Coal Tar Prohibited on County Driveways, Parking Lots

Planning to reseal your driveway or a parking lot?

Take note: Coal tar—a common ingredient in resealing products—can not be used in Montgomery County, according to a bill passed by the Montgomery County Council in September 2012. The bill went into effect Dec. 18, 2012.

"The use of a coal tar-based sealant can lead to a fine of up to $1,000—for both the property owner and the applicator. Passage of the legislation makes Montgomery the first county in Maryland, and one of the largest counties in the nation, to prohibit the sale of the sealants, which have been recognized to contaminate soils, lakes and homes as they disintegrate and run off after application," according to a statement from the office of the County Council.

"The dangerous levels of carcinogens in coal tar sealant make it inherent that we immediately discontinue use of this product in Montgomery County," Council Member Craig Rice, the bill's chief sponsor, said. "There are other safer alternatives on the market that consumers can use that do not have the harmful health and environmental impacts of coal tar."

Coal tar is a byproduct of coal processing and contains high levels of chemicals called polycyclic aromatic hydrocarbons (PAHs). Some PAHs are known human carcinogens, according to the County Council office's statement. "Studies have shown that when coal tar-based sealants are applied on parking lots and driveways, PAHs can be released into nearby surface waters, where they can accumulate in sediments at levels potentially harmful to aquatic wildlife. The presence of PAHs in sediments may increase costs to businesses, homeowner’s associations and others charged with maintaining stormwater management facilities," the statement added.

The bill was co-sponsored by Council Members Marc Elrich, Valerie Ervin, Nancy Navarro and Hans Riemer.

Instead of coal tar, try one of the asphalt-based or latex sealant alternatives available at home improvement stores. If you're hiring a contractor, be sure to ask to see the ingredient list of the sealing product being used to be sure it doesn't contain coal tar, refined coal tar, coal tar pitch or RT-12—all of which are prohibited substances, according to the County Council office.

Information about sealant options is available at www.montgomerycountymd.gov/coaltarban.

Sealant on driveways and parking lots is not permanent. Sealcoat manufacturers generally recommend re-applications every one to five years, depending upon the product. "The particles can be washed off the roadway by rain and carried through storm drains in streams, ponds and stormwater management devices. Other particles can be blown away offsite by wind or tracked indoors on the soles of shoes," according to the County Council office's statement.