Review:
Acoustic Study of the Lake Winds Energy Park
Mason County, Michigan

Prepared by request of Mr. Cary Shineldecker
Mason County Resident

June 23, 2011

__________________________
Robert W. Rand, Member INCE
Rand Acoustics
65 Mere Point Road
Brunswick, Maine 04011

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1.0 Introduction
This review was prepared by request of Mr. Cary Shineldecker, a resident of
Mason County, who expressed concerns regarding potential health effects from
the operation of the Consumers Energy "Lake Winds Energy Park", a wind
turbine facility with 56 Vestas V100-1.8MW wind turbines proposed for Mason
County. Lands comprising the proposed special land use are as shown in Figure
1 (at back). This review presents analysis of two documents:
- Acoustic Study of the Lake Winds Energy Park Mason County, Michigan
Report On Ambient Sound Monitoring, Tech Environmental, Inc., December 14,
2009; January 6, 2011 (1st revision); May 25, 2011 (2nd revision).
- Acoustic Study of the Lake Winds Energy Park Mason County, Michigan
Report On Acoustic Modeling, Tech Environmental, Inc., January 7, 2011; June
9 (1st revision).
1.1 Summary
Community noise impact assessments were not found in the reports.
Independent noise impact assessments by this reviewer show widespread
adverse impacts summarized in Figures 2-A, 2-B and 2-C. Additional review
detail is provided in Sections 2 through 7, with two appendices. Based on this
review of the documents and experience, the proposed facility:
- will very likely exceed the existing regulatory noise limits at numerous
locations on a regular basis due to omission of uncertainties in the prediction
algorithm, omission of increases from night wind shear, and omission of facility
design margin.
- will very likely generate adverse health and welfare impacts from sleep and
activity interference and has potential for vestibular disturbance including
nausea, dizziness, headache, inability to concentrate, anxiety and other adverse
medical symptoms for the population within an area of over 22 square miles.
- does not appear to comply with the Mason County Zoning Ordinance.
- does not appear compatible with the Mason County Comprehensive Plan.

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2. Summary detail
2.1 Figures
Figure 2-A, 2-B, and 2-C (at back of this document) provide striking visual
summaries of the potential for strong, widespread adverse community noise
impact. The figures were adapted by this reviewer from the Tech Environmental
Figure 2 "Maximum Sound Levels" in the report, "Report On Acoustic
Modeling, Tech Environmental, Inc., January 7, 2011; June 9 (1st revision),
using three separate metrics:
Figure 2-A: Community Reaction, EPA Normalized Method, 1974
Figure 2-B: Annoyance, Pedersen et al 2004, and
Figure 2-C: Health Effects, WHO 2009.
It is worth noting that for all three figures, the illustrations probably understate
the likely impact of the proposed facility, because the predictions by Tech
Environmental (June 2011) omit model uncertainties and effects due to wind
shear that would result in 5-10 dB higher sound levels than predicted.
Two areas are highlighted on the figures, the area bounded by 35 dBA, and the
area bounded by 40 dBA. Statistics were derived and shown in Tables 1 and 2.
Table 1. Land area affected by predicted sound levels
35 dBA or higher:
40 dBA or higher:

22.6 square miles (~ 14500 acres)
14.0 square miles (~ 9000 acres)

Table 2. Population affected by predicted sound levels1
35 dBA or higher:
40 dBA or higher:

858
532

1 Estimated at 38 people per square mile, rural areas of Mason County, U.S. Census Bureau (Year 2000).

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2.1.A Community Reaction
The USEPA made recommendations in the 1974 “Levels Document” [2], which
presents a well-researched community reaction prediction methodology,
sometimes referred to as the "Normalized Ldn" method for noise impact
assessment. The EPA noise impact assessment method includes correction
factors for background sound level, previous experience to the noise and sound
character in terms of impulsive noise (Attachment 1). The community impact
reaction can be predicted for wind turbines located in quiet areas with the EPA
methodology.
Using the EPA's modeling corrections allow the reviewers to account for the
features of wind turbine noise that distinguish it from other noise sources.
Figure D-7 in Attachment 1 of this review shows the EPA normalized Ldn
values with no corrections. The process used for this review analysis starts with
converting the predicted Leq noise levels to EPA's Ldn. Leq is measured
directly by sound meters and is predicted in noise models. To convert Leq to
Ldn, a 6 dB adjustment factor is employed assuming steady operation during
day and night, with the Ldn factoring a 10 dB weighting during the night hours,
using Equation 1 shown below.

(1)
For example, an Leq of 45 dBA for a steady-state noise source approximately
equals Ldn 51. Then, the following normalizing correction factors are applied:
0 dB
10 dB
5 dB
5 dB

for year round operation,
for being located in a quiet area,
for no prior experience and,
for tonal or impulsive character.

2 "Information On Levels Of Environmental Noise Requisite To Protect Public Health And Welfare With An
Adequate Margin Of Safety", EPA 550/9-74-004, March 1974.

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With the conversion to Leq (+6 dB) and the correction factors (+20 dB) applied,
the predicted noise levels are evaluated as normalized Ldn and can be assessed
directly with the EPA's case study data for community reactions. Figure 3 below
shows the normalized Ldn noise level on the 'X-axis' and EPA case study
community reactions on the ‘Y-axis’ with the project predicted levels circled.

44.5

35

40

Figure 3. Community reaction to intrusive noise as a function of Normalized Ldn.

The community reaction to the proposed facility can be determined for example,
by assessing the applicant's predicted wind turbine noise level of 35 and 40 dBA
iso-contours (shown as circled numbers in Figure 3). The equivalent normalized
Ldn values are 61 and 66 which are associated with the community reactions at
“Widespread complaints.” Noise levels of 44.5 dBA Leq at nearest neighbors
normalize to Ldn 70.5 which is associated with "Strong appeals to stop noise."
The EPA suggested caution when applying the Normalized Ldn method to quiet
areas with lower background sound levels than those evaluated during the EPA
case studies. The reviewer made additional analyses that confirmed the usefulness of the EPA normalized method for wind turbine noise impacts in quiet
areas (Mars Hill, Freedom, and Vinalhaven, Maine). These were provided to

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Mason County Commissioners in previous transmittals.
It is worth noting that the results mimic the prevailing understanding of
community reaction based on the change in noise level over the background, as
listed in Figure 4 below.

Figure 4. Community response based on the increase in noise.

The Tech Environmental reports document background, L90 sound levels
measured in the 21-32 dBA range. A 10-dB increase from 25 to 35 dBA is
predicted to produce "Widespread complaints", the same as the Normalized Ldn
method produced, with stronger response to increases over 35 dBA.
The Normalized Ldn method remains useful and valid today, and can be found
for example referenced in a 2002 technical report [3] on roller coaster noise.
2.1.B Annoyance
Figure 2-B includes the results of independent wind turbine annoyance research
by Pedersen & Waye in 2004 for non-participating residents [4]. Their data
confirm that there can be an adverse community reaction, with associated
activity interference, for wind turbine noise levels above 32 dBA in rural areas.
It should be noted that Pedersen & Waye data included on Figure 1 were
3 C. Menge, Residential impact criteria and abatement strategies for roller coaster noise, Inter-Noise 2002.
4 Pedersen, E. and K. Pedersson Waye, Perception and annoyance due to wind turbine noise: A dose–response
relationship, Journal of the Acoustical Society of America 116, 2004.

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obtained around multiple wind turbine sites with sizes ranging from 150kw to
600kw, much smaller than the proposed wind turbines in the report under
review. When the wind turbine noise level increases from 35 to 42 dBA, the
Pedersen & Waye 2004 research found that the highly annoyed portion of the
community increased from 6 to 45 percent, with the associated adverse health
effects of “psychological distress, stress, difficulties to fall asleep and sleep
interruption" as described in the conclusions in their 2008 report [5].
2.1.C Health Effects
Figure 2-C illustrates the potential for health effects and adverse health impacts
from the proposed facility. The health effects descriptions are taken from the
WHO 2009 report on health effects due to noise pollution [6]. WHO established
in 2007 the target level of 30 dBA below which no health effects were observed
[7]. In 2009 WHO established 40 dBA as a not-to-exceed, yearly average sound
level. The following table summarizes the WHO peer-reviewed findings of
health effects due to noise.

5 Project Wind Farm Perception, FP6-2005-Science-and-Society-20, Specific Support Action, Project no.
044628.
6 WHO, Night Noise Guidelines For Europe, 2009. ISBN 978 92 890 4173 7.
7 WHO, Night Noise Guidelines For Europe, Final implementation report, 2007, Grant Agreement 2003309.

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Table 1. Health effects observed in the population (WHO 2009).

They include a yearly average sound level of 30 dBA, night, outdoors as the
level below, which there are no observed health effects, the "No Observed
Effects Level" or NOEL. Above the 30 dBA NOEL, health effects including
sleep disturbance were found, mild at lower levels for healthy individuals and
more adverse with higher levels for "vulnerable groups"; children, the elderly,
and people with disease or pre-existing health conditions. Above 40 dBA, the
"No Observed Adverse Effects Level" (NOAEL), adverse health impacts are
clearly evident and more severe for vulnerable groups.
While there has been debate among acousticians as to how to correlate WHO's
2009 yearly-averaged noise level guidelines to a wind turbine noise level and
unique sound character that fluctuates minute to minute depending on wind
speed, wind shear, and other factors, or what criteria best apply to the WHO

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guidelines, there can be little question that adverse health impacts are certain for
average noise levels above 40 dBA and health effects including sleep
disturbance are possible with average noise levels above 30 dBA.
It doesn't take a year to decide if recurring sleep loss is a problem. Most people
have experienced fatigue and other health effects from one poor night's sleep, or
perhaps a few nights of interrupted sleep. Some living near wind turbines have
to leave their homes and go to another location to get a good night's sleep, and
are unable to sell their homes to move away (Mars Hill, Freedom, Vinalhaven,
Maine).

For the proposed project, the associated health effects include the following.
Where levels exceed 35 dBA, annoyance affects a portion of the population.
Associated health effects include awakening, sleep interference, vulnerable
groups such as children, elderly and those with pre-existing conditions or
disease are more susceptible to adverse impacts. The total area with predicted
sound levels above 35 dBA is some 22.6 square miles (14,500 acres.) Some 858
residents are estimated would be exposed to health effects.
Where levels exceed 40 dBA, annoyance affects over a quarter of the
population. Increasing adverse impacts are forecast for all individuals. The area
affected is estimated at 14 square miles (9000 acres). Some 532 residents of the
858 residents inside the 35 dBA contour are estimated would be exposed to
adverse impacts above 40 dBA.
It is worth noting from report review that these numbers are probably low due to
the predicted levels being underestimated by 5 to 10 dB at night.

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2.2 Mason County Zoning Ordinance
The reports prepared by Tech Environmental do not demonstrate to the reviewer
that that the proposed wind turbine facility will meet the requirements of the
Mason County Zoning Ordinance dated June 2, 2011 (Attachment 2). Sections
of the ordinance are supplied below with comments in bold.
- Section 1.03 Statement of Purposes. 1. To promote the public health, safety,
morals, and general welfare. (emphasis added.)
There is a strong potential for adverse noise impact on public health and
welfare in a large region of Mason County from the proposed facility. The
application reports do not assess for potential community impacts.

- Section 16.01 Statement of Purpose. 1. It is the purpose of this Article to
specify the procedure and requirements for the review of special land uses, as
specified in this Ordinance. Uses classified as special land uses are recognized
as possessing unique characteristics (relative to location, design, size, public
infrastructure needs, and other similar characteristics) which require individual
review and approval standards in order to safeguard the general health, safety,
and welfare of the County. (emphasis added.)
There is a strong potential for adverse noise impact on public health and
welfare in a large region of Mason County from the proposed facility.

- Section 16.03 Data Required, Subsection 3.e & f.
The reports reviewed omit supporting statements, evidence, data,
information, and exhibits that address criteria for assessing special land use
applications; i.e. detailed noise impact assessments demonstrating the
ability of the project to operate without adverse impacts on the health and
welfare of the neighbors.
- Section 16.05 Standards for Approval.

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The Planning Commission shall review the particular circumstances and facts
applicable to each proposed special land use in terms of the following standards
and requirements and shall make a determination as to whether the use proposed
and subject site meet all of the following standards and requirements. If it is
determined that the proposed use does meet all of the following standards and
requirements, the use shall be allowed. If it is determined that the proposed use
does not meet all of the following requirements, the use shall not be allowed.
1. Will be in accordance with the goals and objectives of the Mason County
Comprehensive Plan. (emphasis added.)
2. Will be designed, constructed, operated, and maintained in harmony with the
existing or intended character of the general vicinity and that such a use will not
change the essential character of the area in which it is proposed. (emphasis
added.)
3. Will not be hazardous or disturbing to existing or future permitted uses in the
same general vicinity and in the community as a whole. (emphasis added.)
4. Will be served adequately by essential public facilities and services, such as
highways, streets, police and fire protection, storm water drainage, refuse
disposal, water and sewage facilities, and schools or persons or agencies
responsible for the establishment of the proposed use shall be able to provide
adequately for such services.
5. Will not create excessive additional requirements at public cost for facilities
and services and will not be detrimental to the economic welfare of the
community.
6. Will not involve uses, activities, processes, materials and equipment, or
conditions of operation that will be detrimental to any person, property, or
general welfare by reason of excessive production of traffic, noise, vibration,
smoke, fumes, glare, or odors. (emphasis added.)

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7. Will ensure that the environment shall be preserved in its natural state, insofar
as practicable, by minimizing tree and soil removal, adequate setback from
water courses, and by topographic modifications which result in maximum
harmony with adjacent areas.
8. Will not impede the normal and orderly development and improvement of
surrounding property for uses permitted within the Zoning District.
9. Will comply with the requirements of this Ordinance, including Article 21,
Access Management and Highway Overlay District.
The reports raise serious questions for this reviewer as to the ability of the
proposed project to comply in any way with the sections highlighted above.

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2.3 Mason County Comprehensive Plan
The Mason County Comprehensive Plan (MCCP) [8] is the statement of policy
by the County Planning Commission relative to the agreed upon and officially
adopted guidelines for a desirable physical pattern for future community
development. The plan consists of a series of maps, charts, and written material
representing in summary form the soundest concept for community growth to
occur in an orderly, attractive, economical, and efficient manner thereby
creating the very best community living conditions, and includes any unit or part
of such plan and any amendment of such plan or parts thereof.
The reports prepared by Tech Environmental do not demonstrate to the reviewer
that the proposed wind turbine facility is compatible with the goals and vision of
the MCCP. Sections of the ordinance are supplied below with comments.

- "When asked about Mason County, residents use terms like “successful,”
“beautiful,” “scenic,” “clean,” and “stimulating.” Residents are also quick to
say that Mason County is an outdoor recreation paradise and a great place to
raise families or retire." (emphasis added.)
The predicted sound levels in the reports prepared by Tech Environmental are
associated with high levels of annoyance, sleep interference and adverse health
effects and would be incompatible with raising a family or retirement. The
proposed wind turbine facility appears to be incompatible with the MCCP.

- "Where the visual character, sounds, dust, smells, and level of activity of
commercial and industrial development would not be compatible with
residential neighborhoods and important scenic views, they are separated or
buffered." (emphasis added.)
The predicted sound levels in the reports prepared by Tech Environmental are
8 Mason County Comprehensive Plan Update, August 2006.

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associated with high levels of annoyance, sleep interference and adverse health
effects and would be incompatible with residential neighborhoods as reported
from many locations worldwide. The proposed wind turbine facility appears
to be incompatible with the MCCP.

- "The rural landscape does more than simply provide scenery. The benefits of
nature to residents’ mental well-being and the attraction for tourists are
important." (emphasis added.)
The predicted sound levels in the reports prepared by Tech Environmental are
associated with high levels of annoyance, sleep interference and adverse health
effects and would be incompatible with promoting mental well-being or
attracting tourists or future residents wishing to live near scenic areas. The
proposed wind turbine facility appears to be incompatible with the MCCP.

- IV. GOAL – UPDATE AGRICULTURAL ZONING TO BRING IN LINE
WITH MODERN DAY FARMING METHODS. A. Objective – Minimize the
incompatibility of non-farm rural residential areas and large farm production
facilities. … 2. Strategy – Encourage those farm practices that minimize odor,
noise, and environmental risk. (emphasis added.)
As it reads here, the goal of the MCCP is to minimize noise and environmental
risk from farm practices, the principal use of the lands in the area. However,
compared to existing quiet background (L90) sound levels, the reports prepared
by Tech Environmental predict much higher noise levels day and night from the
proposed wind turbine facility. It would not make sense to minimize
incompatibility of large farm production facilities and rural residential areas yet
allow significant noise increases and adverse health effects from the proposed
special use. The proposed wind turbine facility appears to be incompatible
with the MCCP.

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3.0 Community Noise Impact Assessment: General Conclusions
Review of the proposed "Lake Winds Energy Park" wind turbine locations
indicates the following. It should be noted that the conclusions drawn apply to
most homes in the footprint of, or at similar distances to, the wind turbines in the
proposed facility.
3.1. Probable sound levels: Based on direct experience with other wind turbine
sites, continuous average sound levels at the residence could run from mid-30s
to over 50 dBA, depending on wind speed and atmospheric conditions, with 1)
low frequency components from turbines out to 1.5 miles or more from homes
and 2) maximum sound levels several dB higher, experienced as whooshing and
thumping at night. Higher sound levels and peaks could occur at night when
atmospheric stability and layering sets in after the daytime thermal mixing
dissipates (a normal occurrence in the temperate zone). It is worth noting that
the predicted sound levels from the proposed facility appear to be low as they do
not factor in 1) the +/- 3 dB uncertainty in the ISO 9613-2 standard underlying
the model, 2) the potential for disastrous increases of an additional 5 to 10 dB in
night noise levels due to wind shear in stable air (van den Berg 2006), and 3) a
lack of a facility design margin to ensure the proposed facility can meet noise
limits reliably.
3.2. Compliance with sound limits: Tech Environmental has designed the site
right to the wire, conceptually within 0.5 dB of the maximum 10-minute noise
limit in some locations, yet without any design margin and without factoring in
the uncertainties and wind shear effects described above. The likelihood of the
proposed facility exceeding the existing sound limits at multiple locations on a
regular basis is beyond question for this reviewer. The turbines are simply
located too close to residential properties.
3.3. Community reaction: These expected sound levels are 10 to 20 dB higher
than the existing, quiet rural background (L90) sound levels measured by Tech
Environmental. Increases such as these due to a new intrusive noise source are
associated with "Widespread complaints" to "Vigorous community action."

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With the broadly scattered wind turbine locations, these increases and reactions
are expected at most of the homes in the vicinity of the proposed facility. The
reports do not assess for community reaction.
3.4. Preventing complaints: The excessive predicted community reaction is
indicative of insufficient facility design. To be a "good neighbor" means to
design so the facility produces "No reaction" to no-more-than "Sporadic
complaints." In the quiet rural area with background sound levels below 25
dBA, this equates to a maximum acceptable noise limit of no more than 33 dBA
at night. The reports do not establish a dBA-criteria level below the regulatory
limits to ensure no more than sporadic complaints.
3.5. Noise impacts: The Tech Environmental report grouped high ambient
sound levels with low turbine operating states due to use of an inappropriately
low wind shear value, and thereby underestimated the potential for full-output
wind turbine sounds to exceed existing very low ambient background levels by a
wide margin at night during high wind shear in stable atmosphere.
3.6. Soundscape: Typified now by quiet background levels, bird song,
occasional high-altitude aircraft that come and go, and little noise from distant
traffic or industry at night, the sound environment would be irrevocably
degraded by the intrusive industrial noise from the wind turbines within 1.5
miles of each home. Wind turbine noise varies continuously, sounding at times
like "a jet that never lands", or "sneakers in a dryer", and can contain tonal or
screeching sounds from gear noise, blade defects and turning operations.
Whistling sounds that rise and fall repeatedly with the blade rotation can arise
from small dings in the blades; dings which the facility may not be able to locate
or repair.
3.7. Potential adverse health effects: According to WHO, potential health effects
from excessive noise could include increased and possibly unremitting sleep
interference, associated stress conditions, and activity interference. According
to WHO, children and elderly are particularly vulnerable, as would anyone with
pre-existing medical conditions. When people suffering from health and stress

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effects due to wind turbine acoustic emissions relocate away from the wind
turbines, symptoms disappear and they feel better, only to relapse after
returning. There is no physiological habituation to the noise. People never "get
used to it."
3.8. In this reviewer's professional opinion and experience, it appears likely that
there would be activity interference and loss of enjoyment at homes, including
the outdoors around homes as well as acoustic intrusion into homes by low
frequency and infrasonic sound, making it impossible to find a quiet place to
rest. Those with a pre-existing vestibular condition or susceptible to motion
sickness might find themselves experiencing adverse symptoms and might have
to consider relocating to gain relief or possibly, abandoning the home.

3.9. In this reviewer's professional opinion and based on personal experience,
large industrial wind turbines must be considered seriously as capable of
creating an adverse health effect within a certain distance that varies with the
individual. Only by incorporating sufficient distance can a facility owner be
assured that they will not be adversely affecting the health and welfare of nearby
residents (and risking for themselves the expense and damage of lawsuits).
There is no fixed distance for this resolution. However, a distance of 1300 feet
with predicted sound levels of close to 45 dBA must be considered completely
insufficient to protect the public health and welfare for the proposed facility.
Case medical study near a large wind turbine facility in Maine (Nissenbaum
2010) produced the conclusion that a minimum of 2200 meters (7200 feet) is
required to alleviate the most adverse medical impacts. However in some
locations worldwide, symptoms are appearing at farther distances.

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4.0 Adverse medical symptoms: Confirmation by experience
In April 2011 (April 17-19, 2011) on a wind turbine noise survey with long-time
colleague Stephen E. Ambrose, also a Member of INCE, this reviewer was
unexpectedly overcome by the very symptoms described by folks unfortunate
enough to live nearby where an industrial wind turbine facility has been built:
Michigan, Maine (Mars Hill, Freedom, Vinalhaven), Massachusetts (Falmouth),
in upper New York State, the UK, New Zealand, and elsewhere around the
world where wind turbines have been sited too close to residential homes. Both
investigators were severely affected and debilitated the first day and felt
miserable until leaving the area. Symptoms included dizziness, loss of appetite,
headache, nausea, vertigo, inability to concentrate, an overwhelming desire to
get outside, and anxiety. It took more than a week to recover completely once
away from the site. An eye examination was required and new prescription
needed for full-time wear due to persistent eye strain post-survey when using the
computer. Hyperacusis (extreme sensitivity to "normal" sounds) and nausea
(when near low-frequency sounds) was experienced occasionally after the wind
turbine noise exposure in April.
The distance was approximately 1700 feet from one 1.65MW industrial wind
turbine. Relief was obtained, repeatedly, by going several miles away.
The complaints of adverse health effects from people living near large industrial
wind turbines stem not from people simply being cranky or "anti-wind" as some
wind industry proponents have asserted. Some might be tempted to think that
this reviewer was "making up" the experience in April 2011 to gain notoriety or
had fallen victim to the "fear-mongering" of the "anti-wind" rhetoric. Be assured
that this is also incorrect thinking.
This reviewer can now confirm from personal experience that there is a potential
for some people to suffer real, debilitating adverse health impacts from the
acoustic emissions from wind turbines. Imagine sitting at your desk trying to
work and feeling seasick, dizzy or with headache, and cloudy-headed all day
long. This occurred during the survey and for a week or more afterward. Perhaps

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the susceptibility may more pronounced for people who are prone to motion
sickness (this reviewer is) or who have vestibular problems. According to the
vestibular.org, 35 percent of people over age 40 have vestibular dysfunction.
It is vital to understand that the "A-weighted" sound level used in most
regulations and noise ordinances is unable to capture or document the
mechanism producing the adverse medical effects that were experienced.
Symptoms surfaced and intensified indoors where the quiet background was
about 18-20 dBA and outside when the A-weighted sound level was 42-44 dBA.
These levels are below the usual regulatory noise limits in the US stemming
from the EPA's work in the early 1970s. They are below the regulatory limit of
45 dBA set by Mason County for lots with occupied residences.
Extreme caution is suggested. Many reports of adverse medical symptoms have
surfaced near wind turbine facilities, and as time goes by, detail is emerging of
persisting physiological effects. Scientific certainty is emerging as to the relation
between the symptoms experienced near wind turbines and infrasonic sensitivity
in the inner ear [9].
The existing regulatory framework contains the means to control the degree of
annoyance from intrusive noise through regulatory limits (in dBA). There is also
a complete disconnection between the existing regulatory framework in dBA
and the adverse medical impacts from wind turbines. However it appears that
the dBA level may be used indirectly to develop a degree of protection from
adverse medical impacts from wind turbine acoustic emissions. Agreement has
been emerging among acoustic and medical professionals the last few years that
an outdoor sound level not exceeding 30 to 33 dBA may represent an
appropriate target for regulatory limits to protect public welfare from the
adverse effects of wind turbine acoustic emissions. Alternately, a sufficient
distance to achieve these low noise levels in dBA, reliably, may provide a
measure of safety for the health and welfare of people living near wind turbine
facilities.
9 A. Salt, J. Kaltenbach, Infrasound From Wind Turbines Could Affect Humans, Bulletin of Science, Technology
and Society, 2011.

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5.0 INCE Membership and Responsibilities
This reviewer and the owner of Tech Environmental, Mr. Peter Guldberg, are
Members of the Institute of Noise Control Engineering (INCE). Membership in
INCE requires adherence to the INCE Canon of Ethics. The Canon reads as
follows.

CANONS OF ETHICS for the
Institute of Noise Control Engineering of the USA
PREAMBLE
Noise control engineering is an important and learned profession crossing many
branches of science and engineering. The members of the profession recognize
that their work has a direct and vital impact on the quality of life for all people,
and protects and preserves human hearing from the effects of excessive noise
exposure. Accordingly, members of the Institute of Noise Control Engineering of
the United States of America (INCE) must be honest, impartial, fair and
equitable, and must be dedicated to the protection of the public health, safety,
and welfare in the practice of their professional work. INCE members' practice
and professional behavior must adhere to the highest principles of ethical
conduct out of regard for the public, clients, employees, the profession at large,
and the Institute of Noise Control Engineering itself.
I. FUNDAMENTAL CANONS
1. Hold paramount the safety, health and welfare of the public.
2. Provide services only in areas of their competence.
3. Issue public statements in an objective and truthful manner.
4. Act as faithful agents or trustees in all professional matters concerning their
employers, clients, and the Institute.
5. Avoid improper solicitation of professional assignments, and deal with all
professional colleagues, collaborators, and client personnel in a highly ethical
manner under the rules of practice enumerated in these Canons.

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II. RULES OF PRACTICE
1. INCE members shall hold paramount the safety, health, and welfare of the
public in the performance of their professional duties and shall:
a. Notify their client and such other authority as may be appropriate, if their
professional judgment is overruled under circumstances where the public safety,
health, property, or welfare is endangered.
b. Approve only noise control engineering studies, reports, or work which, to the
best of their knowledge and belief, is safe for public health, property, and
welfare and in conformance with accepted practice.
c. Not reveal facts, data or information obtained in a professional capacity
without the proper consent of their client or their employer except as authorized
or by law or by these Canons.
d. Not permit the illegal use of their name or their firm's name.
e. Not associate in business ventures with any person or firm which they have
reason to believe is engaging in or intends to engage in fraudulent or dishonest
business or professional practices.
f. Cooperate with proper authorities by furnishing requested information or
assistance in inquiries into violations of these Canons. …"

The reports prepared by Tech Environmental may depart from the INCE Rules
of Practice as, the predictions by Tech Environmental appear to present a strong
potential for an adverse impact on the health and welfare of the residents of
Mason County. Accordingly it may be appropriate that the reports be revised to
incorporate community reaction assessments and conclusions about the potential
for adverse community reactions and impacts on health, to hold paramount and
take the necessary steps to safeguard the health and welfare of the residents of
Mason County.

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6.0 Report On Ambient Sound Monitoring
This section reviews the Ambient Sound Monitoring report.
3.0 Noise Regulations And Criteria
Tech Environmental presented the most recent Mason County regulatory noise
limits (in dBA) for the project. However, there was no discussion of facility
"criteria" as is generally understood and formulated in industrial acoustics.
There was no assessment of community reaction to the project. These omissions
render the reports insufficient relative to review for the Mason County
Comprehensive Plan and Zoning Ordinance, which both require such
assessments for a complete understanding of the project community noise
impacts.
In industrial acoustics, "criteria" are facility target noise limits crafted in
consultation with the facility owners and sometimes with regulatory agencies,
established from consideration of 1) the facility noise output, 2) the potential to
exceed regulations, 3) the potential to create complaints or adversely affect
public health and welfare, and 4) determination of a facility acoustic design
margin to ensure, reliably, that the facility does not exceed regulations, create
complaints, or adversely affect public health and welfare. A typical acoustic
design margin may be 2 to 3 dB, or more, depending on the degree of
confidence in the facility noise predictions versus distance, and may include
specific or more-stringent acoustic design margins for certain problematic noiseproducing equipment. There is no discussion in the Tech Environmental report
of establishing a criterion for the project that protects public health and welfare.
It is insufficient to design the facility to just barely meet the regulatory limits of
Mason County which are 45 to 50 dBA. As found in Netherlands studies from
2004 to 2009, the adverse health effects of wind turbine noise on people start
below 35 dBA outside, and affect large portions of a population at levels of 35
to 45 dBA outside. Tech Environmental's omission of a facility criterion that
considers the adverse noise impacts of wind turbine acoustic emissions exposes
the population of Mason County to the potential of adverse health effects from
excessive wind turbine noise.

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4.1 Methodology
This section presents a grouping basis for ambient noise measurements by wind
speed at hub height speeds. Tech Environmental apparently based their estimate
of hub height wind speed (95m or 304 feet above ground) using the so-called
"roughness length". Roughness length is defined as the height where the average
wind speed is zero. Tech Environmental selected a roughness length of 0.05 m
(2 inches) from International Standard IEC 61400-11, Section 8.1, Table 1,
Roughness Length for “Farmland with some vegetation”.
It should be noted that a wind shear inferred from a roughness length selected
from a table is not necessarily correlated to the actual wind shear at elevations
where the wind turbines blades turn [10]. The wind speed data referenced by
Tech Environmental came from two met-tower elevations, 47 and 57 meters.
The project blade rotation heights range from 45 meters to 145 meters with a 95meter hub height. Thus the wind-speed data used by Tech Environmental barely
reach into the bottom portion of the atmosphere where the wind turbine blades
rotate.
Large variations in wind speed and direction ("wind shear") can and do occur
especially at night [11]. High winds shears do occur above the project met-tower
monitoring elevations as documented in the Midwest by NREL [12]. From the
NREL study, vastly higher than standard wind shears are found in the region
near the proposed facility. A low wind shear exponent is linked to a higher
ground-wind-speed estimate than actual under higher wind shear. As illustrated
in the figure below, under low wind shear, a hub-height wind speed of about 63/4 m/s is linked to a ground level wind speed of 5 m/s. Under high wind shear,
a hub-height wind speed of about 8-1/4 m/s is linked to a ground level wind
speed of 3-1/2 m/s.

10 P. Gipe, Wind Power, Revised Edition: Renewable Energy for Home, Farm, and Business, 2004. The wind
shear exponent varies with the time of day, season, terrain, and stability of the atmosphere. The equivalent wind
shear for roughness length 0.05m following the 1/7 power law is 0.19, p.41.
11 G.P. van den Berg (2003) Effects of the wind profile at night on wind turbine sound. Journal of Sound and
Vibration 277 (2004) 955–970.
12 K. Smith, G. Randall, and D. Malcolm, Global Energy Concepts, LLC, N. Kelley and B. Smith, NREL,
Evaluation of Wind Shear Patterns at Midwest Wind Energy Facilities, NREL, 2002. During one 10-minute
period just after midnight, the 37-m height wind speed dropped to 5 m/s while the 123-m height wind speed
increased to approximately 16.7 m/s resulting in an average wind shear exponent of 1.0.

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(NREL Figure 9. Day and Night Wind Speed Profiles at the Wisconsin TYP Project)

(NREL Figure 8. Prolonged High Wind Shear Event at the Wisconsin TVP Project)

From the NREL study, the figure above shows a typical high wind shear event
that would not be detected by a two-stage met tower at 47 and 57 meters.
The contract between Consumers Energy and the equipment supplier, Vestas,
formally specified the project's "average" wind shear at 0.27 [13]. This wind
13 Lake Winds Energy Park Turbine Purchase Agreement.

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shear exponent is much higher than the equivalent wind shear inferred by Tech
Environmental (approximately 0.19). Yet the project's "average" wind shear of
0.27 is far less than wind shears documented by NREL (as high as 1.0). It is
worth noting that since wind shear occurs almost always at night, the "average"
daily wind shear of 0.27 can be obtained with "average" night wind shear over
0.4 combined with "average" day wind shear of 0.19.
This indicates that the ambient-noise/wind-speed groupings, table and figures
developed by Tech Environmental are biased. That is, Tech Environmental has
apparently associated higher background sound levels than would be present for
actual hub height wind speeds at the site at night. The Tech Environmental
ambient sound categories could be revised based on the project wind shear
exponent of 0.28 and further to account for the high night wind shears
documented by NREL in the region (wind shear = 1.0). When this is done, it
appears likely that the wind turbines would operate with strong winds aloft yet
with ground-level winds absent and ambient sound levels below 25 dBA.
Tech Environmental makes reference to hub height wind speeds as if they were
measured during the survey, which they were not (example, "hub height winds
were sufficient for low to medium power turbine operation".) With the higher
wind shear values found in the region and specified for the project, it could be
inferred that hub-height wind speeds were sufficient for full-power operation.
4.2 Results and discussion
From the analysis of the previous section, the results in the report appear biased.
The ambient noise levels noted in the report section 4.2 and in the table and
supporting figures appear tied to the wrong hub-height wind speeds due to use
of a low wind shear exponent.
In particular, exception is taken to Tech Environmental's assertion that masking
can occur.
"Existing sound levels will sometimes provide a degree of masking
for wind turbine sound because during a high level of operation
(maximum turbine sound power), existing average Leq sound levels
are above 45 dBA more than 50% of the time and existing quietest-

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interval L90 sound levels are above 40 dBA more than 50% of the
time, while LakeWinds sound at Unpooled parcel occupied
structures will be below 45 dBA. … any masking of turbine sound
by existing sound levels will be more prevalent during low power
turbine operation than for medium and high power operation."
Tech Environmental concludes that masking is possible and more likely at lower
turbine operation. However, as documented by G.P. van den Berg, high shear at
night during stable atmospheric conditions can result in strong winds aloft and
no winds on the ground; turbines running at speed aloft with very low ambient
sound levels, rendering the wind turbine noise highly audible and capable of
producing adverse health impact:
"It is often assumed that there is a fixed relation between the wind
velocity at hub height and at a reference height of 10 meter. This is
the relation valid in a neutral or ‘standard’ atmosphere. No other
relations are given in legislation or international guidelines for
wind turbine sound that are valid in other conditions of the
atmosphere, viz. the stable and unstable conditions.
The atmosphere is unstable when in daytime the air near the
ground is relatively warm from contact with the surface heated by
solar insolation. In that case vertical air movements originate and
the wind profile is not equal to the profile in a neutral atmosphere,
though it does not differ strongly. A stable atmosphere however has
a markedly different wind profile. The atmosphere is stable when
the air close to the ground is relatively cold due to contact with the
ground surface when this cools down at night by radiating heat. A
stable atmosphere occurs especially in nights with a partial or no
cloud cover and the wind is not too strong (close to the ground). In
a stable atmosphere the turbulence has decreased substantially and
as a result layers of air are less strongly coupled. The lower layer
of air is thus less taken along with the wind that at higher altitudes
keeps on blowing, giving rise to greater differences between wind
velocities at different heights.
When the wind profile after sunset changes while the atmosphere
becomes more stable, the difference in wind velocity over the rotor

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increases. This causes a change in the level of the trailing edge
sound. The differences in wind speed lead to variations in the sound
radiated by the blade tips that reach their highest values when a tip
passes the mast. With several turbines the fluctuations in sound can
reinforce one another when they reach the ear of an observer
simultaneously. With two turbines (at the same distance) this leads
to an increase in level of 3 dB, with three turbines to an increase of
5 dB. Near the wind farm the variations were usually 5 dB, but they
could rise to approximately 9 dB, as expected when the fluctuations
of several turbines coincide. From other research and from
descriptions of residents one can establish that the sound of a wind
turbine or wind farm becomes more annoying because of
‘swishing’, ‘sloshing’, ‘clapping’, ‘beating’ or ‘ thumping’. All
descriptions mention a periodic variation on top of a constant noisy
sound. From psycho-acoustic research it has been shown earlier
that human sensitivity to sound fluctuations is high at frequencies
that occur in the night time sound of modern wind turbines. If this
fluctuating sound is sufficiently loud in a bedroom it can cause
sleep disturbance."
And, as documented by Bolin [14], wind turbine noise may be mask-able when
ambient sound levels are approximately 10 dB above wind turbine noise. There
is no plausible foundation provided by Tech Environmental that masking can
occur at differentials less than this. Under high wind shear conditions, ambient
noise levels measured in the low 20s dBA at ground observer level would be
associated with sufficient hub-height wind speeds to turn the turbines up to and
including full power. The conclusion that can be drawn is that there will be no
masking of the wind turbine noise for the proposed facility especially at low
wind speeds.

14 Bolin, K., "Wind Turbine Noise and Natural Sounds- Masking, Propagation and Modeling", Doctoral Thesis,
Royal Institute of Technology, Stockholm, Sweden, 2009.

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7.0 Report On Acoustic Modeling
This section reviews the Acoustic Modeling report. Several summary comments
are made similar to those covering the Ambient Sound Monitoring report.
- There is no discussion in the Tech Environmental report of establishing a
criterion for the project that protects public health and welfare. The Mason
County ordinance specifically requires that the project be designed to protect
public health and welfare, separate from and adjunct to meeting all regulatory
noise limits.
- There was no assessment of community reaction to the project. As a general
guideline, projects should be designed to provoke no more than "Sporadic
Complaints". The predicted sound levels (Figure 2) indicate "Widespread
Complaints" over an area of some 22 square miles, with stronger reactions
possible within some 14 square miles.
- Tech Environmental asserts there will be "masking" of the wind turbine noise
by ambient sound levels. This is refuted in the previous section of this review
(wrong wind shear values re NREL and van den Berg 2006; Bolin 2009).
- Section 2 and Figure 1 of the report in review have a number of inconsistencies
compared to standard acoustical understanding, and are not germane to the
project modeling.
- The acoustic modeling did not incorporate the +/1 3 dB uncertainty stated in
the ISO 9613-2 algorithm for distances out to 1000 meters and indicates the
model may need revision. The modeling did not note that ISO 9613-2 has no
estimate of certainty for distances beyond 1000 meters.
- The acoustic modeling appeared to specify a ground absorption value of 0.5 for
"Winter frozen ground conditions". It is understood that the value for winter
frozen ground conditions is 0.0 and indicates the model may need revision.

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4.6 Infrasound and health effects
As may already be evident to the reader, there are assertions made by Tech
Environmental in this section that simply do not stand up to fact. To be fair, if
Tech Environmental principals have not yet experienced the adverse medical
symptoms themselves, they may not truly understand that there is a real adverse
health impact mechanism involving the acoustic emissions from wind turbines
that is unrelated to the A-weighted sound level or even the C-weighted sound
level, placing the ball squarely in the infrasonic court.
It is worth noting that averaged infrasonic dB readings produced by wind
passing over the microphone do not relate directly to infrasonic
acoustic/pressure pulsations emitted by wind turbines.
This reviewer can attest directly from the unexpected and debilitating impacts
on survey in April 2011. Wind turbine acoustic emissions create adverse
medical symptoms and infrasonic, inaudible acoustic or pressure pulsations
appear to be involved.
Tech Environmental is correct that the infrasonic levels produced by and
measured near wind turbines appear to be inaudible to most people at levels
below about 90 dBG. What Tech Environmental fails to incorporate in their
report is the fact that there is emerging medical science that has documented the
sensitivity of portions of the inner ear to infrasonic energy, energy that the ear
would not hear, at levels starting around 60 dBG, and that there are afferent
pathways linking infrasonic response to the brain.
"Our present understanding of inner ear physiology and of the
nature of wind turbine sounds demonstrates that low-level
infrasound produced by wind turbines is transduced by the OHC of
the ear and this information is transmitted to the cochlear nucleus of
the brain via Type II afferent fibers. We therefore conclude that
dismissive statements such as “there is no significant infrasound
from current designs of wind turbines” are undoubtedly false. The

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fact that infrasound dependent information, at levels that are not
consciously heard, is present at the level of the brainstem provides
a scientific basis for the possibility that such sounds can have
influence on people. The possibility that low-frequency
components of the sound could contribute both to high annoyance
levels and possibly to other problems that people report as a result
of exposure to wind turbine noise cannot therefore be dismissed out
of hand." [15].
As an INCE member, it seems appropriate of Tech Environmental to rethink
their absolute refusal to incorporate medical scientific peer-reviewed published
findings and expand their consideration of the potential for adverse medical
impacts on people living near wind turbines, especially given that a subset of
populations in residential areas near wind turbines all over the world have raised
complaints and described symptoms that point to influence of the vestibular
system. With respect to consideration of the proposed facility, it appears vital to
understand that Tech Environmental's assertions about infrasound not being a
problem appear to be dismissive of people's real suffering and are not in step
with the emerging medical science.

15 A. Salt, J. Kaltenbach, Infrasound From Wind Turbines Could Affect Humans, Bulletin of Science,
Technology and Society, 2011.

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ATTACHMENT 1
COMMUNITY REACTION TO ENVIRONMENTAL NOISE
Excerpt From: Information On Levels Of Environmental Noise Requisite To Protect
Public Health And Welfare With An Adequate Margin Of Safety, 550/9-74-004, March
1974.
There are two methods of indirectly assessing the cumulative effects of environmental
noise on people. These are examining the reactions of individuals or groups of
individuals to specific intruding noises, either (a) with respect to actions taken
(complaints, suits, etc.), or (b) in terms of responses made to social survey
questionnaires. The first category, involving overt action by individuals or groups, is
summarized in this section, and key data regarding the second category, involving
responses indicating annoyance, is summarized in the next section.
In the last 25 years, many new types of noise sources have been introduced into
suburban and urban residential communities. These sources, such a jet aircraft, urban
freeways, new industrial plants, and homeowner equipment, have created numerous
community problems with environmental noise. These problems have provided
significant data and insight relating to community reaction and annoyance and
stimulated the development of several indices for measurement of the magnitude of
intruding noises.
Various U.S. Governmental agencies began to investigate the relationships between
aircraft noise and its effect on people in communities in the early 1950's. This early
research resulted in the proposal of a model by Bolt, Rosenblith and Stevens for
relating aircraft noise intrusion and the probable community reaction. This model, first
published by the Air Force, accounted for the following seven factors:
1. Magnitude of the noise with a frequency weighting relating to human response.
2. Duration of the intruding noise.
3. Time of year (windows open or closed).
4. Time of day noise occurs.
5. Outdoor noise level in community when the intruding noise is not present.
6. History of prior exposure to the noise source and attitude toward its owner.
7. Existence of pure-tone or impulsive character in the noise.
Correction for these factors were initially made in 5 dB intervals since the magnitudes
of many of the corrections were based solely on the intuition of the authors, and it was
considered difficult to assess the response to any greater degree of accuracy. This
model was incorporated in the first Air Force Land Use Planning Guide in 1957 and
was later simplified for ease of application by the Air Force and the Federal Aviation
Administration.

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Recently the day-night sound level has been derived for a series of 55 community
noise problems to relate the normalized measured Ldn with the observed community
reaction. The normalization procedure followed the Bolt, Rosenblith and Stevens
method with a few minor modifications. The correction factors which were added to
the measured Ldn to obtain the normalized Ldn are given in Table D-7. The
distribution of the cases among the various noise sources having impact on the
community are listed in Table D-8. The results are summarized in Figure D-7.
The "no reaction" response in Figure D-7 corresponds to a normalized outdoor daynight sound level which ranges between 50 and 61 dB with a mean of 55 dB. This
mean value is 5 dB below the value that was utilized for categorizing the day-night
sound level for a "residential urban community," which is the baseline category for the
data in the figure. Consequently, from these results, it appears that no community
reaction to an intruding noise is expected, on the average, when the normalized daynight sound level of an identifiable intruding noise is approximately 5 dB less than the
day-night sound level that exists in the absence of the identifiable intruding noise. This
conclusion is not surprising; it simply suggests that people tend to judge the magnitude
of an intrusion with reference to the noise environment that exists without the presence
of the intruding noise source.
The data in Figure D-7 indicate that widespread complaints may be expected when the
normalized value of the outdoor day-night sound level of the intruding noise exceeds
that existing without the intruding noise by approximately 5 dB, and vigorous
community reaction may be expected when the excess approaches 20 dB. The standard
deviation of these data is 3.3 dB about their means and an envelope of +5 dB encloses
approximately 90 percent of the cases. Hence, this relationship between the
normalized outdoor day-night sound level and community reaction appears to be a
reasonably accurate and useful tool in assessing the probable reaction of a community
to an intruding noise and in obtaining one type of measure of the impact of an
intruding noise on a community.
The methodology applied to arrive at the correlation between normalized Ldn and
community complaint behavior illustrated in Figure D-7 is probably the best available
at present to predict the most likely community reaction in the U.S. Unfortunately,
readiness to complain and to take action is not necessarily an early indicator of
interference with activities and annoyance that the noise creates. The fact that
correction for the normal background noise level without intruding noise results in
better correlation of the data points might be interpreted to mean that urban
communities have adapted to somewhat higher residual noise levels that are not
perceived as interfering or annoying. On the other hand, it is more likely that the
higher threshold for complaining is caused by the feeling that higher residual noise is
unavoidable in an urban community and that complaining about "normal" noise would
be useless.

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Table D-7
CORRECTIONS TO BE ADDED TO THE MEASURED DAY-NIGHT SOUND
LEVEL (Ldn) OF INTRUDING NOISE TO OBTAIN NORMALIZED Ldn1
Type of
Correction
Seasonal
Correction

Correction
for Outdoor
Noise Level
Measured in
Absence of
Intruding
Noise

Description
Summer (or year-round operation)

0

Winter only (or windows always closed)

-5

Quiet suburban or rural community (remote from
large cities and from industrial activity and trucking)

+10

Normal suburban community (not located near
industrial activity)

+5

Urban residential community (not immediately
adjacent to heavily traveled roads and industrial
areas)

0

Noisy urban residential community (near relatively
busy roads or industrial areas)

-5

Very noisy urban residential community

-10

No prior experience with the intruding noise

+5

Community has had some previous exposure to
intruding noise but little effort is being made to
control the noise. This correction may also be applied
in a situation where the community has not been
Correction exposed to the noise previously, but the people are
for Previous aware that bona fide efforts are being made to control
Exposure & the noise.
Community Community has had considerable previous exposure
Attitudes
to the intruding noise and the noise maker's relations
with the community are good
Community aware that operation causing noise is
very necessary and it will not continue indefinitely.
This correction can be applied for an operation of
limited duration and under emergency circumstances.
Pure Tone
or Impulse

Amount of Correction
to be Added to
Measured Ldn in dB

0

-5

-10

No pure tone or impulsive character

0

Pure tone or impulsive character present

+5

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Table D-8
NUMBER OF COMMUNITY NOISE REACTION CASES AS A FUNCTION OF
NOISE SOURCE TYPE AND REACTION CATEGORY
Community Reaction Categories
Type of Source

Transportation vehicles,
including:
Aircraft operations
Local traffic
Freeway
Rail
Auto race track

Vigorous Threats Wide Spread
of Legal Action
Complaints

6

No Reaction or Total Cases
Sporadic
Complaints

4
3

12
3
1
1
2

3

7

19

2

1
1
2

Total Transportation

9

Other single-event or
intermittent operations,
including circuit breaker
testing, target shooting,
rocket testing and body
shop

5

Steady state neighborhood
sources, including
transformer substations,
residential air conditioning

1

4

2

7

Steady state industrial
operations, including
blowers, general
manufacturing, chemical,
oil refineries, et cetera

7

7

10

24

Total Cases

22

14

19

55

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Figure D-7
Community Reaction to Intensive Noises of Many Types as a Function of the
Normalized Outdoor Day Night Sound Level of the Intruding Noise1

1. Eldred, K. M., "Community Noise", Environmental Protection Agency NTID 300.3,
December 1971.

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Attachment 2. Mason County Noise Regulations
This section details the Mason County regulatory noise limits on industrial wind
turbines (dated June 2, 2011). Emphasis is added where regulatory requirements
related to public health and welfare were found.
ARTICLE I
TITLE, PURPOSES, AND LEGAL CLAUSES
Section 1.01 Short Title.
This Ordinance shall be known and may be cited as the Mason County Zoning
Ordinance.
Section 1.02 Repeal of Ordinance.
The Mason County Zoning Ordinance, effective March 3, 1972 and all amendments
thereto, are hereby repealed effective coincident with the effective date of this
Ordinance being June 30, 2010.
Section 1.03 Statement of Purposes.
1. To promote the public health, safety, morals, and general welfare.
2. To encourage the use of lands in accordance with their character and
capabilities and to limit the improper use of land.
3. To avoid overcrowding of population.
4. To lessen congestion on the public roads and streets.
5. To reduce hazards to life and property.
6. To reasonably consider the character of each district, its peculiar suitability for
particular uses, the conservation of property values and natural resources, and
the general and appropriate trend and character of land, building, and
population development.
ARTICLE XVI
SPECIAL LAND USE CONDITIONS, REVIEW, AND APPROVAL
Section 16.01 Statement of Purpose.
1. It is the purpose of this Article to specify the procedure and requirements for the
review of special land uses, as specified in this Ordinance. Uses classified as special
land uses are recognized as possessing unique characteristics (relative to location,
design, size, public infrastructure needs, and other similar characteristics) which
require individual review and approval standards in order to safeguard the general
health, safety, and welfare of the County.
2. The following use permit review procedures are instituted to provide an opportunity
to use a lot or parcel for an activity which, under certain circumstances, might be

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detrimental to other permitted land uses and should not be permitted within the same
district, but which use can be permitted under circumstances unique to the proposed
location and subject to conditions acceptable to the community and providing
protection to adjacent land uses. The procedures apply to those Special Land Uses
which are specifically designated as such in the Zoning Ordinance.
Section 16.02 Review and Approval Authority.
The Planning Commission shall have the authority to approve special land use permits,
subject to such conditions of design, operation, and appropriate and reasonable
safeguards as the Commission may require for any special land use included in the
various provisions of this Zoning Ordinance.
Section 16.03 Data Required.
1. Applications for Special Approval Land Uses authorized in this Ordinance shall be
submitted to the Zoning Administrator. Applications shall include the appropriate
number of copies of the site plan and the fees as established by the County Board of
Commissioners. Applications will be processed according to the procedures adopted
by the County.
2. The Zoning Administrator shall review the proposed application to determine if all
required information has been supplied, and forward completed applications and
supporting data in accordance with the provisions of this ordinance. If all required
information is not supplied, the Zoning Administrator shall return the application to
the applicant with a list of information needed.
3. An application for a special land use permit shall include the following:
a. Applicant's name, address, and telephone number.
b. Address and property tax identification number of the proposed site.
c. A signed statement that the applicant is the owner of the proposed site, or is acting
as the owner's representative.
d. A complete site plan containing all the applicable data required by Article XVIII.
e. Supporting statements, evidence, data, information, and exhibits that address
criteria for assessing special land use applications.
f. Any additional information deemed necessary for the Planning Commission to
determine the impact of the proposed special land use on the adjacent properties,
public infrastructure, and community as a whole. Such information may take the
form of, but is not limited to, traffic impact analyses, environmental impact
assessments, market studies (to determine demand, use saturation), fiscal impact
analyses or reports and/or testimony by officials representing state, county or local
departments of public safety (police and fire), health, highways or roads, and/or
environment.

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Section 16.04 Review Process
1. Upon receipt of a complete application for a special use permit, the Planning
Commission shall hold a public hearing in accordance with the notification
requirements of the State law and Section A complete application under this Section
shall be one that addresses the items set forth in Section 16.03.
2. The Planning Commission shall review the proposal and base its decision upon
review of the individual standards for that Special Approval Land Use and the general
standards of this Article.
The Planning Commission shall grant approval of the application with any conditions
it may find necessary or it may disapprove the application. The decision on a Special
Land Use shall be incorporated in a statement of conclusions relative to the Special
Land Use under consideration.
The decision shall specify the basis for the decision and conditions imposed.
a. Approval. If the Planning Commission determines that the particular Special
Approval Land Use(s) shall be allowed, it shall clearly set forth in writing the
particular use(s) which have been allowed.
Thereafter, the Zoning Administrator may issue a zoning permit in conformity with the
particular Special Approval Land Use so approved. In all cases where a particular
Special Land Use has been granted as provided herein, application shall be made to
obtain a zoning permit in the County not later than one year thereafter, or such
approval shall automatically be revoked. The Planning Commission may grant an
extension thereof for good cause after receiving written request from the applicant.
b. Denial. If the Planning Commission shall determine that the particular Special
Approval Land Use(s) requested does not meet the standards of this Ordinance or
otherwise will tend to be injurious to the public health, safety, welfare, or orderly
development of the County, it shall deny the application in writing and clearly set
for the reasons for such denial.
3. The Planning Commission may impose such conditions or limitations in granting
approval as may be permitted by State law and this Ordinance which it deems
necessary to fulfill the spirit and purpose of this Ordinance. The conditions may
include:
a. Assurance that public services and facilities affected by a proposed land use or
activity will be capable of accommodating increased service and facility loads caused
by the land use or activity;
b. Protection of natural resources and conservation of energy;
c. Assurance of compatibility with adjacent uses of land;
d. Promotion of the beneficial use of land in a socially and economically desirable
manner.

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4. Special conditions imposed shall meet each of the following:
a. Be designed to protect natural resources, the health, safety, and welfare, as well
as the social and economic well-being of those who will use the land use or activity
under consideration, residents and landowners immediately adjacent to the
proposed land use or activity, and the community as a whole.
b. Be related to the valid exercise of the police power and purposes, which are affected
by the proposed use or activity.
c. Be necessary to meet the intent and purpose of the zoning regulations; be related to
the standards established in this Ordinance for the land use or activity under
consideration; and be necessary to ensure compliance with those standards.
The conditions imposed with respect to the approval of a land use or activity shall be
recorded in the record of the approval action and shall remain unchanged except
through an amendment process following the same procedure as the initial approval.
The County Clerk shall maintain a record of changes granted in conditions.
5. Postpone: If the special land use application does not meet the requirements of the
Zoning Ordinance, the Planning Commission may postpone action on the site plan to
allow time for additional study and/or site plan revisions.
6. Appeals: Within twenty (20) days following the date of a decision on any Special
Use Permit, an applicant or any aggrieved party, including any governmental body or
agency, may appeal the decision of the County Planning Commission to the Board of
Appeals. Upon the filing of an appeal, the application, all relevant documents and
testimony, and the findings and decision of the County Planning Commission shall be
transmitted to the Board of Appeals.
Section 16.05 Standards for Approval.
The Planning Commission shall review the particular circumstances and facts
applicable to each proposed special land use in terms of the following standards and
requirements and shall make a determination as to whether the use proposed and
subject site meet all of the following standards and requirements. If it is determined
that the proposed use does meet all of the following standards and requirements, the
use shall be allowed. If it is determined that the proposed use does not meet all of the
following requirements, the use shall not be allowed.
1. Will be in accordance with the goals and objectives of the Mason County
Comprehensive Plan.
2. Will be designed, constructed, operated, and maintained in harmony with the
existing or intended character of the general vicinity and that such a use will not
change the essential character of the area in which it is proposed.
3. Will not be hazardous or disturbing to existing or future permitted uses in the
same general vicinity and in the community as a whole.

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4. Will be served adequately by essential public facilities and services, such as
highways, streets, police and fire protection, storm water drainage, refuse disposal,
water and sewage facilities, and schools or persons or agencies responsible for the
establishment of the proposed use shall be able to provide adequately for such
services.
5. Will not create excessive additional requirements at public cost for facilities and
services and will not be detrimental to the economic welfare of the community.
6. Will not involve uses, activities, processes, materials and equipment, or
conditions of operation that will be detrimental to any person, property, or
general welfare by reason of excessive production of traffic, noise, vibration,
smoke, fumes, glare, or odors.
7. Will ensure that the environment shall be preserved in its natural state, insofar as
practicable, by minimizing tree and soil removal, adequate setback from water courses,
and by topographic modifications which result in maximum harmony with adjacent
areas.
8. Will not impede the normal and orderly development and improvement of
surrounding property for uses permitted within the Zoning District.
9. Will comply with the requirements of this Ordinance, including Article 21, Access
Management and Highway Overlay District.
Section 16.06 Issuance of a Zoning Permit.
A zoning permit may be issued by the Zoning Administrator upon approval of the
special land use by the Planning Commission. The zoning permit shall list all the
conditions of approval stipulated by the Planning Commission.
Section 16.07 Reapplication.
No special land use application which has been denied wholly or in part by the
Planning Commission shall be resubmitted until the expiration of twelve (12) months
or more from the date of such denial, except on the grounds of newly discovered
evidence or proof of changed conditions. A reapplication shall be processed in the
same manner as the original application.
Section 16.08 Site Plan Amendments in Conjunction with a Special Land Use.
Any approved site plan shall become part of the record of special land use approval.
Subsequent improvements relative to the authorized use shall be consistent with the
approved site plan, unless a change conforming to this Ordinance receives the mutual
agreement of the landowner and the Planning Commission. A site plan amendment
shall be reviewed and considered in the same manner as the original site plan
application, except as otherwise provided in this Ordinance.
Section 16.09 Validity and Revocation of Special Land Use Permits.
1. Validity of Permit: Once the special land use is established and the conditions of the
permit fulfilled, the special land use permit shall be valid until such time that there is a

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change of conditions or use related to the permit as permitted by the Planning
Commission. The Planning Commission reserves the right to review, with the
applicant and the County Zoning Administrator, the status of Special Use Permits on
an annual basis.
2. Permit Revocation: The Planning Commission shall have the authority to revoke
special land use approval following a hearing, if construction of the approved
improvements does not proceed in conformance with the approved site plan. Upon
discovery of a violation, the Zoning Administrator shall issue a stop work order and a
notice to appear for a hearing before the Planning Commission.
Notice of the hearing date shall be provided to the applicant no less than ten (10) days
prior to the date of the hearing.
Section 16.10 Amending a Special Land Use
Amendments to a special land use permit shall be handled in the same manner as the
initial special land use permit request. Minor non-substantive changes to a site plan in
accordance with Section 18.06 may be made to a special land use permit with the
approval of the Zoning Administrator.
ARTICLE XVII. SPECIAL LAND USE REQUIREMENTS
Section 17.70 Utility Grid Wind Energy Systems
17. Noise levels.
a. Sound Level Limits.
1. The A-weighted equivalent sound level (LAeq) measured at the property line of an
unpooled (single) parcel (as defined in subsection 19 hereof) upon which there is an
occupied building or dwelling shall not exceed 45 dBA. If the unpooled parcel does
not have an occupied principal building or dwelling on it, then the 45 dBA sound limit
may be exceeded at the property line; provided that when an occupied principal
building or dwelling is built on such unpooled parcel after the special land use permit
has been issued, the sound level shall not exceed 45 dBA measured at the nearest wall
of the occupied building or dwelling located on the unpooled parcel and in compliance
with the minimum required front, side and rear yard setbacks then in effect within the
zoning district in which the occupied building or dwelling is located.
2. On a pooled parcel, the ten-minute LAeq sound level measured at the wall of an
occupied building nearest to the wind turbine or turbines shall not exceed 55 dBA.
3. These sound level limits are to be evaluated using the A-weighted equivalent sound
level (LAeq) descriptor. The LAeq should be measured using a ten-minute time
interval.
4. The sound level limits listed above apply to the contribution from the wind energy
system only and do not include contributions from background ambient sounds.

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b. Studies Required.
1) Preconstruction Noise Background Survey. The applicant shall provide a noise
background study at the time of application which indicates Leq, L10, and L90 tenminute sound levels using A-weighting. For applications submitted after the effective
date of this ordinance, the applicant shall submit proposed measurement locations to
the Planning Commission in advance of the survey for review and approval.
Measurement procedures should generally follow the most recent versions of ANSI
S12.18, and ANSI S12.9, Part 3 (with or without an observer present) guidelines. The
selected test locations shall be described with GPS coordinates or some other level of
detail such that the location can be used by others to repeat or verify sound
measurements. Measurements shall be taken using an ANSI or IEC Type 1 Precision
Integrating Sound Level Meter. The noise background study shall report for the period
of monitoring topography, temperature, weather patterns, sources of ambient sound,
and prevailing wind direction. The study shall include a map showing proposed wind
turbine locations, pooled and unpooled parcels, and all occupied buildings.
2) Sound Modeling Study. A predictive sound study of turbine noise shall accompany
an application for a wind energy system to verify that ordinance requirements can be
met for dBA sound levels. The applicant shall present the maximum Sound Power
Level of the proposed turbine on both the dBA and dBC scales, and will calculate the
difference [dBC - dBA] in decibels and compare it to the 20 decibel threshold in IEC
61400-11, Annex A, as an indicator of whether the turbine is likely to produce lowfrequency noise that could create annoyance. For assessing potential low frequency or
vibration problems, refer to Section 17.70 17.d. The sound modeling must follow the
most recent version of International Standard, ISO 9613-2 “Acoustics – Attenuation of
sound during propagation outdoors – Part 2: General method of calculation.” The
sound modeling study shall use wind turbine sound power levels determined
according to the most recent version of IEC 61400 – Part 11. The sound study shall
include a map with sound contour lines for both dBA sound emitted from the proposed
wind energy system. The study shall include a map showing sound contours at 5 dBA
intervals, proposed wind turbine locations, pooled and unpooled parcels, and all
occupied buildings. The predicted values must include sound levels created by all
proposed turbines from the applicant’s project. The sound study shall extend out to the
30 dBA sound contour line or 1 mile from a wind turbine generator, whichever is
closer to the nearest wind turbine.
3) Post Construction Sound Survey. Documentation of sound pressure level
measurements shall be provided to the Zoning Administrator by a third-party qualified
professional selected by the Planning Commission and at the expense of the wind
energy system owner within 12 months of the commencement of the operation of the
project. The post construction study shall be performed at the same locations as the
pre-construction study unless additional locations are required by the Planning
Commission. The study should generally follow the procedures in the most recent
versions of ANSI S12.9 Part 3 (with or without and observer present) and ANSI
S12.18. All sound pressure levels shall be measured with instruments that meet ANSI

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or IEC Type 1 Precision integrating sound level meter performance specifications. In
addition to measuring A-weighted sound levels, at least one monitoring location shall
collect one-third octave band data down to 6.3 Hertz. As part of the study, octave band
data must be measured as addressed in Section 17.70. 17.d. The post construction test
shall verify that equivalent sound level limits in dBA are in compliance with the
standards of this ordinance. The compliance test procedure will use an alternating
series of turbine-on and turbine-off 10-minute Leq measurements when wind speeds
are fairly constant. Measured levels (turbine-on and turbine-off) for similar hub height
wind speeds will be compared to determine the sound level from only the wind
turbines. The firm conducting the study shall collect LA90 and LA10 data. The study
shall address noise complaints on file with the County (as indicated in Section 17.70
(24)) and may require additional study locations as deemed necessary by the Planning
Commission. The firm conducting the post-construction sound survey shall consult
with the Planning Commission, or their representative, prior to conducting the study to
agree on the compliance testing locations. The study shall delineate pooled and
unpooled parcels as well as occupied buildings. Should the sound study indicate a noncompliant measurement, the owner of the wind energy system will be required to
obtain compliance through mitigation or other measures.
c. Wind Rose Chart. The applicant shall submit a Wind Rose Chart at the time of the
application. This is a chart or graph that describes 12 months (or more) of wind data
collected from the proposed project area. This graph or chart will demonstrate
direction, duration, and intensity of the wind (pooled or not). These data will be for
each height of wind sensor mounted on the meteorological tower.
d. Low Frequency Sound and/or Vibration. The applicant shall provide acoustic
modeling at the time of application to assess potential low frequency or vibration
problems. The modeling study of low frequency sound and vibration shall demonstrate
meeting: (1) ANSI S12.9/Part 4 Annex D threshold for minimal annoyance and
beginning of rattles from outdoor low frequency noise as summarized in Section 2.2 2
of the March-April, 2011 Noise Control Eng. article by O’Neal, et al. and (2) the
ANSI S12.2 sound level limits for moderately perceptible vibration and rattles within
homes as modified to equivalent outdoor sound limits in Table 2 of the March-April,
2011 Noise Control Eng. Journal article by O’Neal, et al.. The ANSI S12.2 interior
sound level limits for low frequency sound and perceptible vibration within homes, as
modified to equivalent outdoor sound limits in Table 2 of the March-April, 2011 Noise
Control Eng. Journal article by O’Neal, et al. shall be utilized to determine if outdoor
sound levels will create perceptible vibration or low frequency problems indoors. If
the post-construction sound survey outdoor octave band sound level measurements
reveal that low frequency sound from wind turbines at the exterior of an unpooled,
occupied or non-occupied building may create a vibration or low frequency noise
problem, then further studies should be conducted to assess the problem. The further
studies shall use the above referenced standards (ANSI S12.2 and ANSI S12.9/Part 4
Annex D). If the further study indicates that the low frequency sound/vibration
exceeds acceptable levels, mitigation may be required by the Planning Commission.

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Mitigation may include operational changes to the turbine, modifications to the subject
building or buildings, or other measures as determined by the Planning Commission.
19. Pooling of Parcels.
a. If two or more parcels of land are included in the special land use, they shall be
pooled into a single unit (the “pooled unit”) for purposes of the special land use, in
accordance with this paragraph 19.
Note: "Pooled" parcels are taken to mean the aggregated single unit or units of land
comprised of parcels owned by leasee, participating land owners.

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Figure 1. Site location, Mason County, Michigan.

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56 V100 Turbine Layout 3 Alternate Locations,

Source: Report on Acoustic Modeling, LakeWinds Energy Park, Tech Environmental, June 2011.
Speed Review and overlays: Rand Acoustics, 6-23-2011.

 

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56 V100 Turbine Layout 3 Alternate Locations,

Source: Report on Acoustic Modeling, LakeWinds Energy Park, Tech Environmental, June 2011.
Speed Review and overlays: Rand Acoustics, 6-23-2011.

 

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56 V100 Turbine Layout 3 Alternate Locations,

Source: Report on Acoustic Modeling, LakeWinds Energy Park, Tech Environmental, June 2011.
Speed Review and overlays: Rand Acoustics, 6-23-2011.