TECHNICAL SUPPORT DOCUMENT FOR

THE BOEING COMPANY

BOEING EVERETT

777X PROJECT

Prepared by

Air Quality Program

Washington State Department of Ecology

Olympia, Washington

September 9, 2014
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TABLE OF CONTENTS

1. EXECUTIVE SUMMARY..................................................................................................................................1

2. INTRODUCTION................................................................................................................................................3

2.1. The Permitting Process ................................................................................................................................3

2.1.1. The PSD Process.................................................................................................................................3

2.1.2. The NOC Process................................................................................................................................3

2.2. Site and Project Description.........................................................................................................................4

2.2.1. Site Description ...................................................................................................................................4

2.2.2. Project Description..............................................................................................................................5

3. PSD APPLICABILITY REVIEW .....................................................................................................................15

3.1. Overview and Permitting History ..............................................................................................................15

3.2. Emissions Calculation................................................................................................................................17

3.2.1. Significant Emissions Increases........................................................................................................17

4. BACT.................................................................................................................................................................23

4.1. Definitions and Policy Concerning BACT.................................................................................................23

4.2. BACT Analysis..........................................................................................................................................25

4.2.1. Prep and Spray Paint Booths BACT Analysis...................................................................................25

4.2.2. Available Control Technologies........................................................................................................26

4.2.3. BACT Feasibility Review .................................................................................................................27

4.2.4. Ranking of BACT by Control ...........................................................................................................28

4.2.5. Cost-Effectiveness Evaluation...........................................................................................................28

4.2.6. Thermal Oxidizer ..............................................................................................................................28

4.2.7. Carbon Adsorption ............................................................................................................................29

4.2.8. Regenerative Thermal Oxidizer.........................................................................................................29

4.2.9. RTO with Concentrator.....................................................................................................................29

4.2.10. Low VOC Coatings, High Transfer Efficiency Coating Techniques, and Good Work Practices .....29

4.2.11. Summary of Cost-Effectiveness Analysis.........................................................................................30

4.2.12. Comparison with Other Aerospace BACT Determinations...............................................................33

4.2.13. BACT Selection ................................................................................................................................38

4.3. BACT for Natural Gas Combustion...........................................................................................................39

4.3.1. Available Control Technologies........................................................................................................41

4.3.2. BACT Selection ................................................................................................................................41

4.4. BACT for Emergency Generators..............................................................................................................42

4.4.1. Available Control Technologies........................................................................................................42

4.4.2. BACT Selection ................................................................................................................................42

4.5. BACT for Wing Composite Layup and Curing .........................................................................................42

4.5.1. Available Control Technologies........................................................................................................43

4.5.2. BACT Feasibility Review .................................................................................................................44
iii

4.5.3. RTO with Concentrator.....................................................................................................................44

4.5.4. Thermal Incineration .........................................................................................................................45

4.5.5. Carbon Adsorption ............................................................................................................................45

4.5.6. Ranking of BACT by Control ...........................................................................................................45

4.5.7. Cost-Effectiveness Evaluation...........................................................................................................46

4.6. BACT for Crush Core Press.......................................................................................................................46

4.6.1. Available Control Technologies........................................................................................................46

4.6.2. BACT Feasibility Review .................................................................................................................47

4.6.3. RTO with Concentrator.....................................................................................................................47

4.6.4. Thermal Incineration .........................................................................................................................48

4.6.5. Carbon Adsorption ............................................................................................................................48

4.6.6. Ranking of BACT by Control ...........................................................................................................48

4.6.7. Cost-Effectiveness Evaluation...........................................................................................................49

4.6.8. BACT Selection ................................................................................................................................49

4.7. BACT for Open Floor Emissions...............................................................................................................49

4.7.1. Wing Component Fabrication ...........................................................................................................50

4.7.2. Available Control Technologies........................................................................................................50

4.7.3. BACT Feasibility Review .................................................................................................................51

4.7.4. BACT Selection ................................................................................................................................51

4.8. Toxic Air Pollutants...................................................................................................................................52

5. AMBIENT AIR QUALITY IMPACTS ANALYSIS ........................................................................................52

5.1. Regulatory Requirements...........................................................................................................................52

5.2. Impacts on Class I Areas............................................................................................................................52

5.3. Ozone Impacts............................................................................................................................................54

6. ADDITIONAL IMPACTS ANALYSIS............................................................................................................55

6.1. Air Quality Related Values (AQRV) .........................................................................................................55

6.2. Growth Analysis ........................................................................................................................................56

6.2.1. Construction and Growth Impacts.....................................................................................................56

6.3. Soils and Vegetation Analysis....................................................................................................................56

7. ENDANGERED SPECIES ACT.......................................................................................................................57

8. STATE ENVIRONMENTAL POLICY ACT (SEPA) ......................................................................................57

9. PUBLIC INVOLVEMENT................................................................................................................................57

10. AGENCY CONTACT ..................................................................................................................................58

APPENDIX A. BACKGROUND PSD APPLICABILITY ANALYSIS FOR THE 777X AND PRODUCTION 

RATE INCREASE ......................................................................................................................................................59

APPENDIX B. ESTIMATE OF NON-SIGNIFICANT PSD POLLUTANT EMISSIONS INCREASES FROM 

THE 777X PROJECT..................................................................................................................................................84

REFERENCES ............................................................................................................................................................94

ACRONYMS AND ABBREVIATIONS....................................................................................................................95
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LIST OF FIGURES

Figure 1. The Boeing Everett facility location map.....................................................................................4

Figure 2. The Boeing Everett facility aerial photograph with new 777X Wing Component Fabrication 

Building identified ........................................................................................................................................5

LIST OF TABLES

Table 1. Wing Component Fabrication VOC Emissions from New Emission Units ...................................................7

Table 2. Wing and Body Structures Seal/Paint and Vertical Fin Paint VOC Emissions from New and Modified 

Emission Units.............................................................................................................................................................10

Table 3. Airplane Assembly VOC Emissions from New and Modified Emission Units............................................11

Table 4. Comfort and Process Heating VOC Emissions from New 777X Wing Component Fabrication Building ..12

Table 5. Emergency Diesel Generators VOC Emissions............................................................................................12

Table 6. IRC VOC Emissions from New Emission Units..........................................................................................13

Table 7. Proposed PSD VOC Emission Limit Changes .............................................................................................15

Table 8. Estimated VOC Emissions from 777 Assembly Operations for 2005 through 2013....................................18

Table 9. Projected Actual Emissions of Regulated NSR Pollutants for......................................................................18

Table 10. Baseline Actual Emissions of Regulated NSR Pollutants for Existing 777 Assembly Operations and 

Related 777 Operations (tpy).......................................................................................................................................20

Table 11. Emissions Increases of Regulated NSR Pollutants for New Units (tpy).....................................................20

Table 12. Emissions Increases of Regulated NSR Pollutants.....................................................................................21

Table 13. Pollutant and PSD SERs.............................................................................................................................21

Table 14. New and Modified Booths..........................................................................................................................25

Table 15. BACT Review ............................................................................................................................................27

Table 16. Ranking of Control Technologies...............................................................................................................28

Table 17. Vendor Quote Basis Summary ...................................................................................................................30

Table 18. Summary of Costs for Wing Component Fabrication (WCF) ....................................................................31

Table 19. Summary of Costs for Wing and Body Structure Paint (WBSP)................................................................31

Table 20. Summary of Costs for Airplane Assembly (AA)........................................................................................32

Table 21. RBLC Aerospace Coating Entries Since 2000 (Process Type 41.001).......................................................34

Table 22. RBLC Aerospace Coating Entries Between 1990 and 2000.......................................................................35

Table 23. Summary of Aerospace NESHAP VOC Emission Standards Applicable to the New and Modified 

Emission Units of the 777X Project ............................................................................................................................39

Table 24. Proposed Natural Gas Combustion Units...................................................................................................40

Table 25. Potential Control Technologies for VOCs for Composite Layup and Curing ............................................44

Table 26. Potential Control Technologies for VOCs for Crush Core Press................................................................47

Table 27. Summary of Aerospace NESHAP VOC Emission Standards Applicable to the New and Modified 

Emission Units of the 777X Project ............................................................................................................................51

Table 28. Class I Areas within 200 KM of the Boeing Everett Facility .....................................................................53
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1. EXECUTIVE SUMMARY

Boeing Commercial Airplane’s Everett facility (Boeing Everett) produces wide-body airplanes. 

Boeing Everett currently manufactures the plane models 747, 767, 777, and 787. Boeing 

proposes to produce new models of the Boeing 777. These new models are referred to as the 

Boeing 777X models. Production of the 777X is scheduled to begin in 2017, and make the first

777X delivery in 2020. As production of the 777X ramps up, the production of the current 777 

models will be phased out. 

The 777X will differ from the 777 models in that the 777X wings will be primarily made of 

composite material rather than aluminum. The 777X will have a greater wing span that will 

require folding wing tips so the 777X will fit at the airport’s gates. The 777-9X will have a 

slightly longer fuselage than the longest 777 model currently in production. 

The components for the 777X wing will be made at Boeing Everett in a new building. Final 

assembly of the 777X will occur in the same building where the current models of the 777 are

assembled. 

The 777X project involves two phases. The first phase is a transition from production of the 

traditional 777 models to 777X models. The second phase will be an increase in the maximum 

production capacity and thereafter, production rate from the current rate of about 8.3 777X per 

month (or about 100 planes per year) to as many as 10.4 777Xs per month (about 125 777Xs per 

year).

Phase 1 of the project consists of two components. The first component will make the changes 

to the facility necessary to begin production of the 777X. This will occur while maintaining 

production of legacy 777 models at levels up to about 8.3 airplanes per month, which is 

consistent with the Prevention of Significant Deterioration (PSD) permit number 11-01. The 

changes include constructing a new building in which to manufacture the components for the 

new composite wing, but also creating additional wing and airplane assembly capacity for the 

777X within the existing buildings. 

The second component of Phase 1 will be an increase in 777X production capacity and rate to 

about 8.3 airplanes per month while correspondingly decreasing production of the 777s to the 

point of eventually transitioning to producing only the 777X. During Phase 1, Boeing does not 

plan to exceed a combined production rate (i.e., rate for legacy 777s plus 777Xs) of about 8.3 

airplanes per month. Phase 1 will include the following changes at Boeing Everett to achieve a 

production capacity of 8.3 777Xs per month:

• Construct a new building to fabricate 777X wing components. The new building will 

include new emission units such as autoclaves to cure the wing components and spray 

and sealing booths. 

• Install a new 777X wing spar build-up line in an existing factory building.
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• Install a new 777X wing assembly line in an existing factory building.

• Install a new 777X final assembly line in an existing factory building. 

• Reconfigure the existing 777 final assembly line to accommodate final assembly of the

777X.

• Constructing new 777X vertical fin spray booths and prep booths in an existing factory 

building. 

• Change existing tooling and equipment throughout the 777 factory to accommodate the 

larger 777X body sections and wings. 

Phase 2 is a second independent phase of the Boeing 777X project. Phase 2 will make further 

changes to Boeing Everett to increase overall 777X production capacity to up to about 10.4 

airplanes per month. Phase 2 is tentatively scheduled to begin in 2021, and will involve 

additional tooling and equipment to increase the 777X production capacity. For example, 

additional tape layup machines for fabricating wing panels might be installed in the wing 

component fabrication building, and additional spray booths and a composite press might be 

installed in the interiors manufacturing building. 

Currently, it is anticipated that construction of Phase 1 will begin on or before November 1, 

2014, and construction of Phase 2 will begin on or before December 1, 2021. 

The Washington State Department of Ecology (Ecology) received the PSD application and fee 

for the project on February 20, 2014. Ecology determined the application to be complete on 

March 20, 2014. Boeing submitted a revised PSD permit application on May 23, 2014, and that 

application was determined to be complete on June 23, 2014. 

The proposed project emissions for volatile organic compounds (VOCs) are above the PSD 

threshold. Therefore, a full technical review of the project for VOCs, including a Best Available 

Control Technology (BACT) analysis, and the project’s effect on National Ambient Air Quality 

Standards (NAAQS), PSD increments, visibility, soils and vegetation, is required and included in 

this Technical Support Document (TSD).

The emissions of other air pollutants not subjected to PSD review will be covered in the Puget 

Sound Clean Air Agency’s (PSCAA) Notice of Construction (NOC) approval for this project. 

Ecology has issued several PSD permits to Boeing Everett in past years that established VOC 

emission limits for 777 production. These permits are:

• Permit number PSD-91-06 established a VOC emission limit of 238.8 tons per year (tpy)

for all 777 assembly operations.

• Permit number PSD-05-02 established a VOC emission limit of 205 tpy for interiors 

manufacturing operations associated with all Boeing airplane models and a VOC 
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emission limit of 412 tpy for paint hangar final exterior coating operations for all Boeing 

airplane models. 

• Permit number PSD-11-01 established a VOC emission limit of 34 tpy for three existing 

777 wing spray booths in Building 40-37.

Of the existing VOC emission limits noted above, the 777X project will require an increase in all 

but the paint hangar final exterior coating limit.

2. INTRODUCTION

2.1. The Permitting Process

2.1.1. The PSD Process

PSD permitting requirements in Washington State are established in Title 40, Code of Federal 

Regulations (CFR) § 52.21; Washington Administrative Code (WAC) 173-400-700 through 750; 

and the agreement for the delegation of the federal PSD regulations by the United States 

Environmental Protection Agency (EPA) to Ecology, dated December 10, 2013. 

Federal and state rules require PSD review of all new or modified air pollution sources that meet 

certain criteria in an attainment or unclassifiable area with the NAAQS. The objective of the 

PSD program is to prevent significant adverse environmental impact from emissions into the 

atmosphere by a proposed new major source, or major modification to an existing major source. 

The program limits degradation of air quality to that which is not considered “significant.” PSD 

rules require the utilization of BACT for certain new or modified emission units, which is the 

most effective air pollution control equipment and procedures that are determined to be available 

after considering environmental, economic, and energy factors.

The PSD rules must be addressed when a company is adding a new emission unit or modifying 

an existing emission unit in attainment or unclassifiable area. PSD rules apply to pollutants for 

which the area is classified as attainment or unclassifiable with the NAAQS. PSD rules are 

designed to keep an area with "good" air in compliance with the NAAQS. The distinctive 

requirements of PSD are BACT, air quality analysis (allowable increments and comparison with 

the NAAQS), and analysis of impacts of the project on visibility, vegetation, and soils.

2.1.2. The NOC Process

Boeing Everett’s 777X project is subject to NOC permitting requirements under state of 

Washington regulations Chapters 173-400 and 173-460. PSCAA is the permitting authority for 

all air emission regulatory requirements not included in PSD permitting. This includes the New 

Source Review (NSR) permitting of criteria pollutants that are not PSD-applicable, air toxics 

issues under federal maximum achievable control technology (MACT) and state 173-460 WAC, 

and Title V permitting requirements. The procedure for issuing an NOC permit was established 

in Chapter 70.94 RCW. 
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WAC 173-400-110 outlines the NSR procedures for permitting criteria pollutants. These 

procedures are further refined in WAC 173-400-113 (requirements for new sources located in 

attainment or unclassifiable areas).

WAC 173-460-040 NSR supplements the requirements contained in Chapter 173-400 WAC by 

adding additional requirements for sources of toxic air pollutants (TAPs).

2.2. Site and Project Description

2.2.1. Site Description

The Boeing Everett facility is located in the City of Everett in Snohomish County, Washington 

(see Figure 1). Boeing Everett is situated in the south half of Section 10 and the north half of 

Section 15, Township 28N, Range 4E Willamette Meridian, and consists of the North and South 

Complexes located north and south, respectively, of State Route 526. A building number 

starting with 40 identifies North Complex buildings, and buildings on the South Complex are 

identified with a number starting with 45 (see Figure 2). The proposed project will not increase 

the current footprint acreage of the site. 

The Boeing Everett facility is located in a Class II area that is designated as “attainment or 

unclassifiable” for the purpose of PSD permitting for all pollutants.

Figure 1. The Boeing Everett facility location map

(Source: Boeing application 2nd revision, received May 23, 2014)
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Figure 2. The Boeing Everett facility aerial photograph with new 777X Wing Component Fabrication 

Building identified

(Source: Boeing’s application 2nd revision, received May 23, 2014)

2.2.2. Project Description

The Boeing Company owns and operates the Boeing Everett facility. The existing Boeing 

Everett facility consists of:

• 777 Assembly Operations: Model 777 assembly operations currently occur primarily in 

Buildings 40-04, 40-25, 40-34, 40-35, 40-36, 40-37, and 40-53. 

The primary 777 assembly operations are:

• Wing component fabrication

• Wing assembly

• Body (fuselage) section assembly

• Wing and body structures seal and paint

• Airplane assembly
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The 777X project will add a new building to fabricate composite wing components for the new 

777X wing. The project will also add new operations such as a new vertical fin coating 

operation. The vertical fin on the current 777 models is painted in the existing airplane paint 

hangars after the fin is installed on the airplane. The new vertical fin coating operation requires 

that the fin be coated in a dedicated spray booth before it is installed on the airplane. In addition, 

some existing equipment such as body section spray booths may have to be modified to 

accommodate the larger 777X body sections.

2.2.2.1. Wing Component Fabrication

The wings of the 777X will be primarily made of composite material. The main wing 

components that will be made of composite material include upper and lower panels, front and 

rear spars, and upper and lower panel stringers. The manufacturing process of each of these 

parts is similar and involves the following steps: 

• Wing component layup

• Curing in an autoclave

• Trimming and drilling

• Washing

• Non-destructive inspection

• Preparation for priming (e.g., abrading, solvent cleaning)

• Priming

• Wing component build-up

Composite material is in the form of resin pre-impregnated tape or sheets. Part layup involves 

the manual or automated layup of composite material onto a mandrel (i.e., mold) which is 

preformed into the shape of the part being fabricated. Emissions associated with the part layup 

primarily occur from preparing the mandrel between each layup/cure cycle. Preparing the 

mandrel includes cleaning the surface with solvent, applying a mold release compound, and 

applying a tackifier solution. 

Once the part is laid up on the mandrel, a vacuum bag is sealed around the part and the assembly 

is then sent to an autoclave for curing. In the autoclave, vacuum from a vacuum pump is used to 

hold the bagged part under negative pressure while the autoclave is pressurized with nitrogen and 

heated to the curing temperature of up to about 350 degrees Fahrenheit (°F). The part is then 

held under negative pressure for the entire curing cycle, which is about 12 to 14 hours. 

Emissions during the curing cycle are gases from the composite material and combustion 

emissions from the indirect gas-fired heater that is used to heat the autoclave. The gases travel 

through the vacuum system and are exhausted by the vacuum pump. Boeing is planning for as 

many as three autoclaves, each equipped with a gas-fired heater with a rated heat input of 

approximately 40 million British thermal units per hour (MMBtu/hr). The curing cycle will 

begin with the autoclave initially being brought up to the curing temperature with the natural 
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gas-fired heater for about one to two hours. After this initial heating stage, an electric heater will 

be used to maintain the curing temperature for the rest of the cure cycle. 

Once the part is cured, it is taken out of the autoclave, removed from the bag, and undergoes 

various machining operation such as trimming and drilling. After machining is complete, the 

part is placed in a wash stall and washed using an aqueous solution and water rinse. After 

washing, the parts are inspected for defects. Following inspection, the parts are placed in a prep 

booth where the part surface is abraded and cleaned with solvent prior to being moved to either 

be cleaned within the spray booth or at specially designed equipment cleaning booths. After 

priming, the part might be moved to a heated cure booth to allow the primer to cure. VOC 

emissions will result from the solvent cleaning, spray coating, and curing of the parts as well as 

form cleaning of spray equipment. The trimming, drilling, abrading, and spray coating 

operations result in particulate emissions and will be controlled using a dust collection system 

and spray booth exhaust filters.

Once priming is completed, “build-up” work will be performed on the parts. For example, the 

spars will have stiffeners, bracket, and other components attached, including a portion of the 

leading and trailing edges. The wing panels will similarly undergo some build-up work. This 

type of work consists of open floor mechanical assembly processes (e.g., vacuum pumps, prep 

booths, and spray booths) and will involve the application of VOC containing products such as 

hand wipe cleaning solvents, sealants, and touch-coatings. At this time, it is planned that all the 

wing component fabrication work will take place in a new building with the exception of some 

wing spar build-up work, and possibly wing panel build-up work that will occur in an existing 

building, and the emission units (e.g., vacuum pumps, prep booths, and spray booths) associated 

with the fabrication work will be new. The new emission units and activities and related VOC 

emissions for wing component fabrication are shown in Table 1. Table 1 also lists open floor

activities that will take place as part of wing component fabrication. Boeing believes that such 

activities should not be treated as new emission units since similar open floor activities occur 

throughout the Boeing Everett facility, and can be easily moved about.

Table 1. Wing Component Fabrication VOC Emissions from New Emission Units

Unit ID Emission Unit or Activity

New or 

Modified

Combustion 

Emissions

(lb/plane)

Open 

Floor 

Emissions

(lb/plane)

Stack NonCombustion 

Emissions

(lb/plane)

WCF-1

Open floor activities which include prep of layup 

mandrels (e.g., hand wipe cleaning and application 

of mold release and tackifier) and wing panel and 

wing spar build-up (e.g., hand wipe cleaning and 

sealant application)

New 0.00 1,895 0

WCF-2 Gas-fired heater for liquid nitrogen vaporization unit New 1.45 0 0

WCF-3 Gas-fired process heater for autoclave #1 New 1.45 0 0

WCF-3b Gas-fired process heater for autoclave #2 New 1.45 0 0

WCF-3c Gas-fired process heater for autoclave #3 New 0.00 0 0

WCF-4 Vacuum pump(s) servicing autoclaves New 0.00 0 114
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Table 1. Wing Component Fabrication VOC Emissions from New Emission Units

Unit ID Emission Unit or Activity

New or 

Modified

Combustion 

Emissions

(lb/plane)

Open 

Floor 

Emissions

(lb/plane)

Stack NonCombustion 

Emissions

(lb/plane)

WCF-5

Dust collector(s) used to collect particulates from 

trimming, drilling, and other machining operations on 

cured components

New 0.00 0 0

WCF-6a Wing panel wash stall #1 New 0.12 0 0

WCF-6b Wing panel wash stall #2 New 0.12 0 0

WCF-6c Wing spar and stringer wash stall #1 New 0.03 0 0

WCF-6d Wing spar and stringer wash stall #2 New 0.03 0 0

WCF-7 Gas-fired plasma unit for treatment of wing panel 

stringers New 0.17 0 0

WCF-8a Wing panel prep booth(s) (abrasive blast/sanding, 

solvent hand wipe, edge seal) (see Note 1) New 0.46 0 504

WCF-8b Wing spar prep booth (abrasive blast/sanding, 

solvent hand wipe, edge seal) New 0.00 0 70

WCF-9a Wing panel spray booth #1 New 1.39 0 273

WCF-9b Wing panel spray booth #2 New 1.39 0 273

WCF-9d Wing panel spray booth #3 New 1.39 0 273

WCF-9c Wing spar spray booth New 0.33 0 118

WCF-10a Wing panel primer curing booth #1 New 0.70 0 See Note 2

WCF-10b Wing panel primer curing booth #2 New 0.70 0 See Note 2

WCF-10c Wing spar primer curing booth New 0.17 0 See Note 2

WCF-11 Small quantity paint mix booth New 0.00 0 Less than 1

WCF-12a Coating equipment cleaning booth #1 New 0.00 0 16

WCF-12b Coating equipment cleaning booth #2 New 0.00 0 16

WCF-14 Wing spar seal booth(s) #1 (see Note 3) New 0.18 0 152

Notes:

1. Currently Boeing is considering building one or two wing panel prep booths. If Boeing decides to build two wing panel prep 

booths, the 504 pounds of VOC emissions will be divided between the two booths. 

2. Curing emissions are minimal and included in the spray booth emissions.

3. Currently Boeing is considering building as many as four wing spar seal booths. If Boeing decides to build more than one 

wing spar seal booth, the 152 pounds of VOC emissions per plane will be divided between the multiple booths.

All the emission units shown in Table 1 will be installed in Phase 1 of the project. Additional 

tooling and equipment such as tape-laying machines and additional work positions might be 

installed in Phase 2, but no addition emission units associated with wing component fabrication 

are planned for Phase 2.
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2.2.2.2. Wing Assembly

After the wing panel and wing spar build-up work is complete, the 777X wings will be 

assembled from the completed panels, spars, and ribs which will have been manufactured 

elsewhere. This assembly work primarily consists of open floor mechanical assembly processes 

and will involve the application of VOC-containing products such as hand wipes with cleaning 

solvents, sealants, and touch-up coatings.

Boeing plans to locate the 777X wing assembly line in the main factory building with the 

existing 777 wing assembly line, but at a new location within that building. Neither Phase 1 nor 

Phase 2 require the installation or establishment of any new emission units or modification of 

any existing emission units associated with wing assembly.

2.2.2.3. Body Section Assembly

Body section assembly involves the assembly of individual body section panels into forward, aft, 

and mid body sections. This work consists of open floor mechanical assembly processes and the 

application of VOC products such as hand wipe cleaning solvents, sealants, and touch-up 

coatings.

Boeing plans to locate the 777X body section assembly work in the main factory building with 

the existing 777 body section assembly work, but all 777 body section assembly work will 

transition to a new location within that building. Neither Phase 1 nor Phase 2 will require the 

installation or establishment of any new VOC emission units or modification of any existing 

emission units associated with body section assembly.

2.2.2.4. Wind and Body Structures Seal/Paint and Vertical Fin Paint

Once the 777X wings and individual body sections are assembled, they will be moved to the 

existing 777 wing and body section spray booths in Building 40-37 for cleaning, sealing, and 

coating. The 777X wings will be cleaned, primed, and top coated in the same booths where the 

existing 777 model wings are cleaned, primed, and top coated. Similarly, 777X body sections 

will have their interior structures and a small portion of their exterior structures (e.g., the area 

under the wing fairing) cleaned, sealed, primed, and sprayed with a corrosion-inhibiting 

compound (CIC) in the same booths that the existing 777 model body structures use.

In Phase 1 of the project, some of the existing 777 body section booths may be lengthened to 

accommodate the slightly longer forward and aft fuselage sections of the 777-9X. 

Also, as part of Phase 1, Boeing will add a new prep booth and three new spray booths to coat 

the 777X vertical fins. As noted above, the 777 vertical fin painting is currently completed in the 

existing Boeing Everett airplane paint hangars after the fin is installed on the airplane. The new 

coating operation will result in less aerodynamic drag and requires that the fin be coated in a 

dedicated spray booth before it is installed on the airplane. 
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In Phase 2 of the 777X project, two additional robotic cleaning and coating machines might be 

added to the existing wing booths to achieve a production capacity of up to 10.4 airplanes per 

month. 

The new or modified emission units and related VOC emissions for the wing and body structures 

seal/paint and vertical fin paint are listed in Table 2.

Table 2. Wing and Body Structures Seal/Paint and Vertical Fin Paint VOC Emissions from New 

and Modified Emission Units

Unit ID Emission Unit or Activity

New or 

Modified

Combustion 

Emissions

(lb/plane)

Open 

Floor 

Emissions

(lb/plane)

Stack NonCombustion 

Emissions

(lb/plane)

WBSP-1a Robotic wing spray booth for LH wing Modified 0.00 0 472

WBSP-1b Robotic wing spray booth for RH wing Modified 0.00 0 472

WBSP-2 Forward body section spray booth Modified 0.00 0 209

WBSP-3 Mid body section spray booth Modified 0.00 0 217

WBSP-4 Aft body section spray booth Modified 0.00 0 209

WBSP-6 Forward body section CIC spray booth Modified 0.00 0 194

WBSP-7 Mid body section CIC spray booth Modified 0.00 0 98

WBSP-8 Aft body section CIC spray booth Modified 0.00 0 194

WBSP-10 Vertical fin HLFC prep booth New 0.39 0 20

WBSP-11a Vertical fin HLFC spray booth #1 New 1.14 0 70

WBSP-11b Vertical fin HLFC spray booth #2 New 1.14 0 70

WBSP-11c Vertical fin HLFC spray booth #3 New 1.14 0 70

WBSP = wing and body structure paint

LH = left hand

RH = right hand

HLFC = hybrid laminar flow control

2.2.2.5. Airplane Assembly

Airplane assembly operations include the installation of various airplane systems (e.g., hydraulic, 

fuel, electrical) in the wing and body sections; the installation of the empennage (i.e., vertical fin 

and horizontal stabilizers) onto the aft body section; assembly of the body sections and wings 

into a completed structure; integration of the airplane systems; installation of landing gear, 

engines, and interior components (e.g., seats, sidewalls, partitions); and functional testing. Most 

of these activities occur on the open floor and involve the application of VOC containing 

products such as hand wipe cleaning solvents, sealants, and touch-up coatings. 

As discussed earlier, a new 777X airplane assembly line will be located in the main factory 

building as is the existing 777 airplane assembly line, but at a new location within that building. 
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This new assembly line might only be used for the low-rate initial production of the airplane. 

After a period of time, this new line might be phased out and all 777X final assembly moved to 

the existing 777 final assembly line reconfigured for the 777X.

The only new or modified emission units associated with 777X airplane assembly that will be 

installed as part of Phase 1 of the project are two wing stub ventilated spray coating enclosures. 

These enclosures will be used to capture emissions from coating certain portions of the wing stub 

and wing stub join areas. The enclosures will be filtered as required by the Aerospace National 

Emission Standards for Hazardous Air Pollutants (ANESHAP). One new enclosure will be 

installed in the new 777X airplane assembly line, and the existing wing stub spray booth that is 

part of the existing 777 assembly line will be modified or replaced.

Other than these two ventilation systems, neither Phase 1 nor Phase 2 should require the 

installation or establishment of any new emission units or the modification of any existing 

emission units associated with airplane assembly. VOC emissions from the wing stub ventilated 

spray coating enclosures are shown in Table 3.

Table 3. Airplane Assembly VOC Emissions from New and Modified Emission Units

Unit ID Emission Unit or Activity

New or

Modified

Combustion 

Emissions

(lb/plane)

Open 

Floor 

Emissions

(lb/plane)

Stack NonCombustion 

Emissions

(lb/plane)

AA-2a Wing stub spray coating enclosure #1 New 0.00 0 22

AA-2b Wing stub spray coating enclosure #2 Modified 0.00 0 22

2.2.2.6. 777 Assembly Existing PSD VOC Emission Limits

PSD permit PSD-91-06 established a VOC emission limit of 238.8 tpy for all 777 assembly 

operations. The 777X project will require that this emission limit be increased to 513 tpy to 

account for new wing component fabrication emissions, the higher production rate anticipated in 

Phase 2 of the 777X project, and the new vertical fin prep and spray booths.

PSD permit PSD-11-01 established a VOC emission limit of 34 tpy for the robotic wing spray 

booths and a per wing average emission limit of 0.17 ton. The 777X project will require that 

these emission limits be increased to 59 tpy and 0.25 ton per wing to account for the higher 

production rate anticipated in Phase 2 of the 777X project, the larger size of the composite wing, 

and the different materials used to clean and coat the composite wing.

2.2.2.7. Airplane Manufacturing Support Operations Facilities

In addition to the new heating equipment associated with specific production emissions units 

listed in Table 1-1 and 1-2[A1], there will be additional open space heating and general process 
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heating requirements in the new wing component fabrication building that total approximately 

111 MMBtu/hr. Table 4 lists the expected emissions from these heating processes.

Table 4. Comfort and Process Heating VOC Emissions from New 777X Wing Component 

Fabrication Building

Unit ID Emission Unit or Activity

New or

Modified

Combustion 

Emissions

(lb/plane)

Open 

Floor 

Emissions

(lb/plane)

Stack NonCombustion 

Emissions

(lb/plane)

F-1 Combustion equipment for comfort or 

process heating New 16.88 0 0

The 777X project is expected to require as many as nine new 2,750-kilowatt (kW) backup 

emergency diesel generators for the autoclaves and one 750-kW backup diesel generator for 

other wing manufacturing activities. Table 5 lists the expected VOC emissions from these 

engines.

Table 5. Emergency Diesel Generators VOC Emissions

Unit ID Emission Unit or Activity

New or

Modified

Combustion

Emissions

(tpy)

F-2a Nine 2,750-kW diesel generators New 0.94

F-2b 750-kW diesel generator New 0.03

2.2.2.8. Airplane Manufacturing Support Operations—Interiors Production 

Operations

Interiors production operations primarily occur in the Interiors Responsibility Center’s (IRC’s) 

Building 40-56 and support all airplane models produced at Boeing Everett, as well as the 737 

model produced at Boeing Renton. Interiors production involves the manufacture of stowbins, 

sidewalls, ceilings, partitions, closets, and other cabin interior components. Air emissions occur 

from activities such as spray coating, hand wipe cleaning, screen printing, composite material 

curing, and the use of adhesives, resins, and other VOC containing products. 

No changes to the IRC emission units are planned for Phase 1 of the 777X project. For Phase 2 

of the project, it is anticipated that three adhesive spray booths, a paint booth, and a crushed core 

press will need to be added to the IRC to reach the 777X interiors production rate capacity of up 

to 10.4 shipsets per month. Table 6 lists these new emission units and their estimated VOC 

emissions.
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Table 6. IRC VOC Emissions from New Emission Units

Unit ID Emission Unit or Activity

New or

Modified

Combustion

Emissions

(lb/plane)

Open 

Floor 

Emissions

(lb/plane)

Stack NonCombustion 

Emissions

(lb/year)

IRC-1a Adhesive spray booth #1 New 0 0 17,700

IRC-1b Adhesive spray booth #2 New 0 0 17,700

IRC-1c Adhesive spray booth #3 New 0 0 17,700

IRC-2 Paint spray booth New 0 0 10,000

IRC-3 Crushed core press New 0 0 4,500

PSD permit PSD-05-02 established a VOC emission limit of 205 tpy for all interiors production 

operations at Boeing Everett. This limit covers emissions from 777 interiors production as well 

as interiors production for other Boeing airplane models. The 777X project will require that this 

emission limit be increased to 239 tpy to account for the additional emissions from the new 

emission units anticipated to achieve the higher production rate of up to 10.4 shipsets per month. 

The estimated VOC emissions from interiors production for each 777X are 0.53 ton per airplane.

2.2.2.9. Everett Delivery Center Operations

Everett Delivery Center (EDC) paint hangar and preflight/delivery operations occur in Buildings 

45-01, 45-03, and 45-04 paint hangars; in Building 45-02; in Building 45-334 at the Everett 

Modification Center (EMC) plus the paint hangar in Bay 4 Building 45-334, and on the flight 

line; and support all airplane models produced at Boeing Everett. Air emissions primarily occur 

from activities such as exterior prep and spray coating activities in the paint hangars, and the use 

of hand wipe cleaning solvents and adhesives, resins, and other VOC containing products on the 

flight line. PSD permit PSD-05-02 establishes a VOC emission limit of 412 tpy for all airplane 

manufacturing operations that occur at the EDC, including 777 paint hangar and preflight and 

delivery operations. The project will not require any increase in this VOC emission limit.

Boeing Everett paint hangars, which are all part of EDC, are operating at or near capacity. The 

current paint hangar capacity is less than that necessary to serve the combined production of all 

airplane models at Boeing Everett today, requiring many airplanes to be flown offsite for final 

decorative coating. There are currently no plans to increase onsite paint hangar capacity to 

support the increased 777X production rate enabled by Phase 2 of the project. Therefore, the 

project will not result in an emission increase at the paint hangars. However, other EDC work 

such as coating and cleaning of 777 rudders and elevator and the preflight/delivery work that 

occurs on each airplane on the flight line before it is delivered, will increase as a result of the 

project. The estimated emissions from these activities are 0.15 ton of VOCs per 777X produced.
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Neither Phase 1 nor Phase 2 will require the installation or establishment of any new emission 

units or the modification of any existing emission units associated with the EDC operations.

2.2.2.10. Propulsion Systems Operations

Propulsion systems operations primarily occur in Building 40-54 and involve receiving airplane 

engines and engine struts for 747, 767, and 777 models from offsite and preparing them for 

installation on the airplane. Air emissions are relatively minor and primarily occur from the 

open floor use of hand wipe cleaning solvents, touch-up coatings, and adhesives, resins, and 

other VOC containing products. The VOC emissions from this operation are not subject to a 

PSD or PSCAA established VOC annual emission limit. The estimated emissions from 

propulsion systems are 0.005 ton of VOCs per engine. The 777X has two engines, and the 

estimated emissions are 0.01 of VOCs per 777X produced. 

Neither Phase 1 nor Phase 2 should require the installation or establishment of any new emission 

units or the modification of any existing emission units associated with propulsion systems 

operations.

2.2.2.11. Emergent Operations

Emergent operations involve the emergent, non-routine fabrication and repair of aerospace 

components. Emergent operations support all airplane models produced at Boeing Everett. Air 

emissions from emergent operations are relatively minor and primarily occur from spray coating 

and the use of hand wipe cleaning solvents and adhesives, resins, and other VOC containing 

products. The VOC emissions from this operation are not subject to a PSD VOC emission limit. 

The estimated emissions from these activities are 0.06 ton of VOC per 777X produced. 

Neither Phase 1 nor Phase 2 should require the installation or establishment of any new emission 

units or the modification of any existing emission units associated with emergent operations.

2.2.2.12. Electrical Systems Production Operations

Electrical systems production operations occur in the space that the Electrical Systems 

Responsibility Center (ESRC) shares with the IRC in Building 40-56, and in Building 40-02, and 

primarily support the 747, 767, and 777 airplane models produced at Boeing Everett, as well as 

the 737 model produced at Boeing Renton. Electrical systems production operations involve the 

assembly of wiring harnesses, power panels, and other electrical components. Air emissions are 

relatively insignificant and occur from the use of hand wipe cleaning solvents and adhesives, 

resins, and other VOC containing products. The VOC emissions from this operation are not 

subject to a PSD VOC emission limit. The estimated emissions from these activities are 0.013 

ton of VOC per 777X produced.
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Neither Phase 1 nor Phase 2 should require the installation or establishment of any new emission 

units or the modification of any existing emission units associated with electrical systems 

production operations.

2.2.2.13. Summary of Proposed PSD Permit Changes

Boeing proposed to limit annual natural gas usage from new combustion units related to the 

777X project to 1,000,000 MMBtu/yr. Ecology will include this annual limit of natural gas usage 

as a permit limit. 

Table 7 lists the proposed changes to the VOC emission limits in the current PSD permits. 

Table 7. Proposed PSD VOC Emission Limit Changes

PSD

Permit Emission Unit or Activity

Current

Limit

Proposed

Limit

Increase

(tpy)

91-06 777 Assembly 238.8 tpy 513 tpy 274.2

05-02 Interiors 205 tpy 239 tpy 34

11-01 Wing Painting 34 tpy 59 tpy Note 1

11-01 Wing Painting 0.17 tons/wing 0.24 tons/wing Note 1

11-01 Wing Painting 36.3 tpy 61.3 tpy Note 1

Total Proposed Increase 308.2

Note 1: These emissions are included in 777 assembly current and proposed 

emission limits.

3. PSD APPLICABILITY REVIEW

3.1. Overview and Permitting History

The existing facility is a major PSD stationary source per 40 CFR 52.21(b)(1)(i). Under WAC 

173-400-720 through 750, a project proposed at an existing major stationary source is subject to 

PSD review if the project either is a “major modification” to an existing “major stationary 

source,” or is a major stationary source unto itself. 

Unless otherwise exempted by applicable regulation, a change to an existing major stationary 

source is a major modification if the change results in both a significant emissions increase and a 

significant net emissions increase at the source. “Significant emissions increase” means that the 

emissions increase for any regulated PSD pollutant is greater than the PSD significant emission 

rate (SER) threshold for that regulated pollutant. 

The proposed 777X project will require a PSD permit if both the project’s emissions increase 

and the net contemporaneous emissions increase caused by the project exceed any PSD SERs of 

any NSR pollutant, including greenhouse gases (GHGs). The proposed new building and 
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modifications to the existing buildings at Boeing Everett require a PSD review. In accordance 

with the requirements of 40 CFR 52.21(a)(2), these emission increases associated with the new 

units is based on their potential to emit (PTE). Also, as addressed in the regulation, their 

baseline actual emissions are zero.

The significant emissions increase analysis looks only at the emissions from the proposed project 

and is called Step 1. The significant net emissions increase analysis looks at additional increases 

and decreases from “contemporaneous” projects at the source and is called Step 2. 

For the significant emissions increase analysis, the 777X project will involve both constructing 

new emissions units and modifying existing units. The PSD regulations require use of the hybrid 

test for projects that involve both the addition of new emissions units and the modification of 

existing emissions units. The PSD regulations require use of the hybrid test for projects that 

involve both the addition of new emissions units and the modification of existing emissions units 

(40 CFR 52.21(a)(2)(iv)(f)). Under the hybrid test, a significant emissions increase of a 

regulated NSR pollutant is projected to occur if the sum of the emissions increases for each 

emissions unit, using the actual-to-projected-actual applicability test (40 CFR 52.21(a)(2)(iv)(c) 

for modified units and the actual-to-potential applicability test (40 CFR 52.21(a)(2)(iv)(d)) for 

new units, equals or exceeds the significance threshold for that pollutant as defined in paragraph 

40 CFR 52.21(b)(23). The actual-to-projected-actual applicability test involves adding the 

projected actual emissions from existing emissions units that are modified as part of the project 

or that are otherwise expected to experience an emission increase as a result of the project, and 

then subtracting the past actual emissions (called the “baseline actual emissions”) from those 

units.

However, in lieu of projecting future actual emissions for a particular existing emissions unit, an 

applicant can choose instead to use the unit’s PTE as the unit’s post project emissions (40 CFR 

52.21(b)(41)(ii)(d)). The actual-to-potential test, which is required for all new units being 

constructed as part of the project, involves totaling the potential emissions of the proposed new 

emissions units, then subtracting past actual emissions of those units. A new unit that is being 

constructed as part of the project has a baseline of zero (40 CFR 52.21(b)(48)(iii)). 

If the project would result in a significant emissions increase, then a significant net emissions 

increase analysis is often conducted. However, EPA has clearly stated that calculating a net 

emissions increase is at the source’s option (see, for example, 67, Federal Register 80186, at 

80197 [December 31, 2002]). Therefore, a source may seek a PSD permit based on a calculated 

significant emission increase alone. For the 777X project, Boeing requested that option, and is 

foregoing the Step 2 significant net emission increase analysis. 

 

Essentially, this means that the 777X project will trigger PSD review because the Boeing Everett 

facility currently has the PTE more than 250 tpy of VOC which is a regulated NSR pollutant. 

Therefore, Boeing Everett is considered a “major stationary source” for PSD purposes, as 

defined by 40 CFR 52.21(b)(1)(i).
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As a result of the possible increased 777X production rate enabled by Phase 2 of the project, 

emissions from the existing 777 assembly operations are expected to increase as well as 

emissions from other operations where Boeing Everett produces or processes 777 components 

(including interiors production, some EDC operations, and propulsion systems operations). 

Further, the amount of steam and heat produced at the Boeing Everett facility will increase to 

support the increased production.

3.2. Emissions Calculation

3.2.1. Significant Emissions Increases

The 777X project will involve both modifying existing emission units and constructing new 

emission units. There a hybrid test is required under 40 CFR 52.21(a)(2)(iv)(f). The hybrid test 

involves using the actual-to-projected-actual applicability test (40 CFR 52.21(a)(2)(iv)(c)) for 

modified and debottlenecked units, and the actual-to-potential applicability test (40 CFR 

52.21(a)(2)(iv)(d)) for new units to be constructed as part of the project. In addition, EPA’s 

aggregation policy is to deter sources from attempting to expedite construction by permitting 

several changes separately as minor modifications. In the case of a new project that is 

undergoing PSD permitting, the aggregation analysis is used to determine all of the pollutants 

and emission units that are subject to PSD review. In the situation of the 777X project, all 

projects involving the future production of 777X models has been included in the 777X project.

3.2.1.1. Actual-to-Projected-Actual Applicability Test for Modified and 

Debottlenecked Emissions Units

Debottlenecking is the term used for situations when emission units upstream or downstream 

from the unit(s) undergoing a physical change or change in the method of operation will 

experience an emission increase a result of the project. Emissions increases from debottlenecked 

units are calculated using an actual-to-projected-actual applicability test.

For existing emission units that are being modified or debottlenecked as part of the 777X project, 

the PSD baseline emissions are emissions averaged over any 24 consecutive month period in the 

10 years before Ecology receives a complete application for the project. For a regulated NSR 

pollutant, when a project involves more than one emission unit, only one 24 consecutive month 

period may be used to determine the baseline actual emissions for all emission units being 

changed. However, a different 24 consecutive month period can be used for each regulated NSR 

pollutant (40 CFR 52.21(b)(48)(ii)(d)). For the 777X project, the 10-year period from which the 

baseline period may be selected for all NSR regulated pollutants begins in 2004 and includes the 

full calendar years 2005 through 2013. For “new” units constructed prior to the 777X project 

(i.e., units that have been in operation for less than two years), baseline actual emissions are the 

units’ PTE (40 CFR 52.21(b)(48)(iii)). 
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Table 8 presents the VOC emissions from 777 assembly operations and the number of 777s 

produced for the nine years 2005 through 2013. Boeing selected 2012 and 2013 calendar years 

as the baseline period for VOC emissions.

Table 8. Estimated VOC Emissions from 777 Assembly Operations for 2005 

through 2013

Year

# of 777s

Produced

Estimated VOC 

Emissions Before

Subtracting

Estimated

VOCs

in Waste

(tons)

Estimated VOC 

Emissions After

Subtracting Waste

(tons)

Estimated VOC

Emissions per

Airplane

(tons)

2005 44 107.8 4.2 103.6 2.35

2006 62 117.9 5.9 112.0 1.81

2007 83 179.3 8.7 170.6 2.05

2008 68 152.7 8.2 144.5 2.13

2009 83 164.5 10.1 154.4 1.86

2010 71 133.3 8.0 125.3 1.77

2011 75 146.8 8.6 138.2 1.84

2012 83 167.7 11.2 156.5 1.89

2013 99 181.1 17.1 164 1.66

Note: A 2-month work stoppage occurred in 2008.

Increased 777X production enabled by Phase 2 of the project would be expected to result in 

increased emissions from the existing 777 assembly operations and related combustion from 

boilers and heaters. Table 9 lists the projected actual emissions (at the maximum production rate 

of 10.4 airplanes per month, or 125 airplanes per year) from the 777X assembly operations and 

from the related operations that would experience increased emissions as a result of increased 

production at the assembly operations. Details of the emission estimates are shown in 

Appendices A and B.

Table 9. Projected Actual Emissions of Regulated NSR Pollutants for

Existing 777 Assembly Operations and Related 777 Operations (tpy)

Operation CO NOX PM SOX Lead VOC CO2e

777 Assembly * 265.5

Interiors * 66.3

EDC * 18.8

Propulsion * 1.3

Emergent * 7.5

ESRC * 1.6

Boilers† 55 67 5.1 1.5 0.0004 3.6 79,500

Total 55 67 6.35 1.5 0.0004 364.6 79,500

*Non-combustion PM emissions will primarily be generated from spray coating 
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Table 9. Projected Actual Emissions of Regulated NSR Pollutants for

Existing 777 Assembly Operations and Related 777 Operations (tpy)

Operation CO NOX PM SOX Lead VOC CO2e

operations. Total combined PM emissions from spray coating operations from 

all 777 operations are estimated to be less than or equal to approximately 0.01 

ton per airplane. Therefore, total combined PM projected actual emissions 

from all 777 spray coating operations are estimated to be less than or equal to 

0.01 ton/airplane x 125 airplanes/yr = 1.25 tpy.

†

All combustion-related emissions are accounted for in Boilers.

CO = carbon monoxide

NOX = nitrogen oxides

PM = particulate matter

SOX = sulfur oxides

CO2e = carbon dioxide equivalent

EDC = Everett Delivery Center

ESRC = Electrical Systems Responsibility Center

The existing boilers and heaters provide heat and energy to all operations at the Boeing Everett 

facility, including operations such as office buildings and other airplane model manufacturing 

that are not directly related to 777 production. Therefore, emissions from boilers and heaters are 

treated differently than those from the other operations. The projected actual emissions rate for 

combustion operations is the baseline rate for the entire Boeing Everett facility plus the expected 

additional heat that would be required to support 777X production at the maximum potential 

production rate, based on an average heat usage of 3,206 MMBtu per airplane. Details of the 

emission estimates are shown in Appendices A and B.

VOC emissions from the EDC operations do not include final painting of the airplane exterior, 

which is performed in paint hangars. Currently, the paint hangars at the Boeing Everett facility 

are operating at or near capacity, with many airplanes being flown offsite for final coating. 

Because there are currently no plans to increase paint hangar capacity to support the 777X, the 

777X project will not result in an increase emissions at Boeing Everett facility from paint 

hangars. 

Table 10 shows the baseline actual emissions for calendar years 2012 and 2013 from the 777 

assembly operations and related operations that are expected to experience an emission increase 

as a result of the increased 777X production enabled by Phase 2 of the project, except that carbon 

dioxide equivalent (CO2e) is based on 2006 and 2007, which was the 2-year period with the 

greatest CO2e production rate.
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Table 10. Baseline Actual Emissions of Regulated NSR 

Pollutants for Existing 777 Assembly Operations and Related 

777 Operations (tpy)

Operation CO NOX PM SOX Lead VOC CO2e

777 Assembly * 160

Interiors * 48

EDC * 14

Propulsion * 1

Emergent * 5

ESRC * 1

Boilers† 50 60 4.5 1.1 0.0003 3 72,000

Total 50 60 4.5 1.1 0.0003 233 72,000

∗

Non-combustion PM emissions will primarily be generated from spray 

coating operations. Total combined PM emissions from spray coating 

operations from all 777 operations are estimated to be less than or equal to

approximately 0.01 ton per airplane. Therefore, total combined PM baseline 

actual emissions from all 777 spray coating operations for calendar years 

2012 and 2013 are estimated to be less than or equal to 1 tpy.

†

All combustion-related emissions are accounted for in boilers.

During the baseline period, Boeing Everett did not operate above any legally enforceable 

emission limitation, and there are no new emission standards that affect these units or activities 

that have come into effect between the baseline period and the date of the application. 

Therefore, no adjustments are required under 40 CFR 52.21(b)(48)(ii)(b) or (c).

3.2.1.2. Actual-to-Projected Test for Newly Constructed Emissions Units

For emissions units that will be newly constructed as part of the 777X project, baseline emissions 

are zero and post-project emissions are the units’ PTE. Therefore, the emission increase from 

these new units resulting from the project is their PTE. The proposed new emissions units and 

their associated PTE are identified in Table 11. The PTE for the new non-combustion emission 

units is based on a maximum production rate of 125 airplanes per year. The potential emissions 

from new combustion emissions units are based on a voluntary total combined heat input limit of 

1,000,000 MMBtu per year for all new combustion units associated with this project. Detailed 

calculations are included in Appendices A and B.

Table 11. Emissions Increases of Regulated NSR Pollutants for New Units (tpy)

Emission Unit CO NOX PM SOX Lead VOC CO2e

Wing component fabrication emission 

units (non-combustion) <0.5 235

Vertical fin prep and spray booths <0.1 14

Wing stub spray coating enclosure <0.1 1
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Table 11. Emissions Increases of Regulated NSR Pollutants for New Units (tpy)

Emission Unit CO NOX PM SOX Lead VOC CO2e

Interiors emission units <0.1 34

Emergency engines 11 18 0.6 0.74 0 1 2,100

Combustion emission units 20 6 4 0.50 0 3 59,400

Total for new units 31 24 5.4 1.24 0 288 61,500

3.2.1.3. Hybrid Total Emissions Increase

The total emission increase relating to the 777X project is the sum of the increases from the 

existing units (projected actual minus baseline actual emissions) and the PTE from the newly 

constructed units and is presented in Table 12.

Table 12. Emissions Increases of Regulated NSR Pollutants

for Existing and New Emissions Units (tpy)

Emissions CO NOX PM SOX Lead VOC CO2e

Baseline actual emissions 50 60 5.5 1.10 0.0003 233 72,000

Projected actual emissions from 

existing units 55 67 6.4 1.51 0.0004 365 79,500

Potential emissions from new units 31 24 5.4 1.24 0 288 61,500

Emissions increase 36 31 6.3 1.66 0.0001 420 69,000

PSD Significant Emission Rate 

(SER) 100 40 10 40 0.6 40 75,000

Significant? No No No No No Yes No

The federal rule defines a significant increase to be equal to or exceeding any of the rates listed 

in Table 13 (40 CFR 52.21(b) (23)). The 777X project is not expected to emit measurable 

quantities of fluorides, hydrogen sulfide (H2S), or reduced sulfur compounds (TRS). The 

expected increase in ozone depleting substances is about 2.25 tpy (see Appendix B). As noted in 

Table 12, the emissions increases from the 777X project will exceed the SER for only VOCs. 

Therefore, the project will only have a significant emissions increase for VOCs.

Table 13. Pollutant and PSD SERs

Pollutant SER

CO 100

NOX 40

SO2 40

PM 25

PM10 15
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Table 13. Pollutant and PSD SERs

Pollutant SER

PM2.5 10

Ozone 40 (VOCs or NOX)

∗

Lead 0.6

Fluorides 3

Sulfuric acid mist 7

H2S 10

Total Reduced Sulfur 10

Reduced sulfur compounds 10

Ozone-depleting substances 100†

Greenhouse gases 75,000 CO2e

Note: There are additional rates for municipal waste 

combustors and landfills; however, Boeing does not 

combust or landfill municipal waste at the Boeing Everett 

facility.

∗

VOC and NOX are precursors of ozone.

†

WAC 173-400-720(4) (b) (iii) (B).

SO2: sulfur dioxide

PM10: particulate matter less than 10 microns in diameter

PM2.5: particulate matter less than 2.5 microns in diameter

H2S: hydrogen sulfide

3.2.1.4. Significant Emissions Increase Analysis

If the project causes a significant emissions increase, then the project is a major modification 

only if it also results in a significant net emissions increase (40 CFR 52.21(a)(2)(iv)(a)). The 

777X project will result in a significant emissions increase only for VOCs, and will be 

considered a major modification only if it also results in a significant net emissions increase of 

VOCs. The steps necessary to calculate the net emission increase are outlined in 40 CFR 

52.21(b) (3) (i). As noted earlier in this section, EPA has stated that calculating a net emission 

increase is at the source’s option. So a source may seek a PSD permit based on a calculated 

significant emission increase alone. For the 777X project, Boeing is taking that option and 

foregoing the Step 2 significant net emission increase analysis. 

The 777X project will not exceed the SER of any regulated NSR pollutant except for VOCs. 

Therefore, Boeing submitted an application for PSD review only for VOCs. 

Ecology has discussed the emissions from painting previously in this section. As noted above, 

the emissions from painting completed airplanes in the paint hangars were not included in the 
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777X project PSD application because Boeing is operating those activities at near capacity and 

will not be adding additional paint hangars as part of this project. The paint hangars will not 

experience an increase in utilization as a result of this project. Even if those activities were 

included, the 777X project would not be a major modification for any non-VOC NSR-regulated 

pollutant. 

In addition to regulated NSR pollutants, GHGs are subject to regulation as of January 2, 2011. 

EPA’s PSD rule under 40 CFR 52.21(b) (49) states the following:

Beginning January 2, 2011, the pollutant GHGs is subject to regulation if:

The stationary source is a new major stationary source for a regulated NSR 

pollutant that is not GHGs, and also will emit or will have the potential to emit 

75,000 tpy CO2e or more; or

The stationary source is an existing major stationary source for a regulated NSR 

pollutant that is not GHGs, and also will have an emissions increase of a regulated 

NSR pollutant, and an emissions increase of 75,000 tpy CO2e or more. 

Boeing Everett is an existing major stationary source for a regulated NSR pollutant that is not 

GHGs, and the proposed 777X project is expected to result in a significant increase of VOCs. 

However, the project will not result in an emissions increase of 75,000 tpy of CO2e.

40 CFR 52.21(b) (49) continues:

Beginning July 1, 2011, in addition to the provisions in paragraph (b) (49) (iv) of 

this section, the pollutant GHGs shall also be subject to regulation:

At a new stationary source that will emit or have the potential to emit 100,000 tpy 

CO2e; or 

At an existing stationary source that emits or has the potential to emit 100,000 tpy 

CO2e, when such stationary source undertakes a physical change or change in the 

method of operation that will result in an emissions increase of 75,000 tpy CO2e

or more.

Boeing Everett is an existing stationary source with the PTE 100,000 tpy CO2e; however, the 

777X project will not result in an emissions increase of 75,000 tpy of CO2e. Therefore, the 

GHGs emissions from the project are not subject to PSD review.

4. BACT

4.1. Definitions and Policy Concerning BACT

All new major sources or major modifications are required to utilize BACT for those new and 

modified emission units that will experience an increase in emissions as a result of the project. 

BACT is defined as an emissions limitation based on the maximum degree of reduction for each 

pollutant subject to regulation, emitted from any proposed major stationary source or major 
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modification, on a case-by-case basis, taking into account cost-effectiveness, economic, energy, 

environmental, and other impacts (40 CFR § 52.21(b)(12)).

 

Federal guidance requires each PSD permit applicant to implement a “top-down” BACT analysis 

process for each new or physically or operationally changed emissions unit. Ecology has 

adopted the top-down BACT process for its BACT determinations. This top-down BACT 

analysis process consists of five basic steps described below:1

Step 1. Identify all available control technologies with practical potential for application to 

the specific emission unit for the regulated pollutant under evaluation.

Step 2. Eliminate all technically infeasible control technologies.

Step 3. Rank remaining control technologies by control effectiveness and tabulate a control 

hierarchy.

Step 4. Evaluate most effective controls and document results.

Step 5. Select BACT, which will be the most effective practical option not rejected, based 

on economic, environmental, and/or energy impacts.

If the applicant proposes to implement the most effective or “top” available control strategy, Step 

4 is not necessary.

As shown above, the "top-down" BACT process starts by considering all available emission 

control technologies, and ranks them for further evaluation from most effective to least effective 

technically available control technology. The most effective emission reduction technology is 

then evaluated for economic feasibility. If the technology is proven infeasible based on 

economics, energy, or other environmental considerations, then the next most stringent level of 

reduction is considered. The most stringent level of emissions control that is not determined to 

be technically and economically infeasible is selected as BACT. While the permitting agency 

makes the final BACT decision, the burden is on the applicant to prove why the most stringent 

level of control should not be used.

Boeing provided a 5-step top-down VOCs BACT analysis for the 777X project, which was fully 

evaluated by Ecology.

For the 777X project, the only regulated NSR pollutant for which the project results in a 

plantwide significant emission increase is VOCs. This section will discuss the BACT analysis 

focusing on VOCs for the new and modified prep booths, spray booths, combustion sources, and 

fugitive (open floor) sources using the EPA top-down approach.

 1 See EPA’s Draft New Source Review Workshop Manual, 1990; and PSD and Title V Permitting Guidance for 

Greenhouse Gases <http://www.epa.gov/nsr/ghgdocs/ghgpermittingguidance.pdf>. 
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4.2. BACT Analysis

4.2.1. Prep and Spray Paint Booths BACT Analysis

There are several proposed new or modified prep and spray paint booths anticipated for the 777X 

project. These booths are listed in Table 14. The table presents the total potential VOC 

emissions based on the anticipated annual hours of operation for each of the new or modified 

emissions units.

Table 14. New and Modified Booths

Emission

Unit

Booth

Type Qty.

New/

Modified

Annual Hr

of Operation

(per booth)

VOC

Emissions

(tpy/booth)

Exhaust

Rate

(acfm)

WBSP-2

Forward body

section spray 

booth

1 Might need to be modified to

accommodate larger sections 1,000 12.5 54,900

WBSP-3

Mid body 

section spray 

booth

1 Might need to be modified to

accommodate larger section 1,000 12.5 65,750

WBSP-4 Aft body section

spray booth 1 Might need to be modified toaccommodate larger sections 1,000 12.5 64,000

WBSP-6

Forward body

section CIC 

spray booth

1 Might need to be modified to

accommodate larger sections 625 12.1 33,500

WBSP-7

Mid body 

section CIC 

spray booth

1 Might need to be modified to

accommodate larger sections 625 6.1 44,800

WBSP-8

Aft body section

CIC spray 

booth

1 Might need to be modified to

accommodate larger sections 625 12.1 33,500

WBSP-10

Vertical fin 

HLFC

prep booth

1

NEW (Currently this work is done 

on the 777 vertical fin with final 

coat in the airplane paint 

hangars.)

500 1.3 50,000

WBSP-11a,b,c

Vertical fin 

HLFC

spray booths

3

NEW (Currently this work is done 

with final coat in the airplane 

paint hangars.)

500 4.4 150,000

AA-2 Wing stub 

spray booths 2 One new, one modified 1,000 1.4 4,000

IRC-1a,b,c Adhesive spray 

booths 3 NEW 2,000 8.9 20,000

IRC-2 Paint spray 

booth 1 NEW 2,000 5 20,000

Acfm: Actual cubic feet per minute

VOC emission estimates for paint spray booths include gun and line cleaning operations because 

the paint containers and the spray guns are connected by long lines that need to be cleaned. 

Although the cleaning solution is collected in containers, for the purposes of the emission 

estimates and the BACT analysis, a portion of the gun and line cleaning solvent is assumed to be 

emitted through the booth. 
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BACT analysis was performed for each emission unit operating at the emission rates and exhaust 

flow rates listed in Table 14. Boeing currently uses a combination of low-VOC coatings, high 

transfer efficiency application techniques, and good work practices (i.e., keeping containers of 

coating closed when not in use) to minimize VOC emissions. The Aerospace National Emission 

Standard for Hazardous Air Pollutants (ANESHAP) regulation requires low-VOC coatings, high 

transfer efficiency coating techniques, and these work practices. Therefore, these coatings, 

application techniques, and work practices are considered the base case for BACT.

The cleaning and coating operations planned for the new and modified spray paint booths are as 

follows:

• Aircraft parts cleaning: Before the parts of the airplane can be sealed and/or coated, they 

first must be cleaned and prepped.

• Aircraft parts sealing: Areas on certain parts of the airplane (e.g., parts that will become 

part of a fuel tank or the pressurized fuselage) must be sealed prior to coating.

• Aircraft parts priming: Priming provides corrosion protection and ensures the necessary 

bond between the surface of the airplane components and the topcoat.

• Aircraft parts topcoat: The topcoat is the final coating of the normally visible surfaces of 

the airplane. The topcoat not only provides the final protection of the airplane surface, 

but on the exterior of the fuselage and empennage (the tail assembly of an aircraft, 

including the horizontal and vertical stabilizers, elevators, and rudder) also provides the 

decorative color to the airplane.

• Aircraft parts corrosion inhibiting compound (CIC): Portions of the airplane that are not 

normally visible often need a special coating to further protect them from corrosion.

• Adhesive spray booths: Interior composite panels (e.g., aircraft cabin sidewalls and 

ceilings) are sprayed with adhesive to apply a decorative laminate.

• Spray equipment cleaning: The spray equipment used to perform the operations above is 

cleaned after each use. A small amount of solvent evaporates while cleaning the spray 

equipment.

4.2.2. Available Control Technologies

BACT databases from EPA (EPA, RACT/BACT/LAER Clearinghouse [RBLC]), California Air 

Resources Board (CARB), and South Coast Air Quality Management District (SCAQMD) were 

reviewed for possible control technologies that are both available on the market and proven 

practice in the aerospace or other industries with similar requirements for coating very large 

objects. The technologies reviewed are summarized in Table 15.
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4.2.3. BACT Feasibility Review

The control technologies in Table 15 have been demonstrated and achieved in practice and 

therefore could be feasible technologies for implementation for the 777X project.

Table 15. BACT Review

Control

Technology

Equipment

Description Company

Date

Implemented

Pollutant

Controlled

Control

Efficiency

(%)

Emission

Limit

Database

Reference

Thermal 

oxidizer Spray booth

Watkins 

Manufacturing

Corporation

10/28/2002 VOC 98.9 95% 

control

CARB, BACT

Clearinghouse

RTO Spray booth Arcadia, Inc 2/6/2001 VOC 99.3 .89 lb/hr

CARB, BACT

Clearinghouse,

SCAQMD 

Clearinghouse

RTO Spray booth

Huck 

International 

– Deutsch 

Operations

N/A VOC 90.6 59 lb/day

CARB, BACT

Clearinghouse,

SCAQMD 

Clearinghouse

RTO w/

concentrator Spray booth

Kal-Gard 

Coating &

Mfg, E/M 

Corp.

8/14/2008 VOC Not 

Available 2 tpy CARB, BACTClearinghouse

RTO w/

concentrator Spray booth

Douglas 

Production

Division

3/30/94 VOC 93.2 341 gal/ 

day

CARB, BACT

Clearinghouse,

SCAQMD 

Clearinghouse

Carbon 

adsorption Spray booth

Lippert

Components, 

Inc.

5/8/2002 VOC 99.3 85.5% 

control

CARB, BACT

Clearinghouse

Carbon 

adsorption Spray booth NorthropGrumman 2/25/91 VOC 90 414 lb/day

CARB, BACT

Clearinghouse

Low-VOC 

coatings,

HVLP coating 

gun, best 

management 

practices

Spray booth Dean Baldwin 

Painting LP 09/21/2011 VOC N/A

4.5 lb 

VOC/gal

coating

EPA, RBLC

Clearinghouse

Low-VOC 

coatings,

HVLP coating 

gun, best 

management 

practices

Spray booth Time Aviation 

Services, Inc. 6/18/99 VOC N/A 3 gal/day CARB, BACTClearinghouse

Low-VOC 

coatings,

HVLP coating 

gun, best 

management 

practices

Spray booth

California Air 

National

Guard, 

Fresno

1/22/97 VOC N/A

5.23 lb 

VOC / gal 

coating

CARB, BACT

Clearinghouse

Low-VOC 

coatings,

HVLP coating 

gun,

enclosed gun 

cleaner

Spray booth Toter 12/16/99 VOC N/A

1.09 lb 

VOC /

gal

CARB, BACT

Clearinghouse

RTO = regenerative thermal oxidizer

N/A = not applicable

HVLP = high-volume low-pressure
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4.2.4. Ranking of BACT by Control

The potential control options listed in Table 15 are ranked in Table 16 based on the control 

efficiencies documented as being achieved in practice.

Table 16. Ranking of Control Technologies

Type of Control Technology Control Efficiency Ranking

RTO 99.3% 1

Carbon adsorption 99.3% 2

Thermal oxidizer 98.9% 3

RTO w/concentrator 93.2% 4

Low-VOC coatings, HVLP coating

gun, best management practices N/A 5

4.2.5. Cost-Effectiveness Evaluation

Vendors of paint operation control technologies were contacted by Boeing to assess 

implementation of the different controls available in the marketplace listed in Table 16. Vendor 

quotes were collected and are summarized in the cost-effectiveness evaluation spreadsheets.

Cost-effectiveness evaluations were made following EPA’s guidance for VOC Control by 

Incinerator and by Carbon Adsorption (EPA, 2002). These evaluations are discussed below.

Before discussing the evaluations’ results, note the cost-effectiveness analyses use the standard

default values for construction as provided by EPA unless otherwise noted. Boeing Everett 

expects the installation of any add-on control technology at an existing part of the facility would 

require complicated retrofit construction and expenses. The existing facility has limited space 

available for the footprint of additional equipment, which might require that any add-on controls 

be placed on the roof. The need for additional structural support would have to be evaluated, and 

the existing natural gas lines might need to be upgraded to supply sufficient follow and pressure 

to operate the control equipment as designed. Retrofits and new equipment installation add costs 

to the cost-effectiveness analysis. Providing utilities such as natural gas is expected, but not 

currently available at every location. For these reasons, Boeing projected construction costs for 

both retrofits and for new equipment installed at Boeing Everett’s existing facility are expected 

to be above standard EPA default values for construction for a new facility.

4.2.6. Thermal Oxidizer

A thermal oxidizer uses a burner to destroy VOC emissions prior to release to the atmosphere 

through a stack. This control technology includes preheating the incoming air stream to obtain 

additional fuel efficiencies. In prior BACT reviews for Boeing (PSD application for 737 MAX 

production and capacity increase, February 2013), the thermal oxidizer technologies have been 

demonstrated to be the most expensive technology to implement for this application. It was 
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implemented only once in the industry over 10 years ago (see Table 15 above). Since that 

implementation, other control technologies for coating applications have been implemented.

4.2.7. Carbon Adsorption

Carbon adsorption uses a filter bank of canisters that contain activated carbon which adsorbs the 

VOC emissions as the emissions pass through before being released to the atmosphere. Vendor 

information for the carbon adsorption technology was obtained from Thermal Recover Systems 

(TRS). The carbon adsorption control technology overall cost-effectiveness in dollars per ton 

removed is discussed below.

4.2.8. Regenerative Thermal Oxidizer

A regenerative thermal oxidizer (RTO) was ranked as one of the top control technologies 

available based on control efficiency. VOC emissions created from cleaning and coating 

activities are burned inside an enclosed chamber. Heat from the exhaust gas is recovered in a 

heat exchanger, which allows for fuel efficiencies in sustaining the high burn temperature. 

Vendor information for the RTO technology was obtained from Epcon. The RTO with control 

technology overall cost-effectiveness in dollars per ton removed is discussed in the summary 

section below.

4.2.9. RTO with Concentrator

This control technology augments the RTO methodology with the addition of a concentrator 

wheel. The wheel provides for a more concentrated VOC content in a smaller air stream for 

burning. The concentration of VOCs allows greater fuel efficiencies to be obtained during 

operation. Vendor information for the RTO with concentrator control technology was obtained 

from Anguil. The RTO with concentrator control technology overall cost-effectiveness in 

dollars per ton removed is discussed below in the summary section below.

4.2.10. Low VOC Coatings, High Transfer Efficiency Coating Techniques, and 

Good Work Practices

Boeing Everett currently uses low VOC coatings that meet specifications for airplane coating 

operations. Boeing also uses high transfer efficiency coating techniques, such as high volume 

low pressure (HVLP) spray guns, which provide high transfer efficiency and reduce the overall 

amount of paint required to perform a job. In addition, Boeing uses good work practices to 

minimize VOC emissions, including storing coatings and solvents in closed container, bagging 

solvent hand wipe cleaning rags when not in use, and capturing and containing solvent used for 

cleaning spray equipment. The VOC emissions standards for uncontrolled use will be applied in 

this operation. No cost analysis was performed because Boeing considers this to be the base case 

for BACT.
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4.2.11. Summary of Cost-Effectiveness Analysis

The costs of control technologies identified as being available and technologically feasible for 

the new and modified prep booths and spray booths are summarized in Tables 17 through 20. 

These cost estimates are conservative (potentially underestimating the costs) and include an 

additional construction expense estimated at 15 percent of the Total Purchased Equipment Cost. 

In some cases, that additional expense was included in the vendor’s quote, and in others the 

expense was added. 

Vendor information was not collected for every booth configuration and VOC loading rate 

expected for the 777X project. Vendor cost basis information is summarized in Table 17. Costs 

were scaled from the parameters quoted from vendors in Table 17 to match those emission units 

listed in Table 14. The carbon adsorption quote from Thermal Recovery Systems was obtained 

in 2011 for a previous Boeing PSD application using a 25,000 cubic feet per minute (CFM) air 

flow rate. The same quote was used in this analysis using a conservative cost approach to not 

include inflation costs. The RTO quote from Epcon was for a 33,500 cfm, and a 100,000 cfm 

booth. Quotes for RTO with concentrator from Anguil were provided for 46,800 cfm, 120,000 

cfm, 195,000 cfm, and 400,000 cfm capacity booths. RTO with concentrator equipment

operating costs were only obtained for the 400,000 cfm unit as operating costs are minimal 

compared to the equipment costs. 

For control equipment that would be installed in existing buildings, a 15 percent contingency 

factor was applied. This is a very conservative estimate considering that the thermal oxidizers 

would likely be outside the building, and require considerable duct work and foundation 

supports.

Table 17. Vendor Quote Basis Summary

Type of Control Technology Vendor

Air Flow

Rates

(cfm)

Operating Costs

Inc. in Quote?

Equipment Cost

Contingency 

Inc. in Quote

Regenerative canister thermal oxidize Epcon 33,500 Yes 15%

Regenerative canister thermal oxidizer Epcon 100,000 Yes 0%

Carbon adsorption TRS 25,000 Yes 0%

RTO w/Zeolite concentrator Anguil

46,800

120,000

195,000

No∗ 15%

RTO w/Zeolite concentrator Anguil 400,000 Yes 15% ∗

Operating costs were scaled from four 100,000-cfm units.

The standard method of evaluating the cost-effectiveness of various air pollution control options 

is to calculate the annualized cost of each option and divide that by the amount of emissions that 

would be removed by that option. Using this approach, the annualized cost of removing one ton 
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of VOC emissions was calculated for each applicable control option and is summarized in Tables 

18, 19, and 20.

Table 18. Summary of Costs for Wing Component Fabrication (WCF)

Control Technologies by Emission Unit

Emission

Unit

Unit

Description

TRS Carbon 

Adsorption

Control Costs

($/ton of VOC 

controlled)

Anguil RTO

w/Zeolite 

Concentrator

Control Costs

($/ton of VOC 

controlled)

Epcon Canister 

RTO

Control Costs

($/ton of VOC

controlled)

WCF-8a

Wing panel prep booth(s) (abrasive 

blast/sanding, solvent hand wipe, edge seal) 

(see Note 1)

$177,294 $9,177 $11,638

WCF-8b Wing spar prep booth (abrasive blast/sanding, 

solvent hand wipe, edge seal) $181,961 $19,135 $21,459

WCF-9a,

b, and d Wing panel spray booth (see Note 2) $179,228 $34,789 $47,347

WCF-9c Wing spar spray booth $180,074 $42,914 $48,706

WCF-10a

and 10b Wing panel primer curing booth $217,873 $275,799 $377,238

WCF-10c Wing spar primer curing booth $245,353 $403,271 $454,442

WCF-11 Small quantity paint mix booth $333,083 $498,125 $533,096

WCF-12a

and 12b Coating equipment cleaning booth $184,137 $31,133 $33,318

WCF-14 Wing spar seal booth(s) (see Note 3) $179,439 $20,722 $24,382

Notes:

1. As explained in Note 1 to Table 1, Boeing is considering building one or two wing panel prep booths. It is conservatively assumed for 

purposes of calculating the control technology costs that only one wing panel prep booth will be built. If the control technology costs 

were instead based on two booths, the costs would be higher than those shown in the above table.

2. Although the current plan is to build three wing panel spray booths, it is conservatively assumed for purposes of calculating the 

control technology costs that only two wing panel spray booths will actually be built. If the control technology costs were instead 

based on three booths, the costs would be higher than those shown in the above table.

3. As explained in Note 3 to Table 1, Boeing is considering building from one to as many as four wing spar seal booths. It is 

conservatively assumed for purposes of calculating the control technology costs that only one wing spar seal booth will actually be 

built. If the control technology costs were instead based on two or more booths, the costs would be higher than the costs shown in 

the above table.

Table 19. Summary of Costs for Wing and Body Structure Paint (WBSP)

Control Technologies by Emission Unit

Emission

Unit

Unit

Description

TRS Carbon 

Adsorption

Control Costs

($/ton of

VOC controlled)

Anguil RTO

w/Zeolite

Concentrator

Control Costs

($/ton of

VOC controlled)

Epcon Canister

RTO

Control Costs

($/ton of VOC

controlled)

WBSP-1a and 1b Robotic wing spray booth –

120,000 acfm $180,958 $22,944 $40,850

WBSP-1a and 1b Robotic wing spray booth – 90,000 

acfm $179,209 $18,050 $24,331
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Table 19. Summary of Costs for Wing and Body Structure Paint (WBSP)

Control Technologies by Emission Unit

Emission

Unit

Unit

Description

TRS Carbon 

Adsorption

Control Costs

($/ton of

VOC controlled)

Anguil RTO

w/Zeolite

Concentrator

Control Costs

($/ton of

VOC controlled)

Epcon Canister

RTO

Control Costs

($/ton of VOC

controlled)

WBSP-1a and 1b Robotic wing spray booth – 60,000 

acfm $178,248 $14,126 $13,357

WBSP-2 Forward body section spray

booth $179,654 $32,206 $38,495

WBSP-3 Mid body section spray booth $180,185 $36,908 $43,945

WBSP-4 Aft body section spray booth $180,313 $37,366 $44,477

WBSP-6 Forward body section CIC spray 

booth $177,730 $21,008 $23,958

WBSP-7 Mid body section CIC spray booth $182,221 $54,501 $63,344

WBSP-8 Aft body section CIC spray booth $177,730 $21,008 $23,958

WBSP-10 Vertical fin HLFC prep booth $211,205 $291,315 $329,290

WBSP-11a, 11b,

and 11c Vertical fin HLFC spray booth $190,538 $118,905 $153,698

Table 20. Summary of Costs for Airplane Assembly (AA)

and Interior Fabrication (IRC) Control Technologies by Emission Unit

Emission

Unit

Unit

Description

TRS Carbon

Adsorption

Control Costs

($/ton of

VOC controlled)

Anguil RTO

w/Zeolite

Concentrator

Control Costs

($/ton of

VOC controlled)

Epcon Canister

RTO

Control Costs

($/ton of

VOC controlled)

AA-2a and 2b Wing stub spray booth $199,978 $44,284 $47,829

IRC-1a, 1b, And 1c Adhesive spray booth $183,800 $24,144 $29,528

IRC-2 Paint spray booth $191,095 $42,735 $52,265

The robotic wing spray booths (WPSB-1a and 1b) are designed to operate in three operating 

modes, with ventilation rates of 120,000 cfm, 90,000 cfm, and 60,000 cfm. In that supplement, 

three options were evaluated:

1. Option A is to use a VOC control system for each booth designed to handle all 120,000 

cfm. This option would ensure that all VOC emissions are treated by the control system. 

It would operate all the time that coating or cleaning occurred. About 29.5 tons of VOCs

per year would be treated by each system and no VOC would be untreated.
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2. Option B is to use a VOC control system for each booth designed only to handle up to 

60,000 cfm, the most common operating mode of the robotic booth. Any exhaust above 

60,000 cfm would be vented directly to the atmosphere without going through the VOC 

control system. Because the 60,000 cfm mode represents most of the operation and 

potential emissions, most emissions would be controlled. About 26 tons of VOC would 

be treated per year and about three tons per year would be untreated.

3. Option C is similar to Option B except that the VOC control system for each booth would 

be designed to handle up to 90,000 cfm, and any exhaust greater than 90,000 cfm would 

be vented directly to the atmosphere. About 29.1 tons of VOCs would be treated per 

year, and 0.4 tpy would be untreated. 

Each of these options was evaluated and the results are presented in Table 19. Note that under 

the current Boeing plan, a decision to modify the robotic wing spray booth by installing a second 

robotic spray system in each booth will not be made until Phase 2 of the project and, at that time,

BACT will likely be reevaluated. Phase 2 is tentatively scheduled to begin in 2021.

4.2.12. Comparison with Other Aerospace BACT Determinations

Boeing is currently the only manufacturer of large commercial airplanes in the United States. 

Even though Boeing has some smaller facilities elsewhere in the country and Airbus is scheduled 

to start-up a new airplane assembly plant in Alabama, there are few airplane facilities to compare 

to Boeing Everett due to the size of the planes made at Everett, and the size of the facilities at 

Everett. 

A review of RBLC entries of the last 10 years for aerospace surface coatings (Process Type 

41.001) shows entries for Boeing commercial airplane operations in the Puget Sound area and 

one entry for a Dean Baldwin aircraft refinishing operation in Indiana (Table 21). None of these 

entries indicates that add-on controls were considered BACT. Also, no BACT determinations 

for the Alabama Airbus facility are listed in the RBLC, even though the plant is under 

construction. A further review of the RBLC entries for permits between 1990 and 2003 (Table 

22) indicates some BACT decisions for aerospace coating operations that required add-on 

controls. However, evaluation of the location of each of these operations indicates that each was 

in an ozone nonattainment area at the time of permitting. For example, Huck International is 

located in Los Angeles, an ozone nonattainment area; CA-0889, CA-1045, and CA-0977. For 

each of these RBLC entries, we believe that the control determinations were intended to 

implement LAER for those operations under nonattainment area NSR rather than BACT under 

the PSD program. 
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Table 21. RBLC Aerospace Coating Entries Since 2000 (Process Type 41.001)

ID Co. State

Permit

Date Process

Control

Method

Description BACT

WA-0326 Boeing Commercial

Airplanes Group WA 10/12/2005 Exterior coating operations N/A

WA-0326 Boeing Commercial

Airplanes Group WA 10/12/2005 Final assembly N/A

WA-0326 Boeing Commercial

Airplanes Group WA 10/12/2005 Interiors manufacturing N/A

WA-0330 Boeing Commercial

Airplanes Group WA 10/12/2005 Paint hangar final exterior coating

A BACT review was 

not required because 

Ecology determined 

that there was no 

physical change, or 

change in the method 

of operation, that 

causes or results in an 

emissions increase.

BACT-PSD

WA-0330 Boeing Commercial

Airplanes Group WA 10/12/2005 787 final assembly

A BACT review was 

not required because 

Ecology determined 

that there was no 

physical change, or 

change in the method 

of operation, that 

causes or results in an

emissions increase.

BACT-PSD

WA-0330 Boeing Commercial

Airplanes Group WA 10/12/2005 Interiors manufacturing

A BACT review was 

not required because 

Ecology determined 

that there was no 

physical change, or 

change in the method 

of operation, that 

causes or results in an

emissions increase.

BACT-PSD

WA-0340 The Boeing Company WA 07/27/2007 Paint hangar/final

exterior coating

Other case-bycase

WA-0344 Boeing Commercial

Airplanes Group WA 10/07/2008 Paint booth/hangar

Compliance with 40 

CFR Part 63, Subpart 

GG and low-VOC 

vapor pressure 

cleaning solvents and 

strippers with low 

pressure applicators 

or manual application 

for depainting

BACT-PSD

IN-0126 Dean Baldwin

Painting LP IN 09/21/2011 Aircraft refinishing Other case-bycase

WA-0347 The Boeing Company 

Boeing Renton WA 02/19/2013 Paint booths/hangars/floorActivities

Compliance with 40 

CFR Part 63, Subpart 

GG and low-VOC 

vapor pressure 

cleaning solvents and 

strippers with low 

pressure applicators 

or manual application 

for depainting.

BACT-PSD

WA-0348 The Boeing Company 

Boeing Renton WA 02/19/2013 Paint booth/finalexterior coating

Compliance with 40 

CFR Part 63, Subpart 

GG and low-VOC 

BACT-PSD
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Table 21. RBLC Aerospace Coating Entries Since 2000 (Process Type 41.001)

ID Co. State

Permit

Date Process

Control

Method

Description BACT

vapor pressure 

cleaning solvents and 

strippers with low 

pressure applicators 

or manual application 

for depainting.

Table 22. RBLC Aerospace Coating Entries Between 1990 and 2000

ID Co. State

Permit

Date Process

Control

Method

Description BACT

WA-0326 Boeing Commercial

Airplanes Group WA 10/12/2005 Exterior coating operations N/A

WA-0326 Boeing Commercial

Airplanes Group WA 10/12/2005 Final assembly N/A

WA-0326 Boeing Commercial

Airplanes Group WA 10/12/2005 Interiors manufacturing N/A

WA-0330 Boeing Commercial

Airplanes Group WA 10/12/2005

Paint hangar 

final exterior 

coating

A BACT review 

was not required 

because Ecology

determined that 

there was no 

physical change, or 

change in the 

method of 

operation, that 

causes or results in 

an emissions 

increase.

BACT-PSD

WA-0330 Boeing Commercial

Airplanes Group WA 10/12/2005 787 final assembly

A BACT review 

was not required 

because Ecology 

determined that 

there was no 

physical change, or 

change in the 

method of 

operation, that 

causes or results in 

an emissions 

increase.

BACT-PSD

WA-0330 Boeing Commercial

Airplanes Group WA 10/12/2005 Interiors manufacturing

A BACT review 

was not required 

because Ecology 

determined that 

there was no 

physical change, or 

change in the 

method of 

operation, that 

causes or results in 

an emissions 

increase.

BACT-PSD
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Table 22. RBLC Aerospace Coating Entries Between 1990 and 2000

ID Co. State

Permit

Date Process

Control

Method

Description BACT

WA-0340 The Boeing Company WA 07/27/2007

Paint 

hangar/final

exterior coating

Other case-bycase

WA-0344 Boeing Commercial

Airplanes Group WA 10/07/2008 Paint booth/hangar

Compliance with 

40 CFR Part 63, 

Subpart GG and 

low-VOC vapor 

pressure cleaning 

solvents and 

strippers with low 

pressure 

applicators or 

manual application 

for depainting.

BACT-PSD

IN-0126 Dean Baldwin

Painting LP IN 09/21/2011 Aircraft refinishing

Other case-bycase

WA-0347 The Boeing Company 

Boeing Renton WA 02/19/2013

Paint booths/ 

hangars/floor

activities

Compliance with 

40 CFR Part 63, 

Subpart GG and 

low-VOC vapor 

pressure cleaning 

solvents and 

strippers with low 

pressure 

applicators or 

manual application 

for depainting.

BACT-PSD

WA-0348 The Boeing Company 

Boeing Renton WA 02/19/2013 Paint booth/finalexterior coating

Compliance with 

40 CFR Part 63, 

Subpart GG and 

low-VOC vapor 

pressure cleaning 

solvents and 

strippers with low 

pressure

applicators or 

manual application 

for depainting.

BACT-PSD

WA-0287

Boeing Commercial

Airplanes - Everett 

Facility

WA 12/23/1991

Surface 

coating, 

corrosion 

inhibitor

Best management 

practices. 

Electrostatic, air 

assisted, or airless 

spray equipment. 

Baseline emission 

rate: 11.5 tpy. 

Control efficiency: 

15%-35%.

BACT-PSD

CA-0771

California Air 

National

Guard, Fresno

CA 01/22/1997

HVLP 

applicator used 

to coat parts

Lowest available 

VOC content 

which meets 

military 

specifications.

LAER

CA-0977 Kal-Gard Coatings &

Manufacturing CA 05/28/1997

Metal parts 

coating 

operation

Zeolite 

concentrator and 

thermal oxidizer

LAER
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Table 22. RBLC Aerospace Coating Entries Between 1990 and 2000

ID Co. State

Permit

Date Process

Control

Method

Description BACT

CA-0979 Douglas Products 

Division CA 03/30/1994

Metal parts 

coating 

operation

Concentrator and 

thermal oxidizer LAER

CA-0980 Huck International -

Deutsch Operations CA 03/09/1995

Metal parts 

coating 

operation

Thermal oxidizer LAER

CA-0549 Edwards Air Force 

Base CA 05/07/1993

Hangar-sized 

spray booth for 

aircraft up to 

EC-18

Carbon adsorption 

filter bank w/

flame ionization 

detector to detect 

breakthrough

Other case-bycase

CA-0685 T.B.M. Inc. CA 11/06/1995

Aircraft 

refinishing

operation

Low-VOC 

coatings and 

Hercules GW/R 

enclosed gun

Other case-bycase

UT-0058 Hill Air Force Base UT 12/15/1997

Surface 

coating, 

military 

operations

Zeolite adsorption 

system - M&W 

condesorb fob – 26 

Zeolite adsorption 

cells - 100,000 

acfm @ 80°F -

max loading 122 

lb VOC/hr

Other case-bycase

WA-0045 Heath Tecna 

Aerospace Co. WA 03/27/1992 Spray booth

Carbon adsorber 

(methylene 

chloride)

Other case-bycase

WA-0287

Boeing Commercial

Airplanes - Everett 

Facility

WA 12/23/1991

Surface 

coating, 

corrosion 

inhibitor

Best management 

practices. 

Electrostatic, air 

assisted, or airless 

spray equipment. 

Baseline emission 

rate: 11.5 tpy. 

Control efficiency: 

15%-35%.

BACT-PSD

NAA = Nonattainment area

The RBLC also indicates that add-on controls have been installed at both Edwards Air Force 

Base (AFB) in California and Hill AFB in Utah. Edwards AFB is in an ozone nonattainment 

area. Neither of these entries purports to reflect a BACT decision under PSD. Each of these 

decisions is discussed further below. Boeing was provided information on these facilities by 

CH2M Hill and Air Force personnel familiar with those operations.

Edwards AFB has two booths used to paint airplanes and parts, and the booths have carbon 

adsorption systems installed. The first booth has an air flow of 111,000 cfm with 2.25 tpy of 

uncontrolled VOC emissions. The second booth is much larger (493,000 cfm) with 1.65 tpy of 
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uncontrolled VOC emissions. Both of the carbon systems were installed because the AFB 

believed a cost savings, compared to other control technologies would be achieved while

meeting nonattainment area requirements applying LAER and obtaining offsets.

These systems were supposed to be regenerative carbon systems, but soon after installation the 

regenerative portion failed and was never repaired. Today, carbon is swapped out manually at 

great expense. Albeit infrequently because of decreased VOC emissions over the years. The use 

of good work practices to reduce VOC emissions by using low VOC paints and application 

methods has proved more cost-effective than maintaining the carbon VOC control system and 

running it. This VOC control system’s efficiency is not achieved in practice as designed and 

listed in the EPA RBLC.

Hill AFB was in an ozone nonattainment or maintenance area at the time of permitting and 

installed a Zeolite adsorption system. The initial installation of the unit appears to have been 

associated with technology demonstration and funded under a pollution prevention program. 

This unit has not been operational at Hill AFB for an extended period of time. Boeing was 

unable to determine how long the unit operated or the reason it was taken out of operation. 

Because of this lack of information, Boeing believes that no judgment can be made as to the 

feasibility of such a system for Boeing Everett. Ecology agrees with this assessment.

In summary, Boeing was unable to identify similar aerospace coating operations operated by 

other companies in the United States and could not find a recent BACT determination in EPA’s 

RBLC that requires add-on controls for similar aerospace coating operations. The few older 

determinations that are listed as BACT were intended to implement LAER for those operations 

under nonattainment area NSR rather than BACT under the PSD program.

4.2.13. BACT Selection

In determining BACT, energy, environmental, and economic impacts are taken into account. For 

PSD analysis, VOC is regulated as an ozone precursor. However, ozone formation in the Puget 

Sound area is limited by NOX emissions and not VOC emissions. Therefore, the 777X project is 

not expected to have any measurable effect on ambient ozone levels. In addition, control 

technologies that involve combusting the VOCs will require some additional energy.

As noted above in Tables 18 through 20, the identified add-on control technologies are not

economically feasible for the Boeing Everett facility. After taking into account energy, 

environmental, and economic impacts, add-on control technologies are not considered BACT. 

The Boeing Everett facility will be required to continue to implement the use of low VOC 

coatings, used high transfer efficiency coating equipment, and follow good work practices to 

minimize VOC emissions in compliance with the Aerospace NESHAP VOC emission standards 

in 40 CFR 63 Subpart GG. These requirements are listed in Table 23.

Ecology reviewed the State of South Carolina’s Air Operating Permits number 0560-0372 

(issued on July 23, 2007) , number 0560-0415 (issued on August 2, 2012), and Air Quality State 
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Construction Permit for the Boeing IRC and Propulsion South Carolina number 0560-0415-CB 

(issued on January 22, 2014). These permits are Air Operating and Notice of Construction 

permits, and were found to not be applicable to Ecology’s PSD permitting effort for the Boeing 

777X project.

Ecology also contacted Alabama in regards to the proposed Airbus facility. Ecology discovered 

that Airbus’ facility will be three separate facilities with different owners. One facility will be 

for utilities and owned by Honeywell, Inc. This facility will be permitted for natural gas-fired 

boilers. The second facility is the airplane manufacturing plant, and will be owned by Airbus. 

The third facility will be for painting the completed airplanes. As of March 2014, the application 

had not been submitted. A foreign company will own the painting facility. The Alabama plant’s 

producing a final airplane for Airbus will not require a PSD permit.

Based on all this information, Ecology believes the proposed limits meet BACT requirements.

Table 23. Summary of Aerospace NESHAP VOC Emission Standards Applicable to the New and 

Modified Emission Units of the 777X Project

Production Activity Control Technology

Low-VOC primers Large commercial aircraft component exteriors: 5.4 lb VOC/gal

All other applications: 2.9 lb VOC/gal

Low-VOC topcoats 3.5 lb VOC/gal

Low-VOC cleaning solvents

Hand wipe cleaning solvent: vapor pressure less than 45 

millimeters mercury (mm Hg) at 20°C or solvent meets 

composition requirements in Table 1 in 40 CFR 63.744.

Flush cleaning: use collection system to capture flushed solvent.

High-transfer-efficiency spray coating equipment HVLP, electrostatic, or other equivalent spray coating equipment

Paint gun cleaning, waste solvents, and rags Capture and closed containment

4.3. BACT for Natural Gas Combustion

Manufacturing of the new Boeing Model 777X will require Boeing Everett to install new natural 

gas combustion units. These units include process heaters, space heaters, and a gas-fired plasma 

unit for surface treatment of the wing panel stringers. These new natural gas combustion 

emission units are listed in Table 24. With the exception of the natural gas combustion units 

associated with the vertical fin hybrid laminar flow control (HLFC) prep (WBSP 10) and HLFC 

spray booths (WBSP 11 a, b, and c), all the units identified in Table 24 will be located in the new

wing component fabrication building.

These natural gas-fired combustion units will emit NOX, PM10, PM2.5, CO, SO2, and VOCs. 

Natural gas-fired boilers and heaters less than 50 MMBtu/hr generally fall into the category of 

generic BACT and not case-by-case BACT. The following section presents the generic BACT 

analysis for VOC from natural gas combustion units.
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10–50 MMBtu/hr

Table 24. Proposed Natural Gas Combustion Units

Unit ID Description

Rated

Capacity

(MMBtu/hr)

WCF-3a Gas-fired process heater for autoclave #1 40

WCF-3b Gas-fired process heater for autoclave #2 40

WCF-3c Gas-fired process heater for autoclave #3 40

WCF-9a Space heating - wing panel spray booth #1 13.34

WCF-9b Space heating - wing panel spray booth #2 13.34

WCF-9d Space heating – wing panel spray booth #3 13.34

WBSP-11a Space heating - vertical fin HLFC spray booth #1 10.94

WBSP-11b Space heating - vertical fin HLFC spray booth #2 10.94

WBSP-11c Space heating - vertical fin HLFC spray booth #3 10.94

5– 10 MMBtu/hr

Unit ID Description

Rated

Capacity

(MMBtu/hr)

F-1

Combustion equipment for comfort or process heating not 

otherwise identified elsewhere in this table; multiple units, most 

of which will be less than 5 MMBtu/hr, and all of which will be 

less than 10 MMBtu/hr

Range: < 10 

MMBtu/hr to 

< 5 

MMBtu/hr 

WCF-2 Gas-fired heater for liquid nitrogen vaporization unit (if this 

option is chosen to supply autoclaves with nitrogen 8

WCF-10a Space heating - wing panel primer curing booth #1 6.67

WCF-10b Space heating - wing panel primer curing booth #2 6.67

2–5 MMBtu/hr

Unit ID Description

Rated

Capacity

(MMBtu/hr)

WBSP-10 Space heating - vertical fin HLFC prep booth 3.69

WCF-9c Space heating - wing spar spray booth 3.2

WCF-8a Space heating - wing panel prep booth 2.22

WCF-14 Space heating - wing spar seal booth 2.9
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<2 MMBtu/hr

Unit ID Description

Rated

Capacity

(MMBtu/hr)

WCF-7 Gas-fired plasma unit for treatment of wing panel stringer 1.6

WCF-10c Space heating - wing spar primer curing booth 1.6

WCF-6a Space heating - wing panel wash stall #1 1.11

WCF-6b Space heating - wing panel wash stall #2 1.11

WCF-8b Space heating - wing spar prep booth 0.534

WCF-6c Space heating - wing spar and stringer wash stall #1 0.267

WCF-6d Space heating - wing spar and stringer wash stall #2 0.267

4.3.1. Available Control Technologies

BACT databases from EPA (EPA, RBLC), CARB, and SCAQMD were reviewed for possible 

VOC control technologies that are both available on the market and proven in practice for similar 

sized natural gas boilers and heaters. The review determined that no add-on controls were listed 

as BACT for similar-sized natural gas process heaters, space heaters, or plasma surface treatment 

units.

Acceptable control technologies included good combustion practices. Good combustion 

practices require operating the combustion unit in a manner to reduce incomplete combustion. 

Through the reduction of incomplete combustion, VOC emissions can be reduced. Good 

combustion practices are technically feasible to control VOC emissions from the natural gas 

combustion units.

Boeing will be required to implement the technically feasible control technologies of good 

combustion practices. In addition, Boeing may choose to limit fuel usage on some or all of the 

new combustion devices, but that will be due to establishing emission limits for the process and 

not due to BACT considerations. Thus, further discussion of economic, environmental, and 

energy impacts are not necessary.

4.3.2. BACT Selection

Review of BACT databases and industry standards determined that the only technically feasible 

VOC control methods identified for natural gas combustion units less than 50 MMBtu/hr are 

good combustion practices. Boeing will implement the identified technically feasible control 

option of good combustion practices as BACT for VOC emissions from combustion units less 

than 50 MMBtu/hr.
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4.4. BACT for Emergency Generators

The 777X project will need as many as nine 2,750-kW diesel emergency generators, and one 

750-kW diesel emergency generator for the wing component fabrication building. These dieselfired emergency generators will emit NOX, PM10, PM2.5, CO, SO2, and VOCs.

4.4.1. Available Control Technologies

The emission standards and operating limits of the emergency generators in the size range that 

Boeing will use for the wing component fabrication building are contained in 40 CFR 60 New 

Source Performance Standards, Subpart IIII, Standards of Performance for Stationary 

Compression Ignition Internal Combustion Engines and are considered to be BACT. The 

emission standards are provided in Sections 60.4202 and 60.4205. These standards require 

emergency diesel engines of the size for the 777X project to comply with the Tier 2 emission 

standards in 40 CFR 89.112, which are 6.4 g/kWh for VOC and NOX combined, 3.5 g/kWh for 

CO, and 0.20 g/kWh for particulate. The operating requirements for emergency stationary 

internal combustion engines are provided in 40 CFR 60.4205, which generally limit nonemergency use to 100 hours per year (hr/yr). Boeing assumed in their permit application that 

each engine will operate 100 hr/yr. Boeing’s engines will each be limited in the permit to 100 

hr/yr of operation in non-emergency situations. 

BACT for emergency generators is the emission standards and operating conditions established 

in 40 CFR 60 Subpart IIII.

4.4.2. BACT Selection

Boeing will implement the emission standards and operating conditions established in 40 CFR 

60 Subpart IIII. Therefore, further review of economic, environmental, and energy impacts are 

unnecessary.

4.5. BACT for Wing Composite Layup and Curing

The wings of the 777X will be primarily made of composite material. The composite material is 

in the form of resin pre-impregnated tape or sheets. The main wing components include front 

and rear spars, upper and lower panel stringers, and upper and lower panels. Part layup involves 

the layup of composite material onto a mandrel which is preformed into the shape of the part 

being fabricated. Once the part is laid up on the mandrel, a vacuum bag is sealed around the part 

and the assembly is then sent to an autoclave for curing. In the autoclave, vacuum from a 

vacuum pump is used to hold the bagged part under negative pressure while the autoclave is 

pressurized with nitrogen and heated to the curing temperature of up to about 350°F. The part is 

then held under negative pressure for the entire curing cycle, approximately 12 to 14 hours. 

Emissions during the curing cycle are offgases from the composite material and combustion 

emissions from the indirect gas-fired heater that is used to heat the nitrogen in the autoclave. 

The offgases travel through the vacuum system and are exhausted by the vacuum pump 
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(emission unit WCF-4). Boeing is planning for as many as three autoclaves and six vacuum 

pumps. 

VOC emissions from the vacuum pumps are estimated at 1.2 tpy per pump (7.2 tpy total), and 

were calculated based on the volatile content of the uncured composite material. This VOC 

emission estimate is conservative because a portion of the volatiles in the uncured material may 

be water that is released from the material during curing. The estimated air flow from each of 

the vacuum pumps is 100 dry standard cubic feet per minute (dscfm). This estimated air flow is 

consistent with the measured flow rate taken during a source test conducted on a similar vacuum 

pump used in a similar process at Boeing’s Frederickson facility in 2013 for an EPA Section 114 

Emission Data Request.

The air flow from the vacuum pumps is not constant, and the emission concentrations are not 

consistent. At any time, one vacuum pump or six vacuum pumps may be operating depending 

on the number of parts being laid up and cured. Emission estimates are based on VOCs (and 

potentially non-VOCs like water) lost from the material during the entire layup and curing 

process, but emissions may be higher at certain times during the process than others. The 

estimated emission concentrations are low (approximately 7.5 x 10-5 lb VOC/dscf, or less than 

0.05 percent, on average) with the balance of the emissions being ambient air.

4.5.1. Available Control Technologies

Composite processing, except for some cleaning, coating, and composite tooling operations, is 

not covered under 40 CFR 63, Subpart GG. BACT databases from EPA (EPA, RBLC), CARB, 

and SCAQMD were reviewed for possible control technologies that are both available on the 

market and proven in practice in the aerospace or other industries that manufacture items from 

composite molds. The search provided one determination for the production of structural 

honeycomb for aerospace and other industrial applications by Hexcel Corporation (Hexcel). The 

search also provided two determinations since the year 2000 for polyester resin operations, Lasco 

Bathware and Jacuzzi Whirlpool Bath. The database provided very little information about the 

Hexcel operation or the type of composite material used in the process. The bathtub 

manufacturing facilities use a liquid polyester thermosetting resin that contains styrene 

monomer. 

The wing components will be made of a material containing an epoxy resin rather than a 

polyester resin, and the resin is pre-impregnated into a woven fabric (prepreg). The composition 

and emission characteristics of the prepreg woven fabric emissions are significantly different 

than polyester resin emissions. Boeing also looked at carbon adsorption, which is a typical 

control technology for VOC emissions from a process with a stack. The potential control 

technologies are presented in Table 25.
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Table 25. Potential Control Technologies for VOCs for Composite Layup and Curing

Control

Technology

Database

Reference

Date

Implemented

Control

Efficiency

Emission

Limit

Thermal oxidizer or

RTO

EPA, BACT 

Clearinghouse –

Hexcel

11/25/2009 95%

Regenerative thermal

oxidizer w/concentrator 

EPA, BACT 

Clearinghouse –

Lasco

Bathware

3/13/2007 95% 14.84 lb/hr

RTO w/concentrator

CARB, BACT 

Clearinghouse –

Jacuzzi Whirlpool 

Bath

10/15/2002 90%

Carbon adsorption Often used for control 

of VOC emissions NA >95%

4.5.2. BACT Feasibility Review

Currently, there is no control technology demonstrated in practice for the composite processing 

vacuum pumps. The only information provided for the Hexcel process were the emissions from 

an oven used for the curing of honeycomb blocks and the main hazardous air pollutant (HAP) of 

concern was acetaldehyde. Acetaldehyde may be present in the prepreg material Boeing uses, 

but it is not a significant component of the material. There was no information provided in the 

BACT determination about the type of materials used in the Hexcel process, the airflow rate, or 

the emission rates from the operation. Based on this information, it could not be determined 

whether the Hexcel process was similar to Boeing’s process.

4.5.3. RTO with Concentrator

The bathtub manufacturing facilities use a polyester thermosetting resin that contains styrene 

monomer to manufacture bathtubs. The Lasco Bathware process has an average throughput of 

raw materials of 0.645 ton per hour, which includes gelcoat, laminate, and barrier coat, all of 

which contain styrene monomer in a liquid state. The raw materials are sprayed into open molds 

in a spray booth. There was no emission rate information provided for Jacuzzi Whirlpool Bath.

The VOCs released from the process are drawn into a concentrator, which captures the VOCs by 

adsorption. Hot gas desorbs the VOCs, which are then fed to the thermal oxidizer for 

incineration. The overall efficiency for capture and control is estimated to be 90 to 95 percent.

Boeing’s composite process will use a prepreg containing an epoxy resin rather than a coating 

containing a polyester resin. The resin comes pre-impregnated into a woven material and is not 

in a liquid state. The vacuum pump flow rate and concentration of VOCs in the air stream are 

significantly lower than for the spray booths at Lasco Bathware. This assumption is based on the 
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emission limit of 14.8 lb/hr with a control of 95 percent listed in the determination. This should 

be compared to the maximum expected uncontrolled emission rate of less than one pound per 

hour for each vacuum pump. In addition, combination concentrators or carbon adsorbers and 

thermal oxidizers are intended for sources with high air flow and a high enough VOC emission 

rate to make thermal oxidation viable. The autoclave process does not meet either of these 

criteria. Individually, combustion of the VOC emissions and carbon adsorption has additional 

issues which are discussed below.

4.5.4. Thermal Incineration

Hexcel uses a thermal oxidizer or regenerative thermal oxidizer to combust the VOC emissions 

from the process. When using combustion units for VOC control, the VOC emissions in an air 

stream are injected into a burner or chamber that destroys those emissions prior to release to the 

atmosphere through a stack.

The air flows from the vacuum pumps are not constant and the emission concentrations are not 

consistent. At any time, one vacuum pump or six vacuum pumps may be operating, depending 

on the number of parts to be laid up and cured. Emission estimates are based on VOCs lost from 

the material during the entire layup and curing process, but emissions may be higher at certain 

times during the process than others. The VOC concentrations in the air stream exhausted by the 

vacuum pump are also very low, about 7.5 x 10-5 lb VOC/dscf on average, with the balance of 

the emissions being ambient air. Even without knowing the exact heat content of the VOCs, it is 

evident that the concentration of the VOCs in the offgas is low, less than 0.05 percent. 

Therefore, the heat content of the offgas will be low. The combination of variable operation, 

variable flow rates and low heat content for the offgases make destruction of the offgases in a 

combustion device infeasible.

4.5.5. Carbon Adsorption

Carbon adsorption uses a filter bank of canisters that contain activated carbon, which adsorbs the 

VOC emissions from the air stream as it passes through the carbon before being released to the 

atmosphere. Carbon adsorption has not been used in practice on any aerospace composite layup 

and curing operation. However, carbon adsorption has been used on other low flow, low-VOC 

sources, and is a feasible option for offgases with the characteristics described above.

4.5.6. Ranking of BACT by Control

Carbon adsorption is the only add-on option that is feasible. A well designed and operated 

carbon adsorption system can consistently demonstrate VOC removal efficiencies over 95 

percent.
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4.5.7. Cost-Effectiveness Evaluation

Vendor information for the carbon adsorption technology was obtained from Thermal Recovery 

Systems. Based on Boeing’s situation, potential contaminants and their concentration, the 

temperature of the emission, and the high humidity (3 percent by volume); Thermal Recovery 

Systems thought that between 5 and 10 percent weight capacity for the activated carbon would 

be required. If 8 percent was used as the target, it was believed it would take 90 tons of carbon 

to control 7.2 tpy of emissions. The cost in carbon alone would be over $225,000 per year, or 

over $31,000 per ton operating costs. Based on this cost, Ecology agrees with Boeing 

that carbon adsorption is not cost-effective.

4.6. BACT for Crush Core Press

In a crush core press, a composite “sandwich” layup consisting of a lightweight honeycomb core 

material sandwiched between sheets of resin pre-impregnated woven fabric (prepreg) is placed 

between heated matched dies and then the press is used to apply pressure to the dies until the 

resin in the prepreg sheets cures and hardens (emission unit IRC-3). At the Boeing Everett IRC, 

crushed core presses are used to fabricate all Boeing airplane models’ cabin interior panels, 

which are ceilings and sidewalls. Most of the emissions from the crushed core press come from 

the mold release agent that is applied to the surface of the matched dies. Some VOCs are also 

released by the curing prepreg. 

Emissions from the crush core press were calculated based on the VOC content of the mold 

release and prepreg, and the estimated volume of those materials to be used over a year. The 

estimated volume of materials to be used in the new crush core press was based on the volume of 

materials used in the existing crush core presses at Boeing Everett, and includes a safety factor of 

three to ensure that the potential VOC emissions from the press were not under estimated. For 

the prepreg, the estimated VOC emissions are conservative since it is assumed all the volatiles 

released from the curing prepreg are VOCs, whereas a significant portion of the volatiles may be 

water. The estimated air flow from the crush core press operation is 7,500 cfm. The total VOC 

emission from the unit is 4,500 lb/yr or 2.25 tpy.

4.6.1. Available Control Technologies

Composite processing, except for some cleaning, coating, and composite tooling operations, is 

not covered under the Aerospace NESHAP (40 CFR 63, Subpart GG). BACT databases from 

EPA (EPA, RBLC), CARB, and SCAQMD were reviewed for possible control technologies that 

are both available on the market and proven in practice in the aerospace or other industries that 

manufacture items from composite molds. There were no determinations found for a crush core 

press operation. The search provided one determination for the production of structural 

honeycomb for aerospace and other industrial applications by Hexcel. The database provided 

very little information about the Hexcel operation or the type of composite material used in the 

process.
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The crush core press process is similar to the composite layup and curing operation in that it uses 

resin pre-impregnated fabric, but the prepreg used in the crush core process contains a phenolic 

resin rather than an epoxy resin. However, an estimated 90 percent of the emissions come from 

the use of the mold release compounds. Since there were no control technologies for aerospace 

crush core press emissions in the databases, Boeing also looked at typical control technologies 

for VOC emissions from a process with a stack. The potential control technologies are presented 

in Table 26.

Table 26. Potential Control Technologies for VOCs for Crush Core Press

Control

Technology

Database

Reference

Date

Implemented

Control

Efficiency

Thermal oxidizer or

regenerative thermal

oxidizer

EPA, BACT Clearinghouse –

Hexcel 11/25/2009 95%

Regenerative thermal

oxidizer w/concentrator

Often used for control of

VOC emissions N/A >90%

Carbon adsorption Often used for control of

VOC emissions N/A >95%

4.6.2. BACT Feasibility Review

Currently, no control technologies have been found in practice for the crush core press operation. 

It could not be determined if the Hexcel process was applicable because the only information 

provided for the Hexcel process was that the emissions were from an oven used for the curing of 

honeycomb blocks and the main HAP of concern was acetaldehyde. Acetaldehyde may be 

present in the emissions from the press, but is not a significant component of the prepreg 

material and should not be present in the mold release agent. There was no information provided 

in the BACT determination about the type of materials used in the Hexcel process, the airflow 

rate, or the emissions from the operation. Based on this information, it could not be determined 

whether the Hexcel process was similar to Boeing’s process.

4.6.3. RTO with Concentrator

The VOCs released from the process are drawn into a concentrator, which captures VOCs by 

adsorption. Hot gas desorbs the VOCs, which are then fed to the thermal oxidizer for 

incineration. The overall efficiency for capture and control is estimated to be 90 to 95 percent.

Combination concentrators or carbon adsorbers and thermal oxidizers are intended for sources 

with high air flow and a high enough VOC emission rate (lb/hr) to make thermal oxidation 

viable. The emission rate needs to be high enough to produce a moderately concentrated 

emission from the outlet of the concentrator. The crush core press flow rate and emission rate do 

not meet either of these criteria. Individually, combustion of the VOC emissions and carbon 

adsorption has additional issues which are discussed below.
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4.6.4. Thermal Incineration

Hexcel uses a thermal oxidizer or regenerative thermal oxidizer to combust the VOC emissions 

from the process. When using combustion units for VOC control, the VOC emissions in an air 

stream are injected into a burner or chamber that destroys those emissions prior to release to the 

atmosphere through a stack.

The emission concentrations in the exhaust from the crush core press are low, approximately 8 x 

10-8 lb VOC/dscf on average, with the balance of the emissions being ambient air. Even without 

knowing the exact heat content of the VOCs, it is evident that the concentration of VOCs in the 

offgas are low, and therefore the heat content of the offgas will be low. In addition, the 

concentration of the VOCs in the offgas is very low, conservatively as much as 15 parts per 

million (ppm), but more likely near 7 ppm. Thermal oxidizers have demonstrated poor 

destruction efficiencies when the inlet concentrations are very low. The Bay Area BACT 

guidelines for an oxidizer or adsorber are typically:

• Less than 10 ppm at outlet; or

• Greater than 98.5 percent destruction/recovery efficiency if inlet VOCs are 

greater than 200 to less than 2,000 ppm; or 

• Greater than 97 percent efficiency if inlet VOCs are greater than 200 to less than 

2,000 ppm; or

• Greater than 90 percent efficiency if inlet VOCs are less than 200 ppm.

Some EPA standards allow up to 20 ppm at the outlet. The uncontrolled emission concentration 

for the crush core press is actually lower than the Bay Area BACT guidelines typical emission 

limit.

The low heat content for the offgases and low concentration of VOCs make destruction of the 

offgases in a combustion device not a feasible option.

4.6.5. Carbon Adsorption

Carbon adsorption uses a filter bank of canisters that contain activated carbon, which adsorbs the 

VOC emissions from the air stream as it passes through the carbon before being released to the 

atmosphere. Carbon adsorption has not been used in practice on any aerospace crush core press 

operation. However, carbon adsorption has been used on other low-flow, low-VOC sources.

4.6.6. Ranking of BACT by Control

Carbon adsorption is the only option that is feasible. A well designed and operated carbon 

adsorption system can consistently demonstrate VOC removal efficiencies over 95 percent.
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4.6.7. Cost-Effectiveness Evaluation

Vendor information for carbon adsorption technology on the vacuum pumps for the composite 

layup and curing process was obtained from Thermal Recovery Systems. Thermal Recovery 

Systems informed Boeing that based on the potential contaminants listed and their 

concentrations, the temperature of the emission, and the high humidity (3 percent by volume), 

they would expect between 5 and 10 percent weight capacity for the activated carbon. If they 

used 8 percent as their target, they believe it would take 90 tons of carbon to control 7.2 tpy of 

emissions. The cost in carbon would be over $225,000 per year, or over $31,000 per ton 

operating costs. This does not include capital cost or labor cost.

The crush core press emission concentration of 8 x 10-8 lb VOC/dscf is significantly lower, and 

the air flow is significantly higher at 7,500 cfm than the emissions from the autoclave vacuum 

pumps (7.5 x 10-5 lb VOC/dscf and air flow of 100 to 600 cfm). Because one of the mechanisms 

in the adsorption of compounds on carbon is the concentration gradient, or the difference 

between the concentration of the VOCs in the offgas and the concentration of the compound in 

the carbon, lower concentrations tend to have a negative effect on the weight capacity of the 

carbon. Increases in air flow may also lead to a decrease in the weight capacity of the carbon. 

Based on the $31,000 per ton operating cost for carbon on the composite layup and curing 

vacuum pumps, and the expected even lower weight capacity and potential increase in operating 

cost for the crush core process, Boeing concluded that carbon adsorption is not cost-effective. 

Ecology agrees with this assessment. In addition, the inlet concentration is less than the Bay 

Area BACT typical emission limit of 10 ppm VOC.

4.6.8. BACT Selection

Because no control technologies have been demonstrated to be effective in practice on a crush 

core press, and a cost estimate for just the carbon needed for a carbon adsorption system exceeds 

$31,000 per ton of VOC removed, Boeing does not consider any of the identified add-on control 

technologies in Table 26 to be technically or economically feasible for Boeing Everett. Ecology 

agrees with this conclusion. Boeing will continue to implement the use of low-VOC emitting 

prepreg materials to minimize VOC emissions from the process.

4.7. BACT for Open Floor Emissions

Open floor emissions are also known as fugitive emissions, and are typically emissions that 

result from hand application of cleaners, sealants, and coatings that are not done in a confined 

area such as a paint booth. These activities occur throughout the manufacturing process and in 

very large buildings. The emissions exit the buildings via various openings (e.g., hangar doors, 

roll-up doors, vents, and general building air handling systems). The VOC emissions result from 

the VOCs in the various solvents or coatings. This BACT analysis considers those technologies 

that reduce fugitive VOC emissions from the open floor activities that will take place in the new 

wing component fabrication process. Open floor activities that will take place as part of wing 

assembly, body section assembly, airplane assembly, and other related operations are not 
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addressed here because these operations will take place in existing buildings where these open 

floor activities already occur.

 

4.7.1. Wing Component Fabrication

The wings of the 777X will be primarily made of composite material. The main wing 

components include front and rear spars, upper and lower panel stringers, and upper and lower 

panels. The manufacturing process of each of these parts is similar and involves the following 

major steps:

• Wing component part layup

• Curing in an autoclave

• Trimming and drilling

• Washing

• Non-destructive inspection

• Preparation for priming (e.g., abrading, solvent cleaning)

• Priming

• Wing component part build-up

Fugitive VOC emissions can be generated by the following activities.

Part layup: Part layup involves the manual or automated layup of composite material (in the 

form of resin pre-impregnated tape or sheets) onto a mandrel which is preformed into the shape 

of the part being fabricated. Emissions associated with the part layup primarily occur from 

preparing the mandrel prior to the actual part layup process. Preparing the mandrel involves 

cleaning the surface with solvent, applying a mold release compound, and applying a tackifier 

solution.

Wing component cleaning: Open floor emissions from wipe cleaning primarily occur during the 

part buildup process, but can occur throughout the manufacturing process.

Sealing and touch up coating: Open floor emissions from the application of sealant and 

miscellaneous coatings will primarily occur during the part buildup process, but can occur 

throughout the manufacturing process. Most of the coating of the wing components will take 

place in the spray booths and will not result in open floor emissions. 

Open floor VOC emissions from the wing component fabrication building are estimated to be 

128 tpy.

4.7.2. Available Control Technologies

The open floor activities listed above are addressed and regulated under 40 CFR 63, Subpart GG, 

Aerospace NESHAP. In addition, the VOC emission standards for uncontrolled use of cleaning 

solvents and coatings are defined in 40 CFR 63, Subpart GG, Aerospace NESHAP. These 
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requirements will be applied to these activities. Because of the nature of these open floor 

activities and the fugitive emissions generated by the activities (e.g., numerous locations, low 

VOC concentrations, and low emission rates), and the fact that they may occur anywhere in the 

manufacturing process, capture and control of the fugitive emissions is not feasible. This 

conclusion is supported by the fact that in developing the Aerospace NESHAP, EPA has 

determined that work practices rather than emission standards are the only practical way to 

regulate these open floor emissions.

Boeing uses good work practices (Table 27) to minimize VOC emissions, including storing 

coatings and solvents in closed containers and bagging solvent hand wipe cleaning rags when not 

in use. The Aerospace NESHAP regulation requires low-VOC cleaners and coatings, and these 

work practices. Therefore, these techniques are considered the base case for BACT.

Table 27. Summary of Aerospace NESHAP VOC Emission Standards Applicable to the New 

and Modified Emission Units of the 777X Project

Production Activity Control Technology

Low-VOC primers Large commercial aircraft component exteriors: 5.4 lb 

VOC/gal. All other applications: 2.9 lb VOC/gal

Low-VOC topcoats 3.5 lb VOC/gal

Low-VOC cleaning solvents

Hand wipe cleaning solvent: vapor pressure less than 45 

mm Hg at 20°C or solvent meets composition 

requirements in Table 1 in 40 CFR 63.744.

Flush cleaning: use collection system to capture flushed 

solvent.

High-transfer-efficiency spray coating equipment HVLP, electrostatic, or other equivalent spray coating 

equipment

Paint gun cleaning, waste solvents, and rags Capture and closed containment

4.7.3. BACT Feasibility Review

The use of low-VOC cleaners and coatings, and good work practices in compliance with the 40 

CFR 63, Subpart GG, Aerospace NESHAP requirements have been demonstrated and achieved 

in practice and are therefore considered feasible technologies to implement for the open floor 

activities in the new wing component fabrication building. Boeing believes this is the base case 

for BACT, and uses these techniques for its current operations. 

Boeing will implement all of the base case BACT techniques. Thus, further review of economic 

environmental and energy impacts is unnecessary.

4.7.4. BACT Selection

Boeing will continue to implement the use of low-VOC coatings and cleaners, and good work 

practices to minimize fugitive VOC emissions in compliance with the 40 CFR 63, Subpart GG,

Aerospace NESHAP. 

Based on this information, Ecology believes the proposed limits meet BACT requirements.
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4.8. Toxic Air Pollutants

PSD rules require the applicant to consider emissions of TAPs during the course of a BACT 

analysis, but specifically exempt all pollutants subject to regulation under Section 112 of the 

federal Clean Air Act from regulation under the PSD program. 

The emissions of TAPs will be covered in the PSCAA NOC approval for this project.

5. AMBIENT AIR QUALITY IMPACTS ANALYSIS

5.1. Regulatory Requirements

For PSD, an ambient Air Quality Impacts Analysis (AQIA) is required for all pollutants that are 

emitted in significant quantities to determine the ambient impacts associated with the 

construction and operation of the proposed modifications. The main purpose of the air quality 

analysis is to demonstrate that new emissions emitted from the proposed major stationary source 

or major modification will not cause or contribute to a violation of any applicable NAAQS or 

PSD increment.

The AQIA starts with preliminary modeling for each pollutant to determine whether an applicant 

can forego detailed analysis and preconstruction monitoring. If the projected ambient 

concentration increase for a given pollutant is below the PSD Significant Impact Levels (SILs) 

and Significant Monitoring Concentration (SMCs) for each averaging period, no further analysis 

of the ambient impact is required for that pollutant. 

For those pollutants with averaging periods that have impacts greater than the SIL, a full impact 

analysis is used to demonstrate compliance with NAAQS and PSD increments. 

Typically, the AQIA includes an analysis of impacts to local areas that are within 50 kilometers 

(km) of the project, and a regional air quality impact assessment for impacts beyond 50 km. For 

projects in Washington State, this latter analysis usually includes impacts on Class I areas.

5.2. Impacts on Class I Areas

Because the proposed emission increase in VOCs from the Boeing Everett 777X project would 

exceed 100 tpy, there must be a demonstration that the project would not cause or significantly 

contribute to a violation of the ozone NAAQS. Furthermore, PSD rules require an analysis of air 

quality related values (AQRVs) on federally designated Class I areas. Federally mandated Class 

I areas are defined in the Clean Air Act as having special national or regional value from a 

natural, scenic, recreational, or historic perspective. Class I areas include national parks over 

6,000 acres and wilderness areas and memorial parks over 5,000 acres as of 1977. The impacts 

to these areas are stringently regulated because they have remained relatively untouched by 

development. Therefore, in addition to tighter PSD increment standards for criteria air 
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pollutants, additional analyses of air quality impacts on Class I areas are required. Class I areas 

within 200 km of the Boeing Everett facility are listed in Table 28.

Table 28. Class I Areas within 200 KM of the Boeing Everett Facility

Area

Distance from 

Boeing Everett

to Class 1 Area

(km)

VOC Emissions Increase (Qty.) 

Divided by Distance (Q/D)

(tons VOC/km)

Allowable VOC Emissions 

Increase (Qty.) Divided by 

Distance (Q/D)

(tons VOC/km)

Alpine Lakes Wilderness Area 60 6.9 5.7

Glacier Peak Wilderness Area 70 5.9 4.9

Mount Baker Recreation Area 90 4.6 3.8

Olympic National Park 91 4.6 3.7

North Cascades National Park 108 3.9 3.2

Mount Rainier National Park 123 3.4 2.8

Goat Rocks Wilderness Area 205 2.0 1.7

AQRVs include impacts on visibility, soil, flora, fauna, and aquatic resources within the Class I 

area. The Federal Land Managers’ (FLMs) guidance on evaluating impacts of major projects on 

Class I areas is the Federal Land Managers’ Air Quality Related Values Work Group (FLAG) 

Phase I Report – revised (2010) (National Park Service, 2010). In FLAG, the FLMs have 

developed a tool to screen out projects that would not have a significant impact on AQRVs based 

on annual emissions and distance from a Class I area. This screening tool is called the Q/D 

Method, which is to divide the amount of emission increases in tons per year (Q) by the distance 

to a federal Class I area in km (D). FLAG states that “The FLM role within the regulatory 

context consists of considering whether emissions from a new source, or emission increases from 

a modified source, may have an adverse impact on AQRVs and providing comments to 

permitting authorities (States or EPA). Therefore, the agencies will consider a source locating 

greater than 50 km from a Class I area to have negligible impacts with respect to Class I AQRVs 

if its total SO2, NOx, PM10, and H2SO4 (sulfuric acid) annual emissions (in tons per year, based 

on 24-hour maximum allowable emissions), divided by the distance (in km) from the Class I area 

(Q/D) is 10 or less. The agencies would not request any further Class I AQRV impact analyses 

from such sources.” For the 777X project, the only pollutant that would have a significant 

increase is VOC. VOC is not among the pollutants that the FLMs recommend including in the 

calculation of Q. While VOCs and NOx are recognized as precursors to the formation of ground 

level ozone, which is regulated as a criteria pollutant, the FLAG guidance states that “current 

information indicates most FLM areas are NOx limited” with respect to the formation of ground 

level ozone. A NOx limited region is one where the concentration of ozone depends on the 

amount of NOx in the atmosphere. This occurs when there is a lack of Nitrogen Dioxides, thus

inhibiting ozone titration when oxygen mixes with VOCs. In these regions, controlling NOx

would reduce ozone concentrations. A VOCs limited region is one where concentration of ozone 

depends on the amount of VOCs in the atmosphere. In these regions, controlling VOCs would 

reduce ozone concentrations. The FLAG guidance further states that “until there is enough 
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information available for FLAG to determine whether ozone formation in each FLM area is 

primarily limited by NOx or VOC emissions, we will assume all FLM areas are NOx limited and 

will focus on control of NOx emissions” (FLAG Executive Summary and Section 3.4.5). 

Because there has not been a demonstration that ozone formation in the Puget Sound region’s 

Class I areas is not NOx-limited and VOC is the only pollutant that is expected to have a 

significant increase as a result of the 777X project, there is no need to perform the Q/D analysis 

and it is presumed that the 777X project will have no significant adverse impacts on Class I 

areas.

2

5.3. Ozone Impacts

VOCs are a precursor to ozone. Boeing’s proposed increase in VOC emissions is greater than 

100 tpy and therefore requires an analysis of the effect that the proposed increase in emissions of 

VOCs would have on the area’s ozone levels. The analysis of the 777X project is discussed 

below.

EPA has set primary and secondary ozone standards to protect human health and welfare. On 

March 12, 2008, EPA revised the primary and secondary ozone standards to 0.075 ppm for an 8-

hour average. 

Ozone is formed in the troposphere when sunlight causes complex photochemical reactions 

involving oxides of nitrogen (NOX), VOCs, and carbon monoxide (CO) that originate chiefly 

form gasoline engines and burning of other fossil fuels. Woody vegetation is another major 

source of VOC emissions to NOX emissions within the surrounding airshed, and the relative 

reactivities of the VOC species. NOX and VOCs can be transported long distances by regional 

weather patterns before they react to create ozone in the atmosphere, where it can persist for 

several weeks. Because ozone is a regional pollutant, precursor sources both near and far can 

contribute to ozone formation.

Breathing ozone can trigger a variety of health problems for humans, including chest pain, 

coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. 

Elevated levels of ozone can also reduce lung function by inflaming the linings of the lungs. 

Repeated exposure to elevated concentrations of ozone may permanently scar lung tissue. Ozone 

is also phytotoxic, causing damage to a variety of vegetation (Ashmore et al., 2004). Ozone 

pollution has been shown to reduce plant growth, alter species composition, and predispose trees 

to insect and disease attack. Ozone also causes direct foliar injury to some plant species. Ozone 

affected leaves are marked with discoloration and lesions, and they age more rapidly than normal 

leaves (EPA, 2007).

 2 Nonetheless, for informational purposes the 777X project’s Q/D for all Class I areas within 200 km are shown in

column 3 of Table 28 where Q is that annual emission rate of VOC. As shown in column 3 of Table 28, the ratio of 

Q/D would be less than 10 for all the Class I areas and, according to the FLAG guidance, it could be presumed that 

the project would have no significant adverse impacts on Class I areas. Table 28 also shows that the combined

proposed increases in the annual VOC emissions limits in the existing PSD permits 91-06, 05-02, and 11-01, would 

also result in Q/D being less than 10.
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Ozone enters plants through leaf stomata, causing changes in biochemical and physiological 

process. The mesophyll cells under the upper epidermis of leaves are the most sensitive to 

ozone, and those are the first cells to die. The adjacent epidermal cells then die, forming a small 

black or brown interveinal necrotic lesion that becomes visible on the upper surface of the leaf. 

These lesions, termed oxidant stipple, are quite specific indicators that the plant has been 

exposed to ozone. There are other plant symptoms that can result from exposure to ozone. 

However, these symptoms are non-specific for ozone since other stressors can also cause them to 

occur. In general, the most reliable indicator that ozone has impacted vegetation is oxidant 

stipple.

In addition to effecting individual plants, ozone can also affect entire ecosystems. Plants

growing in areas with high exposure to ambient ozone may undergo natural selection for ozone 

tolerance (EPA, 2007). The final result could be the elimination of the most ozone sensitive 

genotypes from the area (National Park Service, 2010). 

In the Class I areas closest to Boeing Everett, several species are known to be sensitive to ozone, 

including quaking aspen (Populus tremuloides), spreading dogbane (Apocynum 

androsaemifolium), subalpine fir (Abies lasiocarpa), black cottonwood (Populus trichocarpa),

and ponderosa pine (Pinus ponderosa) (Brace et al., 1998). These sensitive species have been 

systematically evaluated and no ozone injury has been documented in the parks.

In a previous PSD permit application for the 787 project (PSD 05-02), Boeing reported that 297 

tpy of VOC emissions would not cause or significantly contribute to an exceedance of any 

NAAQS or PSD increment. The study reported a projected maximum increase in ozone 

concentration of about 0.1 parts per billion (ppb) from a 297 tpy increase in VOC emissions. 

This is a small fraction of the national ambient air quality standard for ozone of 75 ppb for an 8-

hour average. Similarly, for the 737 MAX project in Renton (PSD 12-01), Boeing noted that a 

384 tpy increase from Boeing’s Renton facility would not cause or significantly contribute to an 

exceedance of any NAAQS or PSD increment and in the worst case would only increase the 

maximum ozone concentration by less than 0.35 ppb. As shown in Table 7, Boeing is proposing 

to increase Boeing Everett’s allowed VOC emissions by 308.2 tpy. This is within the range that 

Ecology previously reviewed and determined will not have a significant adverse impact on air 

quality. Therefore, an additional air quality impact analysis addressing the impact of VOC 

emissions from the 777X project is not required.

6. ADDITIONAL IMPACTS ANALYSIS

6.1. Air Quality Related Values (AQRV)

PSD regulations and guidance require an evaluation of the effects of the 777X project’s 

emissions on visibility, local soils, and vegetation in Class I and II areas, the effect of increased 

air pollutant concentrations on flora and fauna in the Class I areas, and the effect of the project 

on construction and population growth in the area surrounding the project. The analyses assess 

increment consumption and impacts on AQRVs in Class I areas. AQRVs include regional 
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visibility or haze, the effects of primary and secondary pollutants on sensitive plants, the effects 

of pollutant deposition on soils and receiving water bodies, and other effects associated with 

secondary aerosol formation. The FLMs for the National Park Service, U.S. Fish and Wildlife 

Service, and U.S. Forest Service have the responsibility of ensuring AQRVs in the Class I areas 

are not adversely affected.

PSD regulations and guidance require additional impact analyses to evaluate the effects of the 

project’s emissions on visibility, local soils, and vegetation in Class I and II areas, and the effect 

of increased air pollutant concentrations on flora and fauna in the Class I areas. The additional 

impact analyses are also used to evaluate the effect of the project on growth in the area 

surrounding the project.

6.2. Growth Analysis

6.2.1. Construction and Growth Impacts

Employment at Boeing Everett is expected to increase by no more than 3,000 employees as a 

result of the 777X project. This growth is less than 10 percent of the potential 45,000 employees 

at the Boeing Everett facility that were added in the Southwest Everett EIS and Planned Action 

(City of Everett, 1997). Additionally, there will not be a significant increase in congestion on 

Washington’s roads and highways as a result of the project. The details of the congestion 

discussion may be found in SEPA Addendum #1 (Revised) Southwest Everett Planned Action 

EIS SEPA #13-019 in Appendix E. Therefore, the proposed 777X project is not expected to 

cause adverse construction and growth related impacts.

6.3. Soils and Vegetation Analysis

EPA guidance3 for most types of soils and vegetation, ambient concentrations of criteria 

pollutants below the secondary NAAQS will not result in harmful effects. Only the VOC 

emissions from the 777X project are subject to PSD review. VOC is regulated as a precursor to 

ozone. However, ozone has no secondary NAAQS. In addition, the expected VOC emissions 

from the 777X project do not trigger a detailed AQIA for Class I area. The incremental increase 

in ozone concentrations directly attributable to the 777X project would be less than about 0.4 ppb 

on an hourly average. Consequently, the impacts on local soils, vegetation, and animals 

attributable to the 777X project will be negligible.

FLAG guidance does not indicate a specific BOC impact on vegetation in the Pacific Northwest. 

The National Park Service has established monitors for ozone in three Class I areas in the state of 

Washington. The three sites are Mount Rainer National Park, Olympic National Park, and North 

Cascades National Park. As previously discussed in the TSD, in the past Boeing demonstrated 

that similar incremental concentrations less than about 0.4 ppb on an hourly average which is a 

 3 Draft EPA New Source Review Workshop Manual, Chapter D, § IIC (EPA, 1990).
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very small fraction of the NAAQS of 75 ppb on an 8-hour average. Therefore, the increase in 

ozone from the 777X project is not likely to harm vegetation or animals.

Project emissions that have the most potential to affect soils and vegetation are those that contain 

either sulfur or nitrogen. SO2 and NOX are not subjected to PSD review for this project because 

their emissions are less than their respective SERs. As a result, no deposition analysis was 

required, but this analysis was conducted and is included in the application.

 

7. ENDANGERED SPECIES ACT

Pursuant to Section V.A. of the Agreement for the Delegation of the Federal Prevention of 

Significant Deterioration Program from the United States Environmental Protection Agency to 

the Washington State Department of Ecology, dated December 10, 2013, Ecology shall not issue 

a PSD permit until EPA has notified Ecology in writing that EPA has satisfied its obligations, if 

any, under Section 7 of the Endangered Species Act (ESA), 16 U.S.C. § 1531 et seq., and 50 

CFR Part 402, Subpart B (Consultation Procedures), and with Section 305(b)(2) of the 

Magnuson-Stevens Fishery and Conservation Act (Magnuson-Stevens Act, MSA), 16 U.S.C. § 

1801 et seq., 50 CFR Part 600, Subpart K (EFH Coordination, Consultation, and 

Recommendations), for federal PSD permits, regarding essential fish habitat. Therefore, the 

final PSD permit will not be issued for this project until EPA has notified Ecology that this 

consultation has been completed.

On August 19, 2014, EPA notified Ecology that they have satisfied their obligations under the 

ESA and the MSA relative to this permitting action. No further ESA or MSA consultation was 

undertaken relative to this action.

8. STATE ENVIRONMENTAL POLICY ACT (SEPA)

Under Washington State rules, a final PSD permit shall not be issued for a project until the 

applicant has demonstrated that SEPA review has been completed for the project. The City of 

Everett is the lead agency for SEPA.

On December 10, 2013, the City of Everett Approved SEPA Addendum #1 (Revised) Southwest 

Everett Planned Action EIS, SEPA #13-019. Ecology concludes that the applicant has 

adequately demonstrated compliance with SEPA requirements.

9. PUBLIC INVOLVEMENT

This PSD permitting action is subject to a minimum 30-day public comment period under WAC 

173-400-740. A newspaper public notice announcing the public comment period was published 

in the Daily Herald on August 1, 2014. In accordance with WAC 173-400-740(2)(a), application 

materials and other related information were made available for public inspection at: 
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City of Everett

Main Library

2702 Hoyt Avenue

Everett, WA 98201

Washington State Department of Ecology

Air Quality Program

300 Desmond Drive SE

Lacey, WA 98503

A public meeting and hearing on the proposed PSD permit was held at 6:30 PM PDT on 

September 2, 2014, at the Future of Flight Aviation Center in the Forward Cabin Conference 

Room, 8415 Paine Field Boulevard, Mukilteo, Washington 98275. No comments were 

submitted at the hearing.

The public comment period closed on September 3, 2014, at 5 PM PDT. No comments were 

submitted.

10. AGENCY CONTACT

Marc Crooks, P.E.

Washington State Department of Ecology

Air Quality Program

P.O. Box 47600

Olympia, WA 98504-7600

(360) 407-6803

marc.crooks@ecy.wa.gov
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APPENDIX A. BACKGROUND PSD APPLICABILITY ANALYSIS FOR THE 777X 

AND PRODUCTION RATE INCREASE
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APPENDIX B. ESTIMATE OF NON-SIGNIFICANT PSD POLLUTANT EMISSIONS 

INCREASES FROM THE 777X PROJECT
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REFERENCES

Ashmore, M., Karlsson, P.E., and H. Pleije, New directions: a new generation of ozone critical 

levels for the protection of vegetation in Europe (correspondence), Atmospheric 

Environment, 38: 2213-2214, 2004.

Brace, S., Peterson, D. L., and D. Horner, Diagnosing Ozone Injury in Vascular Plants of the 

Pacific Northwest, U.S. Department of Agriculture, Forest Service, Pacific Northwest 

Research Station, 1998.

California Air Resources Board, Statewide BACT Clearinghouse, 

<http://www.arb.ca.gov/bact/bact.htm>, California Environmental Protection Agency,

Sacramento, California, 2014.

City of Everett, Southwest Everett Planned Action/Paine Field Subarea and Environmental 

Impact Statement, 1997.

EPA, Draft EPA New Source Review Workshop Manual, 1990. Available at: 

<http://www.epa.gov./ttn/nsr/gen/wkshpman.pdf>

-----, EPA Air Pollution Control Cost Manual, Sixth Edition (EPA 452/B-02-001), January 2002. 

Available at: 

<http://www.epa.gov/oaqps001/lead/pdfs/2002_01_cost_control_%20manual.pdf> 

-----, Review of the National Ambient Air Quality Standards for Ozone: Policy Assessment of 

Scientific and Technical Information, EPA-452/R-07-007, 2007. 

-----, RACT/BACT/LAER Clearinghouse, RBLC Database, Technology Transfer Network Clean 

Air Technology Center, 2014. Available at: 

<http://cfpub.epa.gov/RBLC/index.cfm?action=Home.Home&lang=en>

National Park Service, Federal Land Managers’ Air Quality Related Values Work Group 

(FLAG) Phase I report – revised 2010), 2010. Available at: 

<http://www.nature.nps.gov/air/pubs/pdf/flag/Flag_2010.pdf>

South Coast Air Quality Management District, SCAQMD Clearinghouse, Diamond Bar, 

California, 2014. Available at: <http://www.aqmd.gov/bact/287160.htm>
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ACRONYMS AND ABBREVIATIONS

°

F degrees Fahrenheit

μg/m3 micrograms per cubic meter

ALW Alpine Wilderness

AQIA Air Quality Impacts Analysis

AQRV Air Quality Related Values

BACT Best Available Control Technology

CARB California Air Resources Board

CFR Code of Federal Regulations

CO carbon monoxide

CO2e carbon dioxide equivalent

Ecology Washington State Department of Ecology

EPA United States Environmental Protection Agency

ESA Endangered Species Act

FLAG Federal Land Managers’ Air Quality Relative Values Workgroup

FLM Federal Land Manager

FR Federal Register

GHG greenhouse gas

H2SO4 sulfuric acid mist

HAPs hazardous air pollutants

hr/yr hours per year

kW kilowatt

MACT maximum achievable control technology

MSA Magnuson-Stevens Act

NAAQS National Ambient Air Quality Standards

NESHAP National Emission Standards for Hazardous Air Pollutants

NOC Notice of Construction

NOX nitrogen oxides

NPS National Park Service
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NSR New Source Review

PM particulate matter

PM10 particulate matter less than 10 micrometers in diameter

PM2.5 particulate matter less than 2.5 micrometers in diameter

ppb parts per billion

ppm parts per million

PSD Prevention of Significant Deterioration

PSCAA Puget Sound Clean Air Agency 

PTE potential to emit

Q/d emissions to distance

RBLC RACT/BACT/LAER Clearinghouse

SCR selective catalytic reduction

SEPA State Environmental Policy Act

SER significant emission rate

SIL significant impact level

SO2 sulfur dioxide

SOX sulfur oxides

TAP toxic air pollutant

tpy tons per year

VOC volatile organic compound

WAC Washington Administrative Code