HAMPDEN – Citing the odors emanating from Sawyer Environmental Recovery Facility, the planning board voted 7-1 Wednesday night to deny approval for the landfill’s proposed expansion.

SERF has failed to meet the site plan standard with regard to air quality, according to board member Beric Deane, who made the motion to reject the landfill’s application.

Although SERF has made a real effort to mitigate the problem, residents continue to be bothered by the odors, said Deane, pointing to the “significant testimony” garnered during the public hearing that began several months ago.

“The evidence is exceedingly clear that even though the landfill is operating exactly as it should and is handling the loads exactly as [it’s] supposed to, the odors emanating from the landfill are a nuisance,” he said.

But lone dissenter Richard Peer said that SERF isn’t necessarily the source of the odor. No one has “proved one way or another that the odors are generated there,” he said.

Tight-lipped and grim, SERF officials quickly left the meeting and huddled in the parking lot. “We’ll consider our next move,” is all that SERF attorney Helen Edmonds would say.

The board’s vote came after three hours of testimony and debate focusing mainly on the odors that have plagued residents for months and that SERF has said are caused by landfill gases and the recently installed Hermon sewer system.

Attorney Edmonds offered an update at the beginning of the meeting. Odor scientists hired by SERF to monitor the area last month had concluded that the landfill is not the source of the nuisance odors, she said.

Also, the Hampden Town Office’s complaint log indicated that the total number of complaints is small and that no complaints have been registered since February. All but a couple of calls were from a single person, according to Edmonds, who didn’t name the individual.

But residents and planning board members criticized the reports. The experts made “broad claims” and failed to include qualifying and quantifying statements, said resident Norm Thurlow, who asked that the board table the site plan review until the summer, when odors were bound to increase.

Deane also discounted the survey. “Residents clearly can discern the odors were of nuisance level,” he said. “It doesn’t take a trained scientist to differentiate between landfill gases, sewer gases and FEPR.”

He was referring to Front End Process Residue, the noncombustible waste generated by the Penobscot Energy Recovery Co. in Orrington, which turns towns’ trash into ash, and then brings the ash to SERF.

FEPR is partly responsible for the troublesome odors, experts told the group.

The board rejected SERF’s assurances that it had bigger and better ways to contain odors.

General manager Marty Drew said if the problem worsened, the landfill would resort to an improved system, including a large flare to ignite the landfill gases and burn them off. Large blowers also could be used to suck the gas and create negative pressure.

“We’re fully prepared to do that; all alternatives are available should they be needed,” said Drew, emphasizing that leachate is not the source of the odor.

Meanwhile, Edmonds said that if the planning board approved SERF’s expansion, the landfill would agree to an odor monitoring program for one week four times a year.

If studies indicated a problem, SERF would submit an odor control plan, she said.

But Deane took little comfort in those ideas. Last summer as he traveled to work on Interstate 95, the smell emanating from SERF was so bad that he gagged.

“I find it disingenuous that you say you’ll solve the problem,” he told SERF officials.

Deane also complained that the landfill’s odor report system wasn’t working.

People are reluctant to call because they perceive they’ll be sloughed off, he said.