Washington State 

Implementation Plan Revision

Interstate Transport of Lead, Nitrogen 

Dioxide, and Ground-Level Ozone

March 2015 

Publication no: 15-02-005
Publication and Contact Information 

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

https://fortress.wa.gov/ecy/publications/SummaryPages/1502005.html 

For more information contact:

Department of Ecology

Attn: Air Quality Program

P.O. Box 47600 

Olympia, WA 98504-7600 

Phone: (360) 407.6800 

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

o Headquarters, Olympia 360-407-6000 

o Northwest Regional Office, Bellevue 425-649-7000 

o Southwest Regional Office, Olympia 360-407-6300 

o Central Regional Office, Yakima 509-575-2490 

o Eastern Regional Office, Spokane 509-329-3400 

If you need this document in a format for the visually impaired, call the Air Quality Program at 

360-407-6800. Persons with hearing loss can call 711 for Washington Relay Service. Persons 

with a speech disability can call 877-833-6341.

Interstate Transport of Lead, Nitrogen 

Dioxide, and Ozone

Addressing requirements for the 2008 Lead, 2010 

Nitrogen Dioxide, and 2008 Ozone National Ambient 

Air Quality Standards

by

Air Quality

Washington State Department of Ecology

Olympia, Washington


Table of Contents

Page

List of Figures and Tables................................................................................................... ii

Figures........................................................................................................................... ii

Tables............................................................................................................................ ii

Acknowledgements............................................................................................................ iii

Executive Summary........................................................................................................... iv

Introduction..........................................................................................................................1

Interstate Transport of Lead.................................................................................................3

Background....................................................................................................................3

Washington’s approach..................................................................................................4

Transport Assessment ....................................................................................................5

Interstate Transport of Nitrogen Dioxide.............................................................................7

Background....................................................................................................................7

Washington’s approach..................................................................................................7

Transport Assessment ....................................................................................................9

Emissions Inventory ..............................................................................................9

Air Quality Data and Design Values for neighboring states...............................11

Interstate Transport of Ozone ............................................................................................12

Background..................................................................................................................12

Washington’s approach................................................................................................13

Transport Assessment ..................................................................................................13

Appendix............................................................................................................................14

A. Additional information on Interstate Transport of Lead .....................................14

B. EPA 2015 “Good Neighbor” Memorandum .......................................................21

i
List of Figures and Tables

Page

Figures

Figure 1 Location of lead sources greater than 0.5 tpy in Washington .......................................... 5

Figure 2 Lead sources greater than 0.1 tpy and smaller than 0.5 tpy ............................................. 6

Figure 3 Ambient air monitoring levels and emission estimates for the main categories 

contributing to NOx in Washington.............................................................................................. 10

Figure A 1 Lead sources (<0.5 tpy) in all bordering counties. ..................................................... 14

Figure A 2 Available daily mean values of lead at the Multnomah monitoring site .................... 20

Tables

Table 1 Sources greater than 0.5 tpy in Washington ...................................................................... 5

Table 2 2011 Washington State NOx Emissions Inventory of anthropogenic sources.................. 9

Table 3 Oregon monitoring site measuring NO2 .......................................................................... 11

Table 4 NO2 Design values at the Oregon monitoring site........................................................... 11

Table A 1 List of all lead sources smaller than 0.5 tpy located in bordering counties................. 15

ii
Acknowledgements

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

study:

• Anya Caudill

• Claudia Toro

• Sally Otterson

• Farren Herron-Thorpe

• Clint Bowman

• Jocelyn Jones

• Amber Littlejohn

• Camille St. Onge

• Joanna Ekrem

• Jeff Hunt

iii
Executive Summary

The “good neighbor” or “interstate transport” provisions of the Federal Clean Air Act (CAA) 

protect downwind states from harmful pollution that originates in upwind states. This State 

Implementation Plan (SIP) revision contains Washington’s analysis of the interstate transport of 

lead (Pb), nitrogen dioxide (NO2), and ozone (O3). It finds that Washington’s sources do not 

significantly contribute to Pb, NO2, and O3 air pollution in other states. No new rules are 

proposed.

Lead is a metal found naturally in the environment as well as in manufactured products. 

Environmental Protection Agency (EPA) sets standards for lead air pollution because lead 

exposure can cause health and developmental problems, especially in children. Exposures to low 

levels of lead early in life have been linked to effects on IQ, learning, memory, and behavior.

Lead persists in the environment and accumulates in soils. Historically, the major sources of 

lead were from motor vehicles and industrial sources. Nationwide, lead pollution levels dropped 

sharply when lead was phased out of gasoline starting in the 1970s. Today, the major sources of 

lead are lead smelters, ore and metal processers, and piston-engine aircraft operating on leaded 

aviation gasoline. There are no large smelters in Washington State. Battery recyclers, wood 

products facilities, pulp and paper mills, glass manufacturers, refineries and piston-engine 

aircraft operating on leaded aviation gasoline are minor sources of lead in Washington.

All areas in Idaho, Oregon, and Washington are in compliance with the lead standard set in 2008.

Lead emissions are relatively heavy and do not travel far from the source of emissions.

Ecology’s analysis focused on Washington’s sources of lead pollution that are located near state 

borders with Idaho and Oregon and reviewed existing ambient monitoring data and emissions 

inventories. Ecology found no evidence of significant transport of lead pollution across the state 

border. 

Nitrogen dioxide (NO2) is an indicator of the nitrogen oxides (NOx) pollution. The main source 

of NOx pollution is the combustion processes. A small percentage of NOx is directly emitted, but 

the majority is formed in the atmosphere from a combination of transportation, power plants, offroad equipment, and biomass burning pollution. NOx exposure has been linked to respiratory 

effects including airway inflammation in otherwise healthy people and increased respiratory 

symptoms in people with asthma. Major exposure concerns are localized along the main traffic 

arteries. NOx reacts with other elements and compounds in the air and contributes in the 

formation of ground-level ozone (O3) and fine particles. Fine particles interstate transport 

analysis is separate from this submittal.

All areas in Idaho, Oregon, and Washington are in compliance with the NO2 standard set in 

2010. Ecology reviewed existing ambient monitoring data, emissions inventories, design values 

and EPA guidelines to assess transport of NO2. Ecology found no evidence of significant NO2

pollution across the state border.

Ground-level ozone is the primary component of smog. Ground level ozone forms when 

emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) “cook” in the sun—

making it mainly a summertime pollutant. The major sources of human-made NOx and VOCs 

iv
are emissions from industrial facilities, electric utilities, motor vehicle exhaust, gasoline vapors, 

and chemical solvents. Ozone pollution can travel over hundreds of miles and can affect both 

urban and rural areas. 

Breathing air containing elevated levels of ozone can reduce lung function and increase 

respiratory symptoms. It can aggravate asthma or other respiratory conditions. Ozone exposure 

also has been associated with increased:

• Vulnerability to respiratory infections.

• Medication use by people with asthma.

• Doctors visits.

• Emergency room visits and hospital admissions for individuals with respiratory disease.

Ozone exposure may also contribute to premature death, especially in people with heart and lung 

disease. In addition, repeated exposure to ozone damages sensitive vegetation and trees, 

including those in forests and parks, leading to reduced growth and productivity, increased 

vulnerability to disease and pests, and damaged foliage.

All areas in Idaho, Oregon, and Washington are in compliance with the ozone standard set in 

2008. EPA performed photochemical air quality modeling to project ozone concentrations at air 

quality monitoring sites to 2018—and to estimate each state’s contributions to those 2018 

concentrations. EPA found that Washington does not contribute significantly to ozone pollution 

in other states.

v

Introduction

Washington State Department of Ecology (Ecology) submits this State Implementation Plan 

(SIP) revision to address the requirements of the Clean Air Act (CAA) with regard to the 2008 

Lead (Pb), 2010 1-hour Nitrogen Dioxide (NO2), and 2008 Ozone (O3) National Ambient Air 

Quality Standards (NAAQS). This revision addresses section 110(a)(2)(D)(i) of the CAA that 

requires a SIP to:

(D) contain adequate provisions –

(i) prohibiting, consistent with the provisions of this subchapter, any source or 

other type of emissions activity within the State from emitting any air pollutant 

in amounts which will –

(I) contribute significantly to nonattainment in, or interfere with 

maintenance by, any other State with respect to any such national 

primary or secondary ambient air quality standard....

(II) interfere with measures required to be included in the applicable 

implementation plan for any other state....to prevent significant 

deterioration or to protect visibility

The requirements to control interstate transport of pollutants are often referred to as “good 

neighbor” provisions of the CAA. The intent of the provisions is to ensure that residents and the 

welfare of downwind states are protected from harmful emissions originating in upwind states.

Currently, neither Washington nor its neighboring states (Oregon and Idaho) have nonattainment 

or maintenance areas with respect to Pb, NO2, or O3.

The CAA requires Washington to ensure that any source or type of emissions activity within the 

state will not contribute significantly to nonattainment or interfere with maintenance in another 

state. The Washington SIP, codified in 40 CFR 52 Subpart WW, contains regulations for minor 

source permitting to ensure protection of all relevant NAAQS1. For major sources, Washington 

is already subject to a PSD permitting program operated under an EPA Federal Implementation 

Plan (FIP).

 

The analysis developed by Washington in support of this SIP revision shows no indication of a 

significant Pb or NO2 transport across state borders. EPA’s analysis of ozone transport also 

shows that Washington’s sources do not contribute significantly to areas with ozone pollution in 

other states. Based on our assessment and findings, we assert that Washington does not 

contribute significantly to nonattainment, or interfere with maintenance, in another state with 

respect to the Pb, NO2, and O3 NAAQS. The information reviewed, findings, and conclusions 

are presented in three chapters: the first chapter describes the analysis for the interstate transport 

1 Updated revisions to Washington’s SIP “General Regulations for Air Pollution Sources”, Docket ID no. EPAOAR-2014-0141, effective November 3, 2014

1

 
of Pb, the second chapter details the findings pertaining to interstate transport of NO2, and the 

third chapter reviews EPA’s analysis and findings related to ozone transport.

2
Interstate Transport of Lead

Background

Lead (Pb) is a metal found naturally in the environment as well as in manufactured products. 

Historically, the major sources of lead were fuel combustion from on-road motor vehicles and 

industrial sources. After EPA’s efforts to remove lead from vehicle gasoline, lead emissions 

from the transportation sector decreased dramatically. Today, the major sources are lead 

smelters, ore and metal processers and piston-engine aircraft operating on leaded aviation 

gasoline. Pb associated with coarse particulate material (PM) deposits to a greater extent near 

local industrial sources, while fine Pb-bearing PM can be transported longer distances2.

On October 5, 1978, EPA promulgated primary and secondary NAAQS for Pb. Both were set as 

1.5 micrograms per cubic meter (μg/m3), measured as Pb in total suspended particles (Pb-TSP), 

not to be exceeded by the maximum arithmetic mean concentration averaged over a calendar 

quarter. The standards were published on the 1977 Air Quality Criteria for Lead, which assessed 

the scientific evidence available at the time regarding public health effects as result of exposure 

to lead.

The first review of the Pb standards was initiated in the mid-1980s. Based on the scientific 

assessment, EPA did not propose any revisions to the 1978 Pb NAAQS. The most recent review 

was initiated in November, 2004. Based on the assessment findings and considering the 

significantly different circumstances since Pb was listed in 1976, EPA proposed to revise both 

primary and secondary standards from 1.5 μg/m3 to 0.15 μg/m3

, with a rolling three-month 

period averaging time and a maximum not to be exceeded over a three-year period. The final 

revisions were published in the federal register on November 12, 20083. 

 

EPA’s revisions were based on the weight of scientific evidence demonstrating neurocognitive 

effects of Pb in children. Lead in blood is the most common index of Pb exposure in 

epidemiologic studies of Pb health effects4

. The scientific evidence correlates levels of Pb in air 

with levels of Pb in children’s blood, and Pb in children’s blood with IQ loss. The 0.15 μg/m3

level was estimated to be protective against air Pb-related IQ loss in the most susceptible 

children5.

On October 14, 2011, EPA issued a Guidance on Infrastructure State Implementation (SIP) 

Elements Required Under Sections 110(a)(I) and 110(a)(2) for the 2008 Lead (Pb) National 

Ambient Air Quality Standards (NAAQS). As stated in the guidance, EPA believes that

2 See EPA/600/R-10/075F, Integrated Science Assessment for Lead, Section 1.2.1, EPA, ORD, Research Triangle 

Park, NC, June 2013

3 73 FR 66964

4 See EPA/600/R-10/075F, Integrated Science Assessment for Lead, EPA, ORD, Research Triangle Park, NC, June 

2013

5 See Integrated Review Plan for the National Ambient Air Quality Standards for Lead, EPA, November 2011

3

 
(...) the physical properties of Pb prevent Pb emissions from experiencing the same 

travel or formation phenomena as PM2.5 or ozone. More specifically, there is a sharp 

decrease in Pb concentrations, at least in the coarse fraction, as the distance from a Pb 

source increases. Accordingly, while it may be possible for a source in a state to emit Pb 

in a location and in quantities that may contribute significantly to nonattainment in, or 

interfere with maintenance by, any other state, EPA anticipates that this would be a rare 

situation, e.g. where large sources are in close proximity to state boundaries.

The Guidance indicates also

(...) requirements of subsection(2)(D)(i)(I) (prongs 1 and 2) could be satisfied through a 

state’s assessment as to whether or not emissions from Pb sources located in close 

proximity to their state borders have emissions that impact the neighboring state such 

that they contribute significantly to nonattainment or interfere with maintenance in that 

state. 

EPA suggests that sources that emit less than 0.5 tons per year (tpy) or located more than two

miles from a state border are unlikely to contribute significantly to nonattainment in another 

state6.

Washington’s approach 

Ecology reviewed the 2011 National Emissions Inventory (NEI) list of facilities reporting lead 

emissions and determined their distance from state borders. Subsequently, Ecology assessed the 

information based on EPA’s suggestion regarding significance of sources either larger than 0.5 

tpy or closer than two miles from the border. The information reviewed, findings and 

conclusions are presented in the next section.

6 See Guidance on Infrastructure State Implementation Plan (SIP) Elements Required Under Sections 110(a)(1) and 

110(a)(2) for the 2008 Lead (Pb) National Ambient Air Quality Standards (NAAQS) foot note 7, page 8, September 

13, 2013

4

 
Transport Assessment 

The largest sources of lead in Washington are located in King and Snohomish counties. Table 1 

lists the largest sources and Figure 1 shows their location:

Table 1 Sources greater than 0.5 tpy in Washington

Facility Type Site Name County Emissions 

(tpy)

Distance to 

ID border 

(miles)

Distance to 

OR border 

(miles)

Airport Auburn Muni King 0.61 242 122

Glass Plant

Saint-Gobain 

Containers, 

Inc. (Verallia)

King 0.54 245 135

Airport Harvey Field Snohomish 0.54 233 160

Because of their considerable distance to state borders and the physical properties of Pb, the 

sources listed in Table 1 are unlikely to contribute significantly to nonattainment, or interfere 

with maintenance, in another state.

Figure 1 Location of lead sources greater than 0.5 tpy in Washington (red circles).

Closer to the borders, there are several lead sources reporting less than 0.5 tpy according to the 

2011 NEI. Sources between 0.1 and 0.5 tpy located in counties bordering other states are shown 

in Figure 2. The largest source reports 0.16 tpy and corresponds to the Felts Field Airport in 

5
Spokane. The list of all sources smaller than 0.5 tpy located in bordering counties is in the 

Appendices. 

Since the Guidance suggests that sources smaller than 0.5 tpy are not likely to result in 

significant impact to neighboring states, no further analysis was performed. In addition, there 

are no areas in nonattainment or maintenance with respect to the 2008 lead NAAQS in Oregon or 

Idaho. In fact, Pb levels measured in the Portland-Vancouver-Beaverton area are well below the 

standard (see Appendix A, Figure A-2). The monitor located at the Portland-VancouverBeaverton area (Multnomah site) is located near the Oregon-Washington border. The only 

monitor currently measuring Pb in Idaho is located in Ada County which is far enough from the 

border and does not represent transport of Pb, at least in the coarse fraction, originating in 

Washington. 

After reviewing all the evidence gathered, Ecology is confident affirming that Washington 

sources are unlikely to contribute significantly to nonattainment, or interfere with maintenance, 

with respect to the 2008 lead NAAQS. 

Figure 2 Lead sources greater than 0.1 tpy and smaller than 0.5 tpy (red circles), located in 

bordering counties.

6
Interstate Transport of Nitrogen Dioxide

Background

Nitrogen dioxide (NO2) is one of the components of the nitrogen oxides (NOx) group. EPA’s 

NAAQS uses NO2 as an indicator for NOx. The main source of NO2 is combustion processes. 

A small percentage of NO2 is directly emitted but the majority is formed rapidly from nitric 

oxide (NO) emissions from transportation, power plants, off-road equipment and biomass 

burning.

NO2 is regulated due to its harmful effect on health. NO2 exposure has been linked to respiratory 

effects including airway inflammation in healthy people and increased respiratory symptoms in 

people with asthma. 

A second reason for the regulation of NO2 is its role in the formation of ground-level ozone (O3) 

and fine particulate material (PM2.5). NO2 impacts the ozone cycle directly through photolysis, 

favoring O3 production. Depending on the level of hydroxyl (OH) radicals present, NO2 can 

react to form nitric acid (HNO3) instead. This is the main atmospheric loss process for NOx. 

Nitric acid can either react with ammonia (NH3) to form ammonium nitrate (NH4NO3) (which is 

a main component of PM2.5) or be lost through deposition processes (wet and dry) resulting in 

“acid rain”.

NO2 lifetime in the urban atmosphere is fairly short (~2-6 hours

7

). As a result, transport of NO2

from urban sources is not common, and interstate transport issues are linked to ozone and PM2.5

instead. The main concern regarding NO2 is near-road exposure in areas with traffic congestion. 

Monitoring efforts are usually located close to roads, resulting in air quality data associated with 

local impacts rather than transport issues. 

The first primary standard for NO2 was set by EPA in 1971 as 53 ppb (parts per billion) averaged 

annually. EPA has reviewed the standard twice since then, however, in both occasions it decided 

not to revise it. Instead, in 2010, EPA established an additional primary standard for NO2 at a 

level of 100 part per billion (ppb), based on the 3-year average of the 98th percentile of the yearly 

distribution of 1-hour daily maximum concentrations. On February 17, 2012, EPA published the 

final NO2 designations8 identifying all areas in the United States as unclassifiable/attainment for 

the 2010 1-hour NO2 NAAQS. 

Washington’s approach

In September 2009, EPA issued a Guidance on SIP Elements Required Under Section 110(a)(1) 

and (2) for the 8-hour Ozone and PM2.5 NAAQS (Harnett Guidance). In this guidance, EPA 

directed states to develop an adequate technical analysis to support state’s findings and 

7 See Beirle et al., Megacity Emissions and Lifetimes of Nitrogen Oxides Probed from Space, Science 333, 1737 

(2011)

8 See EPA-HQ-OAR-2011-0572

7

 
conclusions. However, there was no guidance suggesting how to approach a technical analysis 

for NO2. Therefore, Ecology devised the most reasonable methodology possible taking into 

consideration other states submittals, emission inventories, ambient data available for the region 

and the significant fact that all areas are designated attainment or unclassifiable for the 2010 1-

hour NO2 NAAQS. 

Ecology’s approach included the examination of ambient data for states bordering Washington 

within a 50 kilometer radius, the standard distance for modeling analysis9 consistent with EPA’s 

Modeling Guideline. Additionally, Ecology reviewed the most recent NOx emissions inventory 

for the state of Washington and evaluated state trends. 

9 Appendix W to 40 CFR Part 51

8

 
Transport Assessment

Emissions Inventory 

The last detailed emissions inventory (EI) for the State of Washington was developed by 

Ecology in 2011. Table 2 lists anthropogenic source categories used in the 2011 EI:

Table 2 2011 Washington State NOx Emissions Inventory of anthropogenic sources

Source Category Emissions (tons/year)

On-road mobile sources 164,130

Non-road mobile except locomotives, ships and aircraft 31,467

Point sources 26,361

Others

Commercial marine vessels 20,486

Locomotives 15,026

Residential fuel use: natural gas, oil, LPG 4,589

Recreational boats 3,530

Aircraft: military, commercial, general aviation 3,309

Woodstoves, fireplaces, inserts 1,803

Agricultural and silvicultural burning 1,621

Residential outdoor burning: yard waste and trash 557

Commercial fuel use: natural gas, LPG 204

Miscellaneous 28

According to Table 2, On-road mobile sources comprise 57 percent of total NOx emissions, 

Non-road mobile sources represent 11 percent, and the third largest group, Point sources, 

comprises 9 percent of all the NOx emissions in Washington in 2011. It is worth mentioning that 

one of the main point sources (TransAlta Centralia Power Plant) is expected to shut down its two 

coal-fired boilers: one in 2020 and the second 202510. 

National trends indicate that NOx emissions have decreased substantially since 198011. Stricter 

standards for mobile sources as well as regulations for industrial sources suggest that this trend 

will continue. Ecology performed a standard run of the updated Motor Vehicle Emission 

Simulator (MOVES2014, database version 20141021) for Washington, to look specifically at 

future trends in on-road and non-road mobile sources12 reported for the state. Figure 3 shows the 

result of the modeling run. On-road mobile sources are divided by type of fuel (ORMgas and 

ORMdiesel). Figure 3 also shows available NO2 ambient air monitoring data at the Beacon-Hill 

monitoring station that represents the Seattle-Tacoma-Bellevue area, which is the most populated 

area of the state: 

10 “BART Determination Document, TransAlta Centralia Power Plant”, Washington State Department of Ecology, 

revised November 2011 

11 http://www.epa.gov/airtrends/nitrogen.html 12 MOVES2014 incorporates EPA’s NONROAD2008 model

9

 
Figure 3 Ambient air monitoring levels13 and emission estimates for the main categories 

contributing to NOx in Washington

The past trend estimated with MOVES2014 show a steady decrease in NOx emissions from 

mobile sources, which overall agrees with the observed ambient values measured at Beacon-Hill. 

The projected trend suggests that mobile contributions to NOx emissions in the state will 

continue to decrease. 

Currently, there are no nonattainment areas with respect to the 2010 1-hour NO2 NAAQS in 

neighboring states. Ecology concludes that since Washington NOx emissions are projected to 

continue a decreasing trend, it will be even less likely that Washington sources will significantly 

contribute to nonattainment, or interfere with maintenance, in any other state with respect to the 

2010 1-hour NO2 NAAQS. 

13 Data obtained from AirData website. Data shown is only for comparison of trends and does not necessarily meet 

the completeness criteria.

0

5

10

15

20

25

30

35

0

100

200

300

400

500

600

700

800

ambient NOx (ppb)

NOx (tons/day)

Year

ORMgas

ORMdiesel

non-road

Beacon-Hill

10

 
Air Quality Data and Design Values for neighboring states

The monitoring site measuring NO2 in neighboring states and within a 50 kilometer radius is in 

Oregon. Table 3 lists this site’s characteristics. Table 4 shows the latest three design values for 

the Portland-Vancouver-Beaverton area, which is the only station meeting the completeness 

criteria in neighboring states. The design values presented cover a period of 5 years (2009-

2013): 

Table 3 Oregon monitoring site measuring NO2

State County CBSA Site Address Completeness 

Criteria Met

OR Multnomah Portland-VancouverBeaverton, OR-WA 410510080 5824 SE Lafayette Y

Table 4 NO2 Design values at the Oregon monitoring site

CBSA Site Average 2009-2011

(ppb)

2010-2012

(ppb)

2011-2013

(ppb)

PortlandVancouverBeaverton, 

OR-WA

410510080 1 hour 36 34 34

The monitoring site located in the OR-WA border is currently in attainment with respect to the 

2010 1-hour NO2 NAAQS. Therefore, Ecology concludes that Washington sources do not 

contribute significantly to nonattainment, or interfere with maintenance, in any other state with 

respect to the 2010 1-hour NO2 NAAQS. 

11
Interstate Transport of Ozone

Background

Ground-level ozone is the primary component of smog. Ozone that occurs naturally in the upper 

portions of the earth’s atmosphere, often referred to as “good ozone”, forms a layer that protects 

life on earth from the sun’s harmful rays. Ozone that forms at ground level, or “bad ozone”, is 

harmful to breath and damaging to sensitive vegetation and ecosystems. Ground level ozone 

forms when emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) “cook” 

in the sun making it mainly a summertime pollutant. The major sources of human-made NOx

and VOCs are emissions from industrial facilities, electric utilities, motor vehicle exhaust, 

gasoline vapors, and chemical solvents. Ozone pollution can be transported through air over 

hundreds of miles and can affect both urban and rural areas.

Breathing air containing ozone can reduce lung function and increase respiratory symptoms, 

thereby aggravating asthma or other respiratory conditions. Ozone exposure also has been 

associated with increased susceptibility to respiratory infections, medication use by asthmatics, 

doctor visits, and emergency department visits and hospital admissions for individuals with 

respiratory disease. Ozone exposure may also contribute to premature death, especially in 

people with heart and lung disease. In addition, scientific evidence showed that repeated 

exposure to ozone damages sensitive vegetation and trees, including those in forests and parks, 

leading to reduced growth and productivity, increased susceptibility to disease and pests, and 

damaged foliage.

On March 12, 2008, EPA strengthened ground-level ozone NAAQS. EPA revised the

“primary”, or health-based, and “secondary”, ecosystem and welfare-based, 8-hour standards to a 

level of 0.075 parts per million (ppm). In setting the standard, EPA reviewed more than 1700 

new scientific studies indicating strong evidence of adverse health impact of ozone at the level 

above the new standard. However, this standard was not as protective as recommended by 

EPA’s panel of scientific advisors (Clean Air Scientific Advisory Committee) and was 

challenged in court. Subsequently, EPA proposed to reconsider the standard in 2009. In January 

2010, EPA proposed that the new standard is set within the range of 0.060 ppm to 0.070 ppm. 

However, in September 2011, the Administration issued a statement requesting EPA to withdraw 

the proposal and continue to implement the standard that was set in 2008 in anticipation of the 

upcoming scientific and policy review to support the next revision of the ozone standard. At this 

time, EPA is under a court-ordered deadline to promulgate a new or revise existing ozone 

standards in December 2015.

Efforts by the EPA and states to address ozone transport have historically been focused on 

reductions of NOx. Between 1990 and 2006, ground-level ozone declined 9% nationwide. 

Eighty-nine of the original one hundred twenty-six areas designated nonattainment for the 1997 

standard met that standard during the 2004-2006 period. EPA continues to implement measures 

to reduce ozone interstate transport through implementation of the 2005 Clean Air Interstate 

Rule (CAIR), the 2003 NOx Budget Trading Program, and the 2011 Cross-State Air Pollution 

Rule (a litigation-related stay on this rule was lifted in October 2014).

12
Washington’s approach 

On January 22, 2015, EPA issued a Memorandum on Information of the Interstate Transport 

“Good Neighbor” Provision for the 2008 Ozone National Ambient Air Quality Standards 

(NAAQS) under Clean Air Act (CAA) Section 110(a)(2)(D)(i)(I). The attachment to the 

memorandum highlights the results from the Air Quality Modeling Technical Support Document 

for the 2008 Ozone NAAQS Transport Assessment14 (Ozone Transport TSD). In the Ozone 

Transport TSD document, EPA details photochemical air quality modeling it performed to 

project ozone concentrations at air quality monitoring sites to 2018 and to estimate state-by-state 

contributions to those 2018 concentrations. In its analysis, EPA applies the CSARP approach

including the approach for identifying nonattainment and maintenance receptors and for 

identifying upwind states that contribute to these receptors based on the screening threshold (1 

percent of the NAAQS). The memorandum states that based on the modeling results a state 

could either demonstrate that its contribution is below the screening threshold, or it could 

evaluate the scope of its transport obligation and indentify measures to achieve any needed 

emissions reductions.

Ecology reviewed EPA’s modeling of ozone interstate transport for Washington. It indicates that 

most western states contribute less than 1 percent to downwind nonattainment or maintenance 

receptors. Washington’s contribution is estimated to be significantly less than the screening 

threshold. Following the CSARP approach, the memorandum confirms that contributions below 

the screening threshold do not need further evaluation for actions to address transport. 

In accordance with EPA’s approach in CSARP and the 2015 “Good Neighbor” Memorandum, 

and based on the Ozone Transport TSD findings, Ecology asserts that Washington sources do 

not contribute significantly to nonattainment areas or interfere with maintenance of the 2008 

ozone NAAQS. 

Transport Assessment 

Appendix B contains EPA 2015 “Good Neighbor” Memorandum and its attachment discussing 

Air Quality Modeling Results. The Ozone Transport TSD is available on EPA’s website at 

http://www.epa.gov/airtransport/O3TransportAQModelingTSD.pdf. 

14http://www.epa.gov/airtransport/ 

13

 
Appendix. 

A. Additional information on Interstate Transport of 

Lead

Figure A 1 Lead sources (<0.5 tpy) in all bordering counties.

14
Table A 1 List of all lead sources smaller than 0.5 tpy located in bordering counties

County Lead 

(tons) Site Name Facility Type

Spokane 0.16 Felts Field Airport

Clark 0.14 Pearson Field Airport

Benton 0.12 VISTA FIELD Airport

Cowlitz 0.11 Kelso-Longview Airport

Spokane 0.1 Deer Park Airport

Klickitat 9.41E-02 Columbia Gorge Regional Airport

Benton 8.03E-02 Richland Airport

Walla Walla 7.73E-02 Walla Walla Regional Airport

Spokane 7.16E-02 Spokane Intl Airport

Whitman 7.06E-02 Pullman/Moscow Regional Airport

Cowlitz 4.15E-02 Weyerhaeuser NR Company Pulp and Paper Plant

Benton 3.66E-02 Prosser Airport

Whitman 3.60E-02 Whitman Co Memorial Airport

Clark 2.77E-02 Grove Field Airport

Whitman 2.65E-02 WILLARD FIELD Airport

Cowlitz 2.55E-02 Longview Fiber Pulp and Paper Plant

Klickitat 2.30E-02 Roosevelt Regional Landfill Landfill

Whitman 2.16E-02 Rosalia Muni Airport

Spokane 1.61E-02 MEAD FLYING SERVICE Airport

Klickitat 1.44E-02 GOLDENDALE Airport

Pacific 1.40E-02 PORT OF ILWACO Airport

Walla Walla 1.39E-02 MARTIN FIELD Airport

Clark 1.02E-02 FLY FOR FUN Airport

Clark 9.71E-03 GOHEEN Airport

Clark 9.54E-03 WOODLAND STATE Airport

Pacific 7.24E-03 WILLAPA HARBOR Airport

Clark 6.50E-03 Georgia-Pacific Consumer Products 

(Camas) LLC Pulp and Paper Plant

Klickitat 5.50E-03 Roosevelt Landfill Biogas Project No. 1 Electricity Generation via 

Combustion

Pend 

Oreille 4.58E-03 Ione Muni Airport

Clark 2.82E-03 CEDARS NORTH AIRPARK Airport

Spokane 2.67E-03 Mutual Materials Brick, Structural Clay, or Clay 

Ceramics Plant

Walla Walla 1.88E-03 Boise White Paper LLC Pulp and Paper Plant

Benton 1.85E-03 U.S. Dept of Energy

Clark 1.80E-03 PARKSIDE AIRPARK Airport

Whitman 1.64E-03 SCHOEPFLIN Airport

Spokane 1.45E-03 OX MEADOWS Airport

Clark 1.23E-03 BRUSH PRAIRIE AERODROME Airport

Clark 1.23E-03 GREEN MOUNTAIN Airport

15
County Lead 

(tons) Site Name Facility Type

Spokane 1.09E-03 SKY MEADOWS AIRPARK Airport

Clark 1.03E-03 WALTER SUTTONS PRIVATE STRIP Airport

Pend 

Oreille 1.00E-03 Ponderay Newsprint Company Pulp and Paper Plant

Spokane 1.00E-03 Honeywell Electronic Materials

Cowlitz 9.91E-04 MOUNT ST HELENS AERO RANCH Airport

Spokane 9.90E-04 HOMEPORT Airport

Clark 9.26E-04 LA CENTER VIEW-AIR Airport

Clark 9.26E-04 PLEASANT FARM Airport

Garfield 9.12E-04 DYE SEED RANCH INC. Airport

Spokane 8.87E-04 FOWLERS NW 40 Airport

Spokane 8.87E-04 ELLERPORT Airport

Whitman 8.72E-04 GOSSARD FIELD Airport

Skamania 8.63E-04 KEY WAY Airport

Benton 8.57E-04 WOODFIELD Airport

Spokane 8.36E-04 LEES Airport

Pend 

Oreille 8.32E-04 SULLIVAN LAKE STATE Airport

Columbia 8.32E-04 LITTLE GOOSE LOCK AND DAM Airport

Whitman 8.32E-04 LOWER GRANITE STATE Airport

Walla Walla 8.32E-04 LOWER MONUMENTAL STATE Airport

Clark 8.24E-04 BECKER FIELD Airport

Whitman 8.21E-04 HILL Airport

Whitman 8.14E-04 OAKESDALE Airport

Benton 8.06E-04 COOPERS LANDING Airport

Spokane 7.85E-04 SPANGLE FIELD Airport

Spokane 7.85E-04 BOYLE R & D Airport

Spokane 7.85E-04 HARRIS Airport

Spokane 7.85E-04 MULLAN HILL Airport

Spokane 7.85E-04 ISAACSON Airport

Spokane 7.85E-04 FLYING R RANCH Airport

Spokane 7.85E-04 PETES Airport

Spokane 7.85E-04 TAIS LANDING Airport

Clark 7.72E-04 ROBERT L DELANOY Airport

Clark 7.72E-04 DAYBREAK Airport

Clark 7.72E-04 MC CLELLAN FIELD Airport

Klickitat 7.63E-04 SPRING CREEK RANCH Airport

Whitman 7.19E-04 LACROSSE MUNI Airport

Klickitat 7.12E-04 TROUT LAKE Airport

Klickitat 7.12E-04 PORT ELSNER Airport

Skamania 7.09E-04 BROWNS CAPE HORN Airport

Columbia 7.08E-04 WELLER CANYON Airport

16
County Lead 

(tons) Site Name Facility Type

Walla Walla 6.71E-04 PAGE Airport

Walla Walla 6.71E-04 DARCYS AIR STRIP Airport

Whitman 6.67E-04 WALKER Airport

Asotin 6.61E-04 HAWKS RUN Airport

Klickitat 6.61E-04 AEROSTONE RANCH Airport

Klickitat 6.61E-04 BOBS FIELD Airport

Klickitat 6.61E-04 PIPER CANYON Airport

Klickitat 6.61E-04 MERCER RANCH Airport

Pacific 6.61E-04 MARTIN Airport

Skamania 6.58E-04 SKY RIVER RANCH Airport

Garfield 6.56E-04 SCOTT SEED FARM Airport

Wahkiakum 6.56E-04 MICHAIR Airport

Spokane 5.71E-04 CHENEY Rail Yard

Spokane 5.43E-04 TRENTWOOD Rail Yard

Klickitat 5.00E-04 SDS Lumber Company Lumber/Sawmill

Cowlitz 4.19E-04 Emerald Kalama Chemical, LLC Chemical Plant

Spokane 2.93E-04 SI Rail Yard

Spokane 2.39E-04 PARADISE AIR RANCH Airport

Cowlitz 2.22E-04 Mint Farm Generating Station Electricity Generation via 

Combustion

Clark 2.22E-04 VANCOUVER Rail Yard

Klickitat 2.00E-04 HILLCREST Airport

Spokane 1.88E-04 SPOKANE Rail Yard

Cowlitz 1.60E-04 KALAMA Rail Yard

Whitman 1.60E-04 Washington State University Institutional (school, hospital, 

prison, etc.)

Asotin 1.39E-04 ROGERSBURG Airport

Spokane 1.28E-04 N A DEGERSTROM YARD Airport

Klickitat 1.28E-04 MID-COLUMBIA MEDICAL CENTER Airport

Spokane 1.28E-04 HOLY FAMILY HOSPITAL Airport

Skamania 1.28E-04 AIR COLUMBIA Airport

Spokane 1.28E-04 SHAMROCK PORT Airport

Clark 1.28E-04 ORBIT Airport

Walla Walla 1.28E-04 ST MARY MEDICAL CENTER Airport

Asotin 1.28E-04 O & M FACILITIES Airport

Benton 1.28E-04 KENNEWICK GENERAL HOSPITAL Airport

Walla Walla 1.28E-04 WALLA WALLA GENERAL HOSPITAL Airport

Benton 1.28E-04 WNP-2 PLANT SUPPORT FACILITY Airport

Clark 1.28E-04 LEGACY SALMON CREEK HOSPITAL Airport

Skamania 1.28E-04 RAINCREEK Airport

Spokane 1.28E-04 DEACONESS MEDICAL CENTER Airport

Pacific 1.28E-04 WILLAPA HARBOR Airport

17
County Lead 

(tons) Site Name Facility Type

Spokane 1.28E-04 SACRED HEART MEDICAL CENTER 

HELISTOP Airport

Pacific 1.28E-04 OCEAN BEACH HOSPITAL Airport

Skamania 1.28E-04 SAMPSON Airport

Pend 

Oreille 1.28E-04 METALINE RADIO Airport

Pend 

Oreille 1.28E-04 BOUNDARY SUBSTATION Airport

Whitman 1.28E-04 WHITMAN COMMUNITY HOSPITAL Airport

Klickitat 1.28E-04 SKYLINE HOSPITAL EMS Airport

Clark 1.28E-04 ST JOSEPH COMMUNITY HOSPITAL Airport

Cowlitz 1.28E-04 ST JOHNS MEDICAL CENTER Airport

Asotin 1.28E-04 TRI-STATE HOSPITAL EMS Airport

Benton 1.28E-04 KADLEC MEDICAL CENTER Airport

Spokane 1.28E-04 PATHFINDER HELICOPTER Airport

Pend 

Oreille 1.28E-04 NEWPORT COMMUNITY HOSP Airport

Clark 1.28E-04 ROSS COMPLEX Airport

Garfield 1.28E-04 LOWER GRANITE DAM Airport

Cowlitz 1.28E-04 COUGAR Airport

Clark 1.28E-04 SOUTHWEST WASHINGTON 

MEDICAL CENTER Airport

Benton 1.28E-04 HAMMER EVOC SKID PAD Airport

Spokane 1.28E-04 EASTERN STATE HOSPITAL EMS Airport

Asotin 1.28E-04 KIWI AIR Airport

Asotin 1.28E-04 TRI-STATE MEMORIAL HOSPITAL 

EMS Airport

Klickitat 1.27E-04 WISHRAM Rail Yard

Spokane 1.14E-04 Kaiser Trentwood Fabricated Metal Products Plant

Spokane 8.32E-05 YARDLEY Rail Yard

Benton 8.00E-05 Agrium US Inc

Spokane 7.77E-05 Inland Empire Paper Pulp and Paper Plant

Spokane 5.58E-05 MARSHALL Rail Yard

Cowlitz 4.88E-05 LONGVIEW JCT. Rail Yard

Walla Walla 3.76E-05 WALLUA Rail Yard

Asotin 2.77E-05 SNAKE RIVER Airport

Spokane 7.69E-06 TIGHTCLIFF Airport

Wahkiakum 7.69E-06 SKAMOKAWA EAST VALLEY Airport

Whitman 7.69E-06 MC GREGOR Airport

Pacific 7.69E-06 WIRKKALA Airport

Pend 

Oreille 7.69E-06 RIVER BEND Airport

Benton 7.69E-06 MC WHORTER RANCH Airport

Klickitat 7.69E-06 WARWICK Airport

Columbia 7.69E-06 TOUCHET VALLEY Airport

18
County Lead 

(tons) Site Name Facility Type

Spokane 7.69E-06 ELK HEIGHTS Airport

Benton 7.69E-06 COLUMBIA CREST WINERY Airport

Cowlitz 7.69E-06 FLYING K RANCH Airport

Cowlitz 7.69E-06 WALTERS ARV Airport

Asotin 7.69E-06 SKID ROW Airport

Spokane 7.69E-06 Fairchild AFB Airport

Clark 1.51E-06 Clark Public Utilities / River Road 

Generating Project

Electricity Generation via 

Combustion

19
Figure A 2 Available daily mean values of lead at the Multnomah monitoring site

0

0.01

0.02

0.03

0.04

0.05

0.06

1/1/12 4/30/12 8/28/12 12/26/12 4/25/13 8/23/13 12/21/13 4/20/14

Pb (μg/m3)

Multnomah

20
B. EPA 2015 “Good Neighbor” Memorandum

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