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Town turbine noise within legal range; Study concludes noise from second turbine might exceed limits

While the town’s current 1.65-megawatt wind turbine does not exceed legal noise thresholds the addition of a second one at the Wastewater Treatment Facility on Blacksmith Shop Road will come close to doing so and may even surpass both the state and local levels under certain conditions.

As a result, the town may have to take steps to mitigate the noise, although what those will be have yet to be determined.

Yesterday afternoon at Town Hall Assistant Town Manager Heather B. Harper told a group of roughly 25 residents, including many living less than a mile from the first turbine that became operational in March, that her office would continue to work with the neighbors to come up with solutions to address their concerns. But she said that would not halt the construction of the second turbine, which is currently being built.

She estimated it would take 12 to 18 months for town officials “to really determine what the impacts are and what the mitigation strategies might be.”

For some residents that was not sufficient.

“It never stops,” said Terri Pentifallo-Drummey of Blacksmith Shop Road. “You feel it on your chest… We are getting no relief from it.”

Colin P. Murphy of Blacksmith Shop Road asked what would happen in the middle of the night if the turbine exceeded acceptable noise levels. “Who is going to enforce that?’ he asked.

Ms. Harper responded by noting that her office has worked with neighbors since they began complaining about the turbine and its impacts in May. The town hired consultant Harris, Miller, Miller & Hanson of Burlington to determine whether the sound produced by the machine exceeded a 10-decibel increase of ambient sound, which would put it in violation with state noise guidelines. On top of the state limits Falmouth has its own bylaw that limits overall noise to 40 decibels.

In June the town’s consultant began a serious effort at studying the noise issue. The firm selected two long-term sites, studied them over a period of 10 days, and four short-term sites, studied at 10-minute intervals, all sites in close proximity to the wind turbine. The study accounted for sound levels when the turbine was both operational and shut down to record background sound levels.

And, finally, readings were taken at various times of the day, from the afternoon when background sound is highest to late night and early morning when the background sound is the lowest at 28.8 decibels.

Acoustical engineer Christopher Menge presented the findings of that study to residents yesterday afternoon. While the current wind turbine does not come close to violating the state’s 10-decibel increase, Mr. Menge said its sound is discernible.

At that will increase with the addition of the second wind turbine, he said, with computer models showing that the turbine sound comes close to surpassing state thresholds at three specific locations where data was collected in June. Those included 124 Ambleside Drive where the report predicts a 9.96 decibel increase; a 9.6 decibel increase at 27 Ridgeview Street; and a 9.2 decibel increase at 211 Blacksmith Shop Road. In that scenario the wind speed is calculated at 4.4 meters per second. “It is not exceeding 10 decibels, but it is certainly approaching it,” he said.

At two homes at the end of Ambleside Drive, Mr. Menge said the town could be in violation of the state’s acceptable thresholds when wind speeds are in the range of five to six meters per second in the early morning house when ambient noise is the lowest. “You may be slightly getting over the 10-decibel level,” he said. “Whether it is 10 decibels or 11 decibels, we are a borderling case.”

At the the Ambleside Drive homes, he said, the sound may constitute a “classic violation” of the state’s permissible noise levels.

The model also predicts in the report that the two turbines would also increase noise levels at certain properties above the 40-decibel level allowed in the town’s regulations.

In addition to the time of day, Mr. Menge said wind speed plays a factor in hos discernible the noise generated by the turbine will be. At higher wind speeds, he said, “the background noise tends to be enough to cover up the audible noise of the turbine.”

At wind speeds between four and six meters per second, he said, is when the noise of the turbine will be most audible.

In addition to his firm’s report, area residents commissioned their own study conducted by Noise Control Engineering Inc. of Billerica. The firm’s vice president, Michael Bahtiarian explained that its study differed from the town’s in that it looked at quick samples, focuses on seconds instead of minutes, at the home of Neil P. and Elizabeth L. Andersen of Blacksmith Shop Road, who are among the residents upset with the turbine and how it has impacted their lives. He also took samples at a reference point on Brick Kiln Road.

Mr. Bahtiarian said his study showed spikes in noise levels, caused by the wind turbine that would peak above 40 decibels and then return below that level. He compared it to an air conditioning unit in a neighbor’s home that might operate at different speeds, ranging from low to medium to high to super high, which could be more of a nuisance than one remaining at a constant setting.

While the turbine has disrupted residents’ lives, attorney Christopher G. Senie of Westborough said his goal is to ensure future turbine projects do not pose the same impacts on others living in Falmouth.

Mr. Senie, who represents several of the residents in the Blacksmith Shop Road area, said he was in the process of crafting a bylaw related to wind turbines that the town will hopefully adopt as a way to promote green energy while not infringing upon personal rights.

The noise study conducted by the town, he said, shows the inherent conflicts with wind turbines. “It is a very difficult problem. Are we in violation or not? That is you job to deal with,” he said to the public officials, adding that land use can be a difficult problem to deal with. He said adopting a bylaw would be one way of addressing the issue, which he was confident they would want to resolve.