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1900 West Nickerson Street, Suite 201 Seattle, WA 98119
DATE: January 18, 2019
TO: Erik Waligorski, PE – Carollo Engineers, Inc.
FROM: Drew J. Savas – The Greenbusch Group, Inc.
RE: Eastside Interceptor Section 2 Rehabilitation Phase II – Noise Study
Transmitted by: Mail Delivery Fax E-mail
Erik:
The intent of this memorandum is to present predicted sound levels during daytime and
nighttime construction activities, compare predicted sound levels with regulatory criteria,
recommend sound level limits and present potential mitigation for the Eastside Interceptor
Section 2 Rehabilitation Phase II Project (“Project”) in Renton, Washington.
Daytime construction activities will consist of bypass pumping, odor control, general
construction, excavation, restoration, and pipe lining. Daytime activities will occur along the
project alignment shown in Figure 1. Nighttime activities will consist of bypass pumping and
odor control, bypass sewer installation and removal at three locations and pipe lining at four
manholes. Nighttime work will require a noise variance from the City of Renton.
SUMMARY
Daytime operations are expected to comply with the City of Renton and King County Guide
Specification criteria. Nighttime operations are expected to exceed maximum permissible
noise limits. Therefore, it is recommended that a noise variance be obtained from the City of
Renton. A summary of requested sound level limits for anticipated nighttime construction to
occur can be found in Table 13. Daytime operations should not exceed an hourly LEQ of 85
dBA 50 feet from the construction boundary or at residential-use receptors when measured
at the building envelop, whichever is further.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
The Greenbusch Group, Inc.
p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
NOMENCLATURE
Decibel, dBA
The auditory response to sound is a complex process that occurs over a wide range of
frequencies and intensities. Decibel levels, or “dB,” are a form of shorthand that compresses
this broad range of intensities with a convenient numerical scale. The decibel scale is
logarithmic. For example, using the decibel scale, a doubling or halving of energy causes the
sound level to change by 3 dB; it does not double or halve the sound loudness as might be
expected.
The minimum sound level variation perceptible to a human observer is generally around 3 dB.
A 5-dB change is clearly perceptible, and an 8 to 10 dB change is associated with a perceived
doubling or halving of loudness. The human ear has a unique response to sound pressure. It
is less sensitive to those sounds falling outside the speech frequency range. Sound level
meters and monitors utilize a filtering system to approximate human perception of sound.
Measurements made utilizing this filtering system are referred to as “A weighted” and are
called “dBA”.
Table 1. A-weighted Levels of Common Sounds
Sound Sound Level
(dBA)
Approximate Relative
LoudnessA
Jet Plane @ 100 feet 130 128
Rock Music with Amplifier 120 64
Thunder, Danger of Permanent
Hearing Loss 110 32
Boiler Shop, Power Mower 100 16
Orchestral Crescendo at 25 feet 90 8
Busy Street 80 4
Interior of Department Store 70 2
Ordinary Conversation at 3 feet 60 1
Quiet Car at Low Speed 50 1/2
Average Office 40 1/4
City Residence, Interior 30 1/8
Quiet Country Residence, Interior 20 1/16
Rustle of Leaves 10 1/32
Threshold of Hearing 0 1/64
A As compared to ordinary conversation at 3 feet.
Source: US Department of Housing and Urban Development, Aircraft Noise Impact Planning Guidelines for Local Agencies,
November 1972.
January 18, 2019
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Equivalent Sound Level, LAeq
LAeq is the A-weighted level of a constant sound having the same energy content as the actual
time-varying level during a specified interval. The LAeq is used to characterize complex,
fluctuating sound levels with a single number. Typical intervals for LAeq are hourly, daily and
annually.
Sound Power Level, PWL
Sound power is the amount of energy per second generated by a source, measured in watts.
The sound power level (PWL) is a decibel representation with a reference value of 1 pico-watt
(pW). Sound power is independent of distance, path, or influence from any nearby surfaces.
Sound Pressure Level, SPL
Sound pressure level correlates with what is heard by the human ear. SPL is defined as the
squared ratio of the sound pressure with reference to 20 μPa. Sound pressure is affected by
distance, path, barriers, directivity, etc.
Percentage Sound Level, L(n)
L(n) is the sound level that is exceeded n percent of the time; for example, L08 is the level
exceeded 8% of the time. L25 is the sound level exceeded 25% of the time.
Maximum Sound Level, Lmax
Lmax is the maximum recorded root mean square (rms) A-weighted sound level for a given
time interval or event. L max “fast” is defined as a 125-millisecond time-weighted maximum,
while Lmax “slow” corresponds to a 1-second time-weighted maximum.
REGULATORY CRITERIA
Properties surrounding the project area consist of residential, commercial and industrial use.
As of September 19th, 2018, the City of Renton no longer groups multiple zoning designations
into noise districts called Environmental Designations for Noise Abatement (“EDNA”). Instead,
the City has amended Section 8-7-4 of the Renton Municipal Code (“RMC”) to adopt Section
173-60-30 of the Washington Administrative Code (“WAC”). Section 173-60-030 of WAC
states that EDNA classification will be defined by the property’s use. Generally, Class A EDNA
includes residential use properties, Class B EDNA includes commercial use properties and
Class C EDNA includes industrial use properties. Figure 1 provides a graphical representation
of EDNAs in the Project area, along with the Project alignment.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
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Figure 1. Project Location and Nearby EDNAs
Source: King County iMap, The Greenbusch Group, Inc., Bing Maps, City of Renton, Carollo Engineers, Inc.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
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p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
Environmental Sound Level Limits
City of Renton
Maximum permissible environmental sound levels are defined by Section 8-7-2 of the RMC
which adopts Section 173-60-040 of the WAC. These sound level limits are based on the
EDNA the sound source originates from (EDNA of Sound Source) and in which EDNA the
sound is received (EDNA of Receiving Property). A summary of the applicable sound level
limits can be found in Table 2.
Table 2. Environmental Sound Level Limits, L25
EDNA of Sound Source EDNA of Receiving Property
Class A Class B Class C
Class A 55 dBA 57 dBA 60 dBA
Class B 57 dBA 60 dBA 65 dBA
Class C 60 dBA 65 dBA 70 dBA
Source: Section 8-7-2 City of Renton Municipal Code, Section 173-60-040 Washington Administrative Code
Modifications
Modifications to the environmental sound level limits set forth in Table 2 are also outlined in
Section 173-60-040 of the WAC. These modifications are for certain times of day and
classification of receiving properties. These modifications to the environmental sound level
limits include a 10 dBA reduction during the nighttime hours of 10 p.m. and 7 a.m. when the
receiving property is within Class A EDNAs.
Exemptions
Section 173-60-050 of the WAC referenced by Section 8-7-2 of the RMC allows exemptions
from environmental sound level limits set forth in Table 2. Applicable exemptions include all
sounds originating from temporary construction sites as a result of construction activity that
are received in Class B and Class C EDNAs, and in Class A EDNA between the hours of 7
a.m. and 10 p.m.. Construction activities that generate sounds received in Class A EDNAs
between 10 p.m. and 7 a.m. need to comply with sound level limits in Table 2. It is our
interpretation of the RMC that all construction equipment, including bypass pumps and
blowers, would qualify for this exemption.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
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p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
PROJECT-SPECIFIC CRITERIA
King County Guide Specification Section 01 35 43 defines sound level limits and general noise
control requirements for the Project, as summarized below.
• Sound Level Limits
o Noise levels for scrapers, pavers, graders, and trucks shall not exceed 90 dBA and
pile drivers shall not exceed 95 dBA at 50 feet as measured under the noisiest
operating conditions.
o For other equipment, noise levels shall not exceed 85 dBA. Equipment that cannot
meet these levels shall be quieted by use of improved exhaust mufflers, noise
attenuation barriers or other means.
• General Noise Control Requirements
o Noise complaints received by the Project Representative during the Work will be
shared with the contractor. Work with the Project Representative, as required, to
resolve noise related complaints.
o Noisy operations shall be scheduled to minimize their impact.
o Unless otherwise indicated through a noise variance, comply with local controls
and noise level rules, regulations, and ordinances which apply to work performed.
o Each internal combustion engine, used on the job or related to the job, shall be
equipped with a muffler of a type recommended by the manufacturer. No internal
combustion engine shall be operated without said muffler.
o Use electric or hydraulic tools whenever practical to reduce noise.
o Provide notification of special circumstances or emergency conditions that require
work beyond the hours specified as follows:
§ Notify the Project Representative and local authority in advance of any
proposed extended work hours for preauthorization. Include a written
request for authorization per Section 01 14 00 to perform work specified
and the circumstances that warrant this request. Include any additional
measures to mitigate noise generated by this construction activity if
deemed necessary by the Project Representative.
§ If an emergency situation occurs that warrants extended hours, notify the
Project Representative immediately upon determining the need for this
work.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
The Greenbusch Group, Inc.
p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
ACOUSTICAL MODEL
The primary tool used to predict sound levels at nearby properties during nighttime operations
was a 3-D computer noise modeling environment, Cadna/A. Cadna/A utilizes the CADNA
(Control of Accuracy and Debugging for Numerical Applications) computation engine
developed by the Pierre et Marie Curie University of Paris. The model accounts for the effects
of distance, topography, and surface reflections on sound levels.
Locations and sound levels of anticipated equipment were determined from project drawings,
information provided by vendors via Carollo Engineers, Inc and Federal Highway
Administration (FHWA) and various manufacturers. Topography, building locations and
locations of property lines were determined from King County GIS records, Bing Maps, and
Google Maps.
ANALYSIS AND MITIGATION
In addition to daytime construction, nighttime activities are expected to consist of bypass
pumping, odor control and ventilation, excavation and pipe lining. Some of these activities will
occur continuously while others will be short duration and transient. The following analysis
shows the predicted sound levels during these activities as well as sequencing and duration
of the activities.
Nighttime
Sewer Bypass Installation and Removal
Sewer bypass installation and removal will need to occur during nighttime hours at three
locations; one at the norther extent of the project and two at the southern. These locations are
shown in Figure 2.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
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p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
Figure 2. Sewer Bypass Install & Removal Construction Areas
Source: King County iMap., Bing Maps, City of Renton, Carollo Engineers, Inc.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
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p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
Nighttime sewer bypass installation and removal will require the use excavators, trucks and
light plants. Sound levels for this equipment were based upon levels defined in the FHWA
Construction Noise Control Specification 721.560 and manufacturer data. FHWA 721.560
sound levels are maximum sound levels (LMAX) 50 feet from the source and manufacturer data
are sound power levels. The construction equipment sound levels and the predicted
percentage of an hour each piece would be in use (acoustical usage factor) are shown below.
Table 3. Sewer Bypass Equipment Sound Levels
Equipment Usage Factor Sound Level Metric
Excavator 40% 85 dBAA Lmax (slow)
Dump Truck 40% 85 dBAA Lmax (slow)
Light Plant 100% 95 LwA Power Level
Source:FHWA
A Sound level at 50 feet
Sound levels were modeled at nearby EDNA Class A properties by placing the equipment
presented in the previous table within the construction areas shown in Figure 2. Table 4 shows
the results of this modeling. Some cells in Table 4 are blank, this is due to the property being
far from the construction area.
Table 4. Predicted Nighttime Sound Levels during Sewer Bypass Work
Construction
Area
Estimated
duration of
work
Predicted Sound Levels Nighttime
Sound
Level
Limit, L25A
Bristol at
Southport
The Reserve
Apartments
South
Homes
CT109 Install: 5 days
Removal: 5 days 62 dBA 70 dBA - 50 dBA
CT108b Install: 5 days
Removal: 5 days - - 69 dBA 50 dBA
CT108a Install: 5 days
Removal: 5 days - - 74 dBA 50 dBA
A City of Renton Nighttime Sound Level Limits
As shown in the previous tables and figures, predicted sound levels during nighttime sewer
bypass work exceed nighttime sound level limits at nearby Class A EDNA properties.
Therefore, a noise variance from the City of Renton will be required for this work to occur
during nighttime hours. Table 13 provides the recommended sound level limits a variance
should grant to allow this nightwork to take place.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
The Greenbusch Group, Inc.
p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
In addition to the predicted sound levels at nearby EDNA Class A properties, the City has
requested predicted sound levels 300 feet from the construction area. These sound levels can
be found in the following table.
Table 5. Predicted Sound Levels 300 feet from Bypass Install & RemovalA
Receiving Location Predicted Sound Level, LEQ
300 ft from Construction Area 65-69 dBA
A When measured from the center of construction area
Bypass Pumping and Pipe Lining
Once the bypass sewer is installed, bypass pumping and pipe lining can begin. Nightwork for
this phase of construction will consist of two main activities; bypass pumping at the north
staging area and the pipe lining process along the mainline sewer. Bypass pumping will occur
continuously at the north staging area. The pipe lining process requires access to three
manholes simultaneously. One manhole is used for pipe access for the Linabond pipe lining
system and manholes upstream and downstream of the work area are used for the ventilation
and odor control. Pipe lining and the ventilation and odor control will occur simultaneously.
Activities at the north staging area consist of only bypass pumping and odor control. While up
to eight electric bypass pumps may operate during daytime hours, only three are anticipated
to run during nighttime hours, apart from any emergency periods. The odor control unit will
operate continuously during nighttime hours. Table 6 and Table 7 show bypass pumping
equipment sound levels and predicted unmitigated sound levels. Figure 3 shows anticipated
equipment locations within the North Staging Area.
Table 6. Bypass Pumping and Odor Control Equipment Sound Levels
Equipment Sound Power Level
Electric Bypass Pump 97 LwA
Odor Control Unit 74 LwA
Source: Equipment Vendors, Carollo Engineers, Inc.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
The Greenbusch Group, Inc.
p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
Figure 3. Modeled Equipment Locations
Source: The Greenbusch Group, Inc., Bing Maps, Carollo Engineers, Inc.
Table 7. Unmitigated Predicted Nighttime Operation Sound Levels
Receiving Property EDNA Predicted Sound
Level, LEQ
Nighttime Sound
Level Limit, L25A
Gene Coulon Beach Park Class A 38 dBA 50 dBA
The Bristol at Southport Class A 51 dBA 50 dBA
Southport on Lake
Washington Class B 46 dBA None
The Reserve Apartments Class A 56 dBA 50 dBA
A City of Renton Nighttime Sound Level Limits
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
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p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
Predicted unmitigated sound levels from nighttime operations exceed regulatory criteria at
nearby EDNA Class A properties. Therefore, it is recommended that a noise variance from
the City of Renton be obtained for this work. It is recommended only the northern three bypass
pumps operate during nighttime hours and a noise barrier be placed between these bypass
pumps and The Reserve Apartments. The barrier should be constructed such that the pumps
are not visible from anywhere on The Reserve Apartment’s parcel. The barrier should include
two sheets of ¾ inch plywood with at least a 2 inch air gap between the sheets or outdoor
noise curtains with a mass of at least 2 pounds per square foot attached to a fence. The noise
barrier should have no gaps or breaks and meet flush with the ground. Appendix A includes
a Specification Data Sheet for a typical outdoor noise curtain which could be used in this
instance. The barrier should be placed as close to the pumps as possible and be approved
by a Structural Engineer.
A modeled barrier with a length of 50 feet, a height of 8 feet, and spaced 6 feet from the pumps
as seen in Figure 4 was used to predict the effectiveness of the described noise barrier.
Predicted sound levels with the modeled noise barrier are presented in Table 8 and Figure 5.
Predicted mitigated sound levels 300 feet from the electric bypass pumps can be found in
Table 9.
Table 8. Mitigated Predicted Nighttime Operation Sound Levels
Receiving Property EDNA Predicted Sound
Level, LEQ
Nighttime Sound
Level Limit, L25A
Gene Coulon Beach Park Class A 40 dBA 50 dBA
The Bristol at Southport Class A 53 dBA 50 dBA
Southport on Lake
Washington Class B 48 dBA None
The Reserve Apartments Class A 44 dBA 50 dBA
A City of Renton Nighttime Sound Level Limits
Table 9. Mitigated Predicted Nighttime Operation Sound Levels at 300 feetA
Receiving Location Predicted Sound Level, LEQ
North 57 dBA
West 56 dBA
East 55 dBA
South 54 dBA
A When measured from the bypass pumps.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
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Figure 4. Modeled Noise Barrier, South Facing
Source: The Greenbusch Group, Inc., Google Maps, Carollo Engineers, Inc
Reserve
Apartments
Noise Barrier
Bypass Pumps
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
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Figure 5. Predicted Mitigated Nighttime Sound Levels, dBA
Source: The Greenbusch Group, Inc., Google Maps, City of Renton, Carollo Engineer, Inc.
In the event of noise complaints during bypass pumping from properties north of the North
Staging Area, a noise barrier could be placed on all sides of the active bypass pumps. This
noise barrier should be of the same construction as the noise barrier previously described. If
the barrier is constructed of plywood, acoustical absorption should be placed on the interior
walls.
During some periods of nighttime construction, pipe lining will occur at the same time as
bypass pumping and therefore the cumulative sounds must be analyzed. The following
analysis predicts sound levels from the nighttime pipe lining combine d with mitigated sounds
from the bypass pumping at the north staging area .
The pipe lining process will need to occur during nighttime hours at four manholes. Access for
pipe lining will occur at three manholes and the necessary ventilation and odor control will
occur at the same time at manholes upstream and downstream of the work area. These
locations are shown in the following figure.
Reserve
Apartments
Southport on
Lake Wash.
Bristol at
Southport
300’ from
Pumps
January 18, 2019
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Figure 6. Nighttime Pipe Lining Access Areas (Manholes)
Source: King County iMap., Bing Maps, City of Renton, Carollo Engineers, Inc.
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
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p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
Nighttime pipe lining will require the use of a combination of the Linabond pipe lining system,
light-plants, ventilation and odor control. Sound levels for this equipment are based on data
found in FHWA, information provided by Carollo Engineers and various manufacturers. Table
10 shows the equipment’s sound levels along with the usage factor.
Table 10. Pipe Lining Equipment Sound Levels
Equipment Usage
Factor Sound Level Metric
Light Tower 100% 95 LwA Power Level
Supply & Spray-Rig
Truck 40% 80 dBAA Lmax (slow)
Air Scrubber 100% 74 LwA Power Level
Dehumidifier 100% 99 LwA Power Level
Blower 100% 103 LwA Power Level
Heater 100% 94 LwA Power Level
Generator 100% 97 LwA Power Level
Source: FHWA, Carollo Engineers and various manufacturers
A Sound level at 50 feet
Sound levels were modeled at nearby EDNA Class A properties by placing the equipment
presented Table 10 within the construction areas shown in Figure 6. A noise barrier should
be placed between the Supply and Spray-Rig Truck at manhole R02-07 and the Reserve
Apartments. A noise barrier should also be placed between ventilation at manhole R01-32
and the South Homes. These barriers should be the same construction as the bypass pump’s
noise barrier. The trucks or fans should not be visible from anywhere on nearby EDNA Class
A properties with the noise barrier in place.
Table 11 shows the results of this modeling with the recommended noise barriers. Some cells
in Table 11 are blank, this is due to the receptor being far from the construction area.
Table 11. Predicted Mitigated Nighttime Sound Levels during Pipe Lining & Bypass Pumping
Construction Area
Estimated
duration
of work
Predicted Sound Levels Nighttime
Sound
Level
Limit, L25A
Bristol at
Southport
Reserve
Apartments
South
Homes
R02-07
(Supply & Spray-Rig Truck)
R02-06
(Ventilation & Odor Control)
2 months 56 dBA 56 dBA - 50 dBA
R02-01
(Supply & Spray-Rig Truck)
R01-32
(Ventilation only)
2 months 53 dBA 44 dBA 57 dBA 50 dBA
A City of Renton Nighttime Sound Level Limits
January 18, 2019
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Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study
The Greenbusch Group, Inc.
p) 206.378.0569 f) 206.378-0641 www.greenbusch.com
1900 West Nickerson Street, Suite 201 Seattle, WA 98119
As shown in the previous tables and figures, predicted sound levels during pipe lining exceeds
nighttime sound level limits. Therefore, a noise variance from the City of Renton will be
required for this work. Table 13 provides the recommended sound level limits a variance
should grant for this nightwork to take place.
In addition to the predicted sound levels at nearby EDNA Class A properties, the City has
requested sound levels 300 feet from the construction area. These sound levels can be found
in the following table.
Table 12. Predicted Sound Levels 300 feet from Nighttime Pipe LiningA
Receiving Location Predicted Sound Level, LEQ
300 Feet from Construction Area 54-63 dBA
A When measured from the center of construction area
Requested Noise Variance Sound Levels & Noise Monitoring
The following table presents recommended sound level limits to be granted by a noise
variance for the anticipated nightwork.
Table 13. Requ ested Noise Variance Sound Level Limits for Nightwork
Construction Area
Estimated
Duration of
Work
Requested Variance Sound
Level Limits at Class A
EDNAs, Leq(H)
Nighttime
Sound Level
Limit, L25A
Sewer Bypass
CT109 10 days
two 5 day periods 70 dBA 50 dBA
CT108b 10 days
two 5 day periods 70 dBA 50 dBA
CT108a 10 days
two 5 day periods 75 dBA 50 dBA
Bypass Pumping & Odor Control Only
North Staging Area 8 months 55 dBA 50 dBA
Linabond, Bypass Pumping & Odor Control
R02-07 & R02 -06 2 months 56 dBA 50 dBA
R02-01 & R01 -32 2 months 57 dBA at South Homes
55 dBA at Bristol & Reserve Apt. 50 dBA
A City of Renton Nighttime Sound Level Limits
Noise monitoring should be performed during nighttime sewer bypass installation and removal
at the nearest EDNA Class A property to show compliance with noise variance sound level
limits. Noise monitoring should also be performed during nighttime pipe lining at the nearest
EDNA Class A property. Given the constant nature of bypass pumping and odor control, once
pipe lining work is finished at manhole R02-07 and R02-06, noise monitoring should be
January 18, 2019
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performed at The Reserve Apartments and Bristol Apartments until compliance is proven over
a 1 week period.
Daytime – Construction & Pipe Lining
Construction, restoration, and the Linabond pipe lining process are expected to also occur
during weekday, daytime hours and are therefore exempt from the City of Renton sound level
limits. Bypass pumping and odor control will occur continuously during daytime hours and is
also exempt from the City of Renton sound level limits. All daytime operations will be required
to satisfy King County’s Guide Specification sound level limits. Sound originating from
equipment or construction activity during daytime is assessed at 50 feet, per Section 01 35
43 of the Guide Specification. Anticipated daytime equipment and their respective sound
levels can be found in Table 14.
Table 14. Construction Equipment Sound Levels
Equipment Sound Level
at 50 ft
Sound Level
Limit at 50 ftC
Construction
Front End Loader 80 dBA A 85 dBA
Excavator 85 dBA A 85 dBA
Back Hoe 80 dBA A 85 dBA
Concrete Saw 90 dBA A 90 dBA
Vibratory Pile Driver 95 dBA A 95 dBA
Impact Pile Driver 95 dBA A 95 dBA
Pipe Lining System (Linabond)
Supply and Spray-Rig Truck 80 dBA A 85 dBA
300 kW Genset 65 dBA 85 dBA
150 kW In -Line Heater 62 dBA 85 dBA
10 HP Blower 71 dBA 85 dBA
5000 CFM Dehumidifier 67 dBA 85 dBA
1000 CFM Air Scrubber 43 dBA 85 dBA
Bypass Pumping and Odor Control
Electric Bypass Pump 65 dBA B 85 dBA
Odor Control Unit 42 dBA B 85 dBA
A Table 9.1 FHWA Construction Noise and Vibration Handbook (LSmax)
B Carollo Engineers, Inc.
C King County Guide Specification Section 01 35 43
January 18, 2019
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All daytime equipment and activities are expected to satisfy King County Guide Specification
sound level limits. However, the King County Guide Specification only sets criteria for each
piece of operating equipment and does not consider the cumulative sound levels of all
operating equipment. Therefore, it is recommended that sound originating from daytime
construction activities and the Linabond system not exceed an hourly LEQ of 85 dBA 50 feet
from the construction boundary or at residential-use receptors when measured at the building
envelop, whichever is further. It is recommended that the contractor implement the following
to help meet the recommended sound level limits:
• Use only ambient-sensing broadband back-up alarms and minimize backing.
• Noisy equipment and construction activities should be placed or performed as far as
possible from noise sensitive receptors.
• Monitor noise levels during construction.
Additionally, the following may be implemented if further mitigation is required to meet the
recommended sound level limits:
• Limit engine idling to 5 minutes or less.
• Use radios for long-range communication; only use raised voices and public address
systems in an emergency.
• Use upgraded engine exhaust mufflers, engine shrouds, or sound enclosures on
noisier equipment.
• Install noise barrier or noise curtains of similar design to what is previously described
around noisier equipment.
• Use electric and hydraulic equipment in lieu of diesel of pneumatic equipment.
• Perform impact work during times of high ambient sound levels.
Emergency Periods – Daytime and Nighttime
The RMC adopts Section 173-60-050 of the WAC. Section 173-60-050 of the WAC exempts
all sound created by emergency equipment and work necessary for the health, safety and
welfare of the community. It is our interpretation that additional bypass pumping and the use
of backup generators during emergency periods would be exempt from the City of Renton
sound level limits.
Appendix A
Noise Curtain Specification Data Sheet
Spec Data Sheet
NOISE BARRIERS
BBC-SERIES
NOISE BARRIERS/SOUND ABSORBER
COMPOSITES
50 H.P. Almgren Drive x Agawam, MA 01001 x Ph 413.789.1770 fax 413.789.2248 www.soundseal.com
BBC-13X-2 LB-2”Sound Curtains
Sound Seal’s BBC-13X-2 LB-2” offers the benefits of both a noise barrier and a sound
absorber for outdoor applications. This product consists of a two-inch thick vinyl-coated-
fiberglass-cloth faced quilted fiberglass that is bonded to a two-pound per sq. ft. reinforced
loaded vinyl noise barrier. “X” style Sound Curtain panels are constructed with grommets
across the top and bottom, and exterior grade Velcro seals along the vertical edges. The
product is also available in roll form with edges bound or unbound.
x Class A (or 1) flammability rated per ASTM E- 84
x For Indoor or Outdoor Applications
x Available facing colors on quilt: gray, tan, black or off-white
x Available barrier colors: gray, tan, blue or olive drab
Applications:
With its 7+ year life span* in the harshest environments, this product is typically used as a temporary noise barrier on
outdoor applications such as construction site noise mitigation projects. Also available with a one-pound psf noise
barrier or a one-inch thick quilted fiberglass sound absorber.
Product Data:
Description Vinyl coated fiberglass cloth facing on 2” quilted fiberglass/
2 lb-psf reinforced loaded vinyl noise barrier
Flammability Flame Spread: 23.0
Smoke density: 30.0
Nominal thickness 2.0 inches
Temperature range -20q to +180q F
Standard roll size 54” wide x 25’ long
Weight ` 2.45 lb psf
Acoustical Performance:
Sound Transmission Loss
OCTAVE BAND FREQUENCIES (Hz)
Product 125 250 500 1000 2000 4000 STC
BBC-13X-2lb-2” 19 25 33 46 53 58 37
ASTM E-90 & E 413
Sound Absorption Data
OCTAVE BAND FREQUENCIES (Hz)
Product 125 250 500 1000 2000 4000 NRC
BBC-13X-2lb-2” .07 .27 .96 1.13 1.08 .99 .85
ASTM C 423
* when properly installed.