Members of the Board of Environmental Protection want more comments from the public before they vote on new rules governing biomass boilers that burn wood waste.

Incineration of construction and demolition debris to generate electricity or steam has become such a hot issue in Maine that the Department of Environmental Protection proposed new regulatory oversight.

But the rules have been stalled in the review process as BEP members and residents questioned whether the proposals adequately protect people from airborne pollution.

After several hours of debate Thursday, BEP members voted 4-2 to reopen the rules to public comment. In an apparent coincidence, the vote came the same day that officials from Georgia-Pacific Corp.’s Old Town mill, which operates a biomass boiler, announced that the plant was closing its doors.

G-P officials, who cited rising energy costs as one of several reasons for shuttering the mill, had planned to begin burning construction and demolition debris at the mill but were waiting for the new rules. Biomass fuel chips from “green” wood costs $9 a ton, compared to $4 a ton for waste wood.

During Thursday’s BEP meeting, several board members suggested that the department’s proposal allowed biomass boiler operators to burn too high a level of noncombustibles, such as metals and plastics. Noncombustibles can release toxins into the air.

Board members Ernest Hilton and Denis Culley said they believe Maine should be setting a higher standard to force demolition companies and debris processing companies to avoid corrupting waste wood piles with noncombustibles.

Maine is the only New England state to allow biomass boilers and, therefore, imports hundreds of millions of pounds of waste wood annually.

“The state of Maine right now is in a very unique position of helping the industry to establish a model, and the model is, there should be a lot more care taken in demolishing a building,” Hilton said.

Members also questioned the proposal to allow biomass boilers to run solely on wood waste, up from the 50 percent threshold permitted today. DEP staff have said that only one facility in the state – a boiler proposed by GenPower in Athens also stalled by citizen opposition – would be capable of burning 100 percent wood waste.

DEP Commissioner David Littell defended the proposed rules, however, saying Maine would be leading the nation. “As far as we know, we are the most proactive state and would have the most stringent regulations,” Littell said.

The DEP is expected to reopen the comment period for 30 days beginning either next week or the week thereafter.

Given the BEP decision to take public comments, it will be several more months before the agency could adopt new rules on wood waste.