Wind Noise Characteristics Unique, Lack Regulation
| Update: Ambrose letter compliments journalistic integrity Letter: Turbine reporting sets high standard December 23, 2012 12:00 AM I want to congratulate Ariel Wittenberg for her well-written article about the Dec. 6 Institute of Electrical and Electronic Engineers dinner meeting in Westport (“Turbine noise regulations debated,” Dec. 7). I was there as a guest. The article was a concise, accurate and unbiased account of events. SouthCoastToday.com has a very good reporter who maintains a neutral position for the paper. Stephen Ambrose, Windham, Maine |
Wind turbine noise is not like other sounds and is not specifically regulated, according to the presentation of Michael Bahtiarian, vice president of Billericia-based Noise Control Engineering, to an audience of 30. The December 6th program was hosted by the the Institute of Electrical and Electronic Engineers.
Reporter Ariel Wittenberg, writing in South Coast Today, described Bahtiarian’s remarks in Turbine regulations debated at engineer conference.
There are no federal or state regulations relating to wind turbine noise, Bahtiarian said. In Massachusetts, any noise source is considered in violation of noise regulations if it is more than 10 decibels louder than ambient noise, but Bahtiarian said these regulations do not take into account the complex nature of turbine noise.
“Wind turbine sound is what we call aerodynamic amplitude modulation, which means there is a fluctuation of sound that changes as the blades pass through the air,” Bahtiarian said, describing the technical term for what some people call the “wooshing” nature of turbine sound.
Wind turbine noise expert Steve Ambrose interacted with the presenter. In the audience were people from Windwise Falmouth and Fairhaven.
Bahtiarian also brought up an alternative set of sound regulations put together by some Massachusetts electrical engineers that would regulate infrasound, broadband (or typical audible sound) and aerodynamic amplitude modulation. That regulation would put a sound source in violation if it creates either broadband or infrasound more than 6 decibels above ambient sound. Bahtiarian said the alternate regulations have been proposed both to the Falmouth Board of Health and the Cape Cod Commission.
Wind Wise ~ Massachusetts 
With all due respect to the experts, the problem with wind turbine noise complaints is not the result of ineffective and outdated regulations. The problem is a direct result of the sloppiness of acoustical studies required as part of the special permitting process. Acousticians are routinely guaranteeing that that wind turbine noise will be in compliance with existing regulations when in fact, if the regulations were applied as written, they would be reporting just the opposite.
Unfortunately, once the permit is granted, a simple showing that that the acousticians were wrong and the noise is far in excess of what the special permit calls for is not enough to shut the turbine down for violating the terms of the special permit. This gives license to acoustical engineers to produce acoustical studies that are notorious for understating future noise levels for which they cannot be held accountable short of taking expensive legal action which lies beyond the ability of ordinary citizens.
To further complicate matters, a post construction study, such as the one by MassDEP currently underway in Fairhaven, is next to impossible. Ordinarily, the compliance officer would take data with the noise source in operation and compare it to noise data when it is off. In the case of wind turbines the noise at any given receptor point is dependent on wind speed and direction 400 feet in the air. The compliance officer will need to take data for more than a year to capture all the variations due to weather. Then the process will need the full cooperation of the wind turbine owner to cycle the turbines on and off on command during the tests. A further complication, that influences the integrity of the test, is the fact that the owner is in full control of all the data needed to ensure that the turbine is operating normally, and making the maximum level of noise during the test.
At this stage in Fairhaven, Kingston, Scituate, and Falmouth the Board of Health needs to step up and shut the turbines down based simply on the large number of complaints. The MassDEP has a long history to show that in the presence of numerous noise pollution complaints an out of compliance situation is always found. Delaying the decision for as long as two years, as is the case in Falmouth, while data is collected to show compliance is much too burdensome for those impacted negatively by the noise pollution some of which are forced to abandon their homes for a good night’s sleep.