By NANCY MADSEN
TIMES STAFF WRITER
FRIDAY, FEBRUARY 27, 2009
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CLAYTON — The town's wind committee heard its second and possibly final expert at its meeting Thursday.
Paul G. Carr, engineering professor at Cornell University, Ithaca, and one of the founding principals of Bernier, Carr and Associates, Watertown, gave the committee more information on noise and safety setbacks.
Clayton's standing law, like many in the state, uses a 50-decibel limit for sound from turbines. That is the suggestion made by the New York State Energy Research and Development Authority.
"Much of the siting issues are tied to guidelines from NYSERDA, which published model ordinances for towns," he said. "Unfortunately, NYSERDA hired a number of firms who were also hired by energy companies."
He confirmed what Gregory C. Tocci, a senior principal consultant at Cavanaugh Tocci Associates, suggested to the committee. Mr. Carr and Mr. Tocci agreed the best way to control noise levels is to have an ordinance that allows only 5 decibels above pre-construction ambient noise.
Model leases also published by NYSERDA would give developers the right to general noise up to 65 decibels above ambient-noise levels. Under guidelines from the state Department of Environmental Conservation, sound that is 20 decibels above ambient is considered "objectionable."
If ambient is 40 or 45 decibels during the day, the upper limit of 110 decibels is the same level of sound that an accelerating motorcycle or a live rock band would produce.
Information from different wind turbine manufacturers claims current turbine models produce 100 to 105 decibels at the hub.
"It is illogical for NYSERDA to promote that as standard," Mr. Carr said.
Mr. Carr also explained that noise decreases by 6 decibels every time the distance from the noise producer is doubled. So if a turbine produced 100 decibels and the noise needed to be about 35 decibels to meet the ambient-noise-plus-5 requirement, the distance required would be more than 2,000 feet.
The noise consultant for Iberdrola on Horse Creek Wind Farm, CH2MHill, did a good job showing the sound levels in the proposed wind farm area, Mr. Carr said. It found the ambient noise levels to be as low as 28 decibels. And it said that adding the turbines would increase the noise levels by around 15 decibels at residences in the wind farm area.
"That is intrusive," Mr. Carr said. "Unless you put people who are non-leaseholders in a bargaining position to give noise easements to the developers."
He also warned against making short setbacks from roads and participating landowners.
"Public health and safety should not be a measure of a project's success," he said.
By the speed of turbine blades and height of the turbines, Mr. Carr said ice or blade parts could be thrown up to 1,300 feet from the turbine's base.
Committee member Patricia A. Patchen asked him for a number of failures or injuries in the U.S. Mr. Carr said he didn't know exactly how many incidents of failure or injuries there have been, but comparing it to bridge failure, he said, "As engineers, we design for the worst and hope for the best."
During the committee's discussion, members discussed the possibility of health effects from low-frequency noise.
"I want to have something that says, 'You need to do this or people will be sick,'" said member Leslie E. Drake.
Dr. John W. Jepma, another member, said, "You're not going to get what you want — 100 percent this causes this — but the evidence is there that causes concern."
At its next meeting, at 6 p.m. March 12 at the Antique Boat Museum, the committee will bring its suggestions for changing the law and discuss them. It could be the last meeting.
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