Photo Courtesy: USGS/Cascades Volcano Observatory

Proposed State Implementation Plan 

Revision

Tacoma-Pierce County PM2.5Redesignation 

Request and Maintenance Plan

October 2014

Publication Number 14-02-021
2

Publication and Contact Information

This report is available on the Department of Ecology’s website at 

http://www.ecy.wa.gov/programs/air/sips/designations/pm_tacoma.htm. 

For more information, contact:

Joanna Ekrem

Joanna.ekrem@ecy.wa.gov

Air Quality Program

P.O. Box 47600 

Olympia, WA 98504-7600 

(360) 407-6826

Washington State Department of Ecology - www.ecy.wa.gov

For special accommodations or documents in alternate format, call (360) 407-6800, 711 (relay 

service), or 877-833-6341 (TTY).
3

Proposed State Implementation Plan 

Revision

Tacoma-Pierce County PM2.5 Redesignation Request 

and Maintenance Plan

by

Washington State Department of Ecology

Air Quality Program

Olympia, Washington

with 

Puget Sound Clean Air Agency

October 2014

Publication Number 14-02-021
4

Table of Contents

List of Figures and Tables....................................................................................................5

Figures............................................................................................................................5

Tables.............................................................................................................................5

Acknowledgements..............................................................................................................6

Executive Summary.............................................................................................................7

1. Introduction....................................................................................................................11

What is fine particle pollution? ...........................................................................11

Who is affected? ..................................................................................................11

What is in this plan? ............................................................................................12

2. Background....................................................................................................................13

Federal Air Quality Standards.............................................................................13

Area Description..................................................................................................13

Meteorology ........................................................................................................14

3. Air Quality in the Nonattainment Area..........................................................................17

Monitoring Locations..........................................................................................17

Progress in Improving Air Quality ......................................................................17

Seasonal Air Quality Trends ...............................................................................20

2013-2014 Fine Particle Levels...........................................................................21

4. Emissions Inventories....................................................................................................23

Sources of Fine Particle Emissions .....................................................................23

5. Transportation Conformity Requirements.....................................................................26

Motor Vehicle Emissions Budgets......................................................................26

6. Strategies to Reduce Fine Particle Pollution..................................................................28

Residential Wood Smoke ....................................................................................28

Motor Vehicles....................................................................................................31

7. Environmental Justice....................................................................................................33

8. Redesignating the Area to Attainment...........................................................................34

Redesignation Requirements...............................................................................34

9. Maintaining Healthy Air Quality...................................................................................36

Commitment to Continue Monitoring and Verify Continued Attainment ..........36

Contingency Plan.................................................................................................36

10. Next Steps....................................................................................................................38

Redesignation to Attainment ...............................................................................38

Public Participation .............................................................................................38

List of Abbreviations and Other Terms.............................................................................39

Appendices.........................................................................................................................41

Appendix A. Emissions Inventories ............................................................................41

Appendix B. MOVES Inputs.......................................................................................41

Appendix C. Motor Vehicle Emissions Budget Methodology ....................................41

Appendix D. Environmental Justice Questionnaire.....................................................41

Appendix E. Additional Resources..............................................................................41

Appendix F. Response to Comments...........................................................................41

References..........................................................................................................................42
5

List of Figures and Tables

Figures

Figure 1: Map of Tacoma-Pierce County PM2.5 Nonattainment Area and Monitoring Sites...... 14

Figure 2: 98thPercentile 24-hour Fine Particle Pollution Levels by Month, Tacoma–South L 

Street Monitor from 2000–2010 ................................................................................................... 15

Figure 3: Average PM2.5 concentration by hour for a winter day, Tacoma South L Street ......... 16

Figure 4: Fine Particle Levels at Tacoma South L Street and the Federal 24-Hour Standard..... 18

Figure 5: Number of days per year at the Tacoma South L Street monitor with average 

temperatures at or below 35 degrees F and average winds below 1 mile per hour. ..................... 18

Figure 6: PM2.5 Emissions Corrected for Meteorology................................................................ 19

Figure 7: 2006-2014 Seasonal Monthly Mean 98th Percentile PM2.5 Levels at the Tacoma South 

L Street Monitor for home heating months in red (Nov – Feb), and other months (Mar – Oct) in 

blue................................................................................................................................................ 20

Figure 8: 2013 Fine Particle Daily Concentrations over 25 μg/m3, ordered by decreasing 

concentration at the Tacoma South L Street Monitor................................................................... 21

Figure 9: Top 10 Highest PM2.5 Concentrations at Tacoma South L Street through February 23, 

2014, ordered by decreasing concentration. ................................................................................. 22

Figure 10: Tacoma-Pierce County Nonattainment Area Winter Day Fine Particle (PM2.5) 

Emissions by Source Category, 2011 ........................................................................................... 24

Figure 11: Tacoma-Pierce County Nonattainment Area Winter Day Fine Particle (PM2.5) 

Emissions and Trends by Source Category for 2011, 2017, and 2026......................................... 24

Tables

Table 1: Timeline and summary of planning process.................................................................. 10

Table 2: PM2.5 National Ambient Air Quality Standards............................................................. 13

Table 3: Tacoma-South L Street 98th Percentiles and 24-hour Design Values for 2007–2013... 19

Table 4: Tacoma-Pierce County Nonattainment Area Winter Day Fine Particle Emissions in 

Pounds........................................................................................................................................... 25

Table 5: Onroad Motor Vehicle Emissions Budgets (Pounds per winter day)............................ 27

Table 6: Residential Wood Smoke Control Measures in PSCAA Rules..................................... 31

Table 7: Residential Wood Smoke Control Measures in Ecology's rules ................................... 31

Table 8: Redesignation Requirements Addressed in this Plan .................................................... 34

Table 9: Summary of commitments in this maintenance plan..................................................... 38
6

Acknowledgements

The following Ecology staff made significant contributions to the preparation of this document:

 Clint Bowman, Environmental Specialist

 Anya Caudill, Environmental Planner

 Miriam Duerr, Public Involvement Coordinator

 Joanna Ekrem, Environmental Planner

 Laurie Hulse-Moyer, Environmental Planner

 Jeff Johnston, Science and Engineering Section Manager

 Amber Littlejohn, Administrative Assistant

 Julie Oliver, Program Development Section Manager

 Sally Otterson, Environmental Specialist

 Richelle Perez, Environmental Planner

 Nancy Pritchett, Rules and Planning Unit Manager

 Camille St. Onge, Communications Manager

 Stephanie Summers, Environmental Specialist

The authors of this report would like to thank the following people for their contribution to the 

preparation of this revision to the State Implementation Plan:

 Andrew Green, Puget Sound Clean Air Agency

 Rebecca Frohning, Puget Sound Regional Council

 Sarah Harrold, Puget Sound Clean Air Agency

 Jeff Hunt, EPA Region 10

 Robert Kotchenruther, EPA Region 10

 Kit McGurn, Puget Sound Clean Air Agency

 Kelly McGourty, Puget Sound Regional Council

 Erik Saganic, Puget Sound Clean Air Agency

 Kathy Strange, Puget Sound Clean Air Agency

 Joanne Todd, Puget Sound Clean Air Agency

 Phil Swartzendruber, Puget Sound Clean Air Agency
7

Executive Summary

Ecology proposes a revision to an air quality plan called a State Implementation Plan (SIP). The 

part of the plan being revised is for the Tacoma-Pierce County area to be reclassified to

attainment (meeting federal air quality standards) for fine particles (PM2.5). The proposed 

revision also includes a 10-year maintenance plan to keep air quality healthy in the TacomaPierce County area. 

In 2009, EPA declared the greater Tacoma area and surrounding communities in Pierce County a 

nonattainment area for not meeting the federal air quality standard for daily fine particles from 

2006-2008.1 Since then, Ecology and Puget Sound Clean Air Agency (the local clean air agency 

with authority in Pierce County) have been working to reduce fine particle pollution, focusing 

mainly on reducing wood smoke. 

This SIP revision explains Washington’s efforts to improve air quality in the proposed 

Maintenance Area. It was prepared by the Washington Department of Ecology (Ecology) with 

Puget Sound Clean Air Agency (PSCAA), the local clean air agency with jurisdiction in the area. 

The SIP revision documents:

 That the area meets the requirements under the federal Clean Air Act (CAA) to be 

reclassified to attainment;

 A 10-year maintenance plan to keep air quality healthy in the nonattainment area.

 Activities and projects conducted as part of the planning process for the SIP revision.

Why fine particle pollution is a problem

Dust, soot, and smoke are all “particulate matter.” Particulate matter is one of the six criteria air 

pollutants monitored and regulated under the CAA. Fine particles are microscopic, a fraction of 

the diameter of a single human hair. The tiny size of fine particle pollution allows us to inhale it 

easily. The tiny particles travel deep into our lungs and circulatory system. 

As a result, fine particles have both short- and long-term health effects including respiratory 

disease, decreased heart and lung function, asthma attacks, heart attacks, strokes, and premature 

death. These particles can also act as carriers for other toxic and cancer-causing materials. Fine 

particle pollution affects everyone, but has the most harmful effect on children, older adults, and 

people with respiratory and cardiac diseases.

Federal air quality standards

EPA set two National Ambient Air Quality Standards (NAAQS) for fine particle pollution to 

protect public health and the environment. These standards are:

 24-hour (daily) standard. 

 Annual standard.
8

In 2006, EPA strengthened the daily standard concentration for fine particles from 65 

micrograms per cubic meter (μg/m3) to 35 μg/m3.

2

 The Tacoma-Pierce County area was 

designated nonattainment because the 2006-2008 design value of 44 μg/m3exceeded the 35 

μg/m3standard. The design value is a measurement used to determine compliance with the 

standard, and is based on the annual 98th percentile value averaged over three years. 

Where fine particles come from

The fine particle pollution in the Tacoma-Pierce County PM2.5 Nonattainment Area comes 

mainly from smoke due to burning in wood stoves and fireplaces. Fine particle pollution is 

worse during the winter months when more households are burning wood for heat. In addition, 

stagnant weather conditions trap the smoke from these fires close to the ground and cause air 

pollution to build up rapidly. Other smaller sources of fine particle pollution include:

 exhaust from cars and trucks;

 dust;

 large industrial sources; and

 other nonroad engines, equipment, and vehicles, such as construction equipment, buses, 

ships, and trains. 

Strategies to reduce fine particle pollution 

Puget Sound Clean Air Agency (PSCAA) worked closely with the local community and 

convened a Task Force force in 2011 to develop and implement strategies to reduce fine particle

pollution to healthier levels.3 Under the Task Force’s direction, PSCAA implemented three 

significant new programs in the Tacoma-Pierce County PM2.5 Nonattainment Area starting in 

2012:

 Enhanced enforcement of air quality burn bans and a lower burn ban trigger, with path to 

no penalty for first time violators and an exception for households with no alternative 

source of heat. 

 Required removal at a future date certain of old, more polluting uncertified wood stoves, 

with the potential for a free replacement for low-income households. 

 Public education and outreach to raise awareness about burn ban compliance and promote

participation in the wood stove removal and replacement program.

The strategies were supported by legislation passed by the Washington State Legislature in 2012 

(Substitute House Bill 2326 Chapter 219, Laws of 2012) and updated wood stove regulations 

incorporated in the Washington State Implementation Plan (SIP) that provide Ecology and 

PSCAA authority to implement the wood smoke rules and strategies for the Nonattainment Area. 

This SIP revision relies on rules that are currently approved in the Washington SIP. We do not 

propose to include any new rules as part of this SIP revision.

Progress in improving air quality

In 2012, EPA issued a clean data determination that the area met the daily fine particle standard 

based on monitoring data from 2009-2011.4 Recent monitoring data show that air quality has 

improved and the area has continued to attain the standard since 2011. 
9

What is in the SIP revision

This document was prepared by Department of Ecology with Puget Sound Clean Air Agency to

demonstrate that the Nonattainment Area:

 meets CAA requirements for redesignation to attainment for the 2006 daily fine particle 

standard; and

 will maintain the fine particle air quality standard for the next 10 years.

This document includes additional federal planning requirements:

 inventories of air emissions infor 2011, 2017 and 2026 for fine particles and pollution 

that leads to fine particles;

 limits on onroad vehicle emissions to make sure the area continues to meet the standard;

 summary of fine particle reduction strategies and existing permanent and enforceable 

rules that provide Ecology and PSCAA authority to control fine particle pollution;

 summary of efforts to include everyone in the environmental decision-making process 

(regardless of race, color, national origin, or income);

 commitments Ecology and PSCAA make to continue monitoring, verify that the area 

continues to meet the standard, and implement a contingency plan if a future violation 

occurs.

Public Comment Period

Ecology accepted public comments on the proposed redesignation request and maintenance plan 

during a public comment period August 27 to October 3, 2014, and at a public hearing

September 30, 2014. Ecology reviewed, responded to, and incorporated comments before 

finalizing the plan (See Appendix F). 

Next Steps

Ecology will request EPA approve the proposed SIP revision. EPA must approve of Ecology’s 

redesignation request and maintenance plan to remove the “nonattainment” designation and 

reclassify the area to attainment, making it a maintenance area. This would begin a 20-year 

planning cycle designed to make sure that the area remains below the federal standard. This 

maintenance plan covers the first 10 years of that planning cycle. Ecology will submit an 

updated maintenance plan for the second 10 year period, eight years after EPA approves this SIP 

revision. 
10

Table 1: Timeline and summary of planning process

2006  EPA revised the daily PM2.5 NAAQS from 65 to 35 μg/m3

.

5

2007  PSCAA launches uncertified wood stove replacement program.

2009  Parts of Tacoma-Pierce County designated nonattainment for the 2006 PM2.5

NAAQS.

6

2011  PSCAA convenes a Tacoma-Pierce County Clean Air Task Force. The Task 

Force issues a set of recommendations in December 2011.7

 PSCAA launches outreach effort to educate residents about fine particle pollution.

 The three year average daily PM2.5 level (the “design value”) for 2009-2011 drops 

below the NAAQS and remains below the NAAQS in 2012 and 2013.

2012  EPA issues a Clean Data Determination that the area meets the PM2.5 NAAQS.8

 Washington State Legislature passes legislation to advance the recommendations 

of the Task Force.9

 PSCAA starts enhanced enforcement of burn bans. PSCAA continues to provide 

incentives for removal of older, more polluting uncertified wood stoves.

 PSCAA adopts changes to PSCAA Regulation 1-13, Solid Fuel Burning Device 

Standards in October.10

 Ecology submitted a SIP revision to EPA. The revision was approved by EPA, 

effective June 28, 2013.11 The revision included:

o PSCAA’s Regulation 1-13 Solid Fuel Burning Device Standards,

o 2008 emissions inventory for the Nonattainment Area, and

o Motor Vehicle Emissions Budgets.12

2013  Ecology amends Chapter 173-433 WAC Solid Fuel Burning Devices rule. The 

rule is adopted in January 2014 and approved by EPA for inclusion in the 

Washington SIP effective June 9, 2014.13

2014  Ecology, PSCAA and Puget Sound Regional Council (PSRC) complete technical 

work for redesignation request and maintenance plan.
11

1. Introduction

The U.S. Environmental Protection Agency (EPA) sets air quality standards for fine particle 

pollution to protect public health and the environment. In December 2009 EPA classified parts 

of Tacoma-Pierce County as nonattainment for fine particle pollution under the federal Clean Air 

Act (CAA).14 This designation is due to unhealthy levels of fine particle pollution from 2006-

2008 and is a result of two factors: 

 A stronger air pollution limit set by the EPA in 2006; and

 Spikes in fine particle pollution levels during the fall and winter that exceed the limit 

allowed in a 24-hour period.

Since 2010, fine particle pollution levels declined in the Tacoma-Pierce County PM2.5

Nonattainment Area (Nonattainment Area). In 2012, EPA determined that the area met the 

standard based on monitoring data from 2009-2011.15 Recent monitoring data show that the area 

has continued to attain the standard since then. This plan demonstrates how the area meets the 

federal CAA requirements to be redesignated to attainment for the daily fine particle standard 

and demonstrates how the area will continue to meet standard for the next 10 years. 

This plan will be submitted to EPA to support the redesignation request and to request that EPA 

include the associated maintenance plan as a revision to the Washington State Implementation 

Plan (SIP). The SIP consists of plans and rules that demonstrate how Washington will meet 

National Ambient Air Quality Standards (NAAQS). Washington State Department of Ecology 

(Ecology) prepared this plan with Puget Sound Clean Air Agency (PSCAA). PSCAA is the local 

clean air agency with jurisdiction over the Tacoma-Pierce County area. 

What is fine particle pollution?

Fine particle pollution refers to particulate matter 2.5 micrometers in size or smaller (PM2.5). 

Fine particles are microscopic, a fraction (about 1/30th) of the diameter of a single human hair. 

Fine particles come from soot, dust, or unburned fuel suspended in the air, and can also be 

formed from chemical reactions involving gaseous precursors. 

The fine particle pollution in the Nonattainment Area comes mainly from smoke due to burning 

in wood stoves and fireplaces, and exhaust from cars, trucks, and other sources such as buses, 

ships, and trains. Industries also contribute a small portion of fine particle pollution. Fine 

particle pollution is worse during the winter months when more households are burning wood for 

heat. In addition, stagnant weather conditions trap the smoke from these fires close to the ground 

and cause air pollution to build up rapidly. 

Who is affected?

Fine particle pollution poses a serious health risk to residents of the Nonattainment Area. Small 

particles can penetrate deep into the lungs and travel in the circulatory system, affecting the heart 

and lungs. Exposure to fine particle pollution is associated with respiratory disease, decreased 

heart and lung function, asthma attacks, heart attacks, strokes, and premature death. Fine 

particles can also act as carriers for toxic and cancer-causing materials. Fine particle pollution 
12

affects everyone, but has the most harmful effect on children, older adults, and people with 

respiratory and cardiac diseases.

Every year in Washington, fine particle pollution contributes to an estimated 1,100 deaths and 

$190 million in direct and indirect costs from treating illnesses and health conditions that stem 

from fine particle pollution.16 Fine particle effects can result in increased hospital admissions, 

emergency room visits, absences from school or work, and restricted activity days. 

In addition to the health risks, not attaining federal air quality standards has other consequences. 

Industries moving to or expanding in a Nonattainment Area are required to install the most costly 

pollution controls. This can be a disincentive for new businesses to relocate and bring new jobs 

to the region. Also, if the state doesn’t submit this plan to show how the area will achieve 

cleaner air, the EPA could step in and develop and enforce its own plan in the area, and the 

community would have less influence in determining local solutions. Not acting could also 

endanger federal transportation funding for the region and grant funding for air quality. 

What is in this plan?

This plan demonstrates how the Tacoma-Pierce County PM2.5 Nonattainment Area currently 

meets and will continue to meet the 24-hour PM2.5 NAAQS for the next 10 years. It fulfills the 

federal Clean Air Act requirements to redesignate the area to attainment. The plan is organized 

as follows:

 Background – describes the Nonattainment Area and the fine particle pollution problem.

 Air Quality in the Nonattainment Area – summarizes fine particle monitoring data.

 Emissions Inventories – summarizes the main sources and quantity of emissions for 

PM2.5 and precursor emissions for 2011, 2017, and 2026.

 Transportation Conformity Requirements – summarizes the Motor Vehicle Emissions 

Budget set to limit onroad motor vehicle emissions from cars and trucks.

 Strategies to Reduce Fine Particle Pollution – describes critical control measures to 

reduce fine particle pollution, primarily wood smoke.

 Environmental Justice – describes how the agencies incorporated environmental justice 

concerns.

 Redesignating the Area to Attainment– demonstrates how this document fulfills 

federal requirements to redesignate the area to attainment.

 Maintaining Healthy Air Quality– describes the commitment to continue monitoring, 

verify continued attainment, and the contingency plan.

 Next Steps – describes the next steps in the process.
13

2. Background

Federal Air Quality Standards

EPA set two National Ambient Air Quality Standards for fine particle pollution to protect public 

health and the environment. These standards are:

 24-hour (daily) standard.

 Annual standard.

EPA tightened the daily standard concentration for fine particulate matter in 2006 from 65 

micrograms per cubic meter (μg/m3) to 35 μg/m3after reviewing scientific evidence that shortterm exposure to certain levels of fine particle pollution can cause premature death and harmful 

respiratory and cardiovascular effects. 17 

Table 2: PM2.5 National Ambient Air Quality Standards

Averaging Time Level Method

24-hour (daily) 35 μg/m3 Annual 98th percentile, 

averaged over 3 years

Annual 12 μg/m3 Annual mean, averaged over 3 

years

EPA uses the yearly 98th percentile from three years in a row to calculate an average. This 

average is called the design value. EPA compares the design value to the daily standard for fine 

particles, which is 35 μg/m3. If the design value is above 35 μg/m3, the area does not meet the 

standard. The Tacoma-Pierce County area was designated nonattainment because the 2006-2008 

daily design value of 44 μg/m3exceeded the 35 μg/m3standard. 

Area Description

The Nonattainment Area covers most of the greater Tacoma area and the surrounding 

communities within Pierce County’s Urban Growth Area west of State Route 167 (see figure 1 

below). 

The topography surrounding the Nonattainment Area influences its meteorology. Important 

topographical features include:

 Puget Sound to the north and west,

 Cascade Mountains to the east and southeast, and 

 Puyallup River Valley running through the area.
14

Figure 1: Map of Tacoma-Pierce County PM2.5 Nonattainment Area and Monitoring Sites

Meteorology

In the Tacoma area, summers are relatively cool and comparatively dry while winters are mild, 

wet, and cloudy. In November and December, the wettest months, precipitation is frequently 

recorded on over 20 days each month. Usual wind flow is from west-southwest. However, high 

levels of fine particle pollution are associated with very light east-southeast surface winds, as 

well as calm conditions. 

Elevated fine particle levels typically occur during the winter months between October and 

March when temperatures are low (less than 50 degree Fahrenheit) and winds are light (less than 

1.5 miles per hour) (see figure 2 below). During the winter more households are burning wood 

for heat. Stagnant weather conditions trap the smoke from these fires close to the ground and 

cause air pollution to build up rapidly. 
15

Figure 2: 98th Percentile 24-hour Fine Particle Pollution Levels by Month, Tacoma–South L Street 

Monitor from 2000–2010

On days with high levels of fine particle pollution, levels rise rapidly beginning about 3 to 4 pm 

and peak between 12 midnight and 1 a.m. A smaller increase is often observed between 6 a.m. 

and 8 a.m. Outside of the home heating season (non-winter months of April – September), there 

is little variation of the fine particle concentration throughout the day with the exception of July 

days with firework celebrations. Figure 3 shows the winter day pattern of fine particle levels.
16

Figure 3: Average PM2.5 concentration by hour for a winter day, Tacoma South L Street
17

3. Air Quality in the Nonattainment Area 

Monitoring Locations

PSCAA operates three monitoring sites in the Nonattainment Area at the following locations (see 

figure 1 in Section 2):

 Tacoma–South L Street

 Puyallup–128th Street 

 Tacoma Tideflats–Alexander Avenue

EPA uses the data from the Tacoma–South L Street monitor to determine compliance with 

federal health-based fine particle standards. Tacoma–South L Street is the only site of the three 

with a monitor that uses the Federal Reference Method (FRM). The FRM specifies the various 

federal requirements a compliance monitor and its site must meet before EPA can compare its 

data to the fine particle standard. The other two sites provide additional information that help 

PSCAA characterize fine particle levels throughout the Nonattainment Area. 

PSCAA uses information from all three sites to evaluate pollution levels and determine whether 

actions, such as calling a burn ban, are necessary. PSCAA also used temporary and mobile 

monitors to help characterize the fine particle problem and determine the boundaries of the 

Nonattainment Area.

Progress in Improving Air Quality

In 2011, the area attained the federal standard based on monitoring data for 2009-2011. EPA 

issued a “clean data determination” (CDD) in 2012.18 The CDD did not officially redesignate 

the area to attainment but it does relieve the state of certain planning requirements as long as the 

area continues to meet the standard.19 Fine particle concentrations at the Tacoma South L Street 

monitor have remained below the 24-hour national ambient air quality standard since 2011, as 

shown below in figure 4. 

Due to unusually favorable weather conditions, the annual 98th percentile 24-hour fine particle 

pollution level in the Nonattainment Area dropped significantly in 2010. Although average daily 

fine particle levels have increased since 2010, fine particle concentrations have remained below 

the standard. Figure 5 below indicates that the weather conditions in 2013 were not favorable for 

air quality and were the most conducive to high wood smoke concentrations since 2006. Despite 

the unfavorable weather conditions in 2013, the annual 98th percentile for PM2.5 remained below 

the federal standard. This indicates that pollution levels are trending downward when corrected 

for meteorology.
18

Figure 4: Fine Particle Levels at Tacoma South L Street and the Federal 24-Hour Standard

Figure 5: Number of days per year at the Tacoma South L Street monitor with average 

temperatures at or below 35 degrees F and average winds below 1 mile per hour.

0

10

20

30

40

50

60

70

2006 2007 2008 2009 2010 2011 2012 2013

Fine Particle Concentration

micrograms per cubic meter

Year

Federal Standard

Daily PM2.5 (1-year 98th 

percentile)

Fine Particle Levels in Tacoma and Federal Daily Standard 

(Daily PM2.5 [1-year 98th percentile] and Design Value [3-year mean of Daily])

0

2

4

6

8

10

12

14

2006 2007 2008 2009 2010 2011 2012 2013

Number of Days

Year

Number of Days with avg temps ≤ 

35°F and winds ≤ 1mph
19

Table 3 below shows the annual 98th percentile and three year design values. The design value is 

rounded to a whole number and must be below 35 μg/m3to comply with the federal standard. 

Table 3: Tacoma-South L Street 98th Percentiles and 24-hour Design Values for 2007–2013.

Year 98th

Percentile

Design Value

2006-

2008

2007-

2009

2008-

2010

2009-

2011

2010-

2012

2011-

2013

2006 42.7

2007 45.3 44

2008 44.2 46

2009 47.6 38

2010 21.4 35

2011 35.7 28

2012 27.7 32

2013 33.9

Figure 6 below is the result of comparing a statistical model that predicts air pollution based on 

meteorology versus actual observed fine particle concentrations. The statistical model is based 

on 2007-2009 fine particle concentrations and meteorological conditions (winds and 

temperature). In effect, this comparison corrects for meteorology and shows emission trends 

versus the 2007-2009 baseline period. The figure shows that the model over predicts over time, 

indicating that emissions are dropping with meteorology held constant. Extrapolating from the 

figure, fine particle levels on the highest winter days have come down over 10 μg/m3since 2009. 

Figure 6: PM2.5 Emissions Corrected for Meteorology.
20

Seasonal Air Quality Trends

Figure 7 below shows the mean 98th percentile PM2.5 concentrations at the Tacoma South L 

Street monitor for the winter heating season (November through February) in red. The red 

circles indicate the 98th percentile PM2.5 level for each month from November through February, 

beginning Nov. 2006 through Feb. 2014. The bold red line is a statistical fit to the monthly data. 

It indicates a trend of decreasing mean monthly 98th percentile levels of PM2.5 from 2006 to 

February 2014 in the winter months when the levels are typically higher and more likely to 

exceed the federal standard. The red shaded area represents the 95 percent confidence level of 

the distribution, which indicates the uncertainty of the estimate. 

The 98th percentile PM2.5 levels of spring, summer, and early fall months (March through 

October, shown in blue) are consistently below the health-based standard. Its gradual increase 

seems to reflect the one to three percent annual population increase in Tacoma over the same 

period.

Figure 7: 2006-2014 Seasonal Monthly Mean 98th Percentile PM2.5 Levels at the Tacoma South L 

Street Monitor for home heating months in red (Nov – Feb), and other months (Mar – Oct) in blue.
21

2013-2014 Fine Particle Levels

The highest daily concentrations at the Tacoma South L Street site in 2013 were fairly uniform, 

with less than a 2 μg/m3difference between the 4th highest (35.5) and 10th highest (33.7). Figure 

8 below shows the highest daily concentrations at the Tacoma South L Street site. The figure 

illustrates a much smaller difference among the highest concentrations than seen in previous 

years, creating a “plateau” of concentrations near the daily standard. 

Figure 8: 2013 Fine Particle Daily Concentrations over 25 μg/m3, ordered by decreasing 

concentration at the Tacoma South L Street Monitor.

For the first part of 2014, PM2.5 levels at the Tacoma south L monitor have remained below the 

federal standard. Figure 9 below shows the 10 highest PM2.5 levels as recorded on the Tacoma L 

Street monitor through February 23, 2014. 

42

38 37 36 35 35 34 34 34 34 32

30 30 28

26 26 26 25 25

0

5

10

15

20

25

30

35

40

45

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

PM concentration (ug/m3)

Rank

2013 Tacoma South L, Daily PM2.5, 

Samples Ranked Over 25 μg/m3
22

Figure 9: Top 10 Highest PM2.5 Concentrations at Tacoma South L Street through February 23, 

2014, ordered by decreasing concentration.

32 30 30 29

23

21 20 20 19 18

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8 9 10

PM concentration (ug/m3)

Rank

2014 Tacoma South L, Daily PM2.5, 10 Highest 

(Through Monday, Feb 23)
23

4. Emissions Inventories

Fine particles (PM2.5) are emitted directly to the air and are also formed when gaseous precursors 

undergo chemical reactions in the atmosphere to form secondary fine particles. The main 

precursor gases associated with secondary fine particle formation are: 

 Sulfur dioxide (SO2),

 Nitrogen oxides (NOx),

 Volatile organic compounds (VOCs), and

 Ammonia (NH3).

For the Nonattainment Area, federal regulations20 require Ecology to prepare a comprehensive, 

accurate, current inventory of emissions from the Nonattainment Area for emissions fine 

particles (PM2.5) and fine particle precursors. Ecology prepared Nonattainment Area winter day 

and annual inventories for:

 2011, the attainment year;

 2017, an interim year; and

 2026, the final year of the maintenance plan.

We developed winter day inventories because the 24-hour standard focuses on emissions on a 

single day. Additionally, elevated concentrations of fine particles have typically occurred 

between October and March. The emissions inventories and a description of the methodology 

Ecology used for the calculations are included in Appendix A. A summary is included below. 

Sources of Fine Particle Emissions

Figure 10 shows the percentage of fine particles from each source category in the winter day 

inventory for 2011, the attainment year. Seventy-six percent of emissions in the Nonattainment 

Area come from residential wood combustion emitted from wood stoves and fireplaces. 

Figure 11 shows the winter day fine particle emissions sources and trends for 2011, 2017, and 

2026. To demonstrate that the area will maintain the fine particle standard for the next ten years, 

total winter day fine particle emissions from all sources in 2026 must be below 2011 emissions. 

In 2026, fine particle emissions are projected to decline 1 percent from 2011 levels. 

Ecology used a highly conservative approach to project the 2017 and 2026 emissions. The 

projections are higher than expected because they do not take into account expected emission 

reductions from permanent and enforceable wood smoke reduction controls described below and 

in section 6. Ecology’s PM2.5 emissions projections are also conservative because they include 

potential increases in dust due to increased locomotive traffic and coal dust if proposed coal 

terminals are built and operate at full capacity. Conservative projections were also used with 

point sources in the inventory. Unless there was specific information or engineering knowledge 

about a source that indicated projections should be calculated differently, the ten year maximum 

reported emission of PM2.5 was used as the projection for 2017 and 2026. See appendix A for 

more details about the methodology and assumptions used in the emissions inventory. 
24

Figure 10: Tacoma-Pierce County Nonattainment Area Winter Day Fine Particle (PM2.5) Emissions 

by Source Category, 2011

Figure 11: Tacoma-Pierce County Nonattainment Area Winter Day Fine Particle (PM2.5) Emissions 

and Trends by Source Category for 2011, 2017, and 2026.

Residential Wood 

Combustion

76%

Onroad Vehicles

7%

Dust

6%

Major Point 

Sources

4%

Nonroad Vehicles 

& Engines

4%

Other

3%

0 5,000 10,000 15,000 20,000 25,000 30,000 35,000

2011

2017

2026

Pounds per winter day

Residential Wood Combustion Onroad Vehicles Dust

Major Point Sources Nonroad Vehicles & Engines Other
25

Table 4: Tacoma-Pierce County Nonattainment Area Winter Day Fine Particle Emissions in 

Pounds

Source Category 2011 2017 2026

Residential Wood Combustion 25,519 25,355 25,788

Onroad 2,497 1,642 1,149

Dust 2,023 2,069 2,631

Major Point Sources 1,313 1,940 1,848

Nonroad 1,384 957 697

Other 1,025 1,136 1,266

TOTAL 33,761 33,099 33,379

We expect emissions reductions from enhanced burn ban enforcement and removal of old, 

uncertified wood stoves that are not quantitatively reflected in figure 11. PSCAA enhanced its 

burn ban enforcement efforts in the last two heating seasons (fall and winter of 2012-2013 and 

2013-2014) and called 7 burn bans spanning 27 days, based on lower burn ban triggers that were 

adopted into law in the 2012 Legislative session.21 The stricter trigger level enabled PSCAA 

forecasting staff to call burn bans to more effectively avoid exceedances. In addition, PSCAA 

issued over 2,000 Notices of Violation to households that were burning during a burn ban. 

Through their enforcement process, PSCAA helped households mitigate penalties by providing 

incentives to remove uncertified stoves, having them sign up for burn ban email or text alerts, or 

having them pass a clean burn test. All of these actions are geared at changing behavior among 

violators. 

Preliminary data indicate that this process is working – a survey of previous burn ban violators 

reveals low re-violation rates in subsequent burn bans. With outreach to each individual violator 

and a better notified and educated public overall, PSCAA expects the enhanced burn ban 

enforcement to continue to reduce emissions at the very times when it is most important. 

Awareness of burn ban enforcement is growing beyond the pace of Notices of Violation – for 

example, since PSCAA initiated burn ban text alert program in 2012, over 3,700 subscribers 

have signed up (almost twice as many as households that have received violations during burn 

bans). 

We also expect fine particle emissions reductions from replacing older uncertified woodstoves 

with cleaner, more efficient wood or pellet stoves. The emissions projections in figure 11 

incorporate fine particle reductions from historical turnover rates of older stoves and from 

replacement of uncertified stoves with non-wood burning devices through PSCAA’s currently 

funded woodstove changeout program. The projections do not incorporate fine particle 

reductions from a possible increase in the stove turnover rate due to PSCAA’s changeout 

program and the ban of uncertified stoves in the Nonattainment Area after September 2015. 

PSCAA anticipates that the ban will increase participation in the wood stove removal program as 

households seek to comply with the rule. The projections also do not incorporate future more 

stringent federal emissions standards in the proposed New Source Performance Standards for 

Residential Wood Heaters.22
26

5. Transportation Conformity Requirements

Transportation conformity addresses air pollution from onroad mobile sources, such as cars, 

trucks, and transit. Federal and state transportation conformity regulations23 require the 

evaluation of onroad emissions from transportation plans, programs, and projects before their 

implementation. This is to ensure that federal funding and approval are given to onroad 

transportation activities that are consistent with air quality goals. Conforming to a SIP means that 

onroad transportation activities will not cause or contribute to a violation of federal air quality 

standards, worsen air quality, or prevent or delay the improvement of air quality. 

Motor Vehicle Emissions Budgets

Ecology worked with Puget Sound Regional Council to develop motor vehicle emissions budgets 

(MVEBs) for the proposed Maintenance Area. Puget Sound Regional Council is the 

organization responsible for long-range transportation planning in the central Puget Sound 

region. MVEBs establish a limit on the total emissions allowed from onroad mobile sources, 

such as cars, trucks, and buses. The MVEBs are required for nonattainment and maintenance 

areas to make sure that future emissions from onroad mobile sources do not interfere with the 

continued attainment of the fine particle standard. 

Once EPA approves the MVEBs, PSRC and the U.S. Department of Transportation will use the 

budgets to make transportation conformity determinations. In order to demonstrate 

transportation conformity, projected emissions from federally funded transportation plans and 

programs must be less than or equal to the budgets. 

The MVEBs reflect the total on-road emissions projected for 2017 and 2026, plus a portion of 

the available PM2.5 and NOx safety margins. The onroad mobile emissions inventory was 

developed using EPA’s MOVES2010b model and PSRC’s current travel demand model.24 A

conservative margin of safety was added to the MVEB to accommodate uncertainty. A safety 

margin is the amount by which the total projected emissions from all sources of a given pollutant 

are less than the total emissions for the 2011 attainment year, the level required to demonstrate 

continued maintenance of the standard. 25 

A portion of the inventory safety margin was allotted to the onroad motor vehicle emissions 

inventory projections to accommodate the wide array of assumptions that are factored into the 

calculation process. Since assumptions and models change over time, it is necessary to have a 

margin of safety that will accommodate technical uncertainties due to future model updates and 

inputs to EPA’s MOVES model and PSRC’s travel demand model, as well as potential changes 

in regional transportation policies or funding priorities. Appendix C includes additional 

information on MVEB methodology and safety margin. 

Table 5 below contains the MVEBs for the proposed Maintenance Area for the years 2017 and 

2026 for PM2.5 and NOx. The values represent the maximum pounds per winter day of emissions 

that will be allowed from onroad mobile sources. Federal transportation conformity regulations 

require MVEBs for PM2.5 and NOx.

26

 
27

Table 5: Onroad Motor Vehicle Emissions Budgets (Pounds per winter day)

Year PM2.5 NOx

2017 1,888 41,790

2026 1,321 22,880

PSRC held a consultation on the MVEBs and the underlying methodology with the interagency 

air quality consultation partners in the Central Puget Sound region. The consultation partners 

include representatives from the following agencies:

 Puget Sound Clean Air Agency

 Puget Sound Regional Council

 Federal Highway Administration

 Federal Transit Administration

 U.S. Environmental Protection Agency

 Washington State Department of Ecology

 Washington State Department of Transportation.

The consultation partners reviewed and concurred on the MVEB and the methodology.
28

6. Strategies to Reduce Fine Particle Pollution 

The Puget Sound Clean Air Agency worked closely with the local community to develop 

strategies to reduce fine particle pollution to healthier levels. In 2011, PSCAA established the 

Tacoma-Pierce County Clean Air Task Force (Task Force) made up of representatives from 

healthcare, community groups, industry associations, state and local agencies, wood-burners and 

non-burners alike.27 The Task Force agreed that the focus for reductions should be residential 

wood combustion, and also concluded that the Nonattainment Area should implement a range of 

strategies for non-wood smoke sources.28 

Following the Task Force recommendations, PSCAA and Ecology focused on residential wood 

smoke reduction strategies to bring the area into attainment for fine particulate matter. The 

control strategies rely on regulatory and enforcement provisions contained in PSCAA, Ecology, 

and federal rules, and education and outreach to communicate those provisions. In addition, 

reductions from vehicles, trucks, buses, and ships will also help control emissions. 

Residential Wood Smoke

Based on the recommendations of the Task Force, PSCAA partnered with community groups to 

implement three main strategies, starting with the 2012-2013 home heating season: 

 Increased enforcement during air quality burn bans;

 Removal of old, uncertified stoves; and

 Public education and outreach.

We expect substantial emissions reductions with these strategies. However, the emissions 

inventory projections do not include these reductions to allow for a wider margin of safety.29 A 

description of these strategies is included below, along with a summary of state and local rules 

relied on to achieve fine particle reductions from residential wood smoke. 

Enhanced enforcement of air quality burn bans

PSCAA enforces burn bans to prevent unhealthy levels of pollution (PSCAA Regulation 1-

13.05). Burn bans are issued when scientific forecasts and real-time monitoring data indicate 

that pollution will rise to unhealthy levels. There are two stages of burn bans. During Stage 1 

burn bans, use of fireplaces and uncertified wood stoves and inserts, as well as outdoor burning 

are prohibited, and use of pellet stoves and certified wood stoves and inserts are allowed. All 

wood burning is prohibited during a stage 2 burn ban. 

Starting with the 2012-2013 home heating season and continued in 2013-2014, PSCAA 

implemented new burn ban triggers that allow them to call burn bans at lower levels. During this 

time period PSCAA called 7 burn bans spanning 27 days based on the lower burn ban triggers. 

PSCAA also established agreements with local agencies and trained over 60 staff to assist with 

enforcement. Patrol hours increased substantially and burn ban enforcement was extended to 

dusk and at night when more people are burning wood for heat. PSCAA issued over 2,000 

Notices of Violation over the two winters. First time violators of burn bans could avoid paying a 

penalty but repeat violations could result in a fine of up to $1,000.
29

The process for recipients of Notices of Violation is designed to prevent future wood burning 

during stagnant (burn ban) conditions. The process includes potential to mitigate fines by taking 

a clean burn test, removing uncertified stoves, or signing up for notification through email alerts, 

text alerts, or social media. Over the last two winters, PSCAA received over 600 clean burn 

tests.

Removal and replacement of uncertified wood stoves

To improve air quality and protect public health, residents in the Nonattainment Area were 

offered incentives to recycle or replace an old wood stove with cleaner heat. Residents could 

receive up to $350 for the removal and recycling of eligible wood-burning devices, and a 

discount of up to $1,500 for replacing their wood-burning device with certain clean heating 

replacement equipment. Qualified low-income residents could apply to receive a free heating 

replacement. 

Over the last two years, close to $2 million in incentives was provided for residents and 

about1,000 uncertified wood stoves were removed and recycled. Over three quarters of the 

funding has gone to provide low income households a new and cleaner source of heat at no cost. 

In total, over 2,100 uncertified wood stoves have been removed and recycled since PSCAA’s 

first removal and replacement program started in 2007. 

Recognizing the limitations of voluntary and incentive programs, the Task Force recommended a 

date certain removal requirement for old, uncertified wood stoves. PSCAA revised its wood 

stove regulation to require removal of uncertified wood stoves in the Nonattainment Area by 

September 30, 2015. PSCAA’s current removal program runs through June 2015, and is 

designed to achieve as many removals as possible before the September 30, 2015 uncertified 

wood stove ban. PSCAA plans to enforce the ban under PSCAA Regulation 1-13.07.

Public education and outreach

PSCAA launched an outreach campaign, “Air. On the safe side.” in November 2012 to raise 

awareness about burn bans, encourage participation in the wood stove changeout program, and 

engage people and provide them tools to make informed decisions about clean burning practices. 

Key features of the campaign in the 2012-2013 and 2013-2014 heating seasons include:

 Text message alerts - Residents can sign up for free text alerts to notify them when a burn 

ban starts and ends. 3,700 subscribers have signed up so far. Residents can also be 

notified through an active e-mail distribution list. 

 Creation of a new www.airsafepiercecounty.org website and outreach materials and 

visuals based on focus group testing.

 Media coverage – TV, print, and online coverage.

 Online and print advertisements – Tacoma News Tribune and Puyallup Herald.

 Extensive grassroots community outreach – 60 presentations delivered to local 

community groups, newsletter articles distributed through citizen and community groups 

and major employers, posters and flyers distributed.

 Direct mail - 80,000 postcards were sent to low-income households in the areas where 

wood burning is more frequent. An earlier mailing sent postcards to all 220,000 

households in the area.
30

 Posted information on the PSCAA monthly electronic newsletter (16,000 subscribers), 

Facebook, and Twitter. 

The outreach and education activities were completed in close coordination with and with input 

from local Pierce County agency partners.

State and Local Regulatory Framework for Wood Smoke

Washington’s Clean Air Act and Ecology and PSCAA rules establish the regulatory framework 

for limiting unhealthy levels of wood smoke. The framework comprises:

 Emissions standards for new wood burning devices that are more stringent than the 

federal standards set by EPA;

 Opacity standards for smoke plumes;

 Prohibition to burn certain materials;

 Curtailment program (burn bans); and

 Special nonattainment area provisions.

Legislation passed by the Washington State Legislature in 2012 (Substitute House Bill 2326 

Chapter 219, Laws of 2012)30 authorized Ecology and PSCAA to take the following actions in 

the Nonattainment Area:

 Call stage 1 and 2 burn bans at lower thresholds;

 Work with the city, county, or local health department on enforcement assistance;

 Prohibit the use of uncertified wood stoves at a future date;

 Explore options to reduce pollution from fireplaces as a contingency measure if needed to 

meet federal requirements; and

 Provide assistance to households using a woodstove or fireplace to reduce emissions or 

change to cleaner device.

PSCAA and Ecology strengthened local and state rules to reflect the 2012 statutory changes and 

provide the regulatory framework to address fine particle pollution. These rules were submitted

to EPA to include in the Washington State Implementation Plan to protect air quality. 

 PSCAA Regulation 1-13, Solid Fuel Burning Device Standards – Revisions were 

adopted Oct. 25, 2012 and approved by EPA for inclusion in the Washington SIP 

effective June 28, 2013.

31

 Ch. 173-433 WAC, Solid Fuel Burning Devices – Revisions were adopted January 23, 

2014 and approved by EPA for inclusion in the Washington SIP effective June 9, 2014.

32

This SIP revision relies on rules in table 7 below that are currently approved in the Washington 

SIP to attain the standard. We do not propose to include any new rules as part of this SIP 

revision.

 
31

Table 6: Residential Wood Smoke Control Measures in PSCAA Rules

Citation Title Effective Date

PSCAA Regulation I - Article 13: Solid Fuel Burning Device Standards

13.01 Policy and Purpose 12/01/12

13.02 Definitions 12/01/12

13.03 Opacity Standards 12/01/12

13.04 Allowed and Prohibited Fuel Types 12/01/12

13.05 Restrictions on Operation of Solid Fuel Burning Devices 12/01/12

13.06 Emission Performance Standards 12/01/12

13.07 Prohibitions on Wood Stoves that are not Certified Wood 

Stoves

12/01/12 

Table 7: Residential Wood Smoke Control Measures in Ecology's rules

Citation Title Effective Date

Washington Administrative Code, Chapter 173-433 Solid Fuel Burning Device Standards

173-433-010 Purpose 02/23/14

173-433-020 Applicability 02/23/14

173-433-030 Definitions 02/23/14

173-433-100 Emission Performance Standards 02/23/14

173-433-110 Opacity Standards 02/23/14

173-433-120 Prohibited Fuel Types 02/23/14

173-433-140 Criteria for Impaired Air Quality Burn Bans 02/23/14

173-433-150 Restrictions on the Operation of Solid Fuel Burning Devices 02/23/14

173-433-155 Criteria for Prohibiting the Use of Solid Fuel Burning Devices 

that Are Not Certified

02/23/14

Motor Vehicles

We expect to see substantial reductions in PM2.5 and PM2.5 precursor emissions from cars, 

trucks, buses, equipment, and ships due to new engine and fuel standards. 

Clean Cars and Passenger Trucks

In February 2000, EPA issued Tier II emissions standards for new gasoline and diesel light 

trucks and cars and fuel standards to reduce the sulfur content of gasoline.

33 The nationwide rules 

were phased in between 2004 and 2009 and resulted in significant reductions in NOx, PM2.5, and 

sulfur. The Washington State Legislature adopted the California Low Emission Vehicle (LEV 

II) standards in 2005 which set more stringent emissions standards for new light duty vehicles 

and trucks starting with the 2009 model year. 

Following California, in 2012 Washington adopted increasingly more stringent Low Emission 

Vehicle (LEV III) standards to be phased in over the 2015-2025 model years. EPA later 

finalized tighter Tier III vehicle and fuel standards in March 2014 to reduce emissions from 

passenger cars and trucks. The nationwide tailpipe standards are similar in stringency to LEV III 

and will be phased in gradually between model years 2017 and 2025 and the timetable will vary 
32

by vehicle class. The Tier III fuel standards will further reduce the sulfur content of gasoline 

beginning in 2017. 

Clean Diesel Trucks, Buses, and Fuel

Standards to reduce NOx and VOC emissions from heavy-duty diesel and gasoline highway 

vehicles took effect in 2004 and 2005. A second phase of standards began in 2007 and 

established stringent NOx and PM2.5 emissions standards and low sulfur diesel fuel standards 

were implemented for new buses and trucks.

Clean Non-road Diesel Rule

In 2004 EPA adopted a new rule to establish tighter emission limits for large non-road diesel 

engines, such as those used in construction, agricultural, and industrial equipment. New engine 

standards were phased in between 2008 and 2014. The rule also phased in reductions in the 

sulfur content of non-road diesel fuel.

Emission standards for Ocean-Going Vessels

In April 2010, EPA adopted standards that apply to Category 3 engines installed on U.S. vessels 

and to marine diesel fuels produced and distributed in the U.S. The emission standards are being 

phased in starting in 2011. The ultra-low sulfur diesel standard is being phased in by 2015. 

The Emission Control Area (ECA) requirements took effect in 2012 to reduce sulfur levels to 1 

percent in diesel fuel used in ocean going vessels within 200 nautical miles of coastal areas of 

North America. ECA will further require sulfur levels be reduced to 0.1 percent in 2015, 

resulting in a 74 percent reduction in PM2.5 from ocean going vessels. 

Voluntary Diesel Emission Reductions

Federal, state, and local funding and programs are providing assistance to help fleet managers 

reduce idling, use cleaner fuels, install exhaust retrofits and equipment to clean up diesel 

exhaust, and replace older engines with newer, cleaner ones. Projects have been implemented in 

the Tacoma-Pierce County area to:

 Retrofit school buses with cleaner technology, replace aging school buses with new clean 

running buses, and reduce engine idle time;

 Retrofit and reduce engine idle time for public and private fleet vehicles, including fire 

department vehicles, city and county vehicles, transit authority vehicles, waste haulers, 

and construction companies;

 Upgrade passenger and switch locomotive engines to bring them up to the cleanest 

emission standards;

 Reduce passenger and switch locomotive idling;

 Support implementation of the Northwest Ports Clean Air Strategy;

 Retrofit and replace cargo handling equipment and reduce idling at the Port of Tacoma;

 Replace reefer generators with grid electric infrastructure at the Port of Tacoma;

 Install optical character recognition and license plate readers at the Port of Tacoma to 

improve terminal efficiency and reduce gate wait times;

 Replace engines on harbor vessels with new cleaner burning engines;

 Retrofit or replace old, heavy-duty diesel trucks working in the Port of Tacoma; and

 Totem Ocean Trailer Express (TOTE) vessels to use shore power at berth, convert diesel 

vessels to LNG, and use cleaner burning fuels.
33

7. Environmental Justice 

EPA defines environmental justice as the fair treatment and meaningful involvement of all 

people...with respect to the development, implementation, and enforcement of environmental 

laws, regulations, and policies. 

Ecology organized an interagency work group focused on environmental justice which 

developed the following goals:

 Reduce health risks from fine particle pollution in priority communities. Priority 

communities are those the interagency work group identified as potentially having 

disproportionate effects from fine particle pollution or the strategies to reduce fine 

particle pollution. 

 Consider social and environmental effects on priority communities when determining 

how to reduce fine particle pollution.

 Build meaningful public participation in the SIP development and decision making 

processes. Design a communication strategy that informs and engages priority 

communities.

 Direct resources and incentives to priority communities.

 Track our progress and lessons learned in the Nonattainment Area for future planning 

work throughout Washington.

PSCAA, the Tacoma-Pierce County Clean Air Task Force, and Ecology worked together to 

incorporate environmental justice concerns in the development and implementation of fine 

particle reduction strategies. Examples of actions taken to addfress environmental justice 

considerations include:

 Low-income residents and residents with no alternative source of heat were encouraged 

to participate in the woodstove changeout program to receive up to $350 for the removal 

and recycling of eligible wood-burning devices, and a discount of up to $1,500 for a free 

heating replacement. Close to $2 million in incentives was provided, with approximately 

3⁄4 of that going to low-income households. 

 Residents with no other adequate source of heat could apply for an exemption to allow 

them to continue to use their wood stoves during burn bans. 

 Translation and interpretation services were offered for limited English proficient 

communities.

Appendix D includes a questionnaire developed to help Ecology and PSCAA track the actions 

taken in the Nonattainment Area to integrate environmental justice. Ecology worked 

collaboratively with PSCAA to complete the questionnaire. 
34

8. Redesignating the Area to Attainment

Redesignation Requirements

The federal Clean Air Act Section 107 (d) (3) outlines the requirements the state must meet to 

redesignate the Nonattainment Area to attainment.34 A description of how the state has fulfilled 

these requirements is in Table 9 below.

Table 8: Redesignation Requirements Addressed in this Plan

Requirement for 

Redesignation

How Requirement is Met

1. The area has attained the 

2006 24-hour PM2.5 

NAAQS.

In 2012 EPA made a clean data determination that the TacomaPierce County Nonattainment Area met the 2006 24-hour PM2.5 

NAAQS based on complete, quality assured and certified ambient 

air monitoring data from 2009-2011.35 The area has continued to 

attain the NAAQS since then. See section 3.

2. The improvement in air 

quality is due to permanent 

and enforceable reductions 

in emissions.

Sections 3 and 6 of this plan describe improvements in air quality 

resulting from implementation of permanent and enforceable 

control measures.

3. The area has a fully 

approved implementation 

plan under CAA section 

110(k).

When EPA approves this plan, the area will have a fully approved 

implementation plan under CAA section 110(k). 

4. The area has a fully 

approved maintenance plan 

which ensures attainment 

of the NAAQS for at least 

10 years beyond 

redesignation.

When EPA approves this plan, the area will have a fully approved 

maintenance plan demonstrating continued attainment of the 2006 

24-hour PM2.5 NAAQS for 10 years. The maintenance plan 

requirements are addressed in the following sections:

 Attainment inventory – section 4.

 Maintenance demonstration showing maintenance for 10 

years – section 4.

 A commitment to maintain the existing monitoring network 

– section 9.

 A commitment to verify continued attainment – section 9.

 A contingency plan to prevent or correct future violations 

of the NAAQS – section 9.

5. The area has met the 

requirements of CAA 

section 110 and part D.

CAA Section 110:

 Washington submitted an infrastructure SIP for the 2006 

24-hour PM2.5 NAAQS to the U.S. EPA in September

2014, demonstrating compliance with the CAA Section 110 
35

requirements.

CAA Part D Subpart 1 Requirements:

 The clean data determination issued by EPA36 suspends the 

requirements for the state to meet certain planning 

requirements contained in CAA Subpart D for so long as 

the area continues to meet the 24-hour PM2.5 NAAQS, 

including:

o An attainment demonstration,

o Reasonably available control measures,

o Reasonable further progress plan,

o Contingency Measures, and 

o Other SIP planning requirements related to 

attainment of the standard.37

 An emissions inventory is included in section 4 of this 

document to address CAA Section 172(c)(3) requirements. 

 CAA Sections 172(c)(4) and (5) and Sec. 173 stipulate 

nonattainment New Source Review permitting requirements 

for nonattainment areas. EPA policy states that a fullyapproved part D NSR program is not required for an area to 

be redesignated, provided that that the area can maintain the 

standard with a prevention of significant deterioration 

(PSD) program after redesignation.38 The Nonattainment 

Area currently attains the standard with the existing PSD 

program. Therefore nonattainment NSR permitting rules 

are not required.

 CAA Section 176(c) transportation conformity 

requirements are discussed in section 5. Washington will 

follow applicable state and federal conformity procedures.

CAA Part D Subpart 4 Requirements:

 EPA issued a rule that classifies the Tacoma-Pierce County 

PM2.5 Nonattainment Area as a moderate nonattainment 

area.39 The rule does not impose any additional 

requirements for so long as the Nonattainment Area 

continues to attain the 2006 24-hour PM2.5 NAAQS. 
36

9. Maintaining Healthy Air Quality

Commitment to Continue Monitoring and Verify Continued Attainment

Ecology and PSCAA currently operate three PM2.5 monitors in the Tacoma-Pierce County area. 

To demonstrate compliance with the fine particle NAAQS, Ecology and PSCAA commit to 

continue to operate the monitoring network. The air monitoring results will detect any changes 

in the ambient air quality and assist Ecology and PSCAA in verifying continued attainment and 

tracking the progress of the maintenance plan. Ecology and PSCAA will review the air 

monitoring results and design value each year to determine if any contingency measures need to 

be implemented.

Ecology will work with EPA each year through the air monitoring network review process, as 

required by 40 CFR Part 58, to determine:

 The adequacy of the PM2.5 monitoring network;

 If additional monitoring is needed; and

 If/when sites can be discontinued or relocated.

Ecology will follow federal monitoring regulations and will consult with EPA before making any 

changes to the network. Ecology will include a description of any changes in its annual 

monitoring report, and will continue to quality assure the monitoring data to comply with the 

requirements of 40 CFR part 58. 

Contingency Plan

Ecology and PSCAA developed a contingency plan that identifies actions Ecology and PSCAA 

will take to promptly prevent or correct a violation of the 2006 24-hour PM2.5 NAAQS that 

occurs in the Tacoma-Pierce County PM2.5 maintenance area after redesignation. The 

contingency plan identifies:

 The procedures that Ecology and PSCAA will follow to adopt and implement 

contingency measures;

 Specific indicators, or triggers, to determine when contingency measures will be 

adopted; and

 The measures to be considered.40

While these measures do not need to be fully adopted by Ecology or PSCAA prior to the 

occurrence of a NAAQS exceedance or violation, the contingency plan includes a schedule for 

adoption and implementation, and a specific time limit for action to ensure that the contingency 

measures are adopted expeditiously once they are triggered.

Ecology and PSCAA will use the following triggers and perform the following actions within the 

timeline described below as a contingency plan:

Warning level

If the 98th percentile of the 24-hour average daily concentration of PM2.5 reaches 35.5 μg/m3or 

greater in a single calendar year within the Tacoma-Pierce County PM2.5 maintenance area, 

PSCAA will evaluate all appropriate data to determine the cause of the elevated levels, and 
37

whether the elevated PM2.5 levels are likely to continue. This will include air quality data, 

meteorological data, evaluation of wood smoke programs, information on unusual weather 

events (wildfires or winter power outages), and other data to try to determine the cause of the 

exceedance. This evaluation will be performed within 6 months of the end of the year in which 

the annual 98th percentile average daily concentration of PM2.5 reaches 35.5 μg/m3or greater. 

Based on the evaluation, PSCAA will strengthen implementation of existing control measures in 

the following heating season and calendar year as appropriate to reduce emissions and PM2.5

levels. If it is determined that additional emissions reductions are necessary, PSCAA will adopt 

and implement appropriate contingency measures as expeditiously as possible, no later than 18 

months from the determination of a single year exceedance based on quality assured data. If a 

new measure or control is already promulgated and scheduled to be implemented at the federal 

or state level, and that measure or control is determined to be sufficient to prevent a violation of 

the 2006 daily PM2.5 NAAQS, additional local measures may be unnecessary. 

Action Level

If a two-year or three-year average of the 98th percentile of the 24-hour average daily PM2.5 

concentration reaches 35.5 μg/m3or greater, PSCAA will evaluate all appropriate data to 

determine the cause of the elevated levels. A three-year average of the 98th percentile of the 24-

hour average daily concentration that reaches 35.5 μg/m3or greater constitutes a violation of the 

2006 daily PM2.5 NAAQS. The evaluation will include air quality data, meteorological data, 

evaluation of wood smoke and other PM2.5 programs, information on unusual weather events 

(wildfires or winter power outages), and other data to try to determine the cause of the 

exceedance. This evaluation will occur within 6 months of the determination of a violation or 

two-year exceedance. Where appropriate, Ecology and PSCAA will follow the EPA exceptional 

events rules if it is determined that an exceptional event contributed to the violation or two-year 

exceedance, or pursue enforcement actions if the violation of a rule or permit contributed to the 

violation or two-year exceedance.

Based on the findings of the evaluation, PSCAA will identify the appropriate contingency 

measures necessary to correct the violation or two-year exceedance and assure future attainment 

of the 2006 daily PM2.5 NAAQS. The contingency measures may include strengthening 

enforcement and implementation of existing controls and/or additional controls. Additional 

controls could primarily address emissions from residential wood combustion (e.g. emissions 

from fireplaces under the existing authority granted in RCW 70.94.477 (2)(a)) and/or other PM2.5

sources identified in the emissions inventory: onroad and nonroad vehicles (diesel and gasoline), 

industrial sources, and dust. PSCAA commits to expeditiously adopt and implement the 

necessary contingency measures as expeditiously as possible, no later than 18 months from the 

determination of a two-year exceedance or violation based on quality assured data. 
38

10. Next Steps

Redesignation to Attainment 

EPA must approve Ecology’s maintenance plan and request for redesignation to remove the 

“nonattainment” designation. This would begin a 20-year planning cycle designed to make sure 

that the area remains below the federal standards. This maintenance plan covers the first 10 

years of that planning cycle. Ecology commits to submit an updated maintenance plan 8 years 

after redesignation of the Tacoma-Pierce County Area. This update will cover the second 10 year 

period. 

Table 9: Summary of commitments in this maintenance plan

Commitment Lead agency 

1. Continue operation of PM2.5 monitoring network. PSCAA

2. Review monitoring data annually and verify continued 

attainment.

Ecology

3. Implement contingency plan if certain triggers are met. PSCAA

4. Develop second 10 year maintenance plan, due 8 years after this 

maintenance plan is approved.

Ecology

Public Participation

Ecology accepted public comments on the proposed maintenance plan and redesignation request 

during a public comment period from August 27 to October 3 and at a public hearing on 

September 30. Ecology reviewed, responded to, and incorporated comments before finalizing the 

plan (See Appendix F).
39

List of Abbreviations and Other Terms

μg/m3: Micrograms per cubic meter.

98th percentile: The calculation for the 24-hour PM2.5 National Ambient Air Quality Standard 

design value uses the annual 98th percentile from the daily measurements. A percentile is 

a measure used to rank information. For air pollution, the 98th percentile measurement is 

the measurement for the day that has pollution levels higher than 98% of the other days in 

the year. To determine the 98th percentile for a full year of sampling where 365 

measurements are taken, we ignore the highest 2% of measurements – which means the 

highest 7 measurements are ignored (2% of 365 is 7). The 8th highest daily measurement 

is the 98th percentile.

CDD: Clean Data Determination. EPA issued a CDD that the Nonattainment Area met the 

standard for daily fine particle pollution during the three-year period from 2009-2011.

Design Value: EPA uses the design value to determine an area’s compliance with federal health 

based air quality standards known as NAAQS. The 24-hour PM2.5 design value is 35

μg/m3, calculated as a 3 year average of the annual 98th percentile. 

Ecology: Washington State Department of Ecology

Emissions Inventory: Calculation of the amount of pollutants released into the air during a 

specific time span

EPA: United State Environmental Protection Agency

FRM: Federal Reference Method

LEP: Limited English Proficient

Maintenance Area: The Tacoma-Pierce County PM2.5 Maintenance Area. When EPA approves 

this redesignation request, the “nonattainment” designation is removed and the area 

becomes a maintenance area for the next 20 years.

NAAQS: National Ambient Air Quality Standard

Nonattainment Area: The Tacoma-Pierce County Nonattainment Area. A Nonattainment Area 

is an area that does not meet one or more of the federal health based air quality standards 

known as the NAAQS.

NOX: Nitrogen oxide

PM2.5: Another term for fine particles. Particles that are less than 2.5 micrometers in diameter.
40

PSCAA: Puget Sound Clean Air Agency

RCW: Revised Code of Washington

SIP: State Implementation Plan

SIP revision for the Tacoma-Pierce County Nonattainment Area: Washington’s plan to 

improve air quality in the Tacoma-Pierce County Nonattainment Area

SO2: Sulfur dioxide

Tacoma-Pierce County Fine Particle Nonattainment Area: Most of the greater Tacoma area 

and the surrounding communities within Pierce County’s urban growth area west of State 

Route 167. EPA designated this area nonattainment for the 2006 24-hour fine particle 

national ambient air quality standard in 2009

Tacoma–South L Street: The monitoring site in the Nonattainment Area with a monitor that 

uses the FRM. EPA uses data from the FRM monitor at Tacoma – South L Street to 

determine compliance with the federal health based fine particle standards

Task Force: The Tacoma-Pierce County Clean Air Task Force

UGA: Urban growth area

WAC: Washington Administrative Code

VOC: Volatile Organic Compounds
41

Appendices

Appendices are posted as separate documents on Ecology’s website, 

http://www.ecy.wa.gov/programs/air/sips/designations/pm_tacoma.htm. 

Appendix A. Emissions Inventories

Appendix B. MOVES Inputs

Appendix C. Motor Vehicle Emissions Budget 

Methodology

Appendix D. Environmental Justice Questionnaire

Appendix E. Additional Resources 

Appendix F. Response to Comments
42

References

 

1

Federal Register Vol. 74, No. 218, November 13, 2009, 58688, 

http://www.gpo.gov/fdsys/pkg/FR-2009-11-13/pdf/E9-25711.pdf

2

 Federal Register Vol. 71, No. 200, Oct. 17, 2006, 61144, http://www.gpo.gov/fdsys/pkg/FR2006-10-17/pdf/06-8477.pdf#page=1

3

Tacoma-Pierce County Clean Air Task Force, www.cleanairpiercecounty.org

4

Federal Register Vol. 77, No. 171, Sept. 4, 2012, 53772, http://www.gpo.gov/fdsys/pkg/FR2012-09-04/pdf/2012-21560.pdf

5

Federal Register Vol. 71, No. 200, Oct. 17, 2006, 61144, http://www.gpo.gov/fdsys/pkg/FR2006-10-17/pdf/06-8477.pdf#page=1

6

 Federal Register Vol. 74, No. 218, Nov. 13, 2009, 58688, http://www.gpo.gov/fdsys/pkg/FR2009-11-13/pdf/E9-25711.pdf

7

Tacoma-Pierce County Clean Air Task Force, 2011, “Report and Recommendations to Puget 

Sound Clean Air Agency”, 

http://www.cleanairpiercecounty.org/taskforce/CleanAirTaskForceReport_FullReport.pdf

8

 Federal Register Vol. 77, No. 171, Sept. 4, 2012, 53772, http://www.gpo.gov/fdsys/pkg/FR2012-09-04/pdf/2012-21560.pdf 

9

Substitute House Bill 2326, Chapter 219, Laws of 2012, 

http://apps.leg.wa.gov/documents/billdocs/2011-12/Pdf/Bills/Session%20Laws/House/2326-

S.SL.pdf

10 Puget Sound Clean Air Agency, Regulation 1, Article 13, “Solid Fuel Burning Device 

Standards,” http://www.pscleanair.org/regulated/reg1/1-13.pdf

11 Federal Register Vol. 78, No. 103, May 29, 2013, 32131, http://www.gpo.gov/fdsys/pkg/FR2013-05-29/pdf/2013-12514.pdf

12 EPA approved the MVEBs, effective Oct. 21, 2013; Federal Register Vol. 78, No. 182, Sept. 

19, 2013, 57503, http://www.gpo.gov/fdsys/pkg/FR-2013-09-19/pdf/2013-22738.pdf

13 Federal Register Vol. 79, No. 90, May 9, 2014, 26628, http://www.gpo.gov/fdsys/pkg/FR2014-05-09/pdf/2014-10581.pdf

14 Federal Register Vol. 74, No. 218, Nov. 13, 2009, 58688, http://www.gpo.gov/fdsys/pkg/FR2009-11-13/pdf/E9-25711.pdf
43

 

15 Federal Register Vol. 77, No. 171, Sept. 4, 2012, 53772, http://www.gpo.gov/fdsys/pkg/FR2012-09-04/pdf/2012-21560.pdf 

16 Dept. of Ecology, 2009, “Health Effects and Economic Impacts of Fine Particle Pollution in 

Washington,” Publication 09-02-021, 

https://fortress.wa.gov/ecy/publications/SummaryPages/0902021.html

17 Federal Register Vol. 71, No. 200, Oct. 17, 2006, 61144, http://www.gpo.gov/fdsys/pkg/FR2006-10-17/pdf/06-8477.pdf#page=1

18 Federal Register Vol. 77, No. 171, Sept. 4, 2012, 53772, http://www.gpo.gov/fdsys/pkg/FR2012-09-04/pdf/2012-21560.pdf

19 See Code of Federal Regulations 51.1004(c); US EPA, 2004, “Clean Data Policy for the Fine 

Particle National Ambient Air Quality Standards,” Memo from Stephen D. Page, 

http://www.epa.gov/airquality/urbanair/sipstatus/docs/pm25_clean_data_policy_14dec2004.pdf

20 See 40 CFR Part 51 Subpart Z—Provisions for Implementation of PM2.5 National Ambient Air 

Quality Standard

21 Substitute House Bill 2326 Chapter 219, Laws of 2012, 

http://apps.leg.wa.gov/documents/billdocs/2011-12/Pdf/Bills/Session%20Laws/House/2326-

S.SL.pdf

22 Federal Register Vol. 79, No. 22, February 3, 2014, 6330, http://www.gpo.gov/fdsys/pkg/FR2014-02-03/pdf/2014-00409.pdf . 

23 See 40 CFR Part 93 Subpart A; Chapter 173-420 Washington Administrative Code

24 See Appendix A for the emissions inventory documentation and Appendix B for the MOVES 

documentation 

25 Safety margin is defined in 40 CFR 93.101

26 See 40 CFR 93.102 (b)(1) and (2)(iv) and (v)

27 Tacoma-Pierce County Clean Air Task Force, www.cleanairpiercecounty.org

28 Tacoma-Pierce County Clean Air Task Force, 2011, “Report and Recommendations to Puget 

Sound Clean Air Agency”

29 See section 4 and appendix A of this report for more detail

30 Substitute House Bill 2326 Chapter 219, Laws of 2012, 

http://apps.leg.wa.gov/documents/billdocs/2011-12/Pdf/Bills/Session%20Laws/House/2326-

S.SL.pdf
44

 

31 Federal Register Vol. 78, No. 103, May 29, 2013, 32131, http://www.gpo.gov/fsdsys/pkg/FR2013-05-29/pdf/2013-12514.pdf

32 Federal Register Vol. 79, No. 90, May 9, 2014, http://www.gpo.gov/fdsys/pkg/FR-2014-05-

09/pdf/2014-10581.pdf

33 Federal Register Vol. 65, No. 28, February 10, 2000, 6698, http://www.gpo.gov/fdsys/pkg/FR2000-02-10/pdf/00-19.pdf

34 See also US EPA, 1992, “Procedures for Processing Request to Redesignate Areas to 

Attainment,” Memorandum from John Calcagni, 

http://www.epa.gov/glo/designations/1997standards/redesig/documents/RedesignationGuidance-9-04-92.pdf

35

 Federal Register Vol. 77, No. 171, Sept. 4, 2012, 53772, http://www.gpo.gov/fdsys/pkg/FR2012-09-04/pdf/2012-21560.pdf

36 Federal Register Vol. 77, No. 171, Sept. 4, 2012, 53772, http://www.gpo.gov/fdsys/pkg/FR2012-09-04/pdf/2012-21560.pdf

37 See 40 CFR 51.1004(c); US EPA, 2004, “Clean Data Policy for the Fine Particle National 

Ambient Air Quality Standards,” Memo from Stephen D. Page, 

http://www.epa.gov/airquality/urbanair/sipstatus/docs/pm25_clean_data_policy_14dec2004.pdf ; 

Federal Register Vol. 72, No. 79, April 25, 2007, 20586, 72 FR 20586, 

http://www.gpo.gov/fdsys/pkg/FR-2007-04-25/pdf/E7-6347.pdf

38 See US EPA, 1994, “Part D New Source Review (part D NSR) Requirements for Areas 

Requesting Redesignation to Attainment,” Memo from Mary D. Nichols, 

http://www.epa.gov/region7/air/nsr/nsrmemos/101494m.pdf

39 Federal Register Vol. 79, No. 105, June 2, 2014, 31566, http://www.gpo.gov/fdsys/pkg/FR2014-06-02/pdf/2014-10395.pdf

40 Because the area has a clean data determination, the requirement for the contingency plan to 

clearly identify the contingency measures that will be adopted is suspended for so long as the 

area continues to meet the 24-hour PM2.5 NAAQS (See 77 FR 53772, Sept. 4, 2012; 40 CFR 

51.1004(c))