Rubber not only hits the road in Maine, it's buried under it.
The Maine Turnpike Authority's interchange project in Sabattus is consuming some 2 million scrap tires from the state's largest tire pile in Bowdoin. H.E. Sargent Inc., the general contractor, is using almost 19,000 tons of 6-inch scrap tire chips as a sub-base under the roadbed in place of the traditional crushed rock.
Recovery Technologies Group Inc., a Guttenberg, N.J., scrap tire processor, delivered the final load to the site last month.
It is one of the largest volumes of scrap tires ever used in a road project in the U.S.
``It was a big project. It was a tough project. It was not easy,'' said John Sciaba, environmental health and safety director for Recovery Technologies Group.
The state hired Recovery Technologies Group to provide the tire chips for the interchange project. It also is contracting the company to remove the tires from the Bowdoin site. Recovery Technologies Group installed a processing unit at the Bowdoin tire pile to shred tires for the project.
``We got lucky and had a use for the tires 10 miles down the road,'' said Mike Parker, an environmental specialist for the Maine Department of Environmental Protection, who is overseeing the Bowdoin site cleanup.
The Bowdoin site once contained 8 million to 10 million scrap tires, Parker said. The state sued the operator in 1996.
The court issued an injunction against accepting tires at the site as well as an order to remove the tires, which the operator ignored, prompting the state to begin clearing the site, he said. About 1.5 million to 2 million tires are left.
Maine has cleared four of its largest tire piles in the last several years. Five years ago, the state had five sites with at least 1 million scrap tires each.
Only the Bowdoin site remains, Mr. Parker said. The state is now focusing on removing tires from smaller sites, he said.
The state beneficially reuses scrap tires in several ways, including fuel for paper mills, landfill construction and other civil engineering projects such as road and bridge construction.
``We've had more uses than we've had tires. We've been fortunate in that respect,'' Mr. Parker said. ``By hook or by luck or whatever, we've had enough civil engineering projects that have come up.''
Some 40 million tires were used in U.S. civil engineering projects in 2001, 14.2 percent of the scrap tires recovered that year, according to the Rubber Manufacturers Association in Washington.
Maine is at the forefront of using scrap tires in civil engineering applications, and Recovery Technologies Group has worked with the state on several projects, Mr. Sciaba said.
``They're pretty well accepted in the state of Maine,'' Mr. Sciaba said.
But that hasn't always been the case.
``Engineers and the construction folks are used to using one type of material,'' Mr. Parker said. ``Crushed rock has always been crushed rock.''
The DEP has worked with contractors and engineers for several years to point out the benefits of using scrap tires instead of traditional materials, such as shale, for road projects.
``That's taken some time, but it's been well worth it,'' Mr. Parker said.
The Maine Turnpike Authority saved a significant amount of money on the Sabattus interchange project by using shredded tire chips. It is paying Recovery Technology Group $507,600 for the nearly 19,000 tons of tire chips the company delivered. Using traditional fill material, the cost would have been closer to $1 million.
``That right there gets people's attention,'' Mr. Parker said.