DARTMOUTH – The Dartmouth Board of Health weighed some proposed noise regulations for commercial wind turbines in Dartmouth, such as the pair of turbines that were being planned for town property near the municipal wastewater treatment plant, at their Oct. 19 meeting.
The draft regulations were presented by attorney Christopher Senie, who represents the Dartmouth Citizens for Responsible Energy (DCRE), a group of families living on Chase Road and Russells Mills Road, in the neighborhood of the proposed municipal turbines. That project was terminated Monday night by a vote of the Select Board (see related story.)
“I ask that these draft regulations become a subject for a public hearing. I am not asking the Board of Health to take any action today. People will have the chance to study our study; this is not designed to prevent turbines, only to give you a vehicle if there are problems,” he advised.
The town’s consulting engineer, COWI Wind North America staffer Henry Dupont, outlined his qualifications as an expert in wind energy projects, including consulting on the installation of wind turbines at Portsmouth Abby and Otis Air Force Base.
He talked about the potential impact of municipal or privately-built turbines at the town property since the original locations have been reconsidered.
“The south turbine was moved approximately 200 feet to the east, away from Chase Road, and the north turbine was moved approximately 2,000 feet to the southeast, to behind the wastewater treatment plant,” he explained.
The turbines proposed by the Alternative Energy Committee would have had a hub height of 80 meters (262 feet) with a total height of 423 feet, and a blade-swept area of 1.57 acres of land.
“I am very familiar with public outreach. We are following very strict guidelines, and the town is very concerned about making sure the size and site minimize the impact to the neighbors with the neighborhood in mind,” Mr. Dupont said.
According to Dupont, the audible sounds from wind turbines are not unique and are readily found in natural settings such as the sound of waves on the beach. There are two types of noise produced— mechanical noise such as bearings and generators, and the sound of spinning blades.
“To reduce the impact of this noise, heavy insulation is used inside the drive. The the swishing sound of the blades for example, is similar to a glider coming into an airport,” he described.
Although some people living near wind turbines report symptoms such as dizziness and sleep disturbance, the scientific evidence available does not demonstrate a direct causal link between wind turbine noise and adverse health effects, he indicated.
“People who are opposed to the projects are sensitive to the noise; those not opposed don’t report any health effects; mostly it has to do with public perception,” he suggested.
Vice President of Atlantic Design Engineers Richard Tabaczynski further explained that the acoustical studies started with the ambient noise levels measured. “We have taken noise levels including background wind speed during the winter, the quietest time of the year, and sound measurements at the houses along Chase Road to the property. The measurements were about 50 feet off the roadway unto the site,” he said.
The town must comply with the state Department of Environment Protection (DEP) regulations limiting broadband sound level increases from turbines to less than 10 decibils dB(A) above ambient level, or “pure tone” conditions— when any octave band center frequency sound level exceeds the two adjacent center frequency sound pressure levels by 3.0 decibels or more.
Those noise nuisance regulations are stricter that what is being adopted by other states, noted Mr. Dupont.
Attorney Senie suggested that the Board of Health adopt his proposed regulations in order to insure the protection of the health and safety of nearby residents. Themost important section of the draft regulations state, “No wind turbines shall produce an A-weighted sound level that is 6 db or more above the lowest pre-development L90dB level measured during the quietest part of the daytime or nighttime.”
“The DEP standard does not perform well in assessing wind turbine noise, which has a particular character, periodic time varying amplitude, sound pressure levels with a repetition rate of about one per second,” the attorney advised the health board.
Falmouth resident Neil Anderson, who lives 1,320 feet from the Falmouth municipal wind turbine, said he was so concerned about turbine-related health issues that he drove to the Dartmouth meeting to offer his personal experiences.
“We have been before our Falmouth Board of Health for a year, concerned about the effects of wind turbines. I hear swishing noises depending on the weather conditions; I have health-related issues such as headaches, ringing in my ears, some loss of hearing, an increase in blood pressure and mood changes,” he remarked.
At a recent town meeting, Mr. Anderson backed a petition to turn off the turbines, and is working with the State Senate on Bill 02346, designed to protect the health of the citizens from turbine impacts.
“This is a real health issue. Please don’t let the project go through; I have been woken up at night when the turbine is on, and it just pounds, pounds,” he reported.
Noise Control Engineer Michael Bahtiarian noted that since the DEP is falling short on regulations on setback distances, he has proposed 10 times the rotor diameter as an acoustical setback, about 1.2 miles. “Setback distance should be examined,” he suggested.
According to Mr. Bahtiarian, the Mass DEP regs are only guidelines and do not speak at all to probable community responses.
Referring to the Falmouth turbines, Mr. Dupont countered that the 2007 models were bought by the state, but “could not be used and the turbines were without maintenance until 2009. Wind 1 uses a blade pitch to reduce the power outage outlet. To come here to compare completely obsolete turbines is not fair.”
He suggested many sites, including Portsmouth and Otis, have turbines, but no complaints from neighbors. “I called the Board of Health in Portsmouth, and they had no complaints,” he insisted.
About 75 members of the DCRE attended the BOH meeting, with several residents rising to express their concerns. “I moved here because this is the most unbelievable area; it is quiet and so peaceful. Keep that in mind, I ask you,” said Linda Bush.
DCRE spokesperson and Chase Road resident Jeanne Nesto said she has spoken to many people living near turbines, and feels noise is not the only issue for neighbors.
“One person living near Portsmouth said even (window) shades don’t stop the flicker,” she noted.
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