Here is one:
To: The Board of Supervisors, Roanoke County
From: Linda LaPrade, Cave Spring District Resident
Your job of constructing the Windmill Ordinance is not an easy one. You will not please all the people no matter what you do. Thank you for taking the time to explore the many suggestions given to you. Please also consider these things:
1) According to the WHO in their 2009 authoritative document on noise and sleep disturbance, levels between 32 dB and 42 dB will disturb sleep and noise levels of 50dB or higher have been proven to cause health consequences. The same study uses 21dB as a threshold for rural nighttime sleep. World Health Organization 2009; Effects of different levels of night noise on the population’s health.
Average night noise level over one year Health effect observed in the population
- Up to 30dB - Although individual sensitivities and circumstanced may differ, it appears that up to this level no substantial biologic effects are observed.
- 30 to 40 dB - A number of effects on sleep are observed; body movements, awakening, self-reported sleep disturbance, arousals. The intensity of the effect depends on the nature of the source and the number of events. Vulnerable groups (elderly, children and chronically ill) are more susceptible.
- 40-55 dB - Adverse health effects are observed among an exposed population. Many people have to adapt their lives to cope with the noise at night.
- Above 55 dB - The situation is considered increasingly dangerous for public health. Adverse health effects occur frequently, a sizeable portion of the population is highly annoyed and the sleep disturbed. There is evidence that the risk of cardiovascular disease increases.
There is no medical doubt that audible noise such as emitted by modern upwind industrial wind turbines sited close to human residences causes significant adverse health effects. These effects are mediated through sleep disturbance, physiological stress and psychological distress. This is settled medical science.”
An Analysis of the American/Canadian Wind Energy Association sponsored “Wind Turbine Sound and Health Effects An Expert Panel Review, December 2009.” Peer reviewed and published January 2010.
2) The sound is projected outwards, so that it is actually fairly quiet directly beneath the turbine, but farther away the resulting sound, especially of several towers together, has been described to be as loud as a motorcycle, like aircraft continually passing overhead, a "brick wrapped in a towel turning in a tumble drier," "as if someone was mixing cement in the sky," "like a train that never arrives." It is a relentless rumble like unceasing thunder from an approaching storm. Enxco's John Zimmerman admitted at a meeting in Lowell, Vt., "Wind turbines don't make good neighbors." [Click here for one story from Fenner, N.Y., where many other noises have been described, including an eerie screeching as the blade and nacelle assembly turns to catch the wind -- click here for a video recording of these noises.]
3) From Science News…studies are being done about the effects of noise. Research leader Dr Con Doolan, of the University's School of Mechanical Engineering, said the noise generated from wind turbines is 'trailing edge or airfoil noise', the same sort of noise generated at the edge of aircraft wings.
"We know generally what causes that noise – as the turbulent air flows over the sharp edge of the blade it radiates sound much more efficiently, so the noise can be heard at some distance," said Dr Doolan. "Wind turbine noise is very directional. Someone living at the base might not have a problem but two kilometres away, it might be keeping them awake at night," he said.
4) When turbines have been installed with lax regulations, there is little that can be done. For those who have lived near those in operation for a number of years, the stories are clear. I again urge you to examine what those who live near turbines that have been operational for several years say about their quality of life: Letters From Wind Farm Neighbors
5) Many people spoke at the meetings you have held. One thing that I noticed was that many of those speaking in favor of the wind turbines are members of the Sierra Club (see their goals on ‘global warming’ and on alternative energy). Others were those whose livelihoods are dependent on wind energy. Most if not all do not live in the affected areas…many do not live in Roanoke County. Most of the speakers with real concerns who spoke against the setbacks and excessive noise created are those Roanoke County citizens who live near the projected site. To me, their concerns should carry a much greater weight because they and their property are directly affected…and THEY are your citizens.