The Elk River City Council voted unanimously Aug. 13 to approve an ordinance banning the use of coal tar-based sealants citywide on driveways, parking lots or other surfaces effective Jan. 1, 2013. Coal tar-based sealants contain known carcinogens that have been found harmful to humans and wildlife, according to the city of Elk River Environmental Division.
A number of cities have banned the product both locally and nationally.
The purpose of the Elk River ordinance is to regulate the use of sealer products within the city in order to protect, restore and preserve the quality of its waters.
Sealants are coatings used on driveways and parking lots to renew the look of old asphalt and protect the surface from the wear and tear of weather and traffic.
There are two types of sealants: coal tar-based and asphalt-based. Though both varieties have their benefits, it is the environmental consequences that cause concerns about the use of coal tar-based products, according to the city’s Environmental Division. According to a study done by the United States Geological Survey (USGS), coal tar-based sealants contain higher levels of PAHs (polycyclic aromatic hydrocarbons), a class of chemicals that are known to harm fish and pose a risk of cancer in humans with prolonged exposure. The study revealed that sealcoat products based on coal tar contained up to 1,000 times more PAHs than asphalt-based products. Problems arise when the PAHs are washed away by rain or carried away by wind as the sealcoat degrades and deteriorates by sunlight and vehicle traffic. The chemicals contaminate stormwater ponds, streams and lakes and can be tracked into homes.
Elk River’s ordinance prohibits the use of any coal tar-based sealer within city jurisdiction. Some companies and retailers have already discontinued the use and sale of coal tar-based products but there is no current state or federal requirement. The city’s Environmental Division recommends that when hiring a contractor to seal a driveway or parking lot, be sure to request that an asphalt-based sealant be used. Asphalt-based products will typically list asphalt petroleum as the key ingredient. If you are unsure of a product’s ingredients, ask the contractor for a copy of the Material Safety Data Sheet (MSDS), which they are required to maintain. For more information on coal tar-based sealants and the ordinance, go to www.ElkRiverMN.gov.