From his post overlooking the deep concrete pit that holds the region's perpetual trash mountain, equipment operator Matt McCluskey manipulated a joystick to swing a giant claw into place.

Closing it around a lumpy pile, the claw dragged the mass to mix and dismember the countless plastic bags holding every manner of garbage from homes, schools, offices, stores and restaurants.

"You just want to mix everything up so you get good combustion," John Vinson, facility manager at the Covanta trash-to-energy incinerator, explained during a tour this month of the facility off Route 12 in Preston. "The steadier the fuel, the better the burn."

Now, 21 years after it began burning the region's trash, an expansion of the facility's responsibilities for handling the region's waste is being considered.

"We're discussing broadening and bundling services," said Stephen Diaz, vice president for strategic services for Covanta. "Our goal is to keep the 12 communities long-term and provide some additional services."

Since 1992, the incinerator has operated under a contract with the Southeastern Connecticut Regional Resources Recovery Authority, the quasi-public agency for 12 towns that bring about 689 tons of trash per day to the facility. There, the refuse is burned in giant furnaces that reach temperatures exceeding 2,000 degrees. The furnaces heat boilers that produce steam to power turbines that generate enough electricity for 15,000 homes.

"We're making 19.23 megawatts of electricity now, sending it right to CL&P," Vinson said as he read one of the gauges in the control room at the plant.

Now, as the plant begins its third decade of operation, the future of the relationship between plant operator Covanta and the resource recovery authority is being decided. Discussions have begun over a new 25-year contract to replace the one that will expire in 2017. Some significant changes are being considered.

Diaz said the company is offering to provide "one-stop shopping" to the member towns, proposing to handle electronic waste, bulky waste, expired pharmaceuticals and compostable materials. A recycling facility for food waste, similar to the one the company announced in October for its Bristol plant, also is being considered, he said.

Dave Aldridge, executive director of the authority, said the organics recycling facility is generating interest. It would receive food scraps from grocery stores, casinos, restaurants, hospitals, schools and other institutions, and turn them into compost, generating energy through an anaerobic digestion process. At its Bristol incinerator, Covanta is working in partnership with Turning Earth, a King of Prussia, Pa., company, to build such a facility.

'Success story'

Aldridge said negotiations for a new contract began four years ahead of the expiration date so a final agreement could be reached by 2015, the same year the authority's bonds on the plant would be paid off and Covanta could exercise its option to purchase the plant.

The plant, he said, has been "a great success story" for the region, charging member towns $58 per ton, the lowest tipping fee of any of the state's trash-to-energy incinerators. That rate is expected to continue at least through 2015, he said.

Preston First Selectman Robert Congdon said that while the town fought the plant when it first was proposed, he is focused now on achieving the best possible host town agreement with Covanta.

"We know it's not going anywhere," he said.

As the host town, Preston pays about one-third less than the other 11 towns to dispose of its trash. Occasionally, he hears complaints about noise from the 100 trucks a day entering the grounds, but overall it's been a positive addition, he said.

"They've been a good company in our town," he said. "We get almost $1 million in (Payment In Lieu Of Taxes) funds and other benefits to offset the impact."

Casinos exempt

The addition of the composting facility would be a response to state laws passed in 2011 and this year that will require supermarkets, food wholesalers and processors, conference centers, resorts and similar commercial enterprises to separate food waste and send it to a composting facility, provided there is one within 20 miles.

"If you are a large generator of food scraps," said Chris Nelson, supervising environmental analyst for the state Department of Energy and Environmental Protection, "you'll have to compost your food."

Because they are located on sovereign tribal reservation property, the state's two casinos are exempt from the law, he said, although they already do some composting.

The state estimates that about 325,000 tons of food waste from commercial facilities could be recycled annually. Only a small amount is being composted.

"We're encouraging anything to do with increased recycling and diverting," said Gabrielle Frigon, supervising environmental analyst for DEEP.

Diaz, of Covanta, said his company, which operates 45 incinerators worldwide, is running all three of its Connecticut plants at "close to capacity" and is fully supportive of the state's efforts to increase recycling, not just of food wastes but other materials.

James Regan, spokesman for Covanta, noted that at least 100,000 tons of trash being shipped out of state annually instead could be handled by the incinerators, so there would be ample fuel to keep the incinerators operating efficiently even if more waste ends up getting recycled.

"We're in no way trying to hurt those efforts," Regan said.

j.benson@theday.com

Whose trash?

The following towns dispose of trash at the Covanta incinerator:

East Lyme, Griswold, Groton, Ledyard, Montville, New London, North Stonington, Norwich, Preston, Sprague, Stonington and Waterford.