Through efforts of Freshwater Future via a grant from the State of Minnesota and the EPA, Redeemer University College (Hamilton, Ontario) and Humber College (Toronto, Ontario) have committed to no longer use coal tar pavement sealers.
“Sustainability is one of Humber College’s six values as expressed in our current Strategic Plan," according to Lindsay Walker, MASc, LEED Green Associate, Sustainability Manager. "‘We preserve our collective future by embracing the social, ecological and economic impact of our decisions.’ The commitment to not use coal tar sealcoats is something we did operationally, and is most definitely consistent with our values.” Well said. The connection between sustainability and eliminating the use of coal tar sealers deserves a more extensive conversation in a future post.
Canada is similar to the US when it comes to coal tar pavement sealers. Their use is commonplace. Canadian research has uncovered disturbing facts about coal tar sealers. Yet their actions, both personally and legislatively, generally have not caught with up with their understanding of the issue.
A few years ago Environment Canada and the University of Toronto completed an analysis of coal tar sealant use in Ontario. Findings include:
- Coal tar sealants (CTS) are available for commercial and retail users.
- CTS coverage in the greater Toronto area is nearly 6 square miles (14 km2)!
- Sealant scraping concentrations were somewhat lower than published data from Mahler et al. at the USGS (perhaps due to both mislabeling in Canada and non-coal tar lot contamination in the USGS sampling).
- Large loss of PAH's due to volatilization during drying/curing (see graph below). The USGS calculated that curing emissions from the annual use of coal tar sealers in the US surpass all annual PAH emissions from motorized vehicles.
- The average annual, estimated PAH load to surface water and soil is more than 7,000 pounds per year in Toronto.
- A presentation of these findings can be found at this link: https://www.scribd.com/doc/246582925/Ontario-s-Coal-Tar-Sealant-Work-2009-11