Download “Brownsville noise diary, March 3 to August 5, 2008″

1. Audible Sound Limit.

a. No Wind Turbine or group of turbines shall be located so as to cause an exceedance of the pre-construction/operation background sound levels by more than 5 dBA or dBC. The background sound levels shall be the L90 dB sound descriptor (both A and C weighting) measured during a pre-construction noise study during the quietest time of evening or night. Measurements shall be for ten (10) minutes or more. L90 results are valid when L10 results are no more than 15 dB above L90 for the same time period. Noise sensitive sites are to be selected based on wind farm’s predicted sound emissions (in dBA, dBC and 1/3-octaves to blade passage frequency), which are to be provided by developer.

b. A 5 dB penalty is applied for pure tones or when the sound emissions fluctuate in amplitude or frequency over time in reasonable synchronicity with the blade revolution.

2. Inaudible (e.g., Low Frequency) Sound Limit.

a. Not to exceed dBC − dBA greater than 20 dB inside or outside any occupied structure.

3. General Clause.

a. Not to exceed 40 dBA or dBC within 100 feet of any occupied structure.

L. Setbacks. Setbacks shall be measured from the outermost edge of the closest of the circular path of the wind turbine rotor blade. The Town Board may increase the following minimum setbacks on a case-by-case basis, in order to protect public health and safety.

1. Participating Property Line: 1.1 times the total height of the Wind Turbine from the nearest property line of a participating property owner.

2. Non-participating Property Line: Five (5) times the rotor diameter but not less than 1,300 feet from the nearest property line of a non-participating property, unless the owner of the non-participating property grants an easement for a lesser setback. The easement must be recorded with the County Register of Deeds and may not provide for a setback that is less than 1.1times the total height of the Wind Turbine.

3. Public Roads and Highways: 1,300 feet or three (3) times the total height of the Wind Turbine, whichever is greater.

4. Above Ground Power/Telephone Lines: 1,300 feet or three (3) times the total height of the Wind Turbine, whichever is greater, from the nearest above-ground public electric power line or telephone line.

5. Residences & Other Buildings: 2,640 feet from the nearest residence, business, school, daycare facility, church, hospital and other sensitive receptors.

6. Wetlands: 1,000 feet from all sinkholes and wetlands.

7. Water Bodies Setbacks: 1,300 feet from the ordinary high water mark of all navigable water bodies.

8. Parks & Public Property: 2,640 feet from any town, county or state park, property, recreational or rest area.

Download “Wilton, Wisc., Wind Ordinance” (PDF)

Download “Ridgeville, Wisc., Wind Ordinance” (Word document)

Entries of a noise log kept by a Brownsville family who live 3/4 mile east of South Byron in Fond Du Lac County, Wisconsin. The new wind turbines had just gone on line there.

Download “Brownsville noise log, March 3 to July 7, 2008″

Click here for updated diary through August 5, 2008.

Download “Turbine Layout Map, Brownsville, Wis.”

In anticipation of posting testimony given at the public hearing for the town of Union’s wind ordinance on May 29, here is a document submitted by a member of the Town of Union’s Large Wind Turbine Citizens Study Committee regarding a statement widely used by wind developers comparing the noise an industrial wind turbine to the noise of a refrigerator. The committee member tried to track down the source of this quote and submitted these results which are now part of the public record. It reads:

There’s a statement out there that has been used by people involved in the wind industry, most commonly cited on the American Wind Energy Association site that goes like this: “Today, an operating wind farm at a distance of 750 to 1,000 feet is no noisier than a kitchen refrigerator or a moderately quiet room.”

A similar statement appeared in the National Wind Permitting and Siting Guide 2002. So I wrote the NWCC and asked them if they knew the source since there wasn’t a footnote listed with a supporting reference.

They didn’t know.

AWEA referenced the National Renewable Energy Lab as the source, so I wrote them

Even though they were very helpful and put me in touch with their staff noise authority, they could not come up with the author of that statement, however they did copy pages from books that their noise authority called the quintessential references on wind energy and noise.

So, then I Googled it. I typed in the refrigerator statement in question and came up with these statements from the American Wind Energy Association.

Author Tom Gray, AWEA:“Today, an operating wind farm at a distance of 200 meters (658 ft.) is no noisier than a refrigerator “.

Author Tom Gray: “Wind turbine noise (at 200 m) is as loud as your refrigerator heard from the living room”.

Author Tom Gray, AWEA . “Today, an operating wind farm at a distance of 300 meters (987 feet) is no noisier than a kitchen refrigerator or a moderately quiet room”.

Author Tom Gray, AWEA. “Today, an operating wind farm at a distance of 350 meters (1151.5 feet) is no noisier than a kitchen refrigerator or a moderately quiet room”, to:

Author Tom Gray, AWEA. “Today, an operating wind farm at a distance of a quarter of a mile is no noisier than a kitchen refrigerator or a moderately quiet room”

and finally:

Author Tom Gray, AWEA. “Objective measurements with sound meters show that a wind turbine, at a distance of 500 to 750 meters, (1645 to 2467 feet) is no noisier than a kitchen refrigerator or a moderately quiet room. If you doubt this statement, we invite you to visit a wind farm and see for yourself”.

From the very beginning, our committee was determined to take on the challenge of supporting our draft ordinance setback recommendations with references from the wind industry. It may just be an assumption, but we understand if the information comes from the sources that [wind developer] Ecoenergy listed as acceptable, that would then be deemed as a credible source.

Setbacks

AWEA, 1645 to 2467 feet (approx. 1/2 mile) for noise.

NWCC Permitting and Siting Guide 1998, and appropriate distance may be 1000 feet to ½ mile or more for noise.

AWEA Recommended book to buy: Wind Energy Handbook by Tony Burton. A minimum spacing from a dwelling for shadow flicker 10 rotor diameters (1/2 mile). Also added that a spacing of this magnitude is likely to be required in any event by noise constraints…

To note if there is an issue whether or not we are in an area susceptible to shadow flicker, there is Harvest the Wind: A Wind Energy Handbook for Illinois. Even though it wasn’t on the preferred list, Lisa Daniels from Windustry and Wes Slaymaker from Ecoenergy were authors so I thought it would be acceptable. “Shadow flicker may be more of a problem in northern Europe, Canada, and the upper Midwest than elsewhere…”

I looked up upper Midwest on Wikipedia, and Wisconsin is included in the upper Midwest.

Windustry, Best Practices and Policy Recommendations. “Turbines should be sited no less than 5 times their rotor diameter (1320 feet) from property lines unless written permission is given by the neighbor. This recommendation is designed to protect wind rights of all landowners and minimize the impact of wind turbines on neighbors.

Noise Limits:

NREL: National Energy Renewable Laboratory which is part of the US Dept of Energy, said as mentioned earlier that the quintessential reference for wind turbine noise is Wagner 1996 , “Wind Turbine Noise”, and Manwell’s “Wind Energy Explained”.

These pages that they sent me from these books referenced these items in the draft ordinance:

• Germany night time rural noise limit 35 dBA, outdoors.
• A fixed noise limit alone will not eliminate noise complaints.
• A change in the sound level of 5 dB will over ambient noise will typically result in noticeable community response.
• Tonal noise penalty.
• Distance attenuation and sound propagation.
• Differences in noise from day and from night.
• Frequency of noise and dBC filter.
• Aerodynamic Noise.
• Multiple wind turbines. 2 at equal value increases the noise level by 3 dB.
• Weather effects and noise.
• Downwind noise.

In closing, finally some key points from the new AWEA Wind Siting Guide 2008:

“The studies required in the permitting process should be science-based and tailored to the specific site. Each wind developer has a responsibility to further the reputation of the industry by providing appropriate and sound oversight of the regulatory process. (1-3)”

Shadow Flicker

“A wind turbine’s shadow flicker impact area does not generally extend beyond 2 kilometers ( 1 ¼ miles) and high-impact durations (? 200 hours per year) are generally located within approximately 300 meters(987 feet) of the turbine. …The potential for shadow flicker has been raised as a visual issue by close neighbors of wind farm projects. (5-33)”

Sound

“Most states and localities establish noise limits at property boundaries based on specific sound pressure levels measured in decibels. (5-35)”

“The relative increase in sound from the project may be as important, or more important, than the absolute sound levels of the project itself. (5-36)”

Ice Shedding

“It has also been observed that the rotor ice can break off, and if the rotor is moving, can be cast some distance. (5-47)”

Please submit to Public Record.

Thank You.

MORE TESTIMONY: WHAT’S NOISE GOT TO DO WITH IT?

Q: What is Aerodynamic modulation? What is distance attenuation? How do dB’s add up? Three Turbines producing 45db equal what total dB? Do wood frame walls attenuate low frequency and high frequency noise equally?

These questions are part of the following document which was also submitted to the town of Union’s Plan Commission members by a member of the town of Union’s Large Wind Turbine Study Committee who has spent the last year researching the subject of noise from industrial wind turbines.
Here is his testimony:

Public hearing comments

Survey

Government officials have an intrinsic responsibility to protect the citizens. State statute 66.0401 restricted the wind committee research and recommendations to health and safety issues. Now the Plan commission members are faced with the same restriction. The supposed popularity of wind turbines should not carry any weight in making a decision concerning health and safety.

Noise

Noise is subjective. The town government and local residents should decide how much noise we should be subjected to during the nighttime hours. Not a wind developer. The developer has never offered anything less than 45dB which will be 15 to 20 times louder than we have now. Sleep deprivation is a well established health risk. It leads to a multitude of other health related issues.

The World Health Organization has found that sound levels during nighttime and late evening hours should be less than 30 dBA during sleeping periods to protect children’s health.

Atmospheric conditions can wreak havoc with nice clean sound propagation models, especially at night. And, as turbines get bigger, their noise can be deceptively hard to predict. Temperature inversions, wind layers, and other atmospheric effects can lead to surprisingly distant sound impacts. The noise levels can easily be 15 dB louder than predicted.

In some cases, low-frequency noise can become an issue with wind turbines. It is a component of a broadband noise field generated by spinning turbine blades. Low-frequency noise travels greater distances with less loss of intensity than higher-frequency sound.

Noise standards can very easily fail to protect nearby residents from disruptive levels of noise. When standards are exceeded the task of enforcement will quickly out distance the ability of local government and law enforcement. It is crucial that everyone involved (industry, government, residents) resists the easy temptation of relying on “paper” assurances that wind turbines will not create acoustic impacts.

With continual incorporation of best technology and best practices in siting, wind energy need not be stymied by noise issues. However, with noise impacts gaining more public credence, it is clear that the current boom in wind farm development could well backfire, for both the industry and a clean energy future, if the current generation turbines are sited too close to residences.

Noise impacts are not necessarily deal-killers for wind energy, as long as developers are honest about what is likely to be heard and continue to work diligently to investigate the aspects of wind turbine noise that are still not fully understood.

Better to be conservative, accepting the fact that even occasional atmospheric effects should be factored in to siting decisions today, so as to build a reservoir of good will, rather than a rising tide of complaints.

Questions
What is aerodynamic modulation?
What is distance attenuation?
How do dB’s add up? Three turbines producing 45dB each equals what total dB?
Do wood frame walls attenuate low frequency and high frequency noise equally?

If you are unable to answer these questions you need to rely on and trust that the wind committee has researched these issues. The recommendations of the wind committee for setbacks and noise limits should be considered the minimum to protect public health and safety.

Paul Cheverie, chairman of the Eastern Kings Community Council (Prince Edward Island, Canada) said. “There are no rules and regulations on windmills,” “The more we get into it, the more we realize we jumped the gun.”

[end of testimony]

To download the Town of Union’s Large Wind Turbines Study Committee’s Final Report which includes all supporting documentation for the wind ordinance, click here.

To watch video and hear audio of the May 29th Town of Union public hearing, visit the Evansville Observer by clicking here.

To watch a Milwaukee Channel 6 news segment which shows the trouble with living too close to industrial wind turbines, click here.

If you’d like us to send you a free DVD copy of this news segment contact us by clicking here or by writing us at Better Plan, Rock County; PO Box 393; Footville, WI 53537. We’ll be glad to send you a copy right away.

Friday, May 30, 2008 at 01:15PM
The BPRC Research Nerd

“The audible sound emitted by Wind Energy System operations shall not be greater than 5 dBA above the background noise level (L90) for the quietest period of the day measured during the pre-build noise study.”

“No low frequency sound or infrasound from wind energy system operations shall be created which causes the sound pressure level both within the project boundary at any sensitive receptor and within a one-mile radius beyond the project boundary to exceed the following limits [see document].”

“In the event audible noise due to wind energy system operations contains a steady pure tone, such as a whine, screech, or hum, the standards for Audible Sound shall be reduced by five (5) dB(A).”

“In the event the audible noise due to wind energy system operations contains repetitive impulsive sounds, the permitted sound pressure level for Audible Sound (Rule 4) shall be reduced by five (5) dB.”

“In the event the audible noise due to wind energy system operations contains both a pure tone and repetitive impulsive sounds, the standards for Audible Noise (Rule 4) shall be reduced by a total of seven (7) dB.”

“A Wind Energy System that emits sound (or causes structural or human body vibration) with strong low frequency content where the time-average C-weighted sound level exceeds the A-weighted sound level by at least 20 dB when measured inside a structure and adversely affects the subjective habitability or use of any existing dwelling unit, hospital, school, library, nursing home, or other sensitive noise receptor shall be deemed unsafe and must be shut down immediately.”

“Each Wind Energy System shall be set back from the nearest residence, school, hospital, church or public library, a distance no less than one thousand eight hundred (1,800) feet.”

“The County Board may impose a setback that exceeds the other setbacks set out in this ordinance if it deems that such greater setbacks are necessary to protect the public health, safety, and welfare of the community.”

Download “Calumet County Wind Ordinance Amendments”

To: Wisconsin Task Force on Wind Siting Reform
Subject: Comments on Electric Generation and Supply templates
Re: Wind Siting Reform Policy

Please let us take this opportunity to briefly introduce ourselves. We are noise control consultants with many years of experience in community noise and related land-use planning issues. Mr. Kamperman has over 50 years of experience and was active in the early 1970’s assisting the US EPA, states such as Illinois, and many communities in setting their community noise standards and guidelines. Mr. James has over 35 years of experience in the same field and has represented many of the largest corporations in the US on community noise issues and litigation. He has also served on the S12 Working Group for the American National Standards Institute, which has oversight on standards related to acoustics including community noise and works to coordinate ANSI standards with those of ISO and other standards organizations. We are currently involved with assisting some of the communities in Wisconsin with understanding and addressing wind turbine developments proposed for their communities.

We are writing this joint letter to the Task Force because we have mutual concerns about the impact of the work of the Task Force on the communities in Wisconsin that are under consideration for wind farm development. These concerns are a result of our work with those communities and our review of the Task Force’s recent draft Policy documents and the Draft Model Wind Ordinance for Wisconsin (Feb. 7, 2007) and its associated reference guide.

Our review finds substantial errors of fact and understanding regarding community noise and the impact of noise on land-use planning and the safety and health of citizens that would be affected by these policies. We do not intend to address all of them but several of the more egregious errors are addressed in this letter.

It appears to us that there has been little or no input into the work of the Task Force from un-biased and experienced professionals from our profession. Nor does it appear that there has been much, if any input from the medical and research professionals. Mr. Kamperman suggests that one way to resolve this lack of expertise on the Task Force panel would be to include someone with his experience on the Task Force panel. Please consider the offer in the Post Script below.

We would like to address two major errors and failures of understanding in the Task Force’s documents.

First, the limits and guidelines set forth fail to adequately consider the health and safety of the people who will be living in the communities in which the wind energy systems are to be located. For example, there is no scientific evidence currently available from independent medically qualified authorities to support a statement that the 50 dBA sound pressure level to which residents may be subjected on a 24/7/365 basis is safe and healthful for all people including children and those with special needs.

The World Health Organization [Report on the second meeting on night noise guidelines, WHO, Dec. 6-7, 2004] has found that sound levels during nighttime and late evening hours should be less than 30 dBA during sleeping periods to protect children’s health. They noted that a child’s autonomous nervous system is 10 to 15 dB more sensitive to noise than adults. Even for adults, health effects are first noted in some studies when the Lmax sound levels exceed 32 dBA, 10-20 dBA lower than the levels needed to cause awakening. The WHO researchers found that sound levels of 50 dBA or more strongly disrupted hormone secretion cycles. For sounds that contain a strong low frequency component, which is typical of wind turbines, WHO says that the limits may need to be even lower than 30 dBA to not put people at risk.[Community Noise (Berglund et al., 2000)] ANSI standards recommend that no sound pressure levels exceed 65 dB (e.g. No weighting) in the lower frequency ranges to avoid structural vibrations and potential damage. 50 dBA would not protect against this situation, yet studies have shown that wind turbine sounds at residences sometimes exceed 65 dB in the frequency range below 20 Hz.

The recent conference held in Lyons, France, for the purpose of addressing wind turbine noise and health concerns demonstrated that wind turbine sound emissions of the types routinely experienced by people living close to wind farms may have significant cardio-vascular health effects after long term exposure. Again, we caution the Task Force that there is no scientific or medical basis for equating a 50 dBA limit for Wisconsin communities with health and safety.

Both the policy statement and supporting Model Ordinance are woefully lacking any scientific evidence supporting the sound limits and other recommendations that impact the acoustical environment. There is no un-biased evidence presented that the people living near wind turbine installations will not be forced to accept industrial scale operations that could introduce new risks into a community against the will of its citizens. Further, the statements in these documents that 50 dBA is based on review of other statutes and standards adopted by communities with wind farms shows only that the other communities also did not properly research the issues of community noise and its effects on health and safety. There is no objective argument for considering these other standards as a reason to adopt a similar set of limits. The documents provided by the promoters of wind energy that support the methods and limits proposed by the Task Force that we have seen would not pass a peer review by professionals in our field. They, also, should not be used as the basis for guidelines in Wisconsin.

Second, to suggest the use of L10 as a descriptor of background sound levels is an egregious mistake. On what scientific basis has this recommendation been made? L10 is not a descriptor of background sound; L90 is the proper descriptor for background sound. L10 is a descriptor of noisiness from transient events. The wind turbines will produce steady sound emission for protracted periods of time. They should not be judged against transient events, but against the steady background sounds that occur during the periods of the day when quiet is expected.

Wind turbine siting guidelines for noise in Europe and many other parts of the world have adopted L90 to define the sound levels in communities prior to construction of wind farms. In New Zealand, L95 is used. The International Energy Agency (IEA) recommends the use of either L90 or L95 to define background sound levels [Recommended Practices for Wind Turbine Testing, Chapter 10]. L90 has been accepted and incorporated into documents developed by wind industry groups. For example, the British Wind Industry Association (BWEA) recommends that turbine sound levels should be kept to within 5 dBA of the average existing evening or nighttime background noise level and defines background noise level as the L90 sound level [BWEA Wind Turbine Noise Working Group Guidelines].

It should be noted that even when these stricter guidelines are followed that experiences in Europe, Britain and New Zealand show that residents near the wind farms are often subjected to turbine noise that are considered objectionable.

Finally, if the mission of the task force is to enable the mission of the DNR:

“To provide a healthy, sustainable environment and a full range of outdoor opportunities.

“To ensure the right of all people to use and enjoy these resources in their work and leisure.

“To work with people to understand each other’s views and to carry out the public will.”

Then, the views of the communities and citizens of Wisconsin who look to the State for guidance on what amounts to the industrialization of rural Wisconsin should be considered as positive and constructive efforts. Their concerns about noise and other new risks being introduced into their communities are valid. They should not be discredited by labeling their concerns as some form of NIMBYism or obstructionism as was implied in earlier drafts of the policy documents. Doing so devalues the input of Wisconsin’s citizens to the State’s efforts to promote renewable energy.

We appreciate the Task Force taking the time to consider our concerns and hope that they are taken in the most constructive light possible.

George Kamperman, P.E.
Bd. Cert. Member Institute of Noise Control Engineers
Member National Council Acoustical Consultants
Fellow Member, Acoustical Society of America
Kamperman Associates, Inc.
312 Washington Avenue
Wisconsin Dells, WI 53965
Tel: (608) 254-5656
george@kamperman.com

Richard R. James
Full Member, Institute of Noise Control Engineers
Member, Acoustical Society of America (past)
E-Coustic Solutions
P.O. Box 1129
Okemos, MI 48805
Tel: (517) 507-5067
rickjames@e-coustic.com

P.S. from George Kamperman
I feel the wind turbine siting issues are so critical in many areas that I would welcome an opportunity to be a part of the PSC committee responsible for determining wind turbine siting guidelines for the State of Wisconsin. If the State is interested in my involvement in this endeavor I offer my services at no cost.

Downloa “Statement to Wisconsin Task Force on Wind Siting Reform”

Download “Brownsville Diary”

Click here for update to May 13, 2008.

Town of Chilton Wind Ordinance

Town of Clay Banks Draft Wind Ordinance 

Town of Magnolia Wind Ordinance

Town of Union Wind Ordinance

Trempealeau County Wind Ordinance

State of Wisconsin Draft Model Ordinance 

Go to: Wisconsin Wind Ordinances