wisconsin to halt the use of driveway sealants made with coal tar, a source of PAHs. Milwaukee Common Council’s ordinance passed 15-0 Tuesday expands the ban to all pavement sealants with a high PAH level.

A recent federal study has shown the sealants are the main source of PAHs in Milwaukee area river sediments. Ezra Meyer, of the environmental group Clean Wisconsin, said the PAH not only effect aquatic life, but are “a human health hazard as well, being carcinogenic.”

“And these PAHs are shown to have developmental effects when young people are exposed to them,” Meyer said.

In a press release, Alderman Jim Bohl, who authored the ordinance, said PAHs have been shown to drastically increase cancer rates and pose more harm to aquatic life living in streams than any other chemical pollutant.

Other communities in the United States that have banned coal-tar based sealants have seen reductions of PAH in waterways, Meyer said citing a study in Austin, Texas, after coal-tar based sealants were banned.

“There’s some U.S. Geological Survey research that showed a significant reduction in PAH level found in the sediment of one of the urban lakes of the city there,” Meyer said.

Some Milwaukee suburbs are beginning to talk about a ban on coal tar-based sealants, Meyer said. Clean Wisconsin is looking into use of the sealants in other parts of Wisconsin.

Some manufacturers have switched from coal-tar based driveway sealants to those made from asphalt or latex.