Guidance for Evaluating Human Health Impacts in Environmental

Guidance for Evaluating

Human Health Impacts

in Environmental Assessment:

NOISE

Health Canada is the federal department responsible for helping the people of Canada maintain and improve

their health. We assess the safety of drugs and many consumer products, help improve the safety of food, and provide

information to Canadians to help them make healthy decisions. We provide health services to First Nations people and

to Inuit communities. We work with the provinces to ensure our health care system serves the needs of Canadians.

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Publication date: January 2017

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Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

TABLE OF CONTENTS

1. ACRONYMS .............................................. 1

2. PURPOSE OF THIS DOCUMENT .................................. 2

3. INTRODUCTION AND CONTEXT .................................. 3

4. ROLES AND RESPONSIBILITIES WITHRESPECT TONOISE ................. 4

4.1 HEALTH CANADA’S APPROACH TO NOISE ASSESSMENTS

INENVIRONMENTALASSESSMENTS ..................................5

5. IMPACTS ASSOCIATED WITH NOISE ............................... 6

5.1 NOISE-INDUCED HEARING LOSS .....................................6

5.2 NOISE-INDUCED SLEEP DISTURBANCE .................................6

5.3 INTERFERENCE WITH SPEECH COMPREHENSION ..........................7

5.4 INDICATORS OF POTENTIAL HUMAN HEALTH EFFECTS .......................8

6. AN APPROACH FOR ASSESSING THEHEALTHIMPACTS OF NOISE ............11

6.1 IDENTIFICATION OF HUMAN RECEPTORS IN PROJECT AREAS .................12

6.2 ASSESSMENT OF BASELINE NOISE ..................................13

6.3 ASSESSMENT OF PROJECT-RELATED NOISE ............................15

6.4 MITIGATION .................................................18

6.5 ASSESSMENT OF RESIDUAL IMPACTS ................................22

6.6 SOUND LEVEL MONITORING ......................................23

7. ASSESSMENT OF CUMULATIVE EFFECTS ............................24

8. FOLLOW-UP PROGRAMS ......................................25

9. REFERENCES .............................................26

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

TABLES

TABLE 6.1: ESTIMATION OF BASELINE NOISE LEVELS USING QUALITATIVE DESCRIPTIONS

ANDPOPULATION DENSITIES OF AVERAGE TYPES OF COMMUNITIES .......15

TABLE 6.2: CALCULATING SUGGESTED MITIGATION NOISE LEVEL (MNL)

FORCONSTRUCTIONNOISE (BASED ON US EPA 1974) .................20

TABLE 6.3: AN EXAMPLE OF APPLYING CORRECTIONS TO ESTABLISH A SUGGESTED MNL

FORAPROJECTIN A VERY NOISY URBAN COMMUNITY ................20

TABLE 6.4: MITIGATION NOISE LEVELS RELATED TO NUMBER OF BLASTS ............22

APPENDICES

APPENDIXA

GLOSSARY ...........................................28

APPENDIXB

NOISE IMPACTS IN EA CHECKLIST .............................33

APPENDIXC

NOISE CHARACTERISTICS ..................................36

APPENDIXD

INTRODUCTION TO NOISE ..................................38

APPENDIXE

SOUND SOURCES AND SOUNDCHARACTER ......................40

APPENDIXF

DETERMINATION OF PERCENT HIGHLY ANNOYED (%HA) ...............42

APPENDIXG

IDENTIFICATION AND CHARACTERIZATION OF SOME COMMON

RECEPTORLOCATIONS ....................................45

APPENDIXH

COMMONLY APPLIED CONSTRUCTION NOISE MITIGATION MEASURES

ANDCONSIDERATIONS FOR NOISEREDUCTION ....................46

This document may be cited as follows:

Health Canada. 2016. Guidance for Evaluating Human Health Impacts in Environmental Assessment: Noise.

Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario.

Any questions or comments on this document may be directed to:

Environmental Assessment Program, Ottawa, Ontario K1A 0K9

Email: [email protected]

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

ACRONYM MEANING

%HA percent highly annoyed

%HSD percent highly sleep disturbed

ANSI American National Standards Institute

CEAA 2012 Canadian Environmental Assessment Act, 2012

CSA Canadian Standards Association

CTA Canadian Transportation Agency

dB decibel

dBA A-weighted decibels

dBZ Z-weighted decibels

EA environmental assessment

EIS environmental impact statement

ERCB (EUB) Energy Resources Conservation Board, Alberta (formerly Energy and Utilities Board)

FA federal authority

Hz hertz

ISO International Organization for Standardization

Ld daytime sound level

Ldn day-night sound level

Leq equivalent continuous sound level

Ln night-time sound level

LAeq A-weighted equivalent continuous sound level

LAmax maximum A-weighted sound level

LSA local study area

MNL mitigation noise level

NIHL noise-induced hearing loss

RA responsible authority

REDA Radiation Emitting Devices Act

RSA regional study area

SEL sound exposure level

WHO World Health Organization

US EPA United States Environmental Protection Agency

ACRONYMS

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

This document provides generic guidance on predicting health risks related to levels and/or types

of sound predicted in federal environmental assessments (EAs) of proposed major resource and

infrastructure projects (such as mines, dams, pipelines and other projects). It presents the principles,

current practices and basic information Health Canada looks for when it reviews the environmental

impact statement (EIS) or other reports submitted by project proponents as part of the EA process.

It was prepared for the beneﬁt of proponents and their consultants and to support an efﬁcient

and transparent project review process. The foundational information described here should be

supplemented appropriately with additional information relevant to speciﬁc projects.

The guidance was also prepared for responsible authorities (RAs) and stakeholders to the EA process to

communicate our normal areas of engagement and our priorities within these areas to help ensure that

sufﬁcient evidence is available to support sound decisions.

As part of its review, Health Canada may suggest that an RA, review panel or others collect information

not speciﬁcally described here in order to assess the health effects of speciﬁc projects. As the guidance

provided here is generic and designed to support EA under multiple jurisdictions, the scope of our

review will also necessarily be amended according to speciﬁc jurisdictional requirements.

Health Canada updates guidance documents periodically and, in the interest of continuous improvement,

accepts comments and corrections at the following address: [email protected]

Please verify that you are reading the most recent version available by consulting:

www.canada.ca/en/services/health/publications/healthy-living.html#a2.5

PURPOSE OF THIS DOCUMENT

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

INTRODUCTION AND CONTEXT

Health Canada provides expertise to assist RAs, review panels and/or other jurisdictions leading

environmental assessments to determine whether there are potential health risks associated with

proposed projects and how to prevent, reduce or mitigate them.

Health Canada brings to bear its expertise in health risks associated with air quality, water quality,

radiation, noise and country foods when it reviews and provides comments on information submitted

by proponents in support of proposed projects. Health Canada also provides guidance to help

stakeholders, including responsible authorities, review panels and affected communities, better

understand how to conduct health assessments for proposed major resource projects.

This document concerns the assessment of health risks associated with noise. It contains information

on the division of roles and responsibilities for issues related to noise at various levels of government in

Canada, health effects associated with noise, indicators of these effects, and steps in Health Canada’s

preferred approach to assessing noise-related health effects.

Appendix A contains a Glossary that deﬁnes the technical terms used throughout.

Appendix B contains a checklist of noise impacts that can be used to verify that the essential

components of a noise-related health assessment are completed.

Appendices C through H contain additional technical and supplementary information related to noise

assessment in EAs.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

In Canada, noise is managed by different levels of government. Federal examples include Transport Canada

(aircraft noise), the Canadian Transportation Agency (rail noise), and Employment and Social Development

Canada (speciﬁcally the Labour Program: occupational noise in workplaces under federal jurisdiction).

Health Canada has a regulatory role via the Radiation Emitting Devices Act (REDA), which controls the sale

of devices that create an unnecessary noise hazard or do not comply with regulatory standards. Outside of

these speciﬁc federal mandates, noise may be regulated directly through provincial and territorial legislation

and guidelines, or through municipal by-laws, which may apply broadly or only to speciﬁc project types or

sectors. Few or many different criteria may be used to establish noise guidelines, which may include, but

not be limited to, noise impacts on sleep, hearing and high annoyance.

In the context of environmental assessments, one of Health Canada’s roles concerning noise exposure

is to review acoustical assessments for scientiﬁc validity and potential risks to human health from

project-related changes in environmental noise. This role is fulﬁlled via leadership in science, research,

participation in national and international bodies that develop standards (Canadian Standards

Association (CSA) and the International Organization for Standardization [ISO]) and participation

in the development of guidelines (World Health Organization [WHO]) for noise and human health.

Health Canada’s scientists conduct, evaluate and remain current on domestic and international

scientiﬁc research pertaining to the human health impacts of noise. Their expertise regarding the

potential human health effects of noise is made available to responsible authorities conducting

assessments of projects subject to EA legislation. The responsibility for determining the signiﬁcance

of these effects rests with the RAs, review panels or other jurisdictions conducting assessments.

Health Canada does not enforce noise thresholds or standards, but can make available information

and knowledge acquired from Canadian and international sources regarding the potential adverse

human health effects of noise—based on the type of community (e.g. urban, suburban or quiet rural

areas). When noise levels have the potential to induce adverse human health effects, Health Canada

may make available information or knowledge on mitigation measures. When mitigation measures

are to be implemented, appropriate mitigation strategies based on all applicable guidelines should be

considered. Health Canada encourages proponents to consult with other government authorities to

determine which enforceable standards for noise exist for speciﬁc regions.

ROLES AND RESPONSIBILITIES

WITHRESPECTTONOISE

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

4.1 HEALTH CANADA’S APPROACH TO NOISE ASSESSMENTS

INENVIRONMENTALASSESSMENTS

Noise is a somewhat special type of change to the environment, as it is an energy added to the air in the

form of acoustical waves. Below the exposure threshold of biological damage to the ear, noise can also

cause potential health impacts, such as sleep disturbance and/or cause long-term high annoyance, an

indicator of potential health impacts. These impacts depend on the interference of the noise with what

one is trying to do (e.g. sleep, concentrate or communicate) and the expectation of peace and quiet

during such activities (e.g. in a quiet rural area or during Indigenous spiritual ceremonies).

Human response to noise varies among individuals and according to the speciﬁc situation. Response

to noise can be characterized using different methodologies and endpoints, and may be affected by

several factors. These factors include how noise moves from source to receptor, how it is measured,

and what behavioural/physiological and/or psychological changes it evokes in humans.

A particular standard or guideline may not cover all possible considerations or the inherent variability in

noise characterization. Several approaches to assessing noise impacts exist, and these various approaches

often rely on different noise guidelines and/or regulations that may not be easily reconciled. For example,

a guideline may be established to protect against hearing loss, but consideration of additional human

health endpoints, such as sleep disturbance, may also be warranted. Some guidelines and/or regulations

are based on limiting absolute noise levels, whereas others emphasize the relative change in the noise

environment.

This document provides general information on Health Canada’s preferred methodology for various

human health endpoints used to determine these potential impacts. The prediction of potential impacts

is necessary to understand the nature, extent and severity of human health effects that may occur due to

noise generated during various stages of a proposed project. These calculations also serve to evaluate the

feasibility of the project proponent’s planned mitigation measures in reducing human health effects and

whether a speciﬁc mitigation measure is expected to achieve the desired result. Health Canada reviews

the methodology and calculations provided in the noise assessment, as well as the subsequent discussion

of potential noise-related impacts on health, for accuracy and completeness. This information may be

complementary to the applicable regulations, EIS guidelines or requirements of other jurisdictions.

Depending upon the nature of the project, the responsible authority, review panel or other jurisdiction

conducting the EA may want to consider the assessment of noise impacts (speciﬁcally, sleep disturbance)

on off-duty workers residing in or near the project area. Note that occupational exposure is typically

under provincial or territorial jurisdiction, and Health Canada does not review this information in the

context of EAs. Also, Health Canada does not possess information or knowledge on the impacts of noise

on wildlife or ecosystems.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

IMPACTS ASSOCIATED WITH NOISE

In reviewing an EA, Health Canada emphasizes only those endpoints that have demonstrated a

reasonable causal relationship between noise exposure and adverse human health effects. In the context

of an environmental assessment, the associations that have been reported between noise exposure

and hearing loss, sleep disturbance, interference with communication, noise complaints and a high

level of annoyance are particularly relevant (WHO 1999, 2011). The information and knowledge that

Health Canada makes available is based on the following: the modelled changes between the existing

and predicted daytime and night-time sound levels (for construction, operation and decommissioning

activities); predicted noise-level changes at speciﬁc receptor locations (see Appendix G) where people are

or will be present; the characteristics of the noise (e.g. impulsive or tonal); and/or the type of community

(e.g. urban, suburban or quiet rural area).

5.1 NOISE-INDUCED HEARING LOSS

There is no known risk of permanent hearing loss associated with sound levels below 70 A-weighted

decibels (dBA), regardless of the exposure duration. However, as sound levels increase, the duration

of daily exposure becomes an important risk factor for hearing loss. The time period before damage

occurs shortens as the average sound level increases (WHO 1999; Health Canada 2012).

Hearing loss impacts are not typically considered in EAs because project-related sound levels rarely

reach these high levels at the locations of impacted receptors. However, noise-induced hearing loss

(NIHL) may be a concern when project activities such as blasting, pile driving and jack hammering are

expected. When considering impulsive noise, Health Canada suggests following the WHO recommendation

to avoid hearing loss resulting from impulsive noise exposure and that peak sound pressures not exceed

140 Z-weighted decibels (dBZ) for adults and 120 dBZ for children (WHO, 1999).

5.2 NOISE-INDUCED SLEEP DISTURBANCE

Sleep disturbance encompasses the following: difﬁculty falling asleep; awakenings; curtailed sleep

duration; alterations of sleep stages or depth; and increased body movements during sleep. The effects

of sleep disturbance have been shown to include, but are not limited to: increased fatigue; irritability;

and decreased concentration and performance. These effects are generally experienced in the days

subsequent to signiﬁcant disturbances in sleep. Ongoing disturbed sleep has been reported to be linked

to a wide variety of health effects, including, but not limited to cardiovascular effects, mental health and

accidents (WHO 2009; Zaharna and Guilleminault 2010).

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

The guidelines and recommendations of the WHO (1999, 2009) regarding sleep disturbance should be

considered in the EA. In particular, WHO guideline levels should not be exceeded for quiet rural areas

and susceptible populations, such as those in hospitals, or convalescent or senior homes. For estimating

the likelihood of sleep disturbance on any given night, the WHO’s Guidelines for Community Noise (1999)

report a threshold for sleep disturbance as being an indoor sound level of no more than 30 dBA LAeq for

continuous noise, during the sleep period. For individual noise events, the WHO has stated: “For a good

sleep, it is believed that indoor sound pressure levels should not exceed approximately 45 dBA LAmax

more than 10–15 times per night....” Health Canada recognizes that in many cases, people will want to

keep windows at least partially open, depending on the season. Unless speciﬁed otherwise, it is assumed

by Health Canada that an outdoor-to-indoor transmission loss with windows at least partially open is

15 dBA (United States Environmental Protection Agency [US EPA] 1974; WHO 1999). Fully closed windows

are assumed to reduce outdoor sound levels by approximately 27 dBA (US EPA 1974).

More recently, the WHO has published night-time noise guidelines that are intended to protect the public,

including the most vulnerable groups, from adverse health effects associated with sleep disturbance due

to night-time noise. The recommended annual average is 40 dBA Ln outdoors (WHO 2009). As this is

an annual average, there may be times when the sound level is above and below 40 dBA; however, there

should be no long-term impact on health if the annual average does not exceed 40 dBA.

Consistent with the view expressed above, when care facilities, including hospitals, nursing homes,

daycare centres and homes for the elderly, are identiﬁed as receptors that could be impacted by

project-related noise, it is a good practice to consult with these facilities to determine whether certain

sensitivities to sleep disturbance exist during the day. Should any such sensitivities be noted, the

threshold level for sleep disturbance speciﬁed in the WHO’s Guidelines (1999, 2009) may be used to

assess the severity of potential impacts on these receptors. Where there is interest in estimating the

prevalence of sleep disturbance—expressed as the percentage self-reported highly sleep disturbed

(%HSD)—Miedema and Vos (2007) have published dose-response relationships for estimating %HSD

by road, rail and aircraft noise.

5.3 INTERFERENCE WITH SPEECH COMPREHENSION

To maintain good speech comprehension, the recommended sound levels vary, depending on whether

the noise from project activities is measured (or estimated) indoors or outdoors. For good speech

comprehension, speech levels should exceed that of background noise by 15 dB. The same difference is

also desirable for music or television listening. Normal indoor speaking levels are typically 55 to 58 dBA

(Levitt and Webster 1991), which is in line with the US EPA 1974 recommendation that indoor background

noise levels should not exceed 40 dBA to achieve 100% sentence intelligibility. According to the WHO

(1999), speech in relaxed conversation is 100% intelligible in background noise levels of about 35 dBA,

and can be understood fairly well in background levels of 45 dBA. Therefore, Health Canada holds the

view that background noise levels (i.e. noise due to project activities as measured indoors) be maintained

below 40 dBA to sustain adequate speech comprehension.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

People generally tend to speak in a louder voice when outdoors, where the separation between speakers

is typically larger than indoors. In outdoor environments where distances of up to two metres exist

between speakers, US EPA 1974 suggests that 95% sentence intelligibility is acceptable, and recommends

a background noise level of 55 dBA outdoors (i.e. 60 dBA with a 5-dBA margin of safety). To sustain good

outdoor speech comprehension, background outdoor noise levels for continuous noise should be kept

below 55 dBA.

When a school is identiﬁed as a potentially impacted receptor, it is suggested that the EA address the

special sensitivity of this type of receptor to daytime noise. The WHO recommends an ideal background

noise level of 35 dBA in the classroom (WHO 1999). This level is the threshold below which no impacts

are expected. This recommendation is based especially on speech interference, but also on the impacts

of disturbing message communication and the extraction of information (e.g. speech comprehension

and reading), and annoyance.

5.4 INDICATORS OF POTENTIAL HUMAN HEALTH EFFECTS

Health Canada holds the view that certain community reactions to project-related noise represent

potential indicators of adverse health; that is, if the noise is experienced over a long period of time,

it could potentially increase one’s risk of developing health effects. In the context of noise exposure,

two of the most common community reactions are complaints and annoyance.

5.4.1 Noise Complaints

Many municipal policies concerning noise are based on the resolution of complaints. Noise-related

complaints can be an indicator of human health effects and are used, in US EPA 1974, to help identify

sound levels that would protect public health and well-being. Summarizing the US EPA document,

Michaud et al. (2008) state that a “no reaction” response corresponded to a normalized outdoor day-

night sound level (Ldn) of 55 dBA for the intruding noise. They also state that sporadic complaints

can occur in communities when this noise level exceeds 55 dBA or widespread complaints, at a level

exceeding 58 dBA. Michaud et al. (2008) discussed the divergence between “sporadic complaints” and

“widespread complaints,” when the normalized Ldn of the intruding noise (i.e. project noise) reached

62 dBA. Based on this work, Health Canada uses a normalized Ldn of 62 dBA when it considers effects

related to widespread complaints. When project sound levels are greater than a normalized 75 dBA Ldn

level, complaints can be expected to include strong appeals to authorities to stop noise. Reliance on

noise complaints may only provide a partial indication of a noise problem (Michaud et al. 2008) and

when possible, the estimated magnitude of complaints should be supplemented with other measures,

such as the calculated change in the percentage of highly annoyed (%HA) in an average community

and/or estimated impacts on sleep.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

5.4.2 Long-term High Annoyance

Annoyance can be described as the effect of noise that most people are aware of. The consideration of

community annoyance due to noise is useful; the %HA can be thought of as an aggregate indicator of

assorted noise effects, present to varying degrees, which are creating a negative effect on the community

and which may not be measurable when considered as separate negative effects.

High annoyance has been widely used as one way to estimate a community response to noise levels.

High annoyance is an endpoint that is not directly measured but has been synthesized from self-

reported annoyance in numerous large, community-based surveys. Although individual reaction varies

greatly, the reported change in %HA among an average community in reaction to certain sound levels

provides usable exposure-response relationships (Michaud et al., 2008). Thus, the calculated %HA

provides information on how an average community responds to a noise level. Health Canada uses

the change in %HA as an appropriate indicator of noise-induced human health effects from exposure

to project operational noise (see Section 6.3.2) and to long-term construction noise (see Section 6.3.1)

exposure.

There have been more than 50 years of social and socio-acoustic research that either directly or indirectly

studied the impact of noise on community annoyance. These studies have consistently shown that an

increase in noise level is associated with an increase in the percentage of the community indicating that

they are highly annoyed. The relationship between noise levels and high annoyance is stronger than any

other self-reported measure, including complaints. Canadian research on road-trafﬁc noise also shows

that respondents highly annoyed by trafﬁc noise are signiﬁcantly more likely to perceive their annoyance

as having a negative impact on their health (Michaud et al. 2008).

To assess the impacts of noise from projects using this indicator, the project-related change in the sound

environment and the related increase in %HA are evaluated. Using the dose-response relationship

between noise levels and annoyance, as per ISO 1996-1:2003, one can calculate the percentage of a

typical community that would report being “highly annoyed,” expressed as %HA. The %HA increases

exponentially as sound levels increase. Due to the non-linear nature of the relationship between noise

and %HA, there can be a substantial increase in the %HA, with relatively small changes in the noise

environment—in situations where the initial baseline noise level is high. In other words, the higher the

initial noise level, the more the annoyance will increase when there is an increase from the baseline noise

level. In general, this dose-response relationship may be a useful tool in characterizing and quantifying

average community response to noise levels and changes in noise levels.

Health Canada prefers the use of the dose-response relationship only for long-term noise exposure

considerations in EAs, and holds the view that %HA be calculated only for receptors exposed to long-

term project noise (more than one year). It is important to emphasize that these annoyance responses

are not applicable to a particular individual or group, but represent an average community. Appendix

F presents the methodology for obtaining variables used in the equations to calculate %HA. Health

Canada prefers that the increase in %HA per representative receptor (i.e. a group of residences in

similar geographic proximity to the noise source) be evaluated and not the average increase in %HA

for all receptors—which could underestimate the project-related impact on community annoyance.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

Noise mitigation measures should be considered when a change in the calculated %HA at any given

receptor location exceeds 6.5%. The ISO method does not characterize the nature of the increase in

terms of severity of impact. However, the U.S. Federal Transit Administration describes a long-term

increase of more than 6.5%HA as representing a severe project-related noise impact (Hanson et al. 2006).

This increase is based in part on the historical acceptability in the U.S. of no more than a 5-dBA increase

in Ldn in an urban residential environment (not immediately adjacent to heavily travelled roads and

industrial areas). Further justiﬁcation for using an increase of 6.5%HA as a criterion for a severe noise-

related impact may be found in Michaud et al., 2008, and Hanson et al., 2006. ISO 1996-1:2003 notes that

research has shown that there is a greater expectation for, and value placed on, “peace and quiet” in quiet

rural areas, which may be equivalent to up to 10 dB in noise. Unless speciﬁed otherwise in an EA, this

expectation is assumed by Health Canada to be equivalent to an adjustment of 10 dB (ISO 1996-1:2003).

Note that the change in %HA is only one potential indicator of noise-related human health effects and

that all possible human health endpoints may be considered in an assessment. In situations where

baseline noise levels exceed an Ldn of 77 dBA , and project noise levels alone exceed an Ldn of 75 dBA,

it may be too difﬁcult to meet the WHO guidelines for sleep disturbance and vulnerable populations

(see Section 5.2). It may also be too difﬁcult to reduce these environmental noise levels to meet the

levels suggested in Section 5.3, regarding adequate speech comprehension indoors for residents.

Therefore, Health Canada holds the view that mitigation of project noise be applied if it exceeds an

Ldn of 75 dBA, even if the change in %HA does not exceed 6.5%. For example, if project noise alone

exceeds an Ldn of 75 dBA, it may be that the levels noted in Sections 5.2 and 5.3 are not achievable in

typical residences, even in situations where the highest level of outdoor-to-indoor transmission loss is

achieved. In situations like this, project noise should be cautiously mitigated to a level below an Ldn of

75 dBA, which includes a consideration of uncertainty in predictions.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

The approach preferred by Health Canada for noise assessment involves obtaining the best possible

characterization of the acoustical exposure that may impact potential noise receptors. This description

includes sound level and duration, and noise characteristics, such as whether the noise is tonal, impulsive,

highly impulsive, etc. (see Appendix B).

To obtain the highest-quality data in acoustical studies, acoustical assessments should be completed by

professional and properly trained consultants, using equipment and methods that are recognized as the

industry standard for acoustical measurements. Occasionally, limitations may exist in the technology

and expertise available for some projects. Whenever uncertainty exists in the selection of appropriate

monitoring equipment or in the application of standard techniques for noise characterization in EAs,

government authorities are encouraged to consult Health Canada for assistance or additional guidance.

The main steps in assessing the potential health impacts of changes in noise associated with a project

are the following:

• Identify people (receptors) who may be affected by the project-related noise;

• Determine the existing (baseline) noise levels at representative receptors, by measurement

or estimation;

• Predict project-related changes in noise levels for each phase of the project (construction,

operation and decommissioning) and describe the sound characteristics;

• Compare predicted noise levels to relevant guidelines and/or standards;

• Identify and discuss the potential human health impacts associated with predicted changes

in noise levels;

• Consider mitigation measures, their implementation, and any residual effects, after the measures

are implemented;

• Consider community consultation and prepare a complaints-resolution plan; and

• Consider the need for monitoring of noise levels.

AN APPROACH FOR ASSESSING

THEHEALTHIMPACTS OF NOISE

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

6.1 IDENTIFICATION OF HUMAN RECEPTORS IN PROJECT AREAS

It is important to identify and describe all existing and reasonably foreseeable human receptors in the

area that may be inﬂuenced by project-related noise—including a description of how the receptors

were identiﬁed (e.g. recent land use maps, veriﬁcation in person). The characterization of potential

receptors typically includes the distance(s) to the project’s local study area (LSA) and regional study

area (RSA) for each receptor, and map(s) illustrating modelled noise levels from the project at receptor

locations in the study area. While sound levels at one receptor site are typically averaged over time, it

is not appropriate to assess noise impacts using the average increase in sound levels across receptor

locations because sound level ranges, and therefore noise impacts, may be different at different

locations.

Health Canada prefers that noise assessments identify and describe any particular receptors that may

have a heightened sensitivity to noise exposure (e.g. Indigenous Peoples, schools, child care centres,

hospitals). Speciﬁcally note in the EA documentation if receptors with heightened sensitivity are not

present in the study area. A list of commonly encountered receptors and related characteristics is

provided in Appendix G.

When identifying receptor sites at which noise impacts will be assessed, it is a good practice to consider

and note the following:

• how the sites are representative of potentially impacted receptors;

• any receptors who have rented dwellings or land; and

• any receptors who live outside Canada that may be impacted by a project, where applicable.

If any local receptors that may be inﬂuenced by project noise are not being assessed in the EA, provide

a rationale for this exclusion. If no human receptors are (or will be) present in the local or regional

study area during the construction, operation or decommissioning phases of the project, no further

assessment with respect to noise is necessary.

It is important to identify and describe any receptors in rural areas that could be considered to have a

greater expectation of “peace and quiet” (i.e. quiet rural areas). Health Canada considers a “quiet rural

area” to be a rural area with Ldn due to human-made sounds to be below 45 dBA. For areas with the

most stringent permissible noise levels, provincial regulatory criteria may also be used to deﬁne “quiet

rural areas,” provided these areas are adequately described.

Due to the expected heightened sensitivity to noise, baseline levels in quiet rural areas are adjusted

by adding 10 dB (ISO 1996-1:2003, ANSI, 2005). This 10 dB adjustment also applies to the predicted

project noise levels for all phases of the project (i.e. construction, operation and decommissioning)

in determining percent highly annoyed (%HA). The effect of this +10 dB adjustment in quiet rural areas

is to produce a greater change in %HA than would occur with unadjusted noise levels. The exponential

relationship between %HA and noise levels, as discussed in Section 5.4.2, produces increasingly larger

changes in %HA for equal increases in project noise, compared to the baseline level.

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An example follows:

If the initial baseline noise level is 45 dBA and the project-related noise level is 55 dBA, the unadjusted

change in %HA would be 3.01 (using equations in Appendix F). When the +10 dB adjustment to both

baseline and project-related noise is applied in a quiet rural area, the baseline rating level used to

calculate the %HA becomes 55 dBA and the project-related noise rating level becomes 65 dBA in the

calculation of %HA. At these rating levels, the resulting change in %HA is 9.79. Therefore, a 10-dBA

project-related noise increase from a baseline of 45 dBA in a quiet rural area will result in exceeding

the suggested mitigation level of 6.5%, while a 10-dBA increase in project-related noise from a baseline

of 45 dBA in a more urbanized area would not exceed this level.

6.2 ASSESSMENT OF BASELINE NOISE

Baseline noise levels that are determined by measurement or estimation can be applied to noise impact

assessments for all project phases (construction, operation and decommissioning). Health Canada

prefers that measured or valid estimated baseline noise levels for both daytime (Ld) and night-time (Ln)

at all representative receptor locations be assessed and reported in the EA. It is a good practice to clearly

indicate whether sound levels are measured or estimated, and to identify the exact location of the baseline

measurement (e.g. outdoors at the building facade, or on the lower level, upper level, property line, etc.).

6.2.1 Measuring Baseline Noise

When baseline measurement is conducted, Health Canada prefers that the measurement be completed

in accordance with ISO 1996-2:2007 at each representative receptor, and that the reports include the dates

and hours used to characterize these measurements. Sounds that are not generated by human activity

(e.g. ocean, wind and animal noises) should not be included in determining a baseline sound level.

Wind and rain can also create false signals in the microphone used to measure sound levels. As a result,

sound is not measured in the presence of precipitation or when wind speeds exceed 14 km/hr, unless an

appropriate wind screen is used.

To minimize uncertainty of the validity of measured baseline-sound-level data, Health Canada suggests

that the EA report provides the following information:

• the number of hours or days used for measurement, and a rationale for why the reported sound

levels can be considered representative;

• an estimate of seasonal differences and any differences between the weekend and weekday

baseline noise levels;

• where applicable, any differences due to weather conditions;

• all noise sources that contribute signiﬁcantly to the baseline, by type (e.g. trafﬁc, aircraft, trains,

industrial); and

• a characterization of each noise type described in the assessment using descriptors such as

continuous, intermittent, regular impulsive, highly impulsive, high-energy impulsive, and

continuous tonal and intermittent tonal.

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6.2.2 Estimating Baseline Noise

Although the standard approach for baseline sound determinations is direct measurement, there may

be situations where baseline measurement data are not available. In such cases alternative approaches

to estimating baseline levels exist. One conservative (i.e. most protective) approach is to consider a

reasonable worst-case scenario and assume Ldn baselines of 35 dBA for rural areas and 45 dBA for

urban/suburban areas. However, defaulting to these lower baseline sound levels may result in greater

values obtained for change in %HA when calculating noise effects for construction lasting more than

one year or for operational noise. Note that the estimate of an Ldn of 45 dBA for urban/suburban areas

does not consider the inherent variability in baseline noise estimates based on population density,

proximity to busy roads or adjacent industrial activity.

The use of alternative approaches to estimating baseline noise may yield higher baseline estimates

than the reasonable worst-case scenario described above. To adequately review the reliability of such

estimates, Health Canada prefers that sufﬁcient supporting rationale is provided in the EA, particularly

where the accuracy of the selected estimation approach decreases (see below).

Other approaches to estimating baseline noise in order of decreasing accuracy may include the following:

• predictions based on computer models whose inputs, algorithms and outputs are based on

accepted standards;

• manual calculation procedures based on well-accepted models or standards;

• the use of known baseline levels from areas with very similar acoustical environments

(e.g. very similar types of baseline noise sources, distances from sources to receptors,

meteorological conditions, shielding, etc.); and/or

• approximate values from Table 6.1 (see below).

Table 6.1 describes the estimation of baseline noise levels, based on a qualitative description of community

characteristics and an average census-based population density (ERCB Directive 038, 2007). If this method

(based on US EPA 1974 and ERCB 2007) is used in a noise assessment, provide a rationale to support the

validity of its use.

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Table 6.1: Estimation of Baseline Noise Levels Using Qualitative Descriptions

andPopulation Densities of Average Types of Communities

Community Type

(QualitativeDescription)

Average Census Tract

Population Density,

Number ofPeople

Per Square km

Estimated

Baseline

Sound Level

Ldn(dBA)

Quiet rural

dwelling units more than 500 m from heavily travelled roads

and/or rail lines and not subject to frequent aircraft ﬂyovers

28 ≤ 45

Quiet suburban residential

remote from large cities, industrial activity and trucking

249 48–52

Normal suburban residential

not located near industrial activity

791 53–57

Urban residential

not immediately adjacent to heavily travelled roads

andindustrial areas

2493 58–62

Noisy urban residential

near relatively busy roads or industrial areas

7913 63–67

Very noisy urban residential 24,925 68–72

1. Note that a range of values is provided and that selection of the appropriate estimated value would typically be based on

theprecautionary principle in the absence of adequate justiﬁcation for a higher baseline. All day-night sound level (Ldn) values,

exceptthose of the quiet rural area community type, are based on the US EPA levels document (US EPA 1974).

2. The quiet rural area (Ln = 35 dBA) estimated baseline noise level and population density were obtained from ERCB Directive 038

(revisedFeb 16, 2007). The difference between Ld and Ln was obtained from ERCB and US EPA, and was approximated as 10 dBA.

Assuch, quiet rural areas are considered to be less than or equal to 45 dBA Ldn.

6.3 ASSESSMENT OF PROJECT-RELATED NOISE

It is a good practice to document the criteria used to review the human health impacts of project-related

noise and to characterize the potential for change in the sound environment due to any project activity,

including construction, operation and decommissioning. In the noise assessment, it is important to

compare predicted noise levels during construction and operation to the baseline noise levels at each

representative receptor, as this will clearly demonstrate the predicted changes in noise levels experienced

by each receptor. Health Canada suggests that the type of measurements used and the uncertainty

associated with any sound-level monitoring, modelling or estimates be provided for all reported data.

It is important to consider that human health effects related to noise may be evaluated by a variety of

endpoints and indicators, as discussed in Section 5. Health Canada holds the view that the evaluation of

each potential noise-induced human health effect by one method alone is not necessarily representative

of all possible human health effects related to noise exposure. For example, when using %HA as an

indicator in a noise impact assessment, the change in %HA of receptors exposed to long-term noise may

not exceed 6.5%, but these receptors may experience sleep disturbances due to an exceedance of the

WHO indoor sleep-disturbance threshold limits discussed in Section 5.2. When changes in the sound

environment have been characterized, Health Canada suggests that a discussion of the severity of these

changes and how they impact human health be included in the noise assessment. Such an evaluation

would typically describe all appropriate endpoints or indicators used to address potential impacts

on human health, as described in this guidance. Alternative approaches to this evaluation may be

acceptable, provided they are supported by adequate scientiﬁc justiﬁcation.

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In some cases, a less extensive assessment may be warranted. If noise levels at all receptors are not

expected to approach the US EPA’s mitigation noise levels (see Section 6.4.2) or to result in a change in

%HA exceeding 6.5%, as discussed in Section 5.4.2, Health Canada suggests that a scientiﬁcally sound

rationale be provided in the EA—to conﬁrm that noise levels will be well below the level where human

health effects may occur (see Section 5) and that this rationale has been provided in place of a complete

noise impact assessment.

The results and conclusions of the noise assessment should be clearly documented in the EA.

Health Canada suggests that the conclusion include a discussion of whether mitigation measures

and/or follow-up monitoring is warranted.

The following sections discuss the assessment of project-related construction noise of short-and

long-term durations, as well as project operational noise.

6.3.1 Assessing Construction Noise

Noise from construction activities has the potential to negatively impact nearby receptors and is often

the loudest source of project-related noise. Predicted construction noise levels for both daytime (Ld)

and night-time (Ln) at all representative receptor locations should be reported in the EA. To permit

a proper comparison of noise levels, the units, averaging times and other measurement parameters

(including the uncertainty associated with any of the measurements) should be the same as those

used in establishing the baseline.

The method for determining effects related to construction noise depends on the duration of the

construction activities as follows:

i. Short-Term Construction Noise Exposure (< 1 year)

Health Canada suggests using the US EPA (1974) methodology that provides mitigation noise levels (MNLs)

and associated adjustments for community types, to determine if adverse effects are likely and if mitigation

is suggested. This methodology is discussed in Section 6.4.2, Mitigating Short-Term Construction Noise

Exposure (<1 year). Consideration should also be given to potential impacts on sleep, where adverse

impacts are reported to begin when sound levels inside bedrooms exceed 30 dBA for continuous noise

sources and 45 dBA LAmax for discrete noise events (WHO 1999). With an estimated 15 dBA outdoor-to-

indoor transmission loss, the equivalent outdoor levels should be 45 dBA and 60 dBA, respectively.

ii. Long-Term Construction Noise Exposure (≥ 1 year)

Health Canada suggests that construction noise lasting longer than 1 year be assessed as operational

noise. This approach allows for an evaluation of the change in %HA at each receptor, in accordance with

ISO 1996-1:2003. Appendix F describes the methodology and equations related to calculating the change

in %HA for projects. The appropriate adjustments (see Appendix E) may be applied to the A-weighted

calculated or measured noise levels. This method of assessing construction noise is essentially identical

to that of assessing operational noise, as discussed in Section 6.3.2 below. Also, potential impacts on sleep

should be considered when construction activities may occur at night-time (as noted above in short-term

construction).

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There may be insufﬁcient information concerning construction activities to permit an assessment

of their potential impacts at the EA stage. Conservative assumptions based on similar projects

and/or planned activities are often used in estimating noise levels and calculating impacts due to

construction. An example of this estimation technique is to assume that all equipment is operating

simultaneously for a 12-hour period, even though actual impacts are expected to be lower. In these

cases, Health Canada suggests providing as much information as possible on construction activities,

schedules, equipment use and any assumptions used, in addition to an explanation of why a more

detailed assessment is not possible.

It is a good practice to include a description of construction noise as it relates to exposure duration,

rather than construction activity duration. The difference in these perspectives becomes apparent when

considering the impacts of construction noise related to road projects. As a road project progresses, noise

exposure continually varies from receptor to receptor as the geographic location of the construction

equipment changes.

6.3.2 Assessing Project Operational Noise

Predicted operational noise levels for both daytime (Ld) and night-time (Ln) at all representative

receptor locations should be reported in the EA. To permit a proper comparison of noise levels,

the units, averaging times and other measurement parameters (including the uncertainty associated

with any of the measurements) should be the same as those used in establishing the baseline.

As discussed previously, the determination of %HA is a widely accepted indicator of the human health

effects of long-term noise exposure. Similar to comments in Section 6.3.1 ii above, the assessment of

project operational noise may include an evaluation of the change in %HA at each receptor site, in

accordance with ISO 1996-1:2003. Appendix F describes the methodology and equations related to

calculating the change in %HA for projects. The appropriate adjustments (see Appendix E) may be

applied to the A-weighted calculated or measured noise levels. If noise from project operations may

occur at night-time, the assessment of operational noise should also consider potential impacts on sleep.

Modelling sound levels (using appropriate software) is one method that is commonly used to estimate

present or future operational sound levels. In the assessment, clearly identify the model(s) used and

justify their suitability. Speciﬁc models may be selected on a site-by-site basis. Health Canada prefers

that any assumptions used be conservative (i.e. reasonable worst-case scenario) and be adequately

described in the assessment.

If project-related noise levels are provided without being added to the baseline sound levels, this must

be clearly indicated. In assessing impacts on human health, the baseline and project noise are added

together, as their sum represents what noise effects the receptors will actually experience. Other changes

in the sound environment may also be characterized. If project-related operational noise includes audible

tonal or impulsive noise (including regular impulsive, highly impulsive and high-energy impulsive types

of noise [ISO 1996-1:2003] [e.g. blasting]), appropriate adjustments as presented in Appendix E can be

made. Refer to ISO 1996-2:2007 for additional guidance on describing or measuring tonal and impulsive

noise. These adjustments apply only when the noise under consideration is audible at receptor sites. In

situations where more than one source characteristic adjustment is applicable (e.g. impulsive or tonal),

only the higher of the adjustments is used. However, all time-of-day adjustments and the quiet rural area

adjustment are to be added to the highest of the applicable source adjustments.

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6.4 MITIGATION

Noise management and noise monitoring plans, including complaint resolution plans, are often

incorporated as part of the EA’s Environmental Management Plan. When health effects from project-

related noise are possible, Health Canada prefers that a noise management plan detailing the actions

that will be taken to minimize human health impacts due to project noise (mitigation measures) be

developed and included in the EA. Special consideration should be given to mitigation measures for

construction noise that occurs at night, in order to minimize impacts on sleep (i.e. avoiding tonal or

impulsive noise sources at night).

Due to the inherent uncertainty in both predicted and/or measured project noise, additional information

should be provided to demonstrate that exceedances of the MNL or a 6.5% change in %HA are unlikely.

Proposals for speciﬁc mitigation measures to limit noise at receptors where this uncertainty exists should

be provided in the EA.

Health Canada prefers that any noise mitigation measures proposed for the project be described

in sufﬁcient detail to permit Health Canada to adequately review the measures’ impacts on achieving

noise reduction. When describing possible mitigation or other noise management measures, identify the

conditions or circumstances under which various mitigation measures will be applied or implemented.

As it is more effective to use source controls, Health Canada prefers that mitigation measures be applied

to the source rather than the receptor site, where this is technically feasible. It should be noted that some

estimates discussed in Section 5.2 (e.g. noise attenuation by closed windows or enclosed balconies) may

not achieve the desired level of noise reduction, due to variability in construction techniques. While fully-

closed windows are assumed to typically reduce outdoor sound levels by 27 dBA (US EPA 1974), the type

of enclosures that surround the windows or the presence of ventilation ducts may result in an outdoor-to-

indoor noise transmission loss that is lower than 27 dBA.

6.4.1 Community Consultation

Developing a community consultation plan can be helpful when projects propose noisy work

occurring outside of normal working hours or extended work that produces high levels of noise

(such as rock hammering or pile driving). The consultation process may assist in establishing

feasible mitigation measures by targeting receptors that have the greatest potential for human

health-related effects resulting from noise disturbance. Previous experience in assessing community

reaction to noise impacts following community consultation has demonstrated that in these

cases, a community is more likely to be understanding and accepting of noise, and more likely

to make appropriate adjustments to limit noise exposure. This has been noted particularly when

the information provided during the consultation process is accurate and does not attempt to

understate the likely noise level, and when commitments made by the proponent to limit noise

during speciﬁc hours are respected.

The EA should specify whether community consultation with respect to noise has occurred, and

whether any human health concerns have been expressed by potentially impacted receptors.

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The comments or recommendations received during the consultation process may provide an indication

of which project elements are likely to trigger the greatest level of opposition, particularly where noise

issues are identiﬁed. Informing the public about project plans early in the process is encouraged, as this

may provide additional options for mitigation measures, or at the very least, provide the opportunity

to discuss the mitigation measures under consideration. It is a good practice to undertake community

consultation prior to the creation of work schedules (e.g. continuous versus speciﬁc construction times)

and to discuss the preferred means of informing the public of the time and duration of noisy activities.

When construction delays or other problems result in extended construction schedules, Health Canada

suggests that a plan for community consultation be implemented and that this consultation process be

described in the EA, where applicable. When a project proponent deems it to be manageable, it may be

preferable to consult with residents individually.

When the community receives information about expected changes in sound levels through a consultation

process, and feels that concerns with respect to noise may be addressed and resolved, the incidence

of noise-related complaints is frequently reduced. Health Canada suggests that this approach be

considered in managing both minor and major public concerns related to project-related noise. For

more information, refer to ERCB Directive 38 (2007). For information speciﬁc to rail projects, refer to

the Canadian Transportation Agency’s Guidelines for the Resolution of Complaints Over Railway Noise

and Vibration (2008).

6.4.2 Mitigating Short-Term Construction Noise Exposure (<1 year)

Health Canada often suggests mitigation measures to the authority conducting the EA, when the predicted

construction noise level (construction lasting less than one year) exceeds the suggested mitigation noise

level (MNL). To avoid widespread complaints regarding construction noise at receptor sites, where the

exposure duration is less than one year at any given representative receptor site, the basic suggested MNL

is 47 dBA (US EPA 1974). This value has been derived from the data presented in Figure D-7 and Table D-7

in US EPA 1974. The basic MNL is applicable for receptors in quiet suburban or rural areas, assuming that

all of the construction noise is tonal and/or impulsive.

In order to determine whether mitigation is advisable, consider the following:

1. Use the data in Table 6.1 to characterize the community type based on average census tract

population densities and community qualitative descriptions. Validating the community type

may be accomplished by monitoring or calculating baseline noise levels.

2. Use the data in Table 6.2 to identify the applicable correction factors for the relevant community

type and additional corrections (e.g. construction duration, presence of tonal or impulsive noise,

and whether windows are open), and then calculate the suggested construction noise (less than

one year) MNL.

3. If the predicted construction noise levels exceed the suggested MNL for construction phase

(less than one year), the authority conducting the EA should consider noise mitigation measures.

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Table 6.2: Calculating Suggested Mitigation Noise Level (MNL) forConstructionNoise

(Based on US EPA 1974)

Suggested Basic MNL 47 dBA Ldn*

Suggested MNL for various scenarios

Community Description Applied Correction

Factors

Suggested MNL

Quiet suburban or rural +0 dB 47 dBA Ldn

Normal suburban +5 dB 52 dBA Ldn

Urban residential +10 dB 57 dBA Ldn

Noisy urban +15 dB 62 dBA Ldn

Very noisy urban +20 dB 67 dBA Ldn

Additional Corrections

If applicable, add any or all of the following corrections:

Construction duration less than two months +10 dB

Winter (or windows always closed) +5 dB

Negligible tonal or impulsive noise

+5 dB

* Due to backup alarms, slamming tailgates, etc., construction noise normally contains both tonal and impulsive components.

Forthesuggested basic MNL, the reasonable worst-case scenario is used and all of the construction noise is assumed to be

duetotonaland/or impulsive noise.

§ When the contribution from tonal and/or impulsive noise may be negligible, +5 dB may be added to the suggested basic MNL.

HealthCanada prefers that a rationale be provided if this adjustment is applied.

Table 6.3 presents an example of how to establish a mitigation noise level (MNL). The ﬁnal MNL

is obtained through the application of several possible correction factors, as shown in Table 6.3.

Calculated MNLs for other construction projects may vary, depending on the applicable correction

factors speciﬁc to the project type, season and location.

Table 6.3: An Example of Applying Corrections to Establish a Suggested MNL

foraProjectin a Very Noisy Urban Community

Description Applied Correction Suggested MNL

Basic MNL 0 dB 47 (dBA) Ldn

Project occurs in a very noisy urban community +20 (dB) Ldn 67 (dBA) Ldn

Construction duration is less than two months +10 (dB) Ldn 77 (dBA) Ldn

Noise contains negligible tonal or impulsive noise +5 (dB) Ldn 82 (dBA) Ldn

Project occurs during winter or in proximity to residences

where windows cannot be opened

+5 (dB) Ldn 87 (dBA) Ldn

Final MNL 87 (dBA) Ldn

Widespread complaints tend to occur when the suggested MNLs in Table 6.2 are exceeded (US EPA 1974).

Therefore, Health Canada suggests the use of quieter technology or other mitigation measures, rather than

lengthening construction duration (e.g. lowering the noise by having fewer pieces of equipment running

at a time, thereby extending construction duration) to achieve a reduction in human health-related noise

impacts.

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Some examples of quiet technology and procedures are the following:

• vibratory pile driving or boring, instead of impulsive pile driving; and

• ambient-sensitive backup alarms, signal workers, machinery turning circles, and side loading/

unloading trucks to reduce the impact of backup alarms.

If acceptable levels cannot be obtained with quieter technology, community consultation (as discussed in

Section 6.4.1) is preferred, in order to seek consensus on construction operations (e.g. no activity during

night-time or weekend hours). Some commonly applied construction noise mitigation measures and

considerations for noise reduction are described in Appendix H.

6.4.3 Mitigating Long-Term Construction Noise (≥ 1 year)

Health Canada suggests that mitigation be implemented when noise levels during long-term

construction result in a greater than 6.5% increase in %HA. If the change in %HA exceeds 6.5%,

even when implementing quieter technology and construction methods as described in Appendix H,

community consultation is important to establish mutually agreeable work schedules and is an

acceptable means of informing the public of the time and duration of noisy activities.

Communication with potentially impacted residents is especially important when construction must

occur outside daytime hours. Residents’ concerns about blasting or other noisy activities can often

be addressed through community consultation. Some ﬂexibility among impacted residents may

exist regarding construction noise levels, if demonstrable mitigation measures are used. Community

consultation can be useful to determine whether the ability to avoid long periods of construction would

result in greater community acceptance.

In addition to the consultative process, it is a good practice to consider technically and economically

feasible mitigation measures (see Appendix H), in an attempt to reduce noise levels to levels that keep

the change in %HA below 6.5% and protect against sleep impacts. In some cases, monitoring and

working with the impacted community may address community reactions.

6.4.4 Mitigating Blasting Noise

Noise due to blasting has unique characteristics. Therefore, Health Canada holds the view that

for blasting during short-term construction (< 1 year), limits on the number of blasts should be

implemented irrespective of other noise levels due to background sources or construction activities.

Noise effects due to blasting can be assessed in several ways. One approach for blasting exposures

lasting less than one year is to use the US EPA 1974 criterion for sonic booms. The rationale for this

approach stems from the ﬁndings of Schomer et al. (1997), whose research indicates that blasts and

sonic booms create similar levels of annoyance for equal peaks.

According to US EPA (1974), little or no public annoyance is expected to result from any number of daytime

sonic booms per day, if their measured or predicted peak value is below 125-10 log N dB. In this case, dB is

interpreted as meaning Z-weighting (dBZ). Health Canada prefers that the US EPA’s sonic boom criterion

be used as a blasting MNL for blasting that lasts less than one year.

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Table 6.4 presents an example of the assessment technique of establishing an MNL based on

a representative number of blasts.

Table 6.4: Mitigation Noise Levels Related to Number of Blasts

Number of Daytime Blasts (N) Blasting MNL (125-10 log N) (dBZ)

10 115

25 111

50 108

100 105

Health Canada suggests following the recommendations in ISO 1996-1:2003, as described in Appendix E

and Appendix F of this guidance document, for blasting of duration of more than one year (≥ 1 year),

6.4.5 Mitigating Operational Noise

As with long-term construction noise, Health Canada considers high annoyance with noise generated

during a project’s operational phase to be an indicator of human health effects. If the change in %HA

exceeds 6.5% or the suggested target values noted in Section 6.3.2 for project operational noise, Health

Canada suggests that possible mitigation measures target the source, the propagation from source to

receptor site and/or the receptor site itself. These measures include, but are not limited to the following:

• reducing noise output, such as using quieter machinery where technically and economically feasible;

• implementing physical barriers, including noise walls, berms (artiﬁcial ridges or embankments)

and windows with high soundprooﬁng; and

• in some cases, changing project design (e.g. changing the proposed placement of an access road).

In general, implementing mitigation measures that further reduce noise impacts is encouraged.

6.5 ASSESSMENT OF RESIDUAL IMPACTS

An assessment of the residual impacts of a project may include discussion of potential noise impacts

arising from the project, after all proposed mitigation and management measures have been applied.

It is a good practice for this discussion to include characterizing ﬁnal sound levels at representative

receptor locations—in the same manner as is done in establishing the baseline and predicted sound

levels—in addition to discussing the potential impacts that may be expected due to these changes.

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Mitigating adverse noise effects can at times be technically challenging and costly. The severity of potential

impacts on human health caused by noise is only one of many factors that may be considered in making

an overall noise assessment of the project. When mitigation measures are judged to be not technically

or economically feasible, a detailed discussion justifying the exclusion of these measures may be helpful

in addressing potential concerns with respect to residual impacts of project-related noise. In such cases,

the community consultation process discussed in Section 6.4.1 may offer alternative options for limiting

complaints arising from excessive noise.

6.6 SOUND LEVEL MONITORING

The periodic monitoring of sound levels at representative receptor locations can be used to verify

predictions made during the EA process. This monitoring is particularly important when predicted

noise levels approach the level where adverse human health effects are considered likely and mitigation

measures become necessary. If the uncertainty related to predicted sound levels is large and the resulting

impacts are more severe than expected, monitoring is considered particularly useful. It is also helpful to

describe in the EA any commitments to evaluate the need for additional mitigation measures, if actual

project-related noise levels are higher than predicted or if community reaction is stronger than expected.

If post-project monitoring is not being undertaken when predicted noise levels are close to the suggested

mitigation-measure levels, Health Canada holds the view that the EA documentation should include a

rationale explaining why monitoring is not considered appropriate.

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ASSESSMENT OF CUMULATIVE EFFECTS

If the proposed project is in a region where there are other proposed or ongoing development projects

that may contribute to noise levels, an assessment of cumulative effects is an important consideration.

In attempting to predict sound levels from the project when contributions from other sources are

possible, Health Canada suggests that these sources be included in the modelling to establish potential

cumulative effects.

In selecting a baseline for a cumulative effects assessment, the pre-project baseline is the most

appropriate comparison for noise-related human health impacts, as this comparison is predictive

of the absolute change in the noise environment, when all project and additional noise sources are

considered.

For guidance on assessing cumulative effects, consult the Canadian Environmental Assessment

Agency’s website for up-to-date guidance materials: www.ceaa.gc.ca

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Under CEAA 2012, a “follow-up program” means a program to:

a. Verify the accuracy of the environmental assessment of a designated project; and

b. Determine the effectiveness of any mitigation measures.

It may be appropriate to consider a follow-up program for noise if there is uncertainty about

(not a comprehensive list):

• Modelling of project construction and/or operational noise; and/or

• Whether proposed mitigation measures (e.g. the use of novel technologies or materials)

will be effective.

For further and up-to-date information on follow-up programs, contact the Canadian Environmental

Assessment Agency, Canadian Nuclear Safety Commission or National Energy Board, as appropriate.

FOLLOW-UP PROGRAMS

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REFERENCES

American National Standards Institute (ANSI). 1995. Criteria for Evaluating Room Noise (ANSI S12.2-1995

(R1999)). Standards Secretariat Acoustical Society of America.

American National Standards Institute (ANSI). 2005. Quantities and Procedures for Description

and Measurement of Environmental Sound Part 4: Noise Assessment and Prediction of Long-Term

Community Response (ANSI S12.9-2005/Part 4). Standards Secretariat Acoustical Society of America.

Canadian Environmental Assessment Act. S.C. 2012, c. 19, s. 52. 2012. Available online at:

laws-lois.justice.gc.ca/PDF/C-15.21.pdf

Canadian Transportation Agency. (2008). Guidelines for the Resolution of Complaints Over Railway

Noise and Vibration. Available online at: www.otc-cta.gc.ca/eng/rail-complaints

Energy Resources Conservation Board (ERCB), Alberta. Feb. 16, 2007. Directive 038: Noise Control.

Available online at: www.aer.ca/rules-and-regulations/directives

Note: Effective June 17, 2013, the ERCB has been succeeded by the Alberta Energy Regulator (AER). No changes have been made to Directive

038 by the AER, and the Directive continues to contain references to the ERCB. When a new edition of the Directive is issued, the ERCB

references will be revised. The Directive may also contain references to the former Energy Utilities Board (EUB), which had been realigned

to the ERCB on January 1, 2008.

Hansen C et al.(2006) Transit Noise and Vibration Impact Assessment. FTA-VA-90-1003-06 May: 1–274.

Health Canada 2012. It’s Your Health: Noise-Induced Hearing Loss. Available online at:

www.hc-sc.gc.ca/hl-vs/alt_formats/pdf/iyh-vsv/environ/hearing_loss-perte_audition-eng.pdf

International Organization for Standardization (ISO). 2003. ISO 1996-1:2003 Acoustics – Description,

measurement and assessment of environmental noise – Part 1: Basic quantities and assessment

procedures. www.iso.org/iso/catalogue_detail?csnumber=28633

International Organization for Standardization (ISO). 2007. ISO 1996-2:2007 Acoustics – Description,

measurement and assessment of environmental noise – Part 2: Determination of environmental noise

levels. www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=41860

Levitt, H. and Webster, J. C. 1991. Effects of Noise and Reverberation on Speech. In Harris, C.M.

Handbook of Acoustical Measurements and Noise Control, Third Edition (Chapter 16). New York,

New York: McGraw-Hill.

Michaud, D. S., Bly, S. H. P. and Keith, S. E. 2008. Using a change in percentage highly annoyed with

noise as a potential health effect measure for projects under the Canadian Environmental Assessment

Act. Canadian Acoustics. 36, 13–30.

Miedema, HM and Vos, H. (2004). Associations between self-reported sleep disturbance and

environmental noise based on reanalysis of pooled data from 24 studies. Behav Sleep Med 5(1):1–20.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

NOISE

Radiation Emitting Devices Act. R.S.C., 1985, c. R-1. 1985. Available online at:

laws-lois.justice.gc.ca/eng/acts/R-1

Schomer, P. D. and Averbuch, A. 1989. Indoor Human Response to Blast Sounds that Generate Noise.

Journal of the Acoustical Society of America. 86(2), 665–671.

Schomer, P.D. and Neathammer, R. D. 1987. The Role of Helicopter Noise-Induced Vibration and Rattle

in Human Response. Journal of the Acoustical Society of America. 81(4), 966–976.

Schomer, P .D., Sias, J. W. and Maglieri, D. 1997. A Comparative Study of Human Response, Indoors,

to Blast Noise and Sonic Booms. Noise Control Engineering Journal. 45(4), 169–182.

United States Environmental Protection Agency (US EPA). 1974. Information on Levels of

Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin

of Safety (Report No. 550/9-74-004).

United States Federal Transit Administration. 2006. Hanson, C.E., Towers, D.A. and L.D. Meister.

Transit Noise and Vibration Impact Assessment (Report No. FTA-VA-90-1003-06). Prepared by Harris,

Miller, Miller and Hanson Inc. Burlington, Massachusetts. Available online at: www.transit.dot.gov/

regulations-and-guidance/environmental-programs/noise-and-vibration

World Health Organization (WHO). 1999. Guidelines for Community Noise. Berglund, B., Lindvall, T.

and Schwela, D.H (Eds.). Available online at: www.who.int/docstore/peh/noise/guidelines2.html

World Health Organization (WHO). 2009. Night Noise Guidelines for Europe. Hurtley, C. (Ed). Available

online at: www.euro.who.int/en/health-topics/environment-and-health/noise/publications/2009/

night-noise-guidelines-for-europe

World Health Organization (WHO). 2011. Burden of disease from environmental noise. Quantiﬁcation

of healthy life years lost in Europe. Theakston, F. (Ed). Available online at: www.who.int/quantifying_

ehimpacts/publications/e94888/en

Zaharna M, Guilleminault C. Sleep, noise and health: Review. Noise Health 2010;12(47):64–9.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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APPENDIXA

GLOSSARY

TERM DEFINITION

Acoustics The interdisciplinary science that deals with the study of sound, ultrasound

and infrasound (all mechanical waves in gases, liquids and solids).

Ambient sensitive

backupalarms

Alarms that warn workers that a vehicle is backing up. These alarms increase

or decrease in volume based on background noise levels to maintain a readily

noticeable tone to workers, while reducing community noise annoyance.

Thealarms work best on small equipment such as backhoes and trucks.

Note: The Construction Safety Association of Ontario notes that alarms

offer the greatest beneﬁt when trafﬁc is limited to only one or two vehicles.

Thewarning effect of the alarm is greatly reduced when it becomes part of

the background noise on-site.

Annoyance A state, or adverse reaction, that may be referred to as being annoyed,

disturbed, bothered, (or dissatisﬁed).

Noise annoyance: A degree of annoyance measured by a subject’s response

to an annoyance questionnaire as part of a social survey on noise and

annoyance.

High annoyance: A degree of noise annoyance with a minimum cut-off of

71–73 on a scale of 0 to 100 (7–10 if the ISO-recommended scale of 0–10 is

used) or the top two categories (very or extremely) of an adjectival scale.

(ISO/TS 15666:2003

)

Average community A community that would yield the same reaction to noise as that obtained

from social surveys on noise in a large number of communities around the

world (Michaud et al. 2008).

Berm An artiﬁcial ridge or embankment used to shield receptors from intruding noise.

Community An agglomeration of residents whose reaction to noise is being measured.

(For the complaint assessment method using US EPA 1974 only, see the

Michaud et al. 2008, and US EPA 1974 references).

Very noisy urban residential community: day-night sound level (Ldn) typical

range 68–72 dBA, average 70 dBA; no qualitative characterization.

Noisy urban residential community: Ldn typical range 63–67 dBA, average

65dBA; qualitative characterization: near relatively busy roads or industrial areas.

Urban residential community: Ldn typical range 58–62 dBA, average 60 dBA;

qualitative characterization: not immediately adjacent to heavily travelled roads

and industrial areas.

Normal suburban community: Ldn typical range 53–57 dBA, average 55 dBA;

qualitative characterization: not located near industrial activity.

Quiet suburban or rural community: Ldn typical range 48–52 dBA, average

50dBA; qualitative characterization: remote from large cities, industrial

activity and trucking.

1 ISO (2003). ISO/TS 15666:2003 Acoustics – Assessment of noise annoyance of social and socio-acoustic surveys.

www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=28630

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TERM DEFINITION

Decibel A logarithmic unit of measurement that expresses the magnitude of a

physical quantity (pressure, power or intensity) relative to a speciﬁed or

implied reference level. Since it expresses a ratio of two quantities with

the same unit, it is a dimensionless unit. The decibel is useful for acoustics

and confers a number of advantages, such as the ability to conveniently

represent very large or small numbers, and a logarithmic scaling that roughly

corresponds to the human perception of sound. The decibel symbol is often

qualiﬁed with a sufﬁx, which indicates which reference quantity or frequency

weighting function has been used. An example of this is dBA and is discussed

in Appendix D.

Environmental noise Also called community noise, refers to non-occupational noise. The main sources

of community noise include road, rail and air trafﬁc, industries, construction

and public work. In the context of this document, environmental noise refers

almost always, if not entirely, to the above. In a more general context, the term

may also refer to neighbourhood noise and indoor sources; primarily ventilation

systems, home appliances and neighbours (e.g. in apartments). (Adapted from

WHO 1999.)

Equivalent continuous

soundlevel Leq (t)

A sound level obtained from energy averaging over a speciﬁed time interval(t).

This level is obtained using an integrating averaging sound level meter, which

determines the mean of the square of the sound pressure over a speciﬁed

time interval (t), and expresses the result in decibels.

Day-night sound level (Ldn, also referred to as DNL): An equivalent continuous

sound level taken over 24 hours, with the night-time (10 p.m. to 7a.m.)

contributions adjusted by +10 dB. (This is a type of rating level because of

thenight-time adjustments.) The night-time adjustment (or addition of 10dB to

the night-time period) is used to account for the expected increased annoyance

due to noise-induced sleep disturbance and the increased residential population

at night relative to daytime, by a factor of 2–3. US EPA 1974 suggests that in

quiet areas, the night-time levels naturally drop by about 10 dB and this level

ofadjustment has been used with success in the U.S.

Daytime sound level (Ld): An equivalent continuous sound level taken over

15hours from 7 a.m. to 10 p.m. (In some jurisdictions, the start of daytime

hours can be as early as 6 a.m. and the end of daytime hours can be as late

as 11p.m.)

Night-time sound level (Ln): An equivalent continuous sound level taken over

9hours from 10 p.m. to 7 a.m. (In some jurisdictions, the start of night can

be as late as 11 p.m. As well, in some jurisdictions, the end of night can be

asearly as 6a.m.)

Day-night rating level (L

dn): A day-night sound level to which an adjustment

has been added.

Daytime rating level (L

d): A daytime sound level to which an adjustment

hasbeen added.

Night-time rating level (L

n): A night-time sound level to which an adjustment

has been added.

LAeq (t): An A-weighted equivalent continuous sound level in the denoted

time interval.

LAeq (24): An A-weighted equivalent continuous sound level for a speciﬁed

24-hour time interval.

LAeq (1): An A-weighted equivalent continuous sound level for a speciﬁed

1-hour time interval.

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TERM DEFINITION

Frequency weighting A relative value applied to the spectrum of a sound in each deﬁned frequency

interval.

A-weighting (dBA): A weighting of the frequencies in a sound that approximates

the response of the human ear to frequencies in moderately loud sounds

(sound pressure levels in the range of 45-65 dBA).

C-weighting (dBC): A weighting of the frequencies in a sound that

approximates the response of the human ear to frequencies in very loud

sounds. It emphasizes the low frequencies of a sound much more than

theA-weighting.

G-weighting (dBG): A frequency weighting used for infrasound measurements.

It is deﬁned in ISO 7196 as 0 dB at 10 Hz. Between 1 and20Hz (the highest

weighted frequency), the weighting approximates astraight line with a slope

of 12dB/octave.

Z-weighting (dBZ): A frequency weighting deﬁned in International

Electrotechnical Commission (IEC) 61672-1:2002 with 0 dB weighting

from10Hz to 20 kHz, within tolerances deﬁned in the standard.

Infrasound Like Sound but with frequency content below 20 Hz.

Maximum A-weighted

soundlevel (LAmax)

The maximum value of the sound pressure level during a noise event,

measured with a sound level meter using a Fast Time Weighting. This level

can be applied to pass-by noise from transportation noise sources and

impulsive noise events.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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TERM DEFINITION

Noise Unwanted sound.

Low-frequency noise: Noise with frequency content in the range of 20-200Hz.

Where it produces a 16, 31.5 or 63 Hz octave band sound-pressure level of more

than 65, 65 or 70 dBZ, respectively, low frequency noise can be associated

with the introduction of noticeable vibrations and rattles in some structures

(e.g.asfrom a nearby idling locomotive).

Tonal noise: Noise containing prominent (audible) tones such as backup

alarms on trucks. Here “tones” refers to tonal sound, deﬁned in

ISO19961:2003 as sound characterized by a single frequency component

or narrow-band components that emerge audibly, at the receptor position,

from the total sound. If the audibility is in dispute, ISO 1996-2:2007 contains

a (rather complex) method for analyzing a spectrum to determine audible

tonality.

High-energy impulsive noise: Impulsive noise from any high-energy impulsive

sound source, including any explosive source in which the equivalent

mass of TNT (trinitrotoluene) exceeds 50 g, or sources with comparable

characteristics and degrees of intrusiveness. Internationally agreed upon

examples are listed in ISO 1996-1:2003 and include sonic booms, blasting,

quarry and mining explosions, demolition or industrial processes that use

high explosives, explosive industrial circuit breakers and military ordnance

(e.g.armour, artillery, mortar ﬁre, bombs, and the explosive ignition of rockets

and missiles).

Highly impulsive noise: Impulsive noise from any noise source with highly

impulsive characteristics and a high degree of intrusiveness. Internationally

agreed upon examples of sources are listed in ISO 1996-1:2003 and include

impact pile driving, small arms ﬁring, hammering on metal or wood, nail

guns, drop-hammering, drop forging, punch pressing, pneumatic hammering,

pavement breaking, or metal impacts in rail-yard shunting operations.

Regular impulsive noise: Impulsive noise from sources that are neither highly

impulsive nor high-energy impulsive. Internationally agreed upon examples of

these sources are listed in ISO 1996-1:2003 and include slamming car doors

and truck tailgates.

Normalized Ldn A calculated day-night sound level that is used to determine the potential for

widespread complaints. The normalized Ldn is obtained from the measured

value and the addition of various corrections in dB (US EPA 1974).

Octave band A section (band) of a sound spectrum where the ratio of the maximum to

minimum frequency in the band is 2. Nominal centre frequencies (in Hz) of

noise octave bands have been standardized as 16, 31.5, 63, 125, 250, 500,

1000, 2000, 4000, 8000, and 16000.

Sentence intelligibility The ability to recognize key words in a sentence using full concentration

inalaboratory setting. Due to redundancy in normal conversation, all words

inthe sentence may not have been understood.

Signal workers or Signallers People who signal to a vehicle operator to ensure his or her awareness

ofother people. Signallers also warn workers that vehicles are backing up.

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TERM DEFINITION

Sleep disturbance Any of: (i) interfering with falling asleep, (ii) shortening sleep stage duration,

(iii) lessening perceived quality of sleep, (iv) awakening people from sleep,

or(v)increasing body movements (motility) during sleep.

Awakenings: A transient or indeterminate end of sleep. Awakenings can be

measured: (i) behaviourally, by a subject pushing a button upon ﬁnding that

they are aware of awakening, (ii) when a certain threshold of body movement

(motility threshold) is exceeded from a previous low level of body movement

(sleep), and (iii) by an objectively deﬁned change in brain wave pattern

measured by an electroencephalograph (EEG) (Michaud et al. 2008).

Percent awakenings due to noise: Awakenings attributed to noise events

divided by the total number of awakenings multiplied by 100 (normally

thetotals are taken for all subjects in the study).

Sleep stage: a stage of sleep with a well-deﬁned brain wave pattern measured

with an EEG. There are 5 stages of sleep. Sleep stage is also related to muscle

activity and eye movements.

Sound exposure level (SEL) The 1-second equivalent continuous sound level that would be measured if

the total energy in a noise event occurred during that one second. This level

can be applied to pass-bys of transportation noise sources and impulsive

noise events.

Note: The equivalent continuous sound level for an extended time period that

contains a number of noise events can be obtained by energy averaging the

SEL values over the time period.

Time weighting Fast weighting: A time constant of 0.125 second in a sound-level meter used

to smooth the square of the measured sound pressure prior to the expression

of the sound pressure level in decibels.

Slow weighting: A time constant of 1 second used to smooth the square of

the measured sound pressure prior to the expression of the sound pressure

level in decibels.

Transmission loss In environmental noise, the ratio of the sound energy striking a wall

(e.g.theoutside of a residence) relative to the transmitted sound energy

(e.g.into a living room or bedroom), expressed in decibels.

Vibratory pile driving

orboring

A pile driving system that does not rely on an impact hammer but on a rapidly

vibrating hammer that transfers its vibrational energy to the pile to drive it in.

Wind screen A screen, commonly a porous sphere or an egg-shaped structure of open cell

foam, to protect a microphone’s protective grid from turbulence produced

by the passage of wind. For a given wind speed, the lower the frequency

ofnoise to be reduced, the larger the windscreen that is needed.

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APPENDIXB

NOISE IMPACTS IN EA CHECKLIST

This checklist is beneﬁcial in verifying that the main components of a noise impact assessment are

completed. It is useful to include this checklist as an index in an environmental assessment (EA) to

identify the locations of the key components of a noise impact assessment, especially if the information

is found in multiple sections of the EA documentation.

OVERALL (THROUGHOUT THE EA)

Item

1. In addition to the construction phase, are all other project phases, including operation, decommissioning

and abandonment, included in the EA?

2. When modelling techniques are used to estimate present (baseline) or future (construction and operational)

sound levels, are these techniques and any assumptions documented and appropriately justiﬁed?

3. Is information provided that describes any tonal, regularly impulsive, highly impulsive or high-energy

impulsive noise that is audible at receptors during the construction, operation and decommissioning

project phases?

4. Does the EA avoid statements relating to the perceptibility or whether changes in noise are noticeable

based solely on decibel levels?

RECEPTOR IDENTIFICATION AND CHARACTERIZATION

Item Section in EA

5. Are all currently impacted receptors (including Indigenous Peoples) and potential

reasonably foreseeable future receptors, clearly identiﬁed?

6. Is information on all noise-sensitive receptors in the area (including any foreseeable

future receptors) and on distances of receptors from the project, included?

7. Are maps identifying receptor locations relative to the project site, including noise

contour diagrams, provided?

8. Is justiﬁcation provided for any excluded receptors (if applicable)?

9. Are receptors identiﬁed in “quiet rural areas” assigned a +10 dB adjustment

(ifapplicable)?

10. Is a description provided of any community consultation that may have occurred

concerning noise impacts, including any human health concerns expressed by

potential receptors?

IMPACTS ASSOCIATED WITH NOISE

Item Section in EA

11. Does the outdoor annual average for night-time (Ln) exceed 40 dBA?

¨ No ¨ Ye s

12. Do indoor night-time sound levels (or sound levels when nearby

receptors are expected to be sleeping) exceed 30 dBA Leq from

continuous noise sources at any representative receptors?

¨ No ¨ Ye s

13. Are more than 10–15 night-time individual noise events above

45dBA LAmax indoors predicted at any representative receptor?

¨ No ¨ Ye s

14. Is an evaluation of the severity of residual impacts (post-mitigation) on sleep

disturbance included?

15. Is any interference with daytime speech comprehension (indoor

sound levels greater than or equal to 40 dBA or outdoor sound levels

greater than 55 dBA) predicted?

¨ No ¨ Ye s

16. Is an evaluation of the severity of residual impacts (post-mitigation) on speech

comprehension provided in the EA?

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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ASSESSMENT OF BASELINE NOISE LEVELS

Item Section in EA

1 7. Are measured or valid estimates of baseline noise levels provided, including any

uncertainties for both daytime (Ld) and night-time (Ln) at receptors?

18. When measured baseline noise levels are provided, are the hours during which

the measurements were obtained and the exact locations of the measurements

provided?

19. Is a rationale provided explaining why the baseline is considered representative,

including the days, weather conditions and any seasonal variations when monitoring

occurred?

20. Are all noise sources that contribute to the baseline identiﬁed (see Appendix E including

a description of the speciﬁc noise character(s), and appropriate adjustments made?

21. When baseline noise is estimated, are the estimation method and a rationale for using

this method provided?

22. Is a calculation of baseline percent highly annoyed (%HA) at receptors provided?

ASSESSMENT OF CONSTRUCTION NOISE LEVELS

Item Section in EA

23. Are valid estimates (predictions) of construction noise levels provided for both

daytime (Ld) and night-time (Ln) at receptors, including any uncertainties?

24. Are the duration of construction activities impacting each receptor and the method

ofnoise assessment (based on the construction duration) provided?

25. Are construction noise-related impacts and a noise management plan (if applicable)

included?

26. Are construction noise levels estimated or modelled for each receptor, and are

appropriate adjustments identiﬁed? (See Appendix E)

27. When construction noise levels are expected to approach a suggested mitigation

noise level (MNL), are mitigation measures and a noise management plan provided?

28. If an assessment of construction noise impacts is not conducted because the noise

levels are predicted to be below the level for widespread complaints at all receptors,

is a rationale provided?

29. When construction noise is expected to last longer than 1 year at any given receptor,

is an evaluation of the change in %HA (from baseline) at these receptors provided?

Are all applicable adjustments identiﬁed in estimating %HA?

MITIGATION MEASURES

Item Section in EA

30. Are predicted future (operation) daytime (Ld) and night-time (Ln) sound levels

provided for all receptors, using the same parameters that were used to establish

the baseline (e.g. units and averaging times)? Are appropriate adjustments identiﬁed?

(See Appendix E)

31. Is an evaluation of the change in %HA (from baseline) at each receptor provided

foroperational noise?

32. Are the results and conclusions of the operational noise assessment clearly

documented?

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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SSS

Item Section in EA

33. If applicable, is a discussion of whether mitigation measures or follow-up monitoring

are warranted included?

34. When noise is expected to approach suggested mitigation levels either during

project construction or operations, is a discussion of planned or conditional mitigation

measures included?

35. Is a residual impacts assessment discussing noise impacts following mitigation

included?

36. When low-frequency noise is emitted, is information describing impacts of any

anticipated effects (e.g. rattling) and related mitigation measures included?

37. After all of the noise mitigation measures are applied, does

the calculated change in %HA (from baseline) at any of the

representative receptors exceed 6.5%?

¨ No ¨ Ye s

38. Is information provided on how the noise-related complaints will be addressed,

including a description of a complaint resolution process?

ASSESSMENT OF CUMULATIVE EFFECTS

Item Section in EA

39. When other ongoing or reasonably foreseeable future projects in the region may

contribute to noise levels, is a cumulative effects assessment included?

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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APPENDIXC

NOISE CHARACTERISTICS

C.1 TONAL AND IMPULSIVE NOISE

Tonal (e.g. backup alarms on trucks) and impulsive noise (e.g. hammering on metal) are often perceived

as annoying and may have a high potential to disturb receptors (US EPA 1974, ISO 1996-1:2003, ANSI

2005, WHO 1999). Therefore, providing information on tonal, regular impulsive, highly impulsive or

high-energy impulsive project noise that is audible at receptors is suggested. This characterization of

noise is also important in selecting the appropriate corrections and adjustments in the calculation of

noise impacts for construction and operational noise.

As described in ISO 1996-1:2003, regular impulsive noise is sometimes characterized as intrusive but

not as intrusive as highly impulsive noise. Examples of regular impulsive noise include the slamming of

car doors, outdoor ball games, such as football, soccer or basketball, and church bells. Very fast pass-bys

of low-ﬂying military aircraft may also fall under this category.

Impulsive noise sources that have a high degree of intrusiveness may be characterized as either highly

impulsive (deﬁned in ISO 1996-1:2003) or high-energy impulsive, as described in ISO 1996-1:2003.

For details on these noise types, see Appendix A.

ISO 1996-1:2003 recommends making a +5 dB adjustment to tonal and regular impulsive noise sources

and a +12 dB adjustment to highly impulsive noise sources. The expected contribution of project noise

and details on how tonality and impulsiveness were accounted for are important elements of the noise

assessment. See Appendix F for more information.

C.2 LOW-FREQUENCY NOISE

Noise occurring at frequencies below 100 to 200 Hertz (Hz) is generally deﬁned as low-frequency noise.

Low-frequency noise is commonly not well perceived by the human ear but may induce vibrations in

buildings that may be perceptible or cause a “rattle” in these environments. Research indicates that

annoyance related to noise is greater when low-frequency noise is present (ISO 1996-1:2003) and one

of the main reasons is the annoyance caused by rattles (Schomer and Neathammer 1987; Schomer

and Averbuch 1989). As sound environments are usually characterized using A-weighted decibel levels

(dBA) that reﬂect the frequencies most audible to the human ear, the impacts of low-frequency noise

may need to be assessed separately.

Guidance for low-frequency sound (or infrasound) in the 16-63 Hz octave bands stems from the ANSI

standard on environmental sound regarding noise assessment and the related prediction of long-term

community response (ANSI 2005). Where standards or acceptable procedures for the measurement of

these frequencies exist, it is suggested that the EA include a description of the potential impacts and

any mitigation measures concerning the effects of these frequencies.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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The ANSI standard concerns essentially continuous sounds with strong low-frequency content. To

prevent rattles from low-frequency noise and the associated annoyance from this effect, ANSI indicates

that the (energy) sum of the sound levels in the 16-, 31.5- and 63-Hz octave bands be less than 70 dBZ.

If this 70-dBZ “rattle criterion” is exceeded, Health Canada may suggest the implementation of feasible

mitigation measures. ANSI 2005 indicates that there is evidence that noise-induced rattles are very

annoying, and this annoyance may be independent of the number or duration of events.

Additionally, ANSI 2005 provides a more sophisticated mathematical procedure for assessing %HA when

low-frequency noise is present. Health Canada prefers using this procedure when the C-weighted Ldn

exceeds the A-weighted Ldn by more than 10 dB. This is further outlined in Appendix D of ANSI 2005.

C.3 PERCEPTIBILITY

The typical threshold for an increase in sound level that is considered to be “barely perceptible” by the

human ear in a controlled laboratory setting varies from 1 to 5 dBA, depending on the sound pressure

level and frequency of the sound. In community noise applications, a 5-dBA reduction in highway

noise by a barrier is accepted as the minimum that will be clearly noticeable. These ﬁndings cannot be

broadly generalized in the context of assessing community noise impacts.

Changes to the characteristics of the sound from baseline (e.g. a change in frequency, changes in sound

modulation, increased impulsiveness, or a shift in noise from the daytime to being more at night) may

be perceived and may cause noise to be more noticeable, even if the absolute equivalent continuous

sound level (in dBA) is not substantially increased. Consult ANSI S12.9-2005/Part 4, clause A.1.3 for

further information.

It is important to consider that people respond to sound characteristics that do not necessarily

appreciably increase the sound level. Therefore, in the context of an EA, it is suggested that statements

relating to perceptibility or whether changes in noise are noticeable based solely on decibel levels be

avoided, as these statements may be misleading.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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APPENDIXD

INTRODUCTION TO NOISE

SOUND AND NOISE

Sound is deﬁned as mechanical vibrations travelling through the air or other media.

Noise is most simply deﬁned as unwanted sound.

Sound is measured using a calibrated microphone to determine the rapid cyclical changes in

pressure (force per unit area) of the sound wave from the normal atmospheric pressure of about

101,000 pascals (Pa). As the human ear is sensitive to sound waves over a very wide range of maximum

changes in sound pressure, for convenience, this range is compressed by using a logarithmic scale, and

the resulting sound unit used is called a “decibel” (dB). A logarithmic scale is non-linear; as one moves

up the scale, the same change in decibels represents a larger and larger increase in sound pressure.

This means that decibels cannot be added or averaged in the same way as other linear measurements

such as distance or weight.

D.1 SOUND PERCEPTION

Perception of sound is not related to sound level in decibels in a linear manner. For example, a

10-dB increase is the median change in sound level at 1 kHz, which is perceived as being twice as

loud. A typically cited threshold for an increase in sound level that is often stated as being “barely

perceptible” by the human ear varies from 3 to 5 dB (see Appendix B). This threshold is often used in

EAs, which may state that residual sound increases lower than this threshold will not be perceptible;

however, a difﬁculty with this approach is that humans also perceive and respond to changes in

sound characteristics other than loudness. Examples of these characteristics include frequency,

sound modulation, impulsiveness and tonality, which are described in Appendix A.

D.2 WEIGHTING

People do not perceive all sound frequencies equally, and as such, decibel levels are modiﬁed (weighted)

according to the frequencies present in the sound. The modiﬁed levels are termed “A-weighted” and are

reported as dBA rather than dB. The A-weighting reduces the contribution from low and high frequencies

to capture the mid-frequency range to which the average human ear is most sensitive. Note that low-

frequency noise is de-emphasized by A-weighting as its impacts are not perceived as well by the human

ear. However, these low frequencies are factors that can induce rattles and vibrations that can be heard

and felt. There are other ways to weight decibels, such as C-, G- and Z-weighting. C-weighting is applicable

in the EA context to assess the %HA from exposure to frequent blasting (a high-energy impulsive noise)

or, potentially, other project noise sources in which low-frequency noise dominates.

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D.3 ADDING DECIBELS

Sounds often need to be added together to determine sound (or adjusted sound) levels (expressed

in decibels) for use in EAs. The known/measured/predicted values characterizing the sound are also

normally expressed as sound levels in decibels. To add sounds, the starting sound levels Li are changed

to mean square sound pressures, 10

0.1Li

which are added, and then the sum is changed back to decibels.

Some rapid estimations are particularly useful, e.g. if sounds with 2 equal sound levels are added, the

ﬁnal value will be very nearly 3 dB greater than the starting values.

D.4 AVERAGING DECIBELS

In calculating an average sound level over a certain time period, the measured sound pressure at

each time is squared and then averaged over time (mean square sound pressure). The mean square

sound pressure is then converted to decibels. Occasional loud sound events (e.g. a bird landing on

a microphone) may inappropriately inﬂuence an average. Events unrelated to the assessment are,

after being identiﬁed, commonly excluded from the calculation of average sound pressure level.

D.5 MEASUREMENTS ASSOCIATED WITH

SOUND LEVELS REPORTED IN EAS

In the context of noise impact assessment, sound levels are typically reported in average decibel level

over a deﬁned time period. In some cases, a speciﬁc time weighting is also applied to the average, most

commonly as a penalty for night-time sound levels before averaging, to account for the additional

potential for disturbance during these hours. The measurement used to describe the sound level

indicates the duration and time of day of the sound, and whether any weighting was applied. The

following describes the A-weighted metrics most commonly presented in EAs:

Ldn (also termed DNL): indicates that the sound was averaged over 24 hours with 10 dBA added

to night-time sound levels. The standard night-time hours for this measurement are 10:00 p.m. to

7:00 a.m. Tables 6.2 and 6.3 show Ldn used in the calculation of suggested Mitigation Noise Levels

for construction noise exposure less than 1 year.

Ld: average daytime level (standard hours 7 a.m. to 10 p.m. although this varies between 6 a.m. and

11 p.m. in some jurisdictions, such as Ontario).

Ln: average night-time level (10:00 p.m. to 7:00 a.m.).

Leq (24): indicates that the sound was averaged over 24 hours without any adjustment applied.

Leq (1): indicates that the sound was averaged over 1 hour.

Leq (1 hour max): indicates that the average sound level of the worst hour (as measured by a provincial

inspector) in a 24-hour period is being reported.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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APPENDIXE

SOUND SOURCES AND

SOUNDCHARACTER

Appendix F Determination of Percent Highly Annoyed (%HA), lists equations that show how to obtain

%HA values from daytime and night-time rating levels. The rating levels can be estimated from the

application of adjustments to the applicable daytime (Ld) and night-time (Ln) sound levels for the noise

environments with and without the project. The Ld and Ln are obtained by an appropriate combination

of predictions and measurements.

The values of the daytime rating levels L

and the night-time rating levels L

for any applicable noise

source are obtained by applying adjustments to the sound levels that are energy-averaged to obtain Ld

and Ln for the given (i-

) noise source. Adjustments may pertain to a particular type of source or to a

particular character of the noise from a source or to the receiver characteristics.

When adjustments to project or baseline noise are necessary, Health Canada prefers that adjustments

be made by following ISO 1996-1:2003. Details of how to apply adjustments are given in Section 6

of ISO 1996-1:2003, in particular for situations where noise sources of speciﬁc character are audible

and either distinguishable from noise from other sources, or indistinguishable from noise from other

sources. Furthermore, this section of the ISO standard indicates how to determine the rating level from

combined sources.

With respect to receptor characteristics, an adjustment is made for a “quiet rural area,” where a noise

receptor (or group of receptors) has a greater expectation for and value placed on “peace and quiet”.

ISO notes that a +10 dB adjustment should be applied in this situation. In the absence of further

information, Health Canada will assume that receptors with a LAeq (7 a.m.–10 p.m.) of 45 dBA or less

and a LAeq (10 p.m.–7 a.m.) of 35 dBA or less are in a quiet rural area, and warrant a +10 dB adjustment

in the calculation of the change in %HA.

For air trafﬁc sources of noise, Health Canada prefers that a +5 dB adjustment be applied.

For rail trafﬁc, Health Canada prefers that either a -5 dB (note this is a negative adjustment) or 0 dB

adjustment be applied, as applicable. The -5 dB rail trafﬁc adjustment is not applicable to long diesel

trains, or to trains operating at speeds in excess of 250 km/hr. These speciﬁc adjustments fall within the

ranges given in ISO 1996-1:2003.

Road trafﬁc noise and industrial-type noise (including construction noise for the purposes of this

guidance) have a 0 dB adjustment, as speciﬁed in the ISO standard. The 0 dB adjustment for industry/

construction noise applies to only two types of sound levels: (i) from noise sources which are not

audibly tonal at the receptor and (ii) from non-impulsive sources.

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Certain other noise sources, as per ISO 1996-1:2003, are considered regular impulsive (+5 dB

adjustment), highly impulsive (+12 dB adjustment) or high energy impulsive. (The rating level is based

on the C-weighted sound level and can be obtained from Appendix B of ISO 1996-1:2003.) Tonal sound

is also addressed in the ISO standard. Health Canada prefers that a +5 dB adjustment be applied to

noise which is audibly tonal at the receptor. This value falls within the range speciﬁed in the standard.

As per ISO 1996-1:2003, if more than one adjustment applies for the source type or character of a given

single sound source, only the largest adjustment is applied. However, time period adjustments are

always added to the otherwise adjusted levels. Also, the adjustment for receiver characteristics in a

quiet rural area is added to any other adjustments.

ISO 1996-1:2003 also explicitly states that adjustments for tonal character should only be applied when

the “sound is audibly tonal at the receiver location”. The standard also indicates that adjustments for

impulsive source character should only be applied to “impulsive sound sources that are audible at the

receiver location.” The subtle distinction made in ISO 1996-1:2003 between audibly tonal versus audible

sources may only be relevant in consideration of high energy impulsive noise. At long distances, high

energy impulsive artillery ﬁre can change from an impulse to a rumble without substantially affecting

the magnitude of the required adjustment. For more common sources, a source is still impulsive even

if it loses the high frequencies at long distances (e.g. ISO 1996-1:2003 identiﬁes the predominantly low-

frequency car door slam as regular impulsive).

E.1 EXAMPLES

Aircraft noise: Although an aircraft can create prominent tones during aircraft noise events, which

would normally get a +5 dB adjustment, the adjustment for the air trafﬁc type is also +5 dB. Therefore

all the air trafﬁc noise receives a +5 dB adjustment.

Shunting of rail cars: The sound sources which are identiﬁed as highly impulsive in ISO 1996-1:2003

are the “metal impacts in rail-yard shunting operations.” Thus, only the sound level during the time that

the metal impacts are audible should receive the +12 dB adjustment; not the rest of the noise associated

with the shunting activity. The noise due to the engine and motion of the rail cars during shunting is

separate from the impact noise and is thus a separate component with a 0 dB adjustment.

Rail wheel squeal: There are times at the receptor when the noise from the train is audibly tonal, due

to wheel squeal, and the +5 dB adjustment applies. However, for that portion of time where the sound

is no longer audibly tonal at the receptor, the noise from the train receives either 0 or -5 dB adjustment

for source type.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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APPENDIXF

DETERMINATION OF PERCENT

HIGHLY ANNOYED (%HA)

INTRODUCTION

Appendix F presents the methodology and equations for calculating (the change in) percent highly

annoyed (%HA): using Ld and Ln to calculate rating levels L

d and L

n; and using rating levels in

the equations below to determine %HA. These calculations are applicable to projects where the

construction phase ≥ 1 year’s duration, and for projects in the operational phase.

Note: Rating levels are an intermediate step in the calculations of %HA, but are generally not reported

in an EA. Health Canada prefers the reporting of various details about Ld, Ln and the adjustments

applied.

Refer to Section 5.4 for a discussion about complaints and %HA, and consult Appendix A for deﬁnitions.

CALCULATION OF BASELINE, CONSTRUCTION ≥ 1 YEAR

DURATION, AND OPERATION DAYTIME (7 A.M.–10 P.M.)

AND NIGHT-TIME (10 P.M.–7 A.M.) RATING LEVELS

Energy summation of applicable daytime rating levels will result in a daytime rating level which can be

used to calculate %HA.

Daytime rating level

d) = 10 log

[∑ 10

]

(0.1L

)

(F1)

For a quiet rural area, the daytime rating level

d) = 10 + 10 log

[∑ 10

]

(0.1L

)

(F1

quiet rural area

)

Where L

= any applicable daytime rating level and a quiet rural area is considered an area where a

noise receptor (or group of receptors) has a greater expectation for and value placed on “peace and

quiet”. In the absence of further information, Health Canada will assume that receptors with a LAeq

(7 a.m.–10 p.m.) of 45 dBA or less and a LAeq (10 p.m.–7 a.m.) of 35 dBA or less are in a quiet rural area

and warrant a +10 dB adjustment.

The same calculation (using Equations F1 or F1

quiet rural area

) is also applicable to determine the night-time

rating level (L

n) needed to calculate %HA.

2 LAeq is an A-weighted equivalent of continuous sound level in the denoted time period.

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CALCULATION OF %HA

The rating level used to calculate %HA is the day-night rating level (L

dn). In general, to calculate

the relevant change in %HA values due to the project noise, L

dn values are needed for baseline,

construction ≥ 1 year, and operation. The energy summation of baseline and construction L

dn values

(baseline and construction)

) is needed for the construction phase. The energy summation of baseline and

operation L

dn values (L

(baseline and operation)

) is needed for the operation phase. L

dn is a 24-hour energy

averaged rating level in which the contribution from the night-time rating level is artiﬁcially increased

by 10 dB and is calculated using Equation E2.

dn = 10 log

[((15 × 10

) + (9 x 10 ) / 24]

(0.1 × L

d) (0.1 × (L

n + 10))

(F2)

(baseline and construction)

= 10 log

(10

+ 10 )

(0.1 × construction L

dn) (0.1 × baseline L

dn)

(F3a)

(baseline and operation)

= 10 log

(10

(0.1 × operation L

dn)

+ 10 )

(0.1 × baseline L

dn)

(F3b)

The %HA is calculated using Equation F4:

]%HA = 100 / [1 + e

(10.4 - 0.132* L

dn)

(F4)

The %HA (baseline), %HA (baseline and construction), %HA (construction), %HA (baseline and

operation) and %HA (operation) can be obtained by substituting the appropriate L

dn into Equation F4.

The change in %HA for project construction is calculated by subtracting %HA (baseline) from %HA

(baseline and construction).

The change in %HA for project operation is calculated by subtracting %HA (baseline) from %HA

(baseline and operation).

Table F.1 is a worked example showing the project noise levels (i.e. construction phase [≥ 1 year] or

during the operational phase) that would result in a change of 6.5%HA from the baseline to project

scenario. Use this table as a reference to check calculations carried out for a speciﬁc project. This table

presents rating levels, but note that rating levels are not commonly reported in an EA as they are an

intermediate step in calculating %HA (see above).

The table ranges from a baseline of 20 dB (i.e. quiet rural area) up to a project level of 75 dB.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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Table F.1: Worked example showing baseline and project rating levels associated

witha6.5% increase in %HA due to a project’s noise.

Change in %HA between baseline

andproject equals 6.5%

dn baseline

(dB)

dn project

(dB)

total L

(dB)

%HA baseline

(%)

%HA project

(%)

< 20 58.6 58.6 0.0 6.5

35 58.9 59.0 0.3 6.8

42 59.4 59.5 0.8 7. 3

46 59.9 60.1 1.3 7. 8

48 60.2 60.5 1.7 8.2

50 60.6 61.0 2.2 8.7

52 61.1 61.6 2.8 9.3

53 61.3 61.9 3.2 9.7

55 61.9 62.7 4.1 10.6

56 62.2 63.1 4.7 11. 2

57 62.5 63.6 5.3 11. 8

58 62.8 64.1 6.0 12.5

59 63.2 64.6 6.8 13.3

60 63.6 65.2 7. 7 14.2

61 64.0 65.8 8.7 15.2

62 64.5 66.4 9.8 16.3

63 64.9 67.1 11. 1 1 7. 6

64 65.4 67.8 12.4 18.9

65 65.9 68.5 13.9 20.4

66 66.5 69.2 15.6 22.1

67 67.0 70.0 1 7. 4 23.9

68 67.6 70.8 19.4 25.9

69 68.3 71.7 21.6 28.1

70 68.9 72.5 23.9 30.4

71 69.6 73.4 26.3 32.8

72 70.3 74.3 29.0 35.5

73 71.1 75.2 31.8 38.3

74 71.9 76.1 34.7 41.2

75 72.8 77.0 37.8 44.3

76 73.7 78.0 40.9 47.4

77 74.6 79.0 44.1 50.6

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APPENDIXG

IDENTIFICATION AND

CHARACTERIZATION OF SOME

COMMON RECEPTORLOCATIONS

RECEPTOR

LOCATION

CHARACTERIZATION COMMENTS/

CONSIDERATIONS

Commercial premises Retail stores, ofﬁces, research facilities

andlaboratories

Noise effects during business hours

Daycare centres Highly sensitive receptors (children) Noise effects considered during

occupied periods

Entertainment

establishments

Film and television studios, theatres,

restaurants, etc.

Noise effects during periods

ofoperation

Hospitals Highly sensitive receptors (sick people) Noise effects over a 24-hour period

Industrial premises Factories and other industrial plants Potential for additive noise in

cumulative effects assessment

Places of worship

andcemeteries

Churches, mosques, synagogues, temples,

locations where Indigenous Peoples’ cultural

or religious ceremonies occur, etc.

Noise effects during religious

services, meetings or processions

Recreation areas:

Active

Parks and sports grounds Noise effects considered during

occupied periods

Recreation areas:

Passive

Outdoor grounds used for hunting, ﬁshing,

teaching, etc.; includes locations where

Indigenous Peoples may hunt, ﬁsh or gather

country foods

Noise effects considered during

activity periods

Residences:

Permanent

Urban, suburban and rural locations

containing houses, mobile homes and/or

multilevel dwellings

Noise effects over a 24-hour period

with particular emphasis on night-

time noise levels

Residences:

Seasonal

Cottages, campgrounds and RV parks;

includes Indigenous hunting and ﬁshing

cabins, and seasonal camping places

Noise effects considered during

occupied periods

Schools Education facilities from pre-school to

universities; highly sensitive receptors

Noise effects during regular hours

of operation, which may include

evenings and the possibility of

schools being used during summer

Seniors’ residences Highly sensitive receptors (elderly) Consideration of noise effects over

a 24-hour period with particular

emphasis on night-time noise levels

Workers’ living quarters

Locations may be on or off the project site Mitigation measures in the design

of temporary living quarters for

workers to limit noise

3 Occupational exposure and health issues are typically under provincial or territorial jurisdiction, and Health Canada does not review

this information in the context of EAs.

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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APPENDIXH

COMMONLY APPLIED CONSTRUCTION

NOISE MITIGATION MEASURES

ANDCONSIDERATIONS FOR

NOISEREDUCTION

The measures below have been adapted from the New South Wales Interim Construction Noise

Guideline (July 2009), Department of Environment and Climate Change, New South Wales, Australia.

Available at: www.epa.nsw.gov.au/noise/constructnoise.htm

GENERAL MITIGATION MEASURES

• Regularly train workers and contractors to use equipment in ways that minimize noise.

• Ensure that site managers periodically check the site, nearby residences and other sensitive

receptors for noise problems so that solutions can be quickly applied.

• Include in tenders, employment contracts, subcontractor agreements and work method

statements, clauses that assure the minimization of noise and compliance with directions from

management to minimize noise.

• Avoid the use of radios and stereos outdoors and the overuse of public address systems where

neighbours can be affected.

• Avoid shouting, and minimize talking loudly and slamming vehicle doors.

• Keep truck drivers informed of designated vehicle routes, parking locations, acceptable delivery

hours and other relevant practices (e.g. minimizing the use of engine brakes and periods of engine

idling).

NIGHT-TIME MITIGATION MEASURES

• Avoid the use of equipment that generates impulsive noise.

• Minimize the need for reversing alarms.

• Avoid dropping materials from a height.

• Avoid metal-to-metal contact on equipment.

• If possible, schedule truck movements to avoid residential streets.

• Avoid clustering of equipment near residences and other sensitive receptors.

• Ensure that periods of respite are provided in the case of unavoidable maximum noise level events.

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CONSULTATION AND NOTIFICATION

• The community is more likely to be understanding and accepting of project noise if related

information is provided and is frank, and does not attempt to understate the likely noise level, and

if commitments are respected.

NOTIFICATION BEFORE AND DURING CONSTRUCTION

• Provide advance notiﬁcation to people concerning construction duration, deﬁning activities that

are expected to be noisy and their expected duration, what noise mitigation measures are being

applied, and when noise respite periods will occur.

• For night-time work, receptors may be informed in two stages: two weeks prior to construction

and then two days before commencement.

• Provide information to neighbours before and during construction through media such as

letterbox drops, meetings or individual consultation. In some areas, the need to provide

notiﬁcation in languages other than English may be considered. A website may also be established

for the project.

• Use a site information board at the front of the site with contact details, hours of operation and

regular information updates.

• Facilitate contact with people to ensure that everyone can see that the site manager understands

potential issues, that a planned approach is in place, and that there is an ongoing commitment to

minimize noise.

WORK SITE AND EQUIPMENT

• In terms of both cost and results, controlling noise at the source is one of the most effective

methods of minimizing the noise impacts from any construction activities.

QUIETER METHODS

• Examine and implement, where feasible and reasonable, alternatives to rock-breaking work

methods, such as hydraulic splitters for rock and concrete, hydraulic jaw crushers, chemical rock

and concrete splitting, and controlled blasting, such as penetrating cone fracture.

• Consider alternatives to diesel and gasoline engines and pneumatic units, such as hydraulic

or electric-controlled units, where feasible and reasonable. When there is no electricity supply,

consider using an electrical generator located away from residences.

• Examine and implement, where feasible and reasonable, alternatives to transporting excavated

material from underground tunnelling off-site at night-time. (e.g. stockpile material in an

acoustically treated shed during the night and load out the following day).

Guidance for Evaluating Human Health Impacts in Environmental Assessment:

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QUIETER EQUIPMENT

• Examine different types of machines that perform the same function and compare the noise level

data to select the least noisy machine (e.g. rubber-wheeled tractors can be less noisy than steel-

tracked tractors).

• Pneumatic equipment is traditionally a problem. Consider selecting super-silenced compressors,

silenced jackhammers and damped bits, where possible.

• When renting (or purchasing) equipment, select quieter pieces of machinery and construction

equipment, where feasible and reasonable. As well, select the most effective mufﬂers, enclosures

and low-noise tool bits and blades. Always seek the manufacturer’s advice before making

modiﬁcations to any equipment to reduce noise.

• Reduce throttle settings and turn off equipment when it is not being used.

• Examine and consider implementing, where feasible and reasonable, the option of reducing noise

from metal chutes and bins by placing damping material in the bin.

EQUIPMENT MAINTENANCE

• Regularly inspect and maintain equipment to ensure that it is in good working order, including the

condition of mufﬂers.

• For machines with enclosures, verify that doors and door seals are in good working order and that

the doors close properly against the seals.

• Return any leased equipment that is causing noise that is not typical for the equipment. The

increased noise may indicate the need for repair.

• Ensure that air lines on pneumatic equipment do not leak.

SITE MITIGATION MEASURES

• Barriers and acoustic sheds are most suited to long-term ﬁxed works, as in these cases, the

associated cost is typically outweighed by the overall time savings.

WORK SITE LOCATION

• Place as much distance as possible between the machinery or equipment, and residences and

other sensitive receptors.

• Restrict areas in which mobile equipment can operate, so that they are away from residences and

other sensitive receptors at particular times.

• Locate site vehicle entrances away from residences and other sensitive receptors.

• Carry out noisy fabrication work at another site (e.g. within enclosed factory premises) and then

transport products to the project site.

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ALTERNATIVES TO REVERSING ALARMS

• Avoid the use of reversing alarms by designing the site layout to avoid reversing, such as by

including drive-through for parking and deliveries.

• When applicable legislation permits, consider less annoying alternatives to the typical “beeper”

alarms. Examples include smart alarms that are adjustable in volume depending on the ambient

level of noise, and multi-frequency alarms that emit noise over a wide range of frequencies.

MAXIMIZE SHIELDING

• Re-use existing structures rather than demolishing and reconstructing.

• Use full enclosures, such as large sheds, with good seals ﬁtted to doors to control noise from night-

time work.

• Use temporary site buildings and material stockpiles as noise barriers.

• Schedule the construction of permanent walls so that they can be used as noise barriers as early as

possible.

• Use natural landform as a noise barrier. Place ﬁxed equipment in cuttings or behind earth berms.

• Take note of large reﬂecting surfaces on- and off-site that might increase noise levels, and avoid

placing noise-producing equipment in locations where reﬂected noise will increase noise exposure

or reduce the effectiveness of mitigation measures.

PROVIDE RESPITE PERIODS

• Consult with schools to ensure that noise-generating construction works in the vicinity are not

scheduled to occur during examination periods, unless other acceptable arrangements (such as

relocation) can be made.

• When night work near residences cannot be feasibly or reasonably avoided, restrict the number of

nights per week and/or per calendar month that the work is undertaken.

WORK SCHEDULING

• Schedule noisy work during periods when people are least affected.

SCHEDULE ACTIVITIES TO MINIMIZE NOISE IMPACTS

• Organize work to be undertaken during the recommended standard hours, where possible.

• If the construction site is in the vicinity of a sports venue, consider scheduling work to avoid times

when there are special events.

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• When work outside the recommended standard hours is planned, avoid scheduling it on Sundays

or public holidays.

• Schedule work when neighbours are not present (e.g. outside business hours or on weekends,

when commercial neighbours, college students and school students may not be present).

• Schedule noisy activities around times of high background noise (i.e. when local road trafﬁc or

other local noise sources are active) where possible, to provide masking or to reduce the amount

that the construction noise intrudes above the background noise.

DELIVERIES AND ACCESS

• Nominate an off-site truck parking area away from residences for trucks arriving prior to gates

opening and schedule deliveries only during speciﬁed periods.

• Optimize the number of vehicle trips to and from the site. Movements can be organized to

amalgamate loads rather than using a number of vehicles with smaller loads.

• Designate access routes to the site through consultation with potentially noise-affected residences

and other sensitive receptors, and inform drivers of nominated vehicle routes.

• Provide on-site parking for staff and on-site truck waiting areas away from residences and other

sensitive receptors. Truck waiting areas may require walls or other barriers to minimize noise.

NOISE TRANSMISSION PATH

• Physical methods to reduce the transmission of noise between construction locations and

residences or other sensitive receptors are generally suited to construction projects in which there

is long-term noise exposure.

• Reduce the line-of-sight noise transmission to residences and other sensitive receptors using

temporary noise barriers.

• Temporary noise barriers can be constructed from boarding (plywood boards, panels of steel

sheeting or compressed ﬁbre cement board) with no gaps between the panels at the site boundary.

Stockpiles and shipping containers can be effective noise barriers.

• Erect temporary noise barriers before work commences to reduce noise from construction as soon

as possible.

• Where high-rise dwellings adjoin the construction site, the height of a barrier may not be sufﬁcient

to effectively shield the upper levels of the residential building from construction noise. Find out if

this is a consideration for the project and examine alternative mitigation measures, where needed.