PC - Item 3A - Exhibit E - Appendix A - Walnut Grove Mixed Use Air Quality Report
AIR QUALITY and GHG IMPACT ANALYSES
GARVEY WALNUT MIXED USE PROJECT
CITY OF ROSEMEAD, CALIFORNIA
Prepared by:
Giroux & Associates
5319 University Drive, #26
Irvine, CA. 92612
Prepared for:
Phil Martin & Associates
Attn: Phil Martin
1809 E. Dyer Road, Suite 301
Santa Ana, CA 92705
Date:
November 23, 2020
Project No.: P20-024 AQ
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ATMOSPHERIC SETTING
The climate of the Rosemead area, as with all of Southern California, is governed largely by the
strength and location of the semi-permanent high pressure center over the Pacific Ocean and the
moderating effects of the nearby vast oceanic heat reservoir. Local climatic conditions are
characterized by very warm summers, mild winters, infrequent rainfall, moderate daytime on-
shore breezes, and comfortable humidities. Unfortunately, the same climatic conditions that create
such a desirable living climate combine to severely restrict the ability of the local atmosphere to
disperse the large volumes of air pollution generated by the population and industry attracted in
part by the climate.
Rosemead is situated in an area where the pollutants generated in coastal portions of the Los
Angeles basin undergo photochemical reactions and then move inland across the project site during
the daily sea breeze cycle. The resulting smog at times gives the western San Gabriel Valley some
of the worst air quality in all of California. The worst air quality, however, has gradually been
moving eastward. The area of heaviest ozone air pollution has gradually moved eastward from
Pasadena in the 1960’s to Glendora and even Upland/Ontario in the 1990’s. Elevated smog levels
nevertheless persist in the Rosemead area during the warmer months of the year. Despite dramatic
improvement in air quality in the local area throughout the last several decades, the project site is
expected to continue to experience some unhealthful air quality until beyond 2020.
Temperatures in the project vicinity average 62 degrees Fahrenheit annually with summer
afternoons in the low 90’s and winter mornings in the low 40’s. Temperatures much above 100
or below 30 degrees occur infrequently only under unusual weather conditions and even then these
limits are not far exceeded.
In contrast to the slow annual variation of temperature, precipitation is highly variable seasonally.
Rainfall in the eastern portions of Los Angeles County averages 17 inches annually and falls
almost exclusively from late October to early April. Summers are very dry with frequent periods
of 4-5 months of no rain at all. Because much of the rainfall comes from the fringes of mid-latitude
storms, a shift in the storm track of a few hundred miles can mean the difference between a very
wet year and a year with drought conditions.
Winds across the project area are an important meteorological parameter because they control both
the initial rate of dilution of locally generated air pollutant emissions as well as their regional
trajectory. Local wind patterns show a fairly unidirectional daytime onshore flow from the SW-
W with a very weak offshore return flow from the NE that is strongest on winter nights when the
land is colder than the ocean. The onshore winds during the day average 6-8 mph, while the
offshore flow is often calm or drifts slowly westward at 1-3 mph. During the daytime, any locally
generated air emissions are thus transported eastward toward San Bernardino and Cajon Pass
without generating any localized air quality impacts.
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AIR QUALITY SETTING
AMBIENT AIR QUALITY STANDARDS (AAQS)
In order to gauge the significance of the air quality impacts of the proposed project, those impacts,
together with existing background air quality levels, must be compared to the applicable ambient
air quality standards. These standards are the levels of air quality considered safe, with an adequate
margin of safety, to protect the public health and welfare. They are designed to protect those
people most susceptible to further respiratory distress such as asthmatics, the elderly, very young
children, people already weakened by other disease or illness, and persons engaged in strenuous
work or exercise, called "sensitive receptors." Healthy adults can tolerate occasional exposure to
air pollutant concentrations considerably above these minimum standards before adverse effects
are observed. Recent research has shown, however, that chronic exposure to ozone (the primary
ingredient in photochemical smog) may lead to adverse respiratory health even at concentrations
close to the ambient standard.
National AAQS were established in 1971 for six pollution species with states retaining the option
to add other pollutants, require more stringent compliance, or to include different exposure periods.
The initial attainment deadline of 1977 was extended several times in air quality problem areas
like Southern California. In 2003, the Environmental Protection Agency (EPA) adopted a rule,
which extended and established a new attainment deadline for ozone for the year 2021. Because
the State of California had established AAQS several years before the federal action and because
of unique air quality problems introduced by the restrictive dispersion meteorology, there is
considerable difference between state and national clean air standards. Those standards currently
in effect in California are shown in Table 1. Sources and health effects of various pollutants are
shown in Table 2.
The Federal Clean Air Act Amendments (CAAA) of 1990 required that the U.S. Environmental
Protection Agency (EPA) review all national AAQS in light of currently known health effects.
EPA was charged with modifying existing standards or promulgating new ones where appropriate.
EPA subsequently developed standards for chronic ozone exposure (8+ hours per day) and for
very small diameter particulate matter (called "PM-2.5"). New national AAQS were adopted in
1997 for these pollutants.
Planning and enforcement of the federal standards for PM-2.5 and for ozone (8-hour) were
challenged by trucking and manufacturing organizations. In a unanimous decision, the U.S.
Supreme Court ruled that EPA did not require specific congressional authorization to adopt
national clean air standards. The Court also ruled that health-based standards did not require
preparation of a cost-benefit analysis. The Court did find, however, that there was some
inconsistency between existing and "new" standards in their required attainment schedules. Such
attainment-planning schedule inconsistencies centered mainly on the 8-hour ozone standard. EPA
subsequently agreed to downgrade the attainment designation for a large number of communities
to “non-attainment” for the 8-hour ozone standard.
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Table 1
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Table 1 (continued)
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Table 2
Health Effects of Major Criteria Pollutants
Pollutants Sources Primary Effects
Carbon Monoxide
(CO) • Incomplete combustion of fuels and other
carbon-containing substances, such as motor
exhaust.
• Natural events, such as decomposition of
organic matter.
• Reduced tolerance for exercise.
• Impairment of mental function.
• Impairment of fetal development.
• Death at high levels of exposure.
• Aggravation of some heart diseases (angina).
Nitrogen Dioxide
(NO2) • Motor vehicle exhaust.
• High temperature stationary combustion.
• Atmospheric reactions.
• Aggravation of respiratory illness.
• Reduced visibility.
• Reduced plant growth.
• Formation of acid rain.
Ozone
(O3) • Atmospheric reaction of organic gases with
nitrogen oxides in sunlight.
• Aggravation of respiratory and
cardiovascular diseases.
• Irritation of eyes.
• Impairment of cardiopulmonary function.
• Plant leaf injury.
Lead (Pb) • Contaminated soil. • Impairment of blood function and nerve
construction.
• Behavioral and hearing problems in children.
Respirable Particulate
Matter
(PM-10)
• Stationary combustion of solid fuels.
• Construction activities.
• Industrial processes.
• Atmospheric chemical reactions.
• Reduced lung function.
• Aggravation of the effects of gaseous
pollutants.
• Aggravation of respiratory and cardio
respiratory diseases.
• Increased cough and chest discomfort.
• Soiling.
• Reduced visibility.
Fine Particulate Matter
(PM-2.5) • Fuel combustion in motor vehicles,
equipment, and industrial sources.
• Residential and agricultural burning.
• Industrial processes.
• Also, formed from photochemical reactions
of other pollutants, including NOx, sulfur
oxides, and organics.
• Increases respiratory disease.
• Lung damage.
• Cancer and premature death.
• Reduces visibility and results in surface
soiling.
Sulfur Dioxide
(SO2) • Combustion of sulfur-containing fossil fuels.
• Smelting of sulfur-bearing metal ores.
• Industrial processes.
• Aggravation of respiratory diseases (asthma,
emphysema).
• Reduced lung function.
• Irritation of eyes.
• Reduced visibility.
• Plant injury.
• Deterioration of metals, textiles, leather,
finishes, coatings, etc.
Source: California Air Resources Board, 2002.
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Evaluation of the most current data on the health effects of inhalation of fine particulate matter
prompted the California Air Resources Board (ARB) to recommend adoption of the statewide
PM-2.5 standard that is more stringent than the federal standard. This standard was adopted in
2002. The State PM-2.5 standard is more of a goal in that it does not have specific attainment
planning requirements like a federal clean air standard, but only requires continued progress
towards attainment.
Similarly, the ARB extensively evaluated health effects of ozone exposure. A new state standard
for an 8-hour ozone exposure was adopted in 2005, which aligned with the exposure period for the
federal 8-hour standard. The California 8-hour ozone standard of 0.07 ppm is more stringent than
the federal 8-hour standard of 0.075 ppm. The state standard, however, does not have a specific
attainment deadline. California air quality jurisdictions are required to make steady progress
towards attaining state standards, but there are no hard deadlines or any consequences of non-
attainment. During the same re-evaluation process, the ARB adopted an annual state standard for
nitrogen dioxide (NO2) that is more stringent than the corresponding federal standard, and
strengthened the state one-hour NO2 standard.
As part of EPA’s 2002 consent decree on clean air standards, a further review of airborne
particulate matter (PM) and human health was initiated. A substantial modification of federal
clean air standards for PM was promulgated in 2006. Standards for PM-2.5 were strengthened, a
new class of PM in the 2.5 to 10 micron size was created, some PM-10 standards were revoked,
and a distinction between rural and urban air quality was adopted. In December, 2012, the federal
annual standard for PM-2.5 was reduced from 15 g/m3 to 12 g/m3 which matches the California
AAQS. The severity of the basin’s non-attainment status for PM-2.5 may be increased by this
action and thus require accelerated planning for future PM-2.5 attainment.
In response to continuing evidence that ozone exposure at levels just meeting federal clean air
standards is demonstrably unhealthful, EPA had proposed a further strengthening of the 8-hour
standard. A new 8-hour ozone standard was adopted in 2015 after extensive analysis and public
input. The adopted national 8-hour ozone standard is 0.07 ppm which matches the current
California standard. It will require three years of ambient data collection, then 2 years of non-
attainment findings and planning protocol adoption, then several years of plan development and
approval. Final air quality plans for the new standard are likely to be adopted around 2022.
Ultimate attainment of the new standard in ozone problem areas such as Southern California might
be after 2025.
In 2010 a new federal one-hour primary standard for nitrogen dioxide (NO2) was adopted. This
standard is more stringent than the existing state standard. Based upon air quality monitoring data
in the South Coast Air Basin, the California Air Resources Board has requested the EPA to
designate the basin as being in attainment for this standard. The federal standard for sulfur dioxide
(SO2) was also recently revised. However, with minimal combustion of coal and mandatory use of
low sulfur fuels in California, SO2 is typically not a problem pollutant.
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BASELINE AIR QUALITY
Long-term air quality monitoring is carried out by the South Coast Air Quality Management
District (SCAQMD) at various monitoring stations. There are no nearby stations that monitor the
full spectrum of pollutants. Ozone, carbon monoxide, PM-2.5 and nitrogen oxides are monitored
at the Pico Rivera facility, while 10-micron diameter particulate matter (PM-10) is measured at the
Azusa station. Table 3 summarizes the last four years of monitoring data from a composite of these
data resources. The following conclusions can be drawn from this data:
a. Photochemical smog (ozone) levels occasionally exceed standards. The 8-hour state ozone
standard as well as the 1-hour state standard have been exceeded on less than two percent
of all days in the past four years. The 8-hour federal standard has been exceeded on less
than one percent of days for the same period. While ozone levels are still high, they are
much lower than 10 to 20 years ago. Attainment of all clean air standards in the project
vicinity is not likely to occur soon, but the severity and frequency of violations is expected
to continue to slowly decline during the current decade
b. Measurements of carbon monoxide have shown very low baseline levels in comparison to
the most stringent one- and eight-hour standards.
c. Respirable dust (PM-10) levels exceed the state standard on approximately 14 percent of
measurement days in the last four years, but the less stringent federal PM-10 standard has
not been violated once for the same period. Year to year fluctuations of overall maximum
24-hour PM-10 levels seem to follow no discernable trend.
d. A substantial fraction of PM-10 is comprised of ultra-small diameter particulates capable
of being inhaled into deep lung tissue (PM-2.5). There have been only three violations of
the maximum 24-hour concentration of all measurement days in the last four years. PM-
2.5 can be an occasional air quality concern in the project area.
Although complete attainment of every clean air standard is not yet imminent, extrapolation of the
steady improvement trend suggests that such attainment could occur within the reasonably near
future.
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Table 3
Air Quality Monitoring Summary (2016-2019)
(Number of Days Standards Were Exceeded, and
Maximum Levels During Such Violations)
Pollutant/Standard 2016 2017 2018 2019
Ozone
1-Hour > 0.09 ppm (S) 9 7 3 5
8-Hour > 0.07 ppm (S) 6 9 5 7
8- Hour > 0.075 ppm (F) 2 4 2 3
Max. 1-Hour Conc. (ppm) 0.11 0.12 0.12 0.108
Max. 8-Hour Conc. (ppm) 0.08 0.09 0.08 0.09
Carbon Monoxide
1-Hour > 20. ppm (S) 0 0 0 0
1-Hour > 9. ppm (S, F) 0 0 0 0
Max 8-Hour Conc. (ppm) 1.7 2.2 1.8 1.9
Nitrogen Dioxide
1-Hour > 0.18 ppm (S) 0 0 0 0
Max. 1-Hour Conc. (ppm) 0.06 0.07 0.08 0.06
Respirable Particulates (PM-10)
24-Hour > 50 g/m3 (S) 12/60 6/55 10/60 4/61
24-Hour > 150 g/m3 (F) 0/60 0/55 060 0/61
Max. 24-Hr. Conc. (g/m3) 41. 83. 78. 82.
Fine Particulates (PM-2.5)
24-Hour > 35 g/m3 (F) 2/120 1/119 0/133 0/119
Max. 24-Hr. Conc. (g/m3) 46.6 49.5 35.4 29.6
S=State Standard
F=Federal Standard
Source: South Coast AQMD – Pico Rivera Air Monitoring Station for Ozone, CO, NOx and PM-2.5
Azusa Monitoring Station for PM-10
data: www.arb.ca.gov/adam/
AIR QUALITY PLANNING
The Federal Clean Air Act (1977 Amendments) required that designated agencies in any area of
the nation not meeting national clean air standards must prepare a plan demonstrating the steps
that would bring the area into compliance with all national standards. The SCAB could not meet
the deadlines for ozone, nitrogen dioxide, carbon monoxide, or PM-10. In the SCAB, the agencies
designated by the governor to develop regional air quality plans are the SCAQMD and the
Southern California Association of Governments (SCAG). The two agencies first adopted an Air
Quality Management Plan (AQMP) in 1979 and revised it several times as earlier attainment
forecasts were shown to be overly optimistic.
The 1990 Federal Clean Air Act Amendment (CAAA) required that all states with air-sheds with
“serious” or worse ozone problems submit a revision to the State Implementation Plan (SIP).
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Amendments to the SIP have been proposed, revised and approved over the past decade. The most
current regional attainment emissions forecast for ozone precursors (ROG and NOx) and for
carbon monoxide (CO) and for particulate matter are shown in Table 4. Substantial reductions in
emissions of ROG, NOx and CO are forecast to continue throughout the next several decades.
Unless new particulate control programs are implemented, PM-10 and PM-2.5 are forecast to
slightly increase.
The Air Quality Management District (AQMD) adopted an updated clean air “blueprint” in August
2003. The 2003 Air Quality Management Plan (AQMP) was approved by the EPA in 2004. The
AQMP outlined the air pollution measures needed to meet federal health-based standards for ozone
by 2010 and for particulates (PM-10) by 2006. The 2003 AQMP was based upon the federal one-
hour ozone standard which was revoked late in 2005 and replaced by an 8-hour federal standard.
Because of the revocation of the hourly standard, a new air quality planning cycle was initiated.
With re-designation of the air basin as non-attainment for the 8-hour ozone standard, a new
attainment plan was developed. This plan shifted most of the one-hour ozone standard attainment
strategies to the 8-hour standard. As previously noted, the attainment date was to “slip” from 2010
to 2021. The updated attainment plan also includes strategies for ultimately meeting the federal
PM-2.5 standard.
Because projected attainment by 2021 required control technologies that did not exist yet, the
SCAQMD requested a voluntary “bump-up” from a “severe non-attainment” area to an “extreme
non-attainment” designation for ozone. The extreme designation was to allow a longer time period
for these technologies to develop. If attainment cannot be demonstrated within the specified
deadline without relying on “black-box” measures, EPA would have been required to impose
sanctions on the region had the bump-up request not been approved. In April 2010, the EPA
approved the change in the non-attainment designation from “severe-17” to “extreme.” This
reclassification set a later attainment deadline (2024), but also required the air basin to adopt even
more stringent emissions controls.
Table 4
South Coast Air Basin Emissions Forecasts (Emissions in tons/day)
Pollutant 2015a 2020b 2025b 2030b
NOx 357 289 266 257
VOC 400 393 393 391
PM-10 161 165 170 172
PM-2.5 67 68 70 71
a2015 Base Year.
bWith current emissions reduction programs and adopted growth forecasts.
Source: California Air Resources Board, 2013 Almanac of Air Quality
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In other air quality attainment plan reviews, EPA had disapproved part of the SCAB PM-2.5
attainment plan included in the AQMP. EPA stated that the current attainment plan relied on PM-
2.5 control regulations that had not yet been approved or implemented. It was expected that a
number of rules that were pending approval would remove the identified deficiencies. If these
issues were not resolved within the next several years, federal funding sanctions for transportation
projects could result. The 2012 AQMP included in the current California State Implementation
Plan (SIP) was expected to remedy identified PM-2.5 planning deficiencies.
The federal Clean Air Act requires that non-attainment air basins have EPA approved attainment
plans in place. This requirement includes the federal one-hour ozone standard even though that
standard was revoked almost ten years ago. There was no approved attainment plan for the one-
hour federal standard at the time of revocation. Through a legal quirk, the SCAQMD is now
required to develop an AQMP for the long since revoked one-hour federal ozone standard. Because
the current SIP for the basin contains a number of control measures for the 8-hour ozone standard
that are equally effective for one-hour levels, the 2012 AQMP was believed to satisfy hourly
attainment planning requirements.
AQMPs are required to be updated every three years. The 2012 AQMP was adopted in early 2013.
An updated AQMP was required for completion in 2016. The 2016 AQMP was adopted by the
SCAQMD Board in March, 2017, and has been submitted the California Air Resources Board for
forwarding to the EPA. The 2016 AQMP acknowledges that motor vehicle emissions have been
effectively controlled and that reductions in NOx, the continuing ozone problem pollutant, may
need to come from major stationary sources (power plants, refineries, landfill flares, etc.) . The
current attainment deadlines for all federal non-attainment pollutants are now as follows:
8-hour ozone (70 ppb) 2032
Annual PM-2.5 (12 g/m3) 2025
8-hour ozone (75 ppb) 2024 (old standard)
1-hour ozone (120 ppb) 2023 (rescinded standard)
24-hour PM-2.5 (35 g/m3) 2019
The key challenge is that NOx emission levels, as a critical ozone precursor pollutant, are forecast
to continue to exceed the levels that would allow the above deadlines to be met. Unless additional
stringent NOx control measures are adopted and implemented, ozone attainment goals may not be
met.
The proposed project does not directly relate to the AQMP in that there are no specific air quality
programs or regulations governing mixed use development projects. Conformity with adopted
plans, forecasts and programs relative to population, housing, employment and land use is the
primary yardstick by which impact significance of planned growth is determined. The SCAQMD,
however, while acknowledging that the AQMP is a growth-accommodating document, does not
favor designating regional impacts as less-than-significant just because the proposed development
is consistent with regional growth projections. Air quality impact significance for the proposed
project has therefore been analyzed on a project-specific basis.
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AIR QUALITY IMPACT
STANDARDS OF SIGNIFICANCE
Air quality impacts are considered “significant” if they cause clean air standards to be violated
where they are currently met, or if they “substantially” contribute to an existing violation of
standards. Any substantial emissions of air contaminants for which there is no safe exposure, or
nuisance emissions such as dust or odors, would also be considered a significant impact.
Appendix G of the California CEQA Guidelines offers the following four tests of air quality impact
significance. A project would have a potentially significant impact if it:
a) Conflicts with or obstructs implementation of the applicable air quality plan.
b) Results in a cumulatively considerable net increase of any criteria pollutants for which the
project region is non-attainment under an applicable federal or state ambient air quality
standard.
c) Exposes sensitive receptors to substantial pollutant concentrations.
d) Creates objectionable odors affecting a substantial number of people.
Primary Pollutants
Air quality impacts generally occur on two scales of motion. Near an individual source of
emissions or a collection of sources such as a crowded intersection or parking lot, levels of those
pollutants that are emitted in their already unhealthful form will be highest. Carbon monoxide
(CO) is an example of such a pollutant. Primary pollutant impacts can generally be evaluated
directly in comparison to appropriate clean air standards. Violations of these standards where they
are currently met, or a measurable worsening of an existing or future violation, would be
considered a significant impact. Many particulates, especially fugitive dust emissions, are also
primary pollutants. Because of the non-attainment status of the South Coast Air Basin (SCAB)
for PM-10, an aggressive dust control program is required to control fugitive dust during project
construction.
Secondary Pollutants
Many pollutants, however, require time to transform from a more benign form to a more
unhealthful contaminant. Their impact occurs regionally far from the source. Their incremental
regional impact is minute on an individual basis and cannot be quantified except through complex
photochemical computer models. Analysis of significance of such emissions is based upon a
specified amount of emissions (pounds, tons, etc.) even though there is no way to translate those
emissions directly into a corresponding ambient air quality impact.
Because of the chemical complexity of primary versus secondary pollutants, the SCAQMD has
designated significant emissions levels as surrogates for evaluating regional air quality impact
significance independent of chemical transformation processes. Projects with daily emissions that
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exceed any of the following emission thresholds are recommended by the SCAQMD to be
considered significant under CEQA guidelines.
Table 5
Daily Emissions Thresholds
Source: SCAQMD CEQA Air Quality Handbook, November, 1993 Rev.
CONSTRUCTION ACTIVITY IMPACTS
CalEEMod was developed by the SCAQMD to provide a model by which to calculate both
construction emissions and operational emissions from a variety of land use projects. It calculates
both the daily maximum and annual average emissions for criteria pollutants as well as total or
annual greenhouse gas (GHG) emissions.
The project is proposing to develop the site with 42 condominium dwelling units, 5,470 square
feet of office space, 5,520 square feet for a community hall, 1,130 square feet of café/food service
space, 5,274 square feet of retail/service and ancillary uses including a recreation room, gym,
library, and manager’s office. The project will provide 204 parking spaces and the site is 1.057
acres. Construction was modeled in CalEEMod2016.3.2 using default construction equipment and
schedule for a project of this size as shown in Table 6.
Table 6
Construction Activity Equipment Fleet
Phase Name and Duration Equipment
Demolition (20 days)
1 Concrete Saw
1 Dozer
3 Loader/Backhoes
Grading (4 days)
1 Grader
1 Dozer
1 Loader/Backhoe
Construction (200 days)
1 Crane
1 Loader/Backhoe
3 Welders
Pollutant Construction Operations
ROG 75 55
NOx 100 55
CO 550 550
PM-10 150 150
PM-2.5 55 55
SOx 150 150
Lead 3 3
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1 Generator Set
1 Forklift
Paving (10 days)
1 Paver
1 Mixer
1 Paving Equipment
1 Loader/Backhoe
1 Roller
Utilizing this indicated equipment fleet and durations shown in Table 6 the following worst-case
daily construction emissions are calculated by CalEEMod and are listed in Table 7.
Table 7
Construction Activity Emissions
Maximum Daily Emissions (pounds/day)
Maximal Construction
Emissions ROG NOx CO SO2 PM-10 PM-2.5
2021
Unmitigated 54.2 20.0 18.6 0.0 5.6 3.1
Mitigated 54.2 20.0 18.6 0.0 2.9 1.7
SCAQMD Thresholds 75 100 550 150 150 55
Peak daily construction activity emissions are estimated be below SCAQMD CEQA thresholds
without the need for added mitigation. The only model-based mitigation measured applied for this
project was watering exposed dirt surfaces two times per day to minimize the generation of fugitive
dust generation during grading.
Construction equipment exhaust contains carcinogenic compounds within the diesel exhaust
particulates. The toxicity of diesel exhaust is evaluated relative to a 24-hour per day, 365 days per
year, 70-year lifetime exposure. The SCAQMD does not generally require the analysis of
construction-related diesel emissions relative to health risk due to the short period for which the
majority of diesel exhaust would occur. Health risk analyses are typically assessed over a 9-, 30-,
or 70-year timeframe and not over a relatively brief construction period due to the lack of health
risk associated with such a brief exposure.
LOCALIZED SIGNIFICANCE THRESHOLDS
The SCAQMD has developed analysis parameters to evaluate ambient air quality on a local level
in addition to the more regional emissions-based thresholds of significance. These analysis
elements are called Localized Significance Thresholds (LSTs). LSTs were developed in response
to Governing Board’s Environmental Justice Enhancement Initiative 1-4 and the LST
methodology was provisionally adopted in October 2003 and formally approved by SCAQMD’s
Mobile Source Committee in February 2005.
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Use of an LST analysis for a project is optional. For the proposed project, the primary source of
possible LST impact would be during construction. LSTs are applicable for a sensitive receptor
where it is possible that an individual could remain for 24 hours such as a residence, hospital or
convalescent facility.
LSTs are only applicable to the following criteria pollutants: oxides of nitrogen (NOx), carbon
monoxide (CO), and particulate matter (PM-10 and PM-2.5). LSTs represent the maximum
emissions from a project that are not expected to cause or contribute to an exceedance of the most
stringent applicable federal or state ambient air quality standard, and are developed based on the
ambient concentrations of that pollutant for each source receptor area and distance to the nearest
sensitive receptor.
LST screening tables are available for 25, 50, 100, 200- and 500-meter source-receptor distances.
For this project, there are adjacent residential uses such that the most conservative 25 meter
distance was modeled.
The SCAQMD has issued guidance on applying CalEEMod to LSTs. LST pollutant screening
level concentration data is currently published for 1, 2- and 5-acre sites for varying distances. For
this project, the most stringent thresholds for a 1-acre site were applied.
The following thresholds and emissions in Table 8 are therefore determined (pounds per day):
Table 8
LST and Project Emissions (pounds/day)
1.0 acre/25 meters
South San Gabriel Valley CO NOx PM-10 PM-2.5
LST Threshold 673 83 5 4
Max On-Site Emissions
Unmitigated 19 20 6 3
Mitigated 19 20 3 2
CalEEMod Output in Appendix
LSTs were compared to the maximum daily construction activities. As seen in Table 8, with active
dust suppression, mitigated emissions meet the LST for construction thresholds. LST impacts are
less-than-significant.
Therefore, the following construction mitigation measure is necessary to ensure LST thresholds
are maintained below significance thresholds:
• Exposed surfaces will be watered at least two times per day during grading activities
OPERATIONAL IMPACTS
The project would generate 1,009 daily trips using trip generation numbers provided in the project
traffic report. Operational emissions were calculated using CalEEMod2016.3.2 for an assumed
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full occupancy year of 2022. The operational impacts are shown in Table 9. As shown, operational
emissions will not exceed applicable SCAQMD operational emissions CEQA thresholds of
significance.
Table 9
Proposed Uses Daily Operational Impacts (2022)
Operational Emissions (lbs/day)
Source ROG NOx CO SO2 PM-10 PM-2.5
Area* 4.8 0.7 3.8 0.0 0.1 0.1
Energy 0.1 0.6 0.5 0.0 0.1 0.1
Mobile 1.4 6.7 15.8 0.1 4.5 1.2
Total 6.3 8.0 20.1 0.1 4.7 1.4
SCAQMD
Threshold 55 55 550 150 150 55
Exceeds Threshold? No No No No No No
*no wood burning fireplaces-only natural gas
Source: CalEEMod Output in Appendix
CONSTRUCTION EMISSIONS MINIMIZATION
Construction activities are not anticipated to cause dust emissions to exceed SCAQMD CEQA
thresholds. Nevertheless, emissions minimization through enhanced dust control measures is
recommended for use because of the non-attainment status of the air and proximity of residential
uses. Recommended measures include:
Fugitive Dust Control
• Apply soil stabilizers or moisten inactive areas.
• Water exposed surfaces as needed to avoid visible dust leaving the construction site
(typically 2-3 times/day).
• Cover all stock piles with tarps at the end of each day or as needed.
• Provide water spray during loading and unloading of earthen materials.
• Minimize in-out traffic from construction zone
• Cover all trucks hauling dirt, sand, or loose material and require all trucks to maintain at
least two feet of freeboard
• Sweep streets daily if visible soil material is carried out from the construction site
Similarly, ozone precursor emissions (ROG and NOx) are calculated to be below SCAQMD
CEQA thresholds. However, because of the regional non-attainment for photochemical smog, the
use of reasonably available control measures for diesel exhaust is recommended. Combustion
emissions control options include:
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Exhaust Emissions Control
• Utilize well-tuned off-road construction equipment.
• Establish a preference for contractors using Tier 3 or better rated heavy equipment.
• Enforce 5-minute idling limits for both on-road trucks and off-road equipment.
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GREENHOUSE GAS EMISSIONS
“Greenhouse gases” (so called because of their role in trapping heat near the surface of the earth)
emitted by human activity are implicated in global climate change, commonly referred to as
“global warming.” These greenhouse gases contribute to an increase in the temperature of the
earth’s atmosphere by transparency to short wavelength visible sunlight, but near opacity to
outgoing terrestrial long wavelength heat radiation in some parts of the infrared spectrum. The
principal greenhouse gases (GHGs) are carbon dioxide, methane, nitrous oxide, ozone, and water
vapor. For purposes of planning and regulation, Section 15364.5 of the California Code of
Regulations defines GHGs to include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons,
perfluorocarbons and sulfur hexafluoride. Fossil fuel consumption in the transportation sector (on-
road motor vehicles, off-highway mobile sources, and aircraft) is the single largest source of GHG
emissions, accounting for approximately half of GHG emissions globally. Industrial and
commercial sources are the second largest contributors of GHG emissions with about one-fourth
of total emissions.
California has passed several bills and the Governor has signed at least three executive orders
regarding greenhouse gases. GHG statues and executive orders (EO) include AB 32, SB 1368,
EO S-03-05, EO S-20-06 and EO S-01-07.
AB 32 is one of the most significant pieces of environmental legislation that California has
adopted. Among other things, it is designed to maintain California’s reputation as a “national and
international leader on energy conservation and environmental stewardship.” It will have wide-
ranging effects on California businesses and lifestyles as well as far reaching effects on other states
and countries. A unique aspect of AB 32, beyond its broad and wide-ranging mandatory provisions
and dramatic GHG reductions are the short time frames within which it must be implemented.
Major components of the AB 32 include:
• Require the monitoring and reporting of GHG emissions beginning with sources or
categories of sources that contribute the most to statewide emissions.
• Requires immediate “early action” control programs on the most readily controlled GHG
sources.
• Mandates that by 2020, California’s GHG emissions be reduced to 1990 levels.
• Forces an overall reduction of GHG gases in California by 25-40%, from business as usual,
to be achieved by 2020.
• Must complement efforts to achieve and maintain federal and state ambient air quality
standards and to reduce toxic air contaminants.
Statewide, the framework for developing the implementing regulations for AB 32 is under way.
Maximum GHG reductions are expected to derive from increased vehicle fuel efficiency, from
greater use of renewable energy and from increased structural energy efficiency. Additionally,
through the California Climate Action Registry (CCAR now called the Climate Action Reserve),
general and industry-specific protocols for assessing and reporting GHG emissions have been
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developed. GHG sources are categorized into direct sources (i.e. company owned) and indirect
sources (i.e. not company owned). Direct sources include combustion emissions from on-and off-
road mobile sources, and fugitive emissions. Indirect sources include off-site electricity generation
and non-company owned mobile sources.
THRESHOLDS OF SIGNIFICANCE
In response to the requirements of SB97, the State Resources Agency developed guidelines for the
treatment of GHG emissions under CEQA. These new guidelines became state laws as part of
Title 14 of the California Code of Regulations in March, 2010. The CEQA Appendix G guidelines
were modified to include GHG as a required analysis element. A project would have a potentially
significant impact if it:
• Generates GHG emissions, directly or indirectly, that may have a significant impact on the
environment, or,
• Conflicts with an applicable plan, policy or regulation adopted to reduce GHG emissions.
Section 15064.4 of the Code specifies how significance of GHG emissions is to be evaluated. The
process is broken down into quantification of project-related GHG emissions, making a
determination of significance, and specification of any appropriate mitigation if impacts are found
to be potentially significant. At each of these steps, the new GHG guidelines afford the lead agency
with substantial flexibility.
Emissions identification may be quantitative, qualitative or based on performance standards.
CEQA guidelines allow the lead agency to “select the model or methodology it considers most
appropriate.” The most common practice for transportation/combustion GHG emissions
quantification is to use a computer model such as CalEEMod, as was used in the ensuing analysis.
The significance of those emissions then must be evaluated; the selection of a threshold of
significance must take into consideration what level of GHG emissions would be cumulatively
considerable. The guidelines are clear that they do not support a zero net emissions threshold. If
the lead agency does not have sufficient expertise in evaluating GHG impacts, it may rely on
thresholds adopted by an agency with greater expertise.
On December 5, 2008 the SCAQMD Governing Board adopted an Interim quantitative GHG
Significance Threshold for industrial projects where the SCAQMD is the lead agency (e.g.,
stationary source permit projects, rules, plans, etc.) of 10,000 Metric Tons (MT) CO2
equivalent/year. In September 2010, the SCAQMD CEQA Significance Thresholds GHG
Working Group released revisions which recommended a threshold of 3,000 MT CO2e for all land
use projects. This 3,000 MT/year recommendation has been used as a guideline for this analysis.
In the absence of an adopted numerical threshold of significance, project related GHG emissions
in excess of the guideline level are presumed to trigger a requirement for enhanced GHG reduction
at the project level.
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PROJECT RELATED GHG EMISSIONS GENERATION
Construction Activity GHG Emissions
The project is assumed to require approximately one year for construction. During project
construction, the CalEEMod2016.3.2 computer model predicts that the construction activities will
generate the annual CO2e emissions identified in Table 10.
Table 10
Construction Emissions (Metric Tons CO2e)
CO2e
Year 2021 450.5
Amortized 15.0
CalEEMod Output provided in appendix
SCAQMD GHG emissions policy from construction activities is to amortize emissions over a 30-
year lifetime. The amortized level is also provided. GHG impacts from construction are considered
individually less-than-significant.
Project Operational GHG Emissions
The input assumptions for operational GHG emissions calculations, and the GHG conversion from
consumption to annual regional CO2e emissions are summarized in the CalEEMod2016.3.2 output
files found in the appendix of this report.
The total operational and annualized construction emissions for the proposed project are identified
in Table 11. The project GHG emissions are considered less-than-significant.
Table 11
Operational Emissions (Metric Tons CO2e)
Consumption Source
Area Sources 9.9
Energy Utilization 866.8
Mobile Source 915.0
Solid Waste Generation 228.1
Water Consumption 153.3
Construction 15.0
Total 2,188.1
Guideline Threshold 3,000
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CONSISTENCY WITH GHG PLANS, PROGRAMS AND POLICIES
The City of Rosemead has not yet developed a Greenhouse Gas Reduction Plan. The applicable
GHG planning document is AB-32. As discussed above, the project is not expected to result in a
significant increase in GHG emissions. As a result, the project results in GHG emissions below
the recommended SCAQMD 3,000 ton threshold. Therefore, the project would not conflict with
any applicable plan, policy, or regulation to reduce GHG emissions.
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CALEEMOD2016.3.2 COMPUTER MODEL OUTPUT
• DAILY EMISISONS
• ANNUAL EMISSIONS