Though noise from switching engines and commuter rail traffic figured in the technical debate that dominated the Devens Enterprise Commission (DEC) meeting last week, one train never left the station: agreement on how to monitor the compliance of the Evergreen Solar plant with DEC sound standards.
Sound consultants representing Evergreen Solar, the DEC, and Harvard residents whose land abuts Evergreen Solar were at odds, and when the neighbors’ expert stated new objections to the proposed protocol, the commissioners were forced to postpone a formal vote on a protocol for another two weeks.
“In my previous life,” said Harvard DEC member Jim de Zutter, “when we had this kind of situation we took the experts, put them in a room, locked the door, and let ’em out when the job was done. Is that appropriate here?”
“That was the intent,” said Neal Angus, DEC’s staff planner, “but we haven’t been able to bring everyone together prior to these meetings.”
The Evergreen Solar factory, which abuts several residential properties in Harvard, has been in violation of DEC noise regulations since March. But in spite of investments in noise-muffling equipment and sound barriers the company says cost “millions of dollars,” the company has only been able to demonstrate on a few occasions that it can run as quietly as regulations require. Until now, the reason given has been that construction and truck traffic noise during the day and train and cricket noise at night have made it impossible to determine how much of the sound is coming from the plant and how much from other sources. All parties concede that the Evergreen Solar plant is the dominant source and is likely to remain so, however they disagree as to whether the company is in compliance.
Mike Bahtarian, a sound consultant hired by Harvard residents, says there is no compliance. “I have looked through 40 days of recent data, excluding the summer months” he says. “The data does not show compliance.” Greg Tocci, a consultant for Evergreen Solar, and Doug Sheadel, a consultant for the DEC, who have reviewed the same data, disagree.
Even though insects are no longer chirping at night, the sound experts say that unless the plant is shut down entirely, they can’t judge how much noise residents would be experiencing from Devens and the surrounding community had the factory never been built. If they don’t know how much background sound would be present without the factory, they can’t judge Evergreen Solar’s contribution, which DEC limits to an additional 5 decibels at night and 10 decibels by day.
So the Evergreen Solar and DEC consultants have turned to an indirect approach, which would place sound monitors at two of the noisiest locations at the plant, run all plant machinery at full blast to overwhelm any other sounds in the vicinity, and then measure the difference in sound levels between the plant detectors and one currently located on Dunroven Farm (identified as R1). With these numbers, DEC and Evergreen Solar experts argue, they can read the monitors at Evergreen and then calculate whether the noise level at Dunroven Farm is within DEC limits without seeing a monitor reading there. Sound consultants for the DEC and Evergreen Solar reached agreement on a protocol in October, and Evergreen Solar released data last week that shows it can meet the proposed standard with cooling fans running at 60 percent capacity. But Bahtarian and the Harvard residents have yet to accept it, as they made clear at the meeting.
Bahtarian’s objections range from highly technical disagreements over sampling intervals, the elevation of measuring devices, and statistical methods, to the more inflammatory issue of where the sound monitor at Dunroven Farm should be placed, an objection that many thought had been resolved weeks ago (see sidebar).
A decision on how to proceed is expected at the next meeting of the DEC, which has asked for a legal opinion from its staff. Chairman William Marshall has asked the three consultants to prepare a document that lists points of agreement and disagreement, along with suggested solutions, that commissioners can review at the next DEC meeting on Nov. 24. Evergreen’s temporary occupancy license must be renewed on Jan. 31, 2010, but all parties seem willing to give Evergreen all the time it needs to comply with whatever standard is adopted. That could mean waiting until summer when Evergreen Solar shuts down for plant maintenance, during which time ambient sound could be measured at the property line without the factory in operation.
“They’ve been able to operate for a number of months now with sound levels that are tolerable,” says Wallace. “They’re not having the same kind of penetrating impact on us that they had before. The nighttime noise is like a radio that’s always on, but it’s not quite so loud as it was. If you’re walking around the house doing things, you don’t notice it. But when you stop, you say, ‘What is that?’”
