PORTLAND – The Maine Turnpike Authority plans to begin recycling soon-to-be obsolete devices used to track drivers’ toll charges because they contain enough lead to qualify them as hazardous waste.

The battery-operated transponders contain about 50 times the amount of lead to qualify for hazardous material. They will be sent to Connecticut for recycling, according to Stacy Ladner of the state Department of Environmental Protection.

The turnpike authority’s switch from its existing electronic toll system to the multistate E-ZPass system prompted the recycling drive. The old system will be turned off Feb. 1, and more than 5,000 transponders will become useless.

The E-ZPass units have a completely different design. In most cars, they can be attached to the windshield, rather than mounted on the dashboard.

The recycling program is tentatively scheduled to begin Feb. 7 and is one of the latest efforts to cut down on electronic waste in Maine.

Last spring, Gov. John Baldacci signed a law forcing Maine to take some responsibility for recycling televisions, computers and other electronics.

The Maine Turnpike Authority does not yet have a contract to dispose of the transponders. Officials hope to reach an agreement with Green Pages Inc., which has offices in Kittery and would take the devices to Connecticut.

People who paid for the devices will not be required to recycle them in order to get back their $15 deposits, said Dan Pardee, an authority spokesman. But state environmental officials are encouraging all Transpass customers to participate.

Test results show the devices contain 261 milligrams of lead per liter, Ladner said. The minimum level for a product to be considered hazardous in Maine is 5 milligrams of lead per liter.

The turnpike authority is putting the recycling program in place in the midst of marketing the new E-ZPass system. Postcards were sent to all current customers, and a television advertisement will debut on Jan. 3, Paradee said.

So far, the turnpike authority has received applications from about 13,000 customers, about 20 percent of its account holders.

“Obviously, we’ve got a lot of work to do, and everyone’s expecting quite a crush here during the month of January,” Paradee said.