Yarmouth has become the first municipality in Maine to ban the sale and use of coal tar sealant, which one conservation district commissioner likens to “toxic black paint.”

The Town Council approved the ban passed Dec. 16 ahead of a state measure going into effect Oct. 1, 2024. Yarmouth is the only municipality in Maine to pass the prohibition.

“The town felt that we wanted to be a little more aggressive in our enforcement of this new rule,” Town Engineer Steven Johnson said. “So we opted to do a local ban on the material sooner than that.”

A black liquid sealant that is sprayed or painted onto pavement to improve its appearance, coal tar contains more than 200 types of a harmful chemicals known as polycyclic aromatic hydrocarbons, or PAHs. Several of those hydrocarbons are human carcinogens and are harmful to waterways and aquatic life, according to the U.S. Geological Survey.

Friction from car tires can cause the seal coat to come off in small particles, which are then washed off by rain and carried down storm drains and into bodies of water. The particles can stick to tires, soles of shoes and feet and be carried elsewhere, where they can also be inhaled, the Geological Survey says.

Data collected in 2010, 2012 and 2013 from Long Creek in South Portland showed PAHs associated with coal tar-based sealants in sediments in the stream, according to a report by Maine’s Interlocal Stormwater Working Group. The. Geological Survey also collected samples at parking lots and in ditches in and around Augusta, where 2016 data shows PAH concentrations associated with coal tar-based sealants at levels 1,000 times higher than in Long Creek.


Although Yarmouth waterways have not undergone specific PAH testing, development and past use of coal tar sealants near them are similar to that in the Long Creek area, so it’s likely there are similar local levels of coal tar as well, according to Cumberland Soil and Water Conservation District Environmental Planner Damon Yakovleff.

Water quality testing in Yarmouth conducted by the Maine Department of Environmental Protection does not test specifically for PAHs, Johnson said.  The town hasn’t done its own testing because it doesn’t have the staffing or the budget for it, he said.

Royal River Conservation Trust has tested the water in Royal River in Yarmouth around the dams to analyze options for safe dam removal. The testing found the river was clean overall and coal tar in Yarmouth has not specifically created a water quality issue, according to RRCT Executive Director Alan Stearns.

Yakovleff described coal tar sealant as “essentially toxic black paint” that is used for aesthetic reasons.

“I still see commercial applications who use coal tar sealants. I have noticed more and more operators are switching to practices better for the environment, which includes latex products, or even better, simple crack sealing is the best practice we could recommend,” he said. “Pavement sealants are used for aesthetic reasons. From a structural standpoint, simply filling in the cracks with a rubber compound is cheaper, better for the environment and maintains the pavement structure better than a blanket of coal tar would.”

The ban likely won’t have a big impact on businesses.

Glaude & Son Sealcoating in Scarborough said it does not use coal tar and hasn’t for years. Home Depot, Lowe’s, Ace Hardware, which has a location in Yarmouth, and True Value Hardware, with a store in Freeport, all have nationwide bans on the sale of coal tar-based products, according to the working group’s report.

Messages left for area pavement sealing companies, including R.P. Elwell Sealcoating in Yarmouth, Broadturn Sealcoating in Buxton and Kelly’s Sealcoating in Portland about the use of coal tar were not returned.

Websites for local seal coating companies only specify the use of asphalt sealants, which will not be impacted by the ban, Johnson said.

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