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DEP consultant says wind turbine noise exceeded sound standards

Rockland – A consultant for the Maine Department of Environmental Protection found that noise levels near the Fox Islands Wind turbines on Vinalhaven were above the DEP’s nighttime limits. The consultant said “there exists a significant body of consistent meteorological and sound data indicating sound levels greater than applicable limits.”

However, Fox Islands Wind said its sound consultant has consistently concluded that the meteorological and sound data collected over the past nine months have met state requirements.

The DEP plans to meet with officials from Fox Islands Wind to discuss what can be done so the turbines comply with noise level standards, said DEP Project Manager Becky Blais.

DEP consultant Warren Brown studied noise levels for July 17 and July 18 near the Vinalhaven turbines. He found that the sound levels were above the 45-decibel nighttime limit. The sound analysis was conducted in part due to complaints by Fox Island Wind Neighbors, an organization of island residents that seeks to curb what it calls excessive noise from the three 1.5-megawatt turbines.

The DEP noise level limits are 55 decibels during the day and 45 decibels at night. Brown wrote an e-mail to Blais that said the sound levels near the turbines were above the DEP limits even though the turbines were being run at a slower rate to mitigate the noise.

“The July 17 and 18 complaint conditions were very similar with regards to surface wind speeds and [wind turbine generator] output for 80-meter wind speeds (May data) as [Fox Island Wind Neighbors] complaints previously submitted for May 1, 4, 5 and 6 all of which reported sound levels between 46-48 [decibels],” Brown wrote. “Although these complaints were prior to the ‘FIW compliance protocol’ in timing, nonetheless there exists a significant body of consistent meteorological and sound data indicating sound levels greater than applicable limits.”

Blais said Fox Islands Wind will have to meet DEP compliance for sound levels, whether this means powering down the turbines, shutting them off or finding another technological solution.

“Substantial changes are recommended for FIW nighttime operations, limiting WTG sound levels at ML-A [a site] to 45 dBA [a decibel measurement],” Brown wrote.

George Baker is vice president of community wind at the Island Institute and CEO of Fox Islands Wind LLC. He said Brown’s work was a first analysis of data submitted by Fox Islands Wind consultants.

“There are discrepancies and disagreements between experts on how the data should be interpreted,” Baker said.

In particular, there appear to be differences in the treatment of ambient sound levels, Baker said. Baker said there is still a lot of work to be done by experts to get to the bottom of this. “Accounting for ambient sound is a very complex problem,” Baker said.

Baker said Fox Islands Wind is “absolutely committed to being in compliance with state sound regulations.”

In a news release, Art Lindgren, one of the Fox Island Wind Neighbors, said the findings by the DEP consultant were welcome news. “We look forward to working with Fox Island Wind and the Fox Island Electric Cooperative to turn down the turbines so that our peace and quiet is returned and the turbines do not violate state law,” Lindgren said.