018 Greenline Building B_AQ_Report_06282018
Prepared for:
Federal Way Campus, LLC
Prepared by:
Ramboll US Corporation
Lynnwood, Washington
June 2018
Project Number:
1690002845
GREENLINE BUILDING "B"
DEVELOPMENT, FEDERAL WAY,
WASHINGTON
AIR QUALITY REPORT
AIR QUALITY REPORT
Contents i Ramboll
CONTENTS
Contents ................................................................................................................... i
Acronyms and Abbreviations ................................................................................... ii
1. Introduction .................................................................................................... 1
1.1 Background and Project Description ............................................................... 1
2. Affected Environment ...................................................................................... 2
2.1 Regulatory Overview ................................................................................... 2
2.2 Existing Air Quality ...................................................................................... 3
2.2.1 Carbon Monoxide .............................................................................. 3
2.2.2 Ozone .............................................................................................. 4
2.2.3 Inhalable Particulate Matter – PM10 and PM2.5 ..................................... 4
2.2.4 Greenhouse Gases and Global Climate Change ...................................... 5
2.3 Local Climate and Terrain ............................................................................. 6
3. Air Quality Impacts .......................................................................................... 8
3.1 Impacts during Construction ......................................................................... 8
3.2 Impacts during Operation ............................................................................. 8
3.2.1 Traffic-Related Air Quality .................................................................. 8
3.2.2 Emergency Equipment ..................................................................... 10
3.2.3 Mobile Source Air Toxics (MSATs) ...................................................... 11
3.2.4 Greenhouse Gas Emissions ............................................................... 11
4. Mitigation ...................................................................................................... 14
4.1 Mitigation during Construction .................................................................... 14
4.2 Mitigation during Operation ........................................................................ 15
5. Conclusion ..................................................................................................... 16
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Acronyms and Abbreviations ii Ramboll
ACRONYMS AND ABBREVIATIONS
Ambient air quality standard ... health-based standard representing a pollutant concentration
in the ambient air usually over some averaging period like 1
hour, intended to protect the health and welfare of people
with a margin of safety
Ambient air .......................... the air in outdoor locations to which the public has access,
e.g., outside the property boundary of an emissions source
Attainment/Nonattainment ..... a determination and classification made by EPA indicating
whether ambient air quality in an area complies with (i.e.,
attains) or fails to meet (i.e., nonattainment) the
requirements of one or more NAAQS
Averaging time ..................... a specific length of time (e.g., 1 hour, 24-hours, 1 year) over
which measured or model-calculated concentrations of an air
pollutant are averaged for comparison with the NAAQS based
on the same averaging period. Note that some NAAQS are
also based on multi-year averages of certain percentiles of
measured or calculated concentrations.
CO ...................................... carbon monoxide, a criteria air pollutant
CO2 ..................................... carbon dioxide, a greenhouse gas (GHG)
CO2e .................................... Greenhouse gas equivalents (emissions of GHGs expressed
in terms of their "global warning potential" compared to
CO2)
Criteria air pollutant .............. an air pollutant specifically governed by the Federal Clean Air
Act for which ambient air quality standards have been set.
Criteria air pollutants include carbon monoxide, particulate
matter, sulfur dioxide, nitrogen dioxide, ozone, and lead.
DEEP ................................... Diesel engine exhaust particulate matter – usually based on
stack sampling and therefore usually focused on directly
emitted particles that can be captured on filters. DEEP
therefore usually ignores condensable particles that form
with cooling and mixing with air. See also DPM.
Design value ......................... a statistical value representing a pollutant concentration that
describes the air quality status of a given location relative to
the level of the NAAQS. Design values are defined to be
consistent with the individual NAAQS. Design values are
typically used to designate and classify nonattainment areas,
as well as to assess progress towards meeting the NAAQS.
DPM .................................... Diesel particulate matter – sometimes a superset of DEEP
that includes both directly emitted particles and condensable
particles that form after mixing and cooling with air.
Ecology ................................ Washington State Department of Ecology
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Acronyms and Abbreviations iii Ramboll
EPA/USEPA ........................... US Environmental Protection Agency
Fugitive dust......................... Potential air pollutant in the form of dust (or other pollutant)
emitted from a non-point or non-mobile source such as dust
from a road or from a storage pile caused by wind
GHG .................................... Greenhouse gas (e.g., carbon dioxide, methane, NO2) that
contributes to the process of a gradual warming of the
atmosphere that can result in global climate change
Global warming potential........ A measure of the potential of a gas to have an effect that
could lead to climate change due to prolonged residence time
in the atmosphere. This is a standard measure, typically
based on a 100-year time horizon, used to compare GHGs
with the global warming potential of carbon dioxide (CO2),
the most abundant GHG.
Maintenance area .................. an area that was once designated as nonattainment that has
since come into compliance with the ambient air quality
standard but where air quality control measures may remain
in effect (in perpetuity).
Metric ton............................. 1,000 kilograms (kg) = 2,204.6 pounds = tonne (see also
short ton and long ton)
MSAT ................................... Mobile source air toxics are air pollutants from mobile
sources, such as vehicles. Of the 188 air toxics that EPA
regulates, 93 compounds were identified as emitting from
mobile sources. EPA has identified 9 of these compounds as
significant contributors to the national and regional-scale
cancer risk drivers.
MTCO2e ................................ metric tons of greenhouse gas equivalents. See also CO2e.
NAAQS ................................. National Ambient Air Quality Standard
NO2 ..................................... nitrogen dioxide, a criteria air pollutant
Nonattainment area ............... an area delineated by regulatory agencies including US EPA
and the Washington Department of Ecology in which an
ambient air quality standards have been violated and where
there is a program in place designed to reduce air pollution
so that the standard attained.
NOx ..................................... oxide of nitrogen, a general class of air pollutant without a
specific air quality standard but used in monitoring air quality
Particulate matter (PM) .......... air pollutant comprised of solid or liquid particles; PM is
usually characterized based on the particle size. See also
PM10 and PM2.5.
PSCAA ................................. Puget Sound Clean Air Agency; the designated local air
quality control agency in the project area
PM10 .................................... "Coarse" inhalable particulate matter with an aerodynamic
size less than or equal to 10 micrometers (microns)
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Acronyms and Abbreviations iv Ramboll
PM2.5 ................................... "Fine" inhalable particulate matter with an aerodynamic size
less than or equal to 2.5 micrometers (microns)
ppb ..................................... parts per billion (a metric used in quantifying concentrations
of air pollutants)
ppm .................................... parts per million (a metric used in quantifying concentrations
of air pollutants)
SO2 ..................................... Sulfur dioxide, a criteria air pollutant
TAP ..................................... Toxic air pollutant
tpy ...................................... tons per year, an estimate of annual emissions
µg/m3 .................................. micrograms per cubic meter (a metric used in quantifying
concentrations of air pollutants in terms of the mass per
volume of air)
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Introduction Ramboll
1. INTRODUCTION
1.1 Background and Project Description
Federal Way Campus, LLC is proposing to develop a general commodity warehouse on 16.9
acres of land zoned CP-01 within the City of Federal Way, Washington. The proposed
Greenline Building “B” Development (the Project) will be approximately 214,050 square feet
in size and will include accessory parking for up to 245 vehicles. Commercial vehicle ingress
and egress access will occur off Weyerhaeuser Way South, near the interchange ramps for
Highway SR 18 (SR 18). A 50-foot wide managed forest buffer will run along the property
boundary adjacent to Weyerhaeuser Way South, where it forms the boundary of the CP-01
zone and then widen to 100-feet where adjacent SR 18.
At the time of this analysis, the exact use of the warehouse had not been established.
However, it is anticipated that the warehouse will be used for general commodities that do
not require cold storage. Furthermore, the warehouse will not include processing or
manufacturing facilities. Sources of air pollution typical of a general commodities
warehouse include emergency generators and vehicles used by employee commuter trips
and truck deliveries.
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Affected Environment Ramboll
2. AFFECTED ENVIRONMENT
2.1 Regulatory Overview
Air quality is generally assessed in terms of whether concentrations of air pollut ants are
higher or lower than ambient air quality standards established to protect human health and
welfare. Three agencies have jurisdiction over ambient air quality in the project area: the
U.S. Environmental Protection Agency (EPA), the Washington Department of Ecology
(Ecology), and the Puget Sound Clean Air Agency (PSCAA). These agencies establish
regulations that govern both the concentrations of pollutants in the outdoor air and
contaminant emissions from air pollution sources. Although their regulations are similar in
stringency, each agency has established its own standards. Unless the state or local
jurisdiction has adopted more stringent standards, the EPA standards pertain.
To track air quality conditions over time, Ecology and PSCAA maintain a network of
monitoring stations throughout the Puget Sound region. These stations are typically located
where air quality problems may be expected to occur, and so are usually in or near urban
areas or close to specific large air pollution sources. Other stations are used to indicate
regional air pollution levels. Based on monitoring information collected over a period of
years, the EPA and Ecology designate regions as being "attainment" or "nonattainment" for
particular air pollutants. Attainment status is therefore a benchmark of whether air quality
in an area complies with the National Ambient Air Quality Standard (NAAQS) for one or
more "criteria" air pollutants. (1) Regions that were once designated nonattainment that
have since attained the standard are considered air quality "maintenance" areas through
two 10-year cycles of review, after which the area achieves "attainment" if the ambient
standards have been maintained.
The project area is located in the former King County CO and Ozone maintenance area s, but
as of 2017 these areas are considered to be in attainment. Pertinent air pollutants are
discussed in greater detail below. A complete list of local, state, and federal ambient air
quality standards are displayed in Table 1.
(1) The criteria air pollutants are particulate matter, CO, SO2, NO2, ozone, and lead.
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Table 1: Applicable Ambient Air Quality Standards for Criteria Pollutants
Pollutant Terms of Compliance (a) Concentration
Inhalable Particulate Matter
(PM10)
24-Hour Average (µg/m3)
Not to be exceeded more than once per
year, averaged over 3 years
150 µg/m3
Fine Particulate Matter (PM2.5)
Annual Average (µg/m3)
24-Hour Average (µg/m3)
The 3-year average of the annual mean
must not exceed
The 3-year average of the 98th percentile
of daily concentrations must not
exceed
12 µg/m3
35 µg/m3
Carbon Monoxide (CO)
8-Hour Average (ppm)
1-Hour Average (ppm)
The 8-hour average must not exceed more
than once per year
The 1-hour average must not exceed more
than once per year
9 ppm
35 ppm
Ozone (O3)
8-Hour Average (ppm)
The 3-year average of the 4th highest
daily maximum 8-hour average must
not exceed
0.07 ppm
Note: µg/m3 = micrograms per cubic meter; ppm = parts per million
(a) All limits are federal and state air quality standards and represent “primary” air quality
standards intended to protect human health.
2.2 Existing Air Quality
2.2.1 Carbon Monoxide
Carbon monoxide is a by-product of incomplete combustion. CO is generated by vehicular
traffic and other fuel-burning activities, such as residential space heating, especially space
heating using solid fuels such as coal or wood. There are two short-term air quality
standards for CO: a 1-hour average standard of 35 ppm and an 8 hour average standard of
9 ppm.
The impacts of CO are usually localized near the source(s), with the highest ambient
concentrations typically occurring near congested roadways and intersections during periods
of cold temperatures (autumn and winter months), light winds, and stable atmospheric
conditions. Such weather conditions reduce the atmospheric mechanisms that disperse and
dilute pollutants.
The project area is located within the former Puget Sound region CO nonattainment area
(established in 1991) that encompassed a large portion of Everett -Seattle-Tacoma urban
area. By 1996, CO levels in King County had improved and the area was redesignated as a
maintenance area for CO, following EPA approval of the State's Implementation Plan (SIP).
SIPs are prepared to ensure an area will meet the NAAQS for a 20 -year period through the
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adoption of two 10-year maintenance plans. The Washington State SIP for King County
included annual CO emissions budgets and programs for the 20-year period, ending in
October 2016. During the 20-year maintenance period, King County met the annual CO
emissions budgets and monitoring stations did not measure any CO concentrations
exceeding the NAAQS. Therefore, the study area located within King County is now
considered in attainment for CO. (2)
2.2.2 Ozone
Ozone is a reactive form of oxygen created by sunlight-activated chemical transformations
of nitrogen oxides and volatile organic compounds (hydrocarbons) in the atmosphere.
Ozone problems tend to be regional in nature because the atmospheric chemical reactions
that produce ozone occur over a period of time, during which ozone precursors can be
transported far from their sources. Transportation sources like automobiles and trucks are
among the sources that produce ozone precursors.
In the past, due to violations of the federal 1-hour ozone standard, the Puget Sound region
was designated as nonattainment for ozone. In 1997, EPA determined that the Puget Sound
ozone nonattainment area had attained the health-based ozone standard in effect at that
time. EPA then reclassified the Puget Sound region as attainment for ozone and approved
the associated air quality maintenance plan. In 2005, EPA revoked the 1-hour ozone
standard in most areas of the US including the Puget Sound region, which ended the ozone
maintenance status of this region. In March of 2008, the EPA adopted a new more stringent
8-hour average ozone standard of 75 parts per billion (ppb). The 8-hour standard was later
strengthened to 70 ppb for most areas, effective December 2015. (3)
Based on ozone measurements over the last few years, the Puget Sound region may again
be on the brink of becoming nonattainment for ozone. Under present plans and policies, the
ozone attainment/nonattainment status of the area would have no direct effects on the
proposed project.
2.2.3 Inhalable Particulate Matter – PM10 and PM2.5
Particulate matter air pollution is comprised of particles either emitted directly into the air
(e.g., dust) or formed when hot gases cool and condense. Such air pollution is generated
primarily by industrial activities and operations involving fuel combustion and material
handling, and by other fuel combusti on sources like motor vehicle engines, vessel engines,
and residential wood burning. Federal, state, and local regulations set limits for particle
concentrations in the air (i.e., weight per unit volume) based on the size of the particles and
(2) Based on conversations with Joanna Ekrem, State Implementation Planning, Washington State
Department of Ecology (January 2017).
(3) 80 Fed. Reg. 65,292 (Oct. 26, 2015).
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the related potential threat to health. When first regulated, particle pollution limits were
based on "total suspended particulate," which included all size fractions. As sampling
technology improved and the importance of particle size and chemical composition became
more apparent, ambient standards were revised to focus on the size fractions thought to be
most dangerous to human health. Based on the most recent studies, EPA has redefined the
size fractions and set new, more stringent standards for particulate matter ba sed on fine
and coarse inhalable particulate matter to focus control efforts on the smaller size fractions.
There are currently health-based ambient air quality standards for PM10, or particles less
than or equal to about 10 micrometers (microns) in diameter, as well as for PM2.5, or
particulate matter less than or equal to 2.5 microns in diameter. The latter size fraction and
even smaller (ultra-fine) particles are now considered the most dangerous size fractions of
airborne particulate matter because such small particles (e.g. a typical human hair is about
100 microns in diameter) can be breathed deeply into lungs. In addition, such particles are
often associated with toxic substances that are deleterious in their own right that can
adsorb to the particles and be carried into respiratory system.
With the revocation of the federal annual standard for PM10 in October 2006, the focus of
ambient air monitoring and control efforts related to particle air pollution in the Puget Sound
region has been almost entirely on fine particulate matter (PM2.5). The nearest PM2.5
nonattainment area to the Project site encompasses Tacoma and surrounding lowland areas
in Pierce County. (4) However, the Project site is not in this area and is considered to be in
attainment of the PM2.5 standards.
2.2.4 Greenhouse Gases and Global Climate Change
The phenomenon of natural and human-caused effects on the atmosphere that cause
changes in long-term meteorological patterns is known as climate change. Due to the
importance of the greenhouse effect and related atmospheric warming to climate change,
the gases that affect such warming are called greenhouse gasses (GHGs). The GHGs of
primary importance are CO2, methane, and nitrous oxide. Because CO2 is the most
abundant of these gases, GHGs are usually quantified in terms of CO2e (carbon dioxide
equivalent), based on their relative longevity in the atmosphere and the related "global
warming potential" of these constituents. CO2 is not considered an air "pollutant" that
causes direct health-related effects, so it is not subject to ambient air quality standards
used to gauge pollutant concentrations in the air.
(4) Additional information, including maps of the Tacoma-Pierce County nonattainment area can be
found at https://ecology.wa.gov/Regulations-Permits/Plans-policies/State-implementation-
plans/Maintenance-SIPs.
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Fuel combustion used for transportation is a significant source of GHG emissions, primarily
through the burning of gasoline and diesel fuels. National estimates indicate the
transportation sector (including on-road, construction, airplanes, and vessels) accounts for
about 31 percent of total domestic CO2e emissions from fossil fuels in 2014. (5) The
Washington State GHG emissions inventory for 2010-2013 reported that transportation
accounts for 43 percent of statewide GHG emissions; (6) the higher percentage is due to
lower GHG emissions from electrical generation because the state relies heavil y on
hydropower for electricity.
No specific federal, state, or local emission reduction requirements or targets are applicabl e
to the proposed Project, and there are no generally accepted emission level thresholds
against which to assess potential localized or global consequences of GHG emissions. In the
Washington State GHG emissions inventory for 2010-2013, Ecology estimated state-wide
annual GHG emissions in 2013 at about 94 million MTCO2e. (6) Estimated annual worldwide
GHG emissions for 2010 were about 46 billion MTCO2e. (7) The GHG emissions associated
with project operation were analyzed in this report using the King County Dep artment of
Development and Environmental Services SEPA GHG Emissions Worksheet. (8)
2.3 Local Climate and Terrain
Weather is one of several variables that influence air quality, with wind (speed and
direction) and atmospheric stability being two major factors that affect dispersion. Periods
with stable high-pressure systems and periods that include nighttime thermal inversions due
to the low solar heating of the land in winter create stable atmospheric conditions. It is
during these very stable atmospheric conditions when little vertical dispersion occurs, and
high concentrations of air pollutants emitted at ground level typically occur. Ground -level
emitted pollutants include CO from motor vehicles and particulate matter from vehicles and
wood stoves.
In the Puget Sound region, summers are cool and comparatively dry and winters are mild,
wet, and cloudy. The winter months are dominated by a stronger south wind and frequent
precipitation. Annual average precipitation in the region is around 38 inches. Annual mean
temperature in the urban areas of Seattle/Tacoma is about 53°F. The annual mean wind
speed is about seven mph, with a predominately southerly wind direction (i.e., from the
(5) Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2014, April 2016,
https://www.epa.gov/sites/production/files/2016-04/documents/us-ghg-inventory-2016-chapter-3-
energy.pdf.
(6) https://ecology.wa.gov/Research-Data/Scientific-reports/Statewide-greenhouse-gas-inventory
(7) https://www.epa.gov/climate-indicators/climate-change-indicators-global-greenhouse-gas-
emissions
(8) The King County Department of Development and Environmental Services SEPA GHG Emissions
Worksheet, accessed December 2017, is available at: https://www.kingcounty.gov/depts/permitting-
environmental-review/info/SiteSpecific/ClimateChange.aspx
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south). The Puget Sound Clean Air Agency (PSCAA) maintains records of wind data, and
wind roses are available on their web site at: (http://pscleanair.org/154/Air-Quality-Data).
However, PSCAA does not measure wind parameters near the project area.
In some instances terrain can also influence air quality. While the greater Puget Sound area
is located between mountainous terrains, the study area includes low level hills and is
located less than four miles from Puget Sound.
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Air Quality Impacts Ramboll
3. AIR QUALITY IMPACTS
3.1 Impacts during Construction
Construction of the proposed project could temporarily change localized air quality. For
example, dust from construction activities would contribute to ambient concentrations of
suspended particulate matter. Construction contractor(s) would have to comply with the
PSCAA regulations requiring all reasonable precautions be taken to minimize fugitive dust
emissions.
Construction would require the use of heavy trucks and smaller equipment such as
generators and compressors. These engines would emit air pollutants that would slightly
degrade local air quality. There is little or no danger of these emissions resulting in pollutant
concentrations that would exceed a health-based ambient air quality standard. Nonetheless,
emissions from construction equipment, and especially from diesel-fueled engines, are
coming under increasing scrutiny because of their suspected risk to human health , and
pollution control agencies are now urging that emissions from diesel -powered equipment be
minimized to the extent practicable in order to reduce potential health risks.
Some phases of construction would cause odors detectable to some people in the area. This
would be particularly true during paving operations using asphalt. The construction
contractor(s) would have to comply with the PSCAA regulations during activities that emit
odor bearing air contaminants. Such odors from paving operations would be short term.
Construction equipment and material hauling can affect traffic flow in a project area. Given
that there is heavy traffic during some periods of the day, scheduling haul traffic during off
peak times (e.g., between 9 a.m. and 4 p.m.) would have the least effect on other traffic
and would minimize indirect increases in traffic related emissions.
With implementation of required measures to provide reasonable controls of dust and odors,
construction of the proposed project would not be expected to result in significant air quality
impacts.
3.2 Impacts during Operation
3.2.1 Traffic-Related Air Quality
The Project would result in new vehicular traffic to and from the facility that would increase
traffic in the Project vicinity and result in increased traffic-related emissions. To assess and
quantify the potential for localized air quality impacts due to this increase in traffic-related
emissions, projected future traffic conditions with and without the project were evaluated
using the Washington State Intersection Screening Tool (WASIST). This analysis focused on
the potential for carbon monoxide (CO) emissions to cause l ocalized “hot spots” based on
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EPA guidance. (9) EPA guidance recommends screening for intersections with “level of
service” (LOS) “D” or worse because longer traffic delays have a greater potential to result
in CO air quality impacts. This hot spot review evaluated signalized intersections in the
vicinity of the Project that would be most affected by Project-related traffic during peak-
hour periods.
LOS and per-vehicle delay for the AM and PM peak periods are provided in Table 2.
Projected intersection conditions indicate the Weyerhaeuser Way S and SR-18 ramp
intersections would perform worse during the PM peak period. Therefore, the PM peak-
period traffic conditions were used to screen for CO air quality impacts where concentrati ons
might exceed the health-protective ambient air quality standards.
Table 2. Peak-Period Signalized Intersection Conditions
Signalized
Intersection
Existing (2017) 2020 No Build(a) 2020 Build
LOS Delay (sec) LOS Delay (sec) LOS Delay (sec)
AM Peak Period
Weyerhaeuser Way S
/ SR-18 WB Ramps C 29.0 D 48.3 D 41.0
Weyerhaeuser Way S
/ SR-18 EB Ramps B 16.6 B 18.9 C 20.5
PM Peak Period
Weyerhaeuser Way S
/ SR-18 WB Ramps D 44.5 D 51.6 D 53.1
Weyerhaeuser Way S
/ SR-18 EB Ramps C 33.1 C 34.0 D 36.6
Notes:
(a) Traffic data obtained from 2019 With-Project (With Building A Only) from Traffic Impact Analysis.
Source: Level of service (LOS) and delay provided by Transportation Engineering NorthWest, 2018.
For additional information, refer to the Traffic Impact Analysis memorandum.
Air quality screening modeling was conducted using the latest version of the WSDOT
WASIST tool. (10) This screening modeling tool applies worst-case assumptions to estimate
CO concentrations at nearby locations. This model uses vehicle emission factors estimated
using the latest available tool from the EPA, the MOVES2014 model. (11) WASIST also
(9) U.S. Environmental Protection Agency (U.S. EPA). 1992. Guideline for Modeling Carbon Monoxide
from Roadway Intersections. Office of Air Quality Planning and Standards. Technical Support Division.
Research Triangle Park, North Carolina. EPA-454/R-92-005.
(10) Washington State Intersection Screening Tool (WASIST) Version 3.0, Washington State
Department of Transportation, June 2015.
(11) Jim Laughlin, WSDOT Air, Noise, and Energy Program Technical Manager, email of 5/18/2015
announcing the release of WASIST 3.0
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includes a selection of preconfigured intersections, including three options for intersections
with one-way streets. The one-way "2 x 2 w/1 Lt Turn" intersection type was selected as
the best fit for the Weyerhaeuser Way S and SR-18 ramp intersections. Near-road receptors
were placed along both sides of each roadway at 3, 25, 50, and 100 meters from cross
streets, 3 meters from the nearest traffic lane, and 1.8 meters above the ground (i.e.,
typical sidewalk locations at breathing height).
The WASIST modeling results are listed in Table 3. As shown under assumed worst-case
conditions, modeling results indicate CO concentrations near the most congested
intersections in the Project study area would be far less than the 35 ppm 1-hour and 9 ppm
8-hour health based ambient air quality standards. Model results also demonstrate that at
these intersections, Project-related traffic would not increase CO concentrations over future
No Build conditions. These findings indicate that the Project would not likely cause or
contribute to any significant traffic-related air quality impacts.
Table 3. WASIST Calculated PM Peak-Period CO Concentrations
Signalized
Intersection
Averaging
Period
Existing (2017) 2020 No Build(a) 2020 Build
Concentration
(ppm)
Concentration
(ppm)
Concentratio
n (ppm)
Weyerhaeuser Way S /
SR-18 WB Ramps
1-Hour 5.6 5.6 5.6
8-Hour 5.4 5.4 5.4
Weyerhaeuser Way S /
SR-18 EB Ramps
1-Hour 5.9 5.6 5.6
8-Hour 5.6 5.4 5.4
Notes:
Model concentrations include a 5-ppm background to reflect the potential contribution from other traffic or
sources in the vicinity. This is a very conservative assumption.
(a) Modeled for 2020 and based on 2019 traffic volumes
Source: Ramboll, based on modeling using the WSDOT WASIST tool
3.2.2 Emergency Equipment
One or more emergency generators may be required to ensure safe and consistent
operation of the Project. Emissions associated with emergency generators result from the
combustion of fossil fuels and would occur during emergency use or routine testing of the
generators.
PSCAA Regulation I, Section 6.0(c) exempts some sources of air pollution from Notice of
Construction applications and Order of Approvals. Sources defined in 6.03(c) are not
expected to cause or contribute to local air quality impacts. Stationary internal combustion
engines, including emergency generators, with less than 50 horsepower output or those that
are operated less than 500 hours per year are included in these exemptions. If the Project
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identifies a need for larger emergency engines or engines that operate more than 500 hours
per year, a permit would be required to ensure the emissions would not cause or contribute
to an air quality impact.
3.2.3 Mobile Source Air Toxics (MSATs)
In addition to the "criteria" air pollutants like CO discussed above, there a re a variety of
other potentially hazardous air pollutants for which health-based ambient air quality
standards have not been established. Of the identified hazardous air pollutants, some have
been designated as mobile source air toxics (MSATs). MSATs are emitted by on-road and
off-road vehicles with internal combustion engines burning biofuels, diesel, or gasoline. Of
these vehicles, heavy-duty diesel trucks are the largest contributor of MSATs. Actual data
related to potential effects of MSATs as well as the mechanisms related to analyzing
dispersion of MSATs are incomplete or unavailable, so specific analyses of these substances
are not as yet typically performed. However, the FHWA has released interim guidance for
considering during the process of NEPA evaluations for transportation projects subject to
FHWA review. While the Project is not subject to FHWA review, FHWA guidance for
screening level review for MSATs was applied in the event there is interest or concern
regarding such emissions related to thi s project.
The traffic impact analysis indicates a total of 954 daily passenger and truck trips (477
inbound, 477 outbound) would result due to the Project. The daily project-related traffic
volumes are far fewer than the 140,000 to 150,000 annual average daily traffic (AADT)
threshold that FHWA states may result in a higher potential for MSAT effects. In addition,
MSAT emissions in future years are expected to decline compared with existing levels of
emissions as a result of national emission control programs. For example, FHWA projects
MSAT reductions from on-highway vehicles of 90 percent between 2010 and 2050. (12)
3.2.4 Greenhouse Gas Emissions
The GHG emissions associated with the proposed development were calculated using King
County’s SEPA GHG Emissions Worksheet. King County’s GHG worksheet estimates all GHG
emissions that are created over the life span of a project from construction materials, fuel
used during construction, energy consumed during a building operation, and transportation
by building occupants.
Note that is analysis does not quantify or consider any potential efforts to reduce either
GHG emissions or resource consumption by incorporating sustainable features into the
development. However, it is assumed that sustainable features would be incorporated into
(12) Federal Highway Administration (FHWA). 2016. Updated Interim Guidance on Air Toxic Analysis in
NEPA Documents. Web Page Accessed June 2018:
https://www.fhwa.dot.gov/environment/air_quality/air_toxics/policy_and_guidance/msat/.
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the Project to reduce such impacts. These sustainable features would be considered in the
approach to the design of buildings, and in ongoing site programming and management.
The results are presented in Table 4.
Table 4: Estimated Greenhouse Gas Emissions (MTCO2e)
Components Area
(sq.ft.)
Lifespan
Emissions(a)
Annual
Emissions(b)
Warehouse and Storage(c) 214,050 122,382 1,958
Notes:
(a) Estimated of lifecycle emissions are based on an assumed average useful life of about 62.5
years for all types of structures that are not considered residential. These emissions are
reported in MTCO2e representing to metric tons (tonnes) of carbon dioxide equivalent, or
2,204.62 pounds of CO2. This metric is a standard measure of CO2 equivalent emissions that
include CO2 and other GHGs.
(b) Annual emissions estimates are based on dividing total emissions by assumed facility useful
lifespan as indicated in note (a) above.
(c) Defined as buildings used to store goods, manufactured products, merchandise, raw materials,
or personal belongings (such as self-storage).
Source: Ramboll
The Project is expected to produce about 122,000 metric tons (tonnes) of CO2 equivalent
(MTCO2e) over a 62.5 year lifespan. Annually this corresponds to about 2,000 tonnes. To
put these values into context, in the Washington State GHG emission inventory for 2010 -
2013 (as mentioned in section as mentioned in section 2.2.4), Ecology estimated state-wide
annual GHG emissions in 2013 were about 94 million MTCO2e. Estimated annual worldwide
GHG emissions for 2010 were about 46 billion MTCO2e. Thus, the Project annual GHG
emissions represents approximately 0.002 percent of estimated annual 2013 GHG emissions
within Washington, and much smaller percentages of worldwide emissions.
It is important to note that the scale of global climate change is so large that the impacts
from one project, no matter the size, would almost certainly have no discernible effect on
increasing or decreasing global climate change. In reality, any such effects can only be
considered on a “cumulative” basis. It is, therefore, appropriate to conclude that the
Project’s GHG emissions would combine with emissions across the City, County, State,
nation, and planet to cumulatively contribute to increases or decreases in the rate and
effects of global climate change.
And to reiterate, the estimates the Project GHG emissions do not consider any potential
efforts to reduce GHG emissions and/or resource consumption by incorporating sustainable
features into the development, although such sustainable features would be incorporated
into the Project by virtue of the City and State Building and Energy Code requirements and
likely use of green building technologies.
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The GHG emissions associated with the Project would contribute to the cumulative carbon
footprint of King County. No significant climate change impacts would be expected due to
project-related GHG emissions.
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4. MITIGATION
4.1 Mitigation during Construction
The construction contractor(s) would be required to comply with all relevant federal, state,
and local air quality laws, and would be required to control dust and odors sufficiently to
comply with PSCAA regulations. The Washington Associated General Contractors brochure
Guide to Handling Fugitive Dust from Construction Projects and PSCAA suggest a number of
methods for controlling dust and reducing the potential exposure of people to emissions
from diesel equipment. The following is a list of possible mitigation measures that could be
implemented to reduce potential air quality impacts during construction of the project.
• Use only equipment and trucks that are maintained in optimal operational condition
• Require all off road equipment to be retrofit wi th emission reduction equipment
(i.e., require participation in Puget Sound region Diesel Solutions by project sponsors
and contractors), including particulate matter traps and oxidation catalysts to reduce
MSATs
• Use biodiesel or other lower-emission fuels for vehicles and equipment
• Use carpooling or other trip reduction strategies for c onstruction workers
• Stage construction to minimize overall transportation system congestion and delays
to reduce regional emissions of pollutants during construction
• Implement restrictions on construction truck idling (e.g., limit idling to a maximum of
5 minutes)
• Locate construction equipment away from sensitive receptors such as fresh air
intakes to buildings, air conditioners, and sensitive populations
• Locate construction staging zones where diesel emissions won't be noticeable to the
public or near sensitive populations such as the elderly and the young
• Spray exposed soil with water or other suppressant to reduce emissions of PM 10 and
deposition of particulate matter
• Pave or use gravel on staging areas and roads that would be exposed for long
periods
• Cover all trucks transporting materials, wet materials in trucks, or provide adequate
freeboard (space from the top of the material to the top of the truck bed), to reduce
PM10 emissions and deposition during transport
• Provide wheel washers to remove particulate matter that would otherwise be carried
off site by vehicles to decrease deposition of particulate matter on area roadways
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• Remove particulate matter deposited on paved, public roads, sidewalks, and bicycle
and pedestrian paths to reduce mud and dust; sweep and wash streets continuously
to reduce emissions
• Cover dirt, gravel, and debris piles as needed to reduce dust and wind blown debris
• Route and schedule construction trucks to reduce delays to traffic during peak travel
times to reduce air quality impacts caused by a reduction in traffic speeds
4.2 Mitigation during Operation
The analyses described above indicate the proposed project would be unlikely to result in
any significant adverse air quality impacts. Consequently, no operational mitigation
measures are warranted or proposed.
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Conclusion Ramboll
5. CONCLUSION
With the appropriate application of some or all of the mitigation measures described above
and consistent use of best management practices, no significant air quality impacts are
expected with the proposed warehouse facility in Federal Way, Washington.