The 4.7 million automobile and truck tires that Marylanders throw away every year have spawned sooty fires and mountains of unwanted rubber, but they may end up helping create healthier oysters, cheaper electricity and longer-lasting highways.
State officials, preparing to draft a new program for dealing with one of the most nettlesome of waste problems, are contacting organizations and companies that might have solutions to offer.
In February, the officials hope to be able to begin collecting a $1-per-tire fee for all new tires sold in the state, as mandated by the General Assembly last spring. The money is to be spent on cleaning up tire dumps and promoting recycling and other uses for discarded tires.
"There's a lot of interest and people are looking into what can be done," said Larry Walsh, a project engineer with the Maryland Environmental Service, a unit of the Division of Natural Resources.
The service has contacted or been contacted by a wide range of groups involved in the industry, from retreaders to sophisticated recyclers who freeze and pulverize tires. At some point, the state will request formal proposals from groups that want to use some of the tire-fee money to recycle, reuse or somehow get rid of the tires without landfilling, Walsh said.
Among the ideas: partially sinking tires in concrete and submerging them in Chesapeake Bay or the ocean for fish or oysters to use as artificial reefs. Other states have found some success with this approach, Walsh said.
"The oysters seem to like to attach to them," he said.
Another company, Tiregator Inc. of Houston, Texas, is considering building a plant in Maryland. The company freezes tires so the rubber can be cracked away from the steel belts and other metal. The rubber is then ground into a powder that can be used in highway asphalt.
"The roads and pavements in Maryland could absorb all of the tires in Maryland," said Daniel Callahan, president of Tiregator. A native of the Maryland-DC area, he would like to expand to the Northeast and possibly move the corporate headquarters back here, he said.
A recycling plant would employ about 10 people, he said.
The company also uses tires as fuel, either by burning them at high temperatures or converting them to a flammable gas.
"We are definitely going to be in that part of the world," he said.
State officials this month began laying a test stretch of rubber-laced asphalt on Md. 543 in Harford County. Past tests have shown such asphalt lasts longer, but may not be worth the price, which can be twice that of conventional asphalt, said Walsh.
He said several organizations have expressed an interest in using tires for fuel. When burned at high temperatures, tires release more energy and less sulfur than does coal, he said. They also can be heated in special kilns to produce gas and oil that can be burned for energy, he said.
Other companies have devised ways of turning the rubber in old tires into useful products, such as floor mats for cars, he said. Other than through retreading, tires cannot be recycled into tires again because of the chemicals and processes used to make them, Walsh said.
"It's not like aluminum or glass that you can melt and turn back into the same product," he said.
Companies that can demonstrate an ability to turn the old tires into new products may receive capital for start-up or get a per-tire fee from the state fund, he said.
"We're looking for a system which would include several different things," Walsh said.
Officials estimate that Marylanders throw away nearly 5 million tires a year. Many of them are recycled, but 15 million are now in 24 illegal dumps. Nationwide, about 240 million tires are disposed of annually, and more than 2 billion have piled up.