TORONTO-Concerns over possible environmental ramifications may block a project to use 140,000 shredded tires as a base for a highway overpass outside Toronto. The Ontario Ministry of Environment and Energy claims the 2-inch tire shreds would be more economical and durable than the foam currently used as a base for overpass embankments.
``It will, in the long run, lead to a better road because tires by their very nature won't decompose,'' said Eileen Smith, manager of the ministry's scrap tire project.
Furthermore, using the rubber chips in road projects would help decrease the number of scrap tires found throughout North America. Between 8 million and 10 million discarded tires pile up in Ontario annually, Ms. Smith said.
The Ontario ministry wants to use the embankment project near Ancaster, a Toronto suburb, as a two-year experiment.
The planned base material would contain 60 percent tire chips and 40 percent dirt. It would be covered with about five feet of additional dirt, which the road would be laid on.
If environment and highway officials are pleased with the tires' performance after two years, they'll use the material in other road improvements, Ms. Smith said.
If the experiment doesn't work, the province will rebuild the embankment at no cost to the town.
But the possible benefits and the rebuilding provision haven't allayed completely the fears of town leaders.
Among their concerns is the possibility of hazardous materials leaching from the tires. The province is willing to monitor any runoff that occurs throughout the two-year experiment, ministry officials said.
The Ancaster council has yet to decide whether to approve the project. In the meantime, Ms. Smith said she is providing the council with additional information concerning similar construction methods in the U.S. and Europe.
Rubber road bases have been tried in Oregon, Maine, Minnesota, Vermont and France, she said. Additional states are planning similar experiments.