Trash companies, which are responsible for collecting and disposing the nation's garbage, actually don't always handle their own used tires.
What was common practice years ago of throwing old tires into the back of the collection vehicle headed off to the landfill has given way to a different approach for some firms.
Tires, once they can be used no more, are often returned and recycled through retreading companies.
According to a 2003 estimate, there are about 179,000 trash trucks on U.S. roads. With each truck typically needing 10 or 12 tires, that means there are a couple million trash truck tires in use in this country at any given time.
And the difficult nature of the business means those tires can take a beating at landfills and while maneuvering in tight spaces along their collection routes.
Only new tires are used for wheels in the steer position on the front of trash trucks at Waste Connections Inc., said Greg Thibodeaux, director of maintenance for the Folsom, Calif.-based company. And that's pretty much the industry's standard.
Once those tires initially wear out and are retreaded, they are moved to the drive positions in the rear of the vehicle, he said.
A variety of factors determine just how many times tire casings can be retreaded. Waste Connections, for example, won't retread a tire more than five times or that is more than 5 years old, Mr. Thibodeaux said.
But it's not off to the landfill for this rubber from Waste Connections. ``You don't do that any more,'' he said.
Instead, the tire is returned to the company's retreader, Bandag Inc. in this case, and finds new life.
``We will scrap it. They will charge us a scrap tire fee. They will dispose of the tire,'' Mr. Thibodeaux said. ``The tires are ground up and used for many different purposes.''
Waste Industries USA Inc. of Raleigh, N.C., also keeps close tabs on its tires, Fleet Manager David Peck said.
Waste Industries, which has operations in several states, figures a front-load truck gets about 6,500 miles and eight weeks from a set of new front tires.
Switching out front tires on a consistent basis gives the company enough used casings that can be retreaded and used on the rear axles of their vehicles where many more tires are located.
``I don't gamble with steering tires,'' Mr. Peck said.
Once the tires do migrate to the back of the company's vehicles, Waste Industries continues to keep a close watch over them.
``We have very strict guidelines on our retreads-nothing over four years old,'' he said.
``Typically we can get about 2½ retreads per casing,'' he said. ``Sometimes you can get can get six, sometimes you don't even get two.''
Both Waste Industries USA and George Leck & Son Inc., a small Ivyland, Pa.-based trash hauler, send their retreads back to their tire retreading companies.
``We buy them new, we recap them two times and our tire company takes them back,'' owner George Leck said.
His company also extends the life of the tires by rotating them often, he said.
Tires are such an important issue at Republic Services Inc. that the company created a class dubbed ``Tires 101'' aimed at general managers, maintenance managers and operations managers. Tires 101 is designed to help those employees manage their tires from cradle to grave, program creator Jerry Milano said.
Republic Services, based in Fort Lauderdale, Fla., disposes of its used tires in a couple different ways, he said, depending on the location. Some tires are collected by Republic, if a company-owned landfill is nearby. In other locations, the tires are returned to the retreading company, Mr. Milano said.
At Waste Management (WM) Inc. of Houston, the nation's largest trash hauler, the location of the trash collection operation helps determine how worn out tires are ultimately handled, said Rick Fitzpatrick, WM's technical maintenance manager for tires.
``From our perspective as a company, we want to be as green as possible. So we look for ways to reuse the rubber,'' he said.
That can include chipping the tires and using those chips as daily landfill cover material in certain locations.
Shredded tires also can be used as fuel, for example, and some are thrown away if no local recycling option exists, Mr. Fitzpatrick said.
``Landfilling them is not a good option for many reasons,'' he said, because tires cannot be compacted and, therefore, take up a lot of landfill space.
Waste Management goes through an estimated 300,000 tires per year, he said.
The waste industry, as a whole, probably retreads the average tire about twice before the casing is discarded, Mr. Fitzpatrick said. ``And Waste Management is a little better than that on our primary [tire] size,'' he said.
Jim Johnson is a reporter with Waste News, a sister publication of Tire Business