MPCA asks schools to help reduce stormwater pollutionSince July 2010, Minnesota state agencies have been restricted from purchasing coal tar-based pavement sealers because they contain harmful chemicals that pollute stormwater.
Since July 2010, Minnesota state agencies have been restricted from purchasing coal tar-based pavement sealers because they contain harmful chemicals that pollute stormwater. In addition, 21 cities in Minnesota ban the use of coal tar-based products within their boundaries. (Last Friday, July 20, Minneapolis became the 22nd Minnesota city to ban the sale and use of coal tar-based sealants. Its ban will be effective Jan. 1, 2013.)
The MPCA has received questions from schools on this topic, and is encouraging school district superintendents and charter school directors to join their state and city counterparts in phasing out any remaining use of coal tar-based sealers on surfaces at their schools.
Asphalt parking lots and driveways need regular inspection and care to preserve the surface, extend the life of the pavement and, if desired, maintain a uniform appearance. Although there are many kinds of sealers available, some are better for the environment than others.
Coal tar-based sealers contain high levels of chemicals called polycyclic aromatic hydrocarbons (PAHs). Some PAHs are known human carcinogens and may also harm fish and other aquatic life. Studies show that PAHs are released from coal tar-based sealcoats. The PAHs can contaminate surface water and stormwater, and make it costly for cities to remove PAH-contaminated sediments from stormwater ponds.
Last week MPCA Commissioner John Linc Stine sent a letter to school district superintendents and charter school directors across the state to encourage ending the use of coal tar-based sealants on paved surfaces they manage and maintain.
“Shopping centers, schools, colleges, government buildings and businesses often have large surface lots that need maintenance,” said Al Innes, pollution prevention expert at the MPCA. “Changing to products with no PAHs or reduced levels of PAHs can prevent a significant amount of pollution in stormwater ponds that can be quite costly for communities to clean up.”
For more information on coal tar-based sealants and the ban, visit the MPCA Restriction on Coal Tar-Based Sealants webpage.