UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 10 

1200 Sixth Avenue, Suite 900 

Seattle, WA 98101-3140 

Stu Clark, Air Quality Program Manager 

Washington State Department of Ecology 

PO Box 47600 

Olympia, W A 98504-7600 

Craig Kenworthy, Executive Director 

Puget Sound Clean Air Agency 

1904 Third Avenue - Suite 105 

Seattle, WA 98101 

NO V 2 0 2013 OFFICE OF 

AIR, WASTE AND TOXICS 

Re: Review of Draft Kent, Seattle, and Tacoma, W A, Second 10-Year Limited Maintenance 

Plan for Coarse Particulate Matter (PM 10) 

Dear Mr. Clark and Mr. Kenworthy: 

We have reviewed the draft version of the Kent, Seattle, and Tacoma, WA, Second 10-Year 

Limited Maintenance Plan for PM1o to identify potential deficiencies prior to final submission 

for approval by the U.S. Environmental Protection Agency (EPA). We have concluded that the 

draft version sent to the EPA on September 27, 2013, would likely be approvable into the 

Washington State Implementation Plan. However, the EPA will make a final decision based on 

our review of the complete State Implementation Plan that is submitted following your public 

process and after consideration of any comments we receive as part of the Environmental 

Protection Agency public process. If you have any questions please feel free to contact me at 

206-553-1271 or have your staff contact Debra Suzuki, Air Platming Unit Manager, at 206-553-

0985 or Jeff Hunt, stafflead, at 206-553-0256. 

0 Printed on Recycled Paper 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 10 

1200 Sixth Avenue, Suite 900 

Seattle, WA 98101-3140 

OFFICE OF 

AIR. WASTE AND TOXICS 

10/25113 

MEMORANDUM 

SUBJECT: Review ofDraft Kent, Seattle, and Tacoma Second 10-Year Limited Maintenance 

Plan for Coarse Particulate Matter (PM10) 

FROM: Jeff Hunt, Air Quality Planne d~ 

TO: Debra Suzuki, Air Programs Unit Manager 

The Washington Department of Ecology (Ecology) and Puget Sound Clean Air Agency 

(PSCAA) asked the Environmental Protection Agency (EPA) Region 10 to review the draft Kent, 

Seattle, and Tacoma, WA, Second 10-Year Limited Maintenance Plan for PM1o so that any errors 

or EPA concerns can be addressed prior to submission of the final package to the EPA. Barring 

significant changes as a result of public comment, Ecology intends to submit a finalized version 

of this draft for the EPA's approval into the Washington State Implementation Plan (SIP). 

Robert Kotchenruther and I coordinated closely with PSCAA and Ecology in reviewing the 

methodology, inventories, and technical analysis in this draft plan. Generally speaking, it 

follows the same format and methodology used in the Thurston County Second 10-Year Limited 

Maintenance Plan for PM10, which received no public comments and was finalized by the EPA 

on October 3, 2013 (78 FR 61188). Similar to the Thurston County maintenance area, all three 

maintenance areas in PSCAA' s jurisdiction have been attaining the PM 10 standard since 1990. 

PM10 levels have steadily declined well below the limited maintenance plan threshold of98 

j.!g/m

3 (Kent= 46±3 jlg/m3

, Seattle= 50±5 jlg/m3

, and Tacoma= 58±8 ~tg , using a correlated 

estimation model similar to the Thurston County plan). 

Overall, this should be a noncontroversial action. Because the EPA previously received a 

comment on the fine particulate matter (PM2.5) inventories for Tacoma related to the locomotive 

transport of coal, it is possible we may receive a similar comment in this action. PSCAA and 

Ecology worked closely with Robert Kotchenruther to develop an estimation of locomotive 

inventories, including possible fugitive dust emissions. Total locomotive estimated emissions 

during the critical winter day period, including locomotive-related fugitive dust, are small 

relative to other source categories (Kent = 6%, Seattle = 5%, and Tacoma = 2%). Because total 

locomotive emissions are such a small proportion of the inventory and PM10 levels are already 

quite low and steadily declining, it is my determination that locomotive transport of coal will 

have little to no impact on overall attainment of the PM10 standard in these maintenance areas. 
Based on my evaluation of the limited maintenance plan criteria, I believe this draft plan meets 

the Clean Air Act requirements for incorporation into the SIP barring any significant public 

comments or changes in EPA policy. I included a copy of my analysis as Attachment A. 

Attachment B is a sample Federal Register notice based on the proposed rulemaking Thurston 

County Second 10-Year PMJO Limited Maintenance Plan signed by Dennis McLerran on July 

22, 2013. Upon final submission, I will review any changes to Ecology's SIP revision along 

with any comments received during the state or local public comment periods in making my final 

determination. 

2 
Attachment A- EPA Review of PSCAA / 

Ecology draft: 

"Kent, Seattle, and Tacoma, WA 

Second 10-year Limited Maintenance Plan 

for PM1o" 

As submitted on: 

September 27, 2013 

The EPA analysis is contained in text boxes, such as this one, 

throughout the document. 
Table of Contents 

Executive Summary ... ... ........ .. .... ... ........ ..... .......... ........... .............................. .. .............. ..................... ......... .. 9 

1. Introduction .......................... .............................. .............. .. ....................... ...... ................................... . 10 

Particulate Matter Standards ...... ...................... ........... ..... ................. ........................................... ...... 10 

M a i ntena nee Area Com pi iance History ................................................ .......... .. .................... .............. 10 

Plan Structure ................................. ...................... ... .. ............................................ .......................... .... 11 

2. Background .. .. ... ................... ... ....... ..... ... ..... ............................. ......... ... ................. .... ..... .. .................... 12 

Geographic Area ............. .... .. ....... ........ ............ ..... ................ .. .. ............. ................ ...... .............. .......... 12 

Compliance History ..... .. .................................. .. ........................... ....... ................................................ 17 

3. Limited Maintenance Plan Option ...................... ..... .. .. ........................................ ................................ 17 

NAAQS Qualification Criterion ................ .................................. ................ ............ ..... .. .. ..................... 18 

Design Value Criterion ............................................................................................ ............................. 19 

Motor Vehicle Regional Analysis Criterion ............................ ...... .. ..................................................... . 21 

LM P Qualification .. .. ............................. ................................ .................. ....... ................ ... .................. . 22 

4. Particulate Matter Man itori ng ............. .............. .. ................ ............. ......... ... ....................................... 23 

4.1. PM10 Concentrations ............................ .. ....... .............. .. .... ............ ....................... ..... .............. ............. 23 

Kent Maintenance Area ....................................... ............. ......... ......... ....... .... .. ....................... ....... ..... 23 

Kent Monitoring ...... ....................... ....... ... ....... .................. .................. .. .. ..... .. ..................................... 24 

Seattle Maintenance Area ...... ........ ....... ... ......... ............................... ....... ........ .............. .. .. .. ........... .... . 26 

Seattle Monitoring ......... ... .......... .................................. .... .. .. .. .. .......... .. .. ................... ........................ . 26 

Tacoma Maintenance Area ............................. ........................ ....................... ..................................... 28 

4.2. Model Development .............. ........ .................................................. ........................... ................... .... .. 30 

Kent ............................... ........ ........... .......... .............. .................................. .... .. ........... ... ... .................. 30 

Seattle ........ .. ..... ..................................... .... ................ ...... ............ .................. .. ..... .... .......................... 32 

Tacoma ........... ... ................ ... ... ........... ...... ........... ................................ ....... .................. ...................... . 34 

PM10 Violation Unlikely ....... .............. ........ .. ....... ............... ................ .......... .. ....... ............ ......... .......... . 36 

4.3. Current PM10 and PM2.

5 Data Availability .......... .. ............................................................ ................... .. 37 

5. Emission Inventory ........ ..... ... .................... ........ .................. ....... ....... .. .. ... .............. ....... .. ... ............. ..... 38 

Emission years and categories .............. ............ .. .............. ......... ... ......... .......................... ........... .. .. .... 38 

ii 
Emission inventory geography ..................................................... .. .................. ................................... 39 

Significant source categories ..................................................................... .......................................... 39 

Maintenance Plan Inventory ................ .. ............................. ................................................................ 40 

6. Control Measures ................................................................................................................................. 41 

Emission Reduction Programs ................................................................ ........... .................................. 42 

Wood Smoke Curtailment .................................................................................................................... 42 

Fugitive Dust ........................................................................................................................................ 43 

Industrial Sources ................................................................................................................................ 43 

Diesel Emissions ............................................ .......................... .................................... ... ..................... 43 

Voluntary diesel emissions reductions: ................... ..... .. .................................................................... 44 

Outdoor burning ................ ............................ ......................... ............................................................ 45 

Control Measures in PSCAA Rules ............................................................................. ............ .............. 45 

7. Contingency Measures ......................................................................................................................... 47 

Contingency Measure Trigger ..................................... ........................................................................ 47 

8. Commitment to Continued Monitoring and Verification of Continued Attainment .......................... .48 

9. Summary of Maintenance Plan Commitments .................................................................................... 49 

Appendix A ......................................................................................................................................... A-1 

Appendix B ................ .......................................... ............................................................................... B-1 

Appendix C ...................................................................... ................................ ............................... .... C-1 

Appendix D ......................................................................................................................................... D-1 

iii 
Table of Figures 

Figure 2.1: The Kent, WA PM10 Maintenance Area ......................... ........................................................... 14 

Figure 2.2: The Seattle, WA PM10 Maintenance area ................................................................................. 15 

Figure 2.3: The Tacoma, WA PM10 maintenance area ................................................................................ 16 

Table 3.1: Three-year design values calculated using the most recent three years of estimated PM10 

concentrations ........................................... ~ .............................. .................................................................. 18 

Table 3.2: Tabular Estimation of PM10 Design Values3 ......................................................... .................... 20 

Table 3.3: Five-Year Design Values for Kent, Seattle, and Tacoma ............................................................ 20 

Table 3.4: Margin of Safety Comparison ................................................... ................................................. 22 

Figure 4.1.1: Kent Historical PM10 Concentrations .................................................................................... 23 

Figure 4.1.2: PM10 and PM2.5 data used to develop the PM10 to PM2.5 relationship ................................ 24 

Figure 4.1.3: PM 2.

5 monitoring data used to estimate PM10 concentrations from 2008-present.. ............ 25 

Figure 4.1.4: Seattle Historical PM 10 Concentrations .. ........................ ....................................................... 26 

Figure 4.1.5: PM10 and PM2.

5 data used to develop the PM10 to PM2.5 relationship ........................ .......... 27 

Figure 4.1.6: PM2.5 monitoring data used to estimate PM10 concentrations from 2008-present.. .. .......... 27 

Figure 4.1.7: Tacoma Historical PM10 Concentrations ................................................................................ 28 

Figure 4.1.8: Tacoma monitoring data used to calculate the PM 10 PM2.5 relationship ............................. . 29 

Figure 4.2.1: Summer and Winter PM10 to PM 2.5 from 1999-2007 at the Kent Monitoring Site .. ............. 31 

Figure 4.2.2: Estimated PM10 to Measured PM10 for the years 1999-2007 ............................................... 32 

Figure 4.2.3: Summer and Winter PM10 to PM 2.

5 from 1999-2007 at the Seattle Monitoring Site ........... 33 

Figure 4.2.4: Estimated PM10 to Measured PM10 for the years 1999-2007 ............................................... 34 

Figure 4.2.5: Summer and Winter PM10 to PM2.5 from 1999-2007 at the Tacoma Monitoring Site .. ........ 35 

Figure 4.2.6: Estimated PM10 to Measured PM10 for the years 1999-2007 ............................................... 35 

Table 4.2.7 PM2.5 concentrations corresponding to a PM10 concentration of 150 11g/m3 ......................... 36 

Table 5.1: Emission Categories used in this LMP ....................................................................................... 39 

Table 5.2: Seattle, Tacoma, and Kent Maintenance Area Annual and Winter Day PM 10 Emissions ...... .. .. 40 

Table 6.1: PSCAA Regulation I- Article 8: Outdoor Burning .. .......... .. ........................................................ 45 

Table 6.2: PSCAA Regulation I-Article 9: Emission Standards ................................. ................................. 45 

Table 6.3: PSCAA Regulation I- Article 13: Solid Fuel Burning Device Standards ..................................... 46 

Table 9.1: Second 10-Year LMP Commitments .......................................................................................... 49 

Table A.1: Kent PM10 Maximums and 5-Year Design Values, 1999-2007 ............................................... A-3 

Table A.2 : Kent, Washington Modeled PM10 5-Year Design Values, 2008-2012 ................................... A-4 

Table A.3 : Seattle, Washington PM10 Maximums and 5-Year Design Values, 1999-2007 ...................... A-5 

Table A.4: Seattle, Washington Modeled PM10 5-Year Design Values, 2008 - 2012 ............................... A-6 

Table A.5: Tacoma, Washington PM10 and 5-Year Design Values, 1999-2007 .............................. ......... A-7 

iv 
Table A.6: Tacoma, Washington Modeled PM10 5-Year Design Values, 2008- 2012 .......................... ... A-8 

Table A.7: Design Values used for Motor Regional Analysis ................................. ................................. A-10 

Table A.8: Projected 10-year Increase in VMT ................................... .................................................... A-10 

Table A.9: Calculation of Motor Vehicle Design Value ........................................................................... A-11 

Table A.10: Margin of Safety Comparison .............................................................................................. A-12 

Table C.1: List of 2011 Emission Categories ............. ................................................................................. C-1 

Table C.2: 1994 emission categories with their respective 2011 representative emission category ....... C-1 

Table C.3: Spatial surrogate and sources of data for sub-county region (maintenance area) estimates. C-3 

Table C.4: Tons of PM10 by wood burning device, King and Pierce County ............................................. C-5 

Table C.5: PM10 Maintenance Area Population Data .. ..... ........................................................................ C-5 

Table C.6: Tons of PM10 by wood burning device in each maintenance area: ........................................ C-6 

Table C.7: Paved road dust PM10 emissions with the fraction of the maintenance areas vehicle miles 

traveled ... ..... .............................................. .............................................................................. .................. C-7 

Table C.8: MOVES Model Parameters and Data Sources .......................................................................... C-9 

Table C.9: Onroad mobile PM10 emissions with the fraction ofthe maintenance areas vehicle miles 

traveled .................... ...................................................................................................... .......................... C-10 

Table C.10: Unpaved road dust PM10 emissions with the fraction of the maintenance areas vehicle miles 

traveled ........... ............................................................................................ ............................................. C-11 

Table C.11: Fraction of Port Areas in Maintenance Areas .. .................................................................... C-12 

Table C.12: PM10 emissions breakdown in tons of port and marine emissions within each maintenance 

area by subcategory ...... ............................................................................................................. ............. C-13 

Table C.13: List of emission sources and methods used to estimate locomotive emissions .................. C-14 

Table C.14: Values used in the rail coal dust emission factor equation ............................. ..................... C-16 

Table C.15: Estimated annual locomotive PM10 emissions by category .. .............................................. C-17 

Table C.16: Maintenance area fraction of the rail line of the total county rail for estimating passenger 

and coal dust emissions ........................................................................................................................... C-18 

Table C.17: Fraction of county rail activity in the maintenance area for line haul estimates ................. C-18 

Table C.18: The number of industrial sources (active or inactive) reporting PM10 emissions between 

1994 and 2011. ........................................................................................................................................ C-19 

Table C.19: PM10 Emissions from all industrial sources from 1994 to 2011: ......................................... C-20 

Table C.20: Estimated annual emissions by reporting industrial source ................................................ C-20 

Figure D.1: The Kent, WA PM10 Maintenance area .................................................................................. D-4 

Figure D.2: The Seattle, WA PM10 Maintenance area ............... ..................................................... .......... D-5 

Figure D.3: The Tacoma, WA PM10 maintenance area .................................. ........... ............. ................... D-6 

Table D.4: 1994 PM10 Average Daily Emissions from the 1997 maintenance plan ................................. D-7 

Table D.S: Emission Categories to be used in this LMP .......................... ................................................... D-8 

Table D.6: MOVES Model Parameters and Data Sources .......................................................... .. ...... ...... D-10 

v 
Table 0.7: The number of industrial sources (active or inactive) reporting PM10 emissions between 1994 

and 2011. ................................................................................................................................................. 0-12 

Table 0.8: PM10 Emissions from all industrial sources from 1994 to 2011: ........................................... 0-13 

Table 0.9: Spatial Surrogates ................................................................................................................... 0-15 

vi 
Acronyms and Abbreviations 

ADVMT ....................................... Average Daily Vehicle Miles Traveled 

AERR .......................................... Air Emissions Reporting Rule 

AP42 ........................................... EPA's Compilation of Air Pollutant Emission Factors 

AQI ............................................. Air Quality Index 

AQS ........................................... Air Quality System 

BNSF ........................................... Burlington Northern Santa Fe Railway 

bscat .. ······ ····································· A measure of light scatter, scattering coefficient 

CAA ............................................ Clean Air Act 

CAAA .......................................... Clean Air Act Amendments 

CARB .......................................... California Air Resources Board 

CNG ............................................ Compressed Natural Gas 

CRAB .......................................... County Road Administration Board 

DOL ............................................ Department of Licensing 

DQO ........................................... Data Quality Objectives 

DV .............................................. Design Value 

ECA ............................................. Emission Control Area 

Ecology ....................................... Washington State Department of Ecology 

EPA ................................ ............. U.S. Environmental Protection Agency 

FEM ............................................ Federal Equivalent Method 

FR ............................................... Federal Register 

FRM ............................................ Federal Reference Method 

FTA ............................................. Federal Transit Administration 

GIS .............................................. Geographic Information Systems 

g/hr ............................................ grams per hour 

HPMS ......................................... U.S. DOT Highway Performance Monitoring System 

IPP/QAP .................................... Inventory Preparation Plan and Quality Assurance Plan 

LMP ...... ..................................... Limited Maintenance Plan 

MA ............................................. Maintenance Area 

MOS .......................................... Margin of Safety 

MOVES ......................... .............. Motor Vehicle Emission Simulator 

NAA ............................................ Nonattainment area 

NAAQS ....................................... National Ambient Air Quality Standards 

NAMS ......................................... National Ambient Monitoring Sites 

vii 
NEI ........................................... .. EPA's National Emission Inventory 

NESHAP ...................................... National Emission Standards for Hazardous Air Pollutants 

NRLM .. ............... ........................ Non-Road, Locomotive, and Marine 

NSPS ........................................... New Source Performance Standards 

OLS .......................................... ... Ordinary Least Squares 

ODEQ ......................................... Oregon Department of Environmental Quality 

OSPI ........................................... Office of the Superintendent of Public Instruction 

PS.CAA ........................................ Puget Sound Clean Air Agency 

PM 10 ........................................... Particulate Matter, ten microns or less 

PM 2.

5 .......................................... Particulate Matter, 2.5 microns or less 

RACM ......................................... Reasonably Available Control Technologies 

RWC .......................................... Residential Wood Combustion 

SIP ............................................. State Implementation Plan 

SLAMS ....................................... State and Local Ambient Monitoring Sites 

TCMA ......................................... Thurston County Maintenance Area 

TRPC .......................................... Thurston Regional Planning Council 

TEOM ......................................... Tapered Element Oscillating Microbalance 

TSP ............................................. Total Suspended Particulate 

ULSD ...................... .................... Ultra Low Sulfur Diesel 

UP ...................................... ........ Union Pacific Railroad 

I 3 . b' 11g m ......................................... m1crograms per cu 1c meter 

VMT ........................................... Vehicle Miles Traveled 

WRAP ......................................... Western Regional Air Partnership 

WSDOT ...................................... Washington State Department of Transportation 

viii 
Executive Summary 

EPA analysis- the EPA's analysis is contained in the detailed sections, so there are no 

comments on the executive summary or introductory text. 

Portions of Kent and the industrial areas of the Duwamish Valley in Seattle and the Tideflats ofT acoma 

meet the federal24-hour standard for particulate matter 10 micrometers and smaller (PM10). This 

State Implementation Plan (SIP) revision explains how these areas will continue to meet the standard 

through 2020. 

The Environmental Protection Agency (EPA) sets air quality standards for particulate matter to protect 

public health. Particulate pollution is classified by its size, PM10 is considered coarse particulate matter 

and PM2.5 is considered fine particulate matter. Particles less than 10 micrometers can penetrate into 

the lungs and cause short and long-term health problems. There are separate 24-hour standards for 

PM10 (150 j..lg/m3) and PM2.5 (35 j..lg/m3) because particle size is directly linked to their potential for 

causing health problems. 

These three areas were classified as nonattainment areas in 1990 by the Environmental Protection 

Agency (EPA) for the 24-hour PM10 National Ambient Air Quality Standard (NAAQS). The Kent, Seattle, 

and Tacoma PM10 nonattainment areas were reclassified to maintenance areas in 1993, 1995, and 

1995, respectively. The Clean Air Act (CAA) requires a two 10-year maintenance plans for the three 

areas, the first 10-year maintenance plan was submitted to the EPA in 1997. This plan is the second and 

final10-year maintenance plan and fulfills the CAA requirement. 

The Kent, Seattle, and Tacoma PM10 maintenance areas are currently well below the 24-hour NAAQS 

for PM10. Compliance with this standard is maintained if PM10 values do not exceed 150 j..lg/m3 more 

than once a year, on average, over three years. 

The areas qualify to submit a streamlined Limited Maintenance Plan (LMP) because the 5-year Design 

Values for these areas do not exceeded 98 j..lg/m3 -a screening threshold- and meet other criteria. 

LMPs are for areas that show little risk of re-violating the PM10 NAAQS. 

PM10 concentrations are estimated using the historic relationship between PM10 and PM2.5 described 

in Section 4. PSCAA will continue to operate ambient PM2.5 monitors in all three maintenance areas. 

Three-year design values from PM10 concentrations for the three maintenance areas will be estimated 

annually to verify continued attainment of the NAAQS. Five year design values will be calculated to 

verify continuing qualification for the LMP option. Direct PM10 monitoring will be reestablished if 

calculated PM10 design values reach 98 j..lg/m3, the LMP option screening threshold . 

The control and contingency measures from the attainment and maintenance plans are still in place. All 

existing PM10 control measures will continue in the region and are described in Section 6. Primary 

control strategies include a residential wood smoke control program, fugitive dust ·program, and a 

9 
prohibition on outdoor burning. PSCAA's Regulation 1- Article 13.07 (b) provides for prohibition of the 

use of uncertified woodstoves for the sole purpose of meeting CAA requirements for contingency 

measures. The contingency measure will be triggered if the estimated PM10 concentrations violate the 

PM10 NAAQS at the maintenance area monitors. 

1. Introduction 

This State Implementation Plan (SIP) revision explains how the PM 10 maintenance areas of Kent, Seattle, 

and Tacoma currently meet and will continue to meet the 1987 National Ambient Air Quality Standard 

(NAAQS) for particulate matter ten microns or smaller (PM10) through 2020. Puget Sound Clean Air 

Agency (PSCAA) prepared this plan with the Washington State Department of Ecology (Ecology). PSCAA 

is the local clean air agency with jurisdiction over the Kent and Seattle maintenance areas in King County 

and the Tacoma maintenance area in Pierce County. 

Particulate Matter Standards 

The Environmental Protection Agency (EPA) sets air quality standards for particulate matter to protect 

public health. Particulate matter pollution is a public health issue because smaller particles can 

penetrate deep into the lungs and cause health problems. Particulate matter comes from soot, dust, 

unburned fuel suspended in the air, and can also be formed in the air from chemical reactions involving 

gaseous precursors. EPA revised the particulate matter NAAQS from total suspended particulate (TSP) 

to PM 10 on July 1, 1987, since smaller particles were determined to be more harmful. The primary 

health-based 24-hour standard for PM10 is 150 llg/m3

, and cannot be exceeded more than once a year 

on average over three years. A 24-hour standard for fine particulate matter 2.5 microns or smaller 

(PM2.5) was set to 65 11g/m3 on July 18, 1997, and was revised to 35 11g/m3 in 2006. 

Maintenance Area Compliance History 

EPA analysis- the EPA verified that the dates, citations, and summaries of the original 

attainment plans and the 151 10-year maintenance plan are correct. 

The Kent, Seattle, and Tacoma PM 10 maintenance areas were designated Group 1 PM10 areas in 1987 by 

the Environmental Protection Agency (EPA) for having a greater than 95% probability of violating the 24-

hour PM10 standard. These areas were then classified as nonattainment areas in 1990 as required for 

Group I areas by the 1990 Amendments to the Clean Air Act (CAA). The PM 10 attainment plan for Kent 

was fully approved by EPA on July 27, 1993 (58 FR 40059) and the plans for Tacoma and Seattle were 

fully approved by EPA on October 25, 1995 and October 26, 1995, respectively (60 FR 54599 and 60 FR 

54812). EPA approved the first 10-year maintenance plan on March 13, 2001 (66 FR 14492). 

This second 10-year maintenance plan is a Limited Maintenance Plan (LMP) and demonstrates 

continued attainment of the NAAQS through 2020 at existing PM2.5 monitors in the Puget Sound region. 

PM10 concentrations will be estimated using the relationship between PM 10 and PM2.5 described in 

10 
Section 4. All existing PM 10 control measures will be continued in the region and are described in Section 

6. 

Primary control strategies included in the PM10 attainment and maintenance plans for the three areas 

included a residential wood smoke control program, a fugitive dust program, and a prohibition on 

opening burning, and industrial emission controls. The control and contingency measures from the 

attainment and maintenance plans are still in place. PSCAA's Regulation I- Article 13.07 (b) provides for 

prohibition of the use of uncertified wood stoves for the sole purpose of meeting CAA requirements for 

contingency measures. The contingency measure will be triggered if the estimated PM 10 concentrations 

violate the PM10 NAAQS at the maintenance area monitor based on nephelometer and/or FEM 

monitoring of PM2.s· 

PSCAA will.continue to operate ambient PM2.5 monitors in all three maintenance areas. PM10 

concentrations will be estimated based on these measurements and the values will be evaluated 

annually to verify continued attainment of the NAAQS. PM10 monitoring will be reinstituted if calculated 

design values reach 98 11g/m3

. If air quality degrades significantly or if there are significant changes in 

any of the assumptions of this LMP, PSCAA will re-evaluate the plan. 

Plan Structure 

This SIP revision includes the compliance history for Kent, Seattle, and Tacoma and describes how the 

areas met and will continue to meet the standard, as well as what will be done if an area violates the 

NAAQS. This plan also includes other EPA-required elements, such as an emissions and monitoring 

review and public process requirements. 

This document is organized as follows : 

Section 2 -Background - describes the area's compliance history and contains background 

information on the PM 10 standard 

Section 3- Lim ited Maintenance Plan (LMP) Option- describes the criteria an area must meet to 

qualify for this option and how the three maintenance areas meet these criteria 

Section 4- PM10 Monitoring History - provides a brief history of monitoring in the three 

maintenance areas, an evaluation of the relationship of PM10 to PM2.5 and justification for using an 

alternative monitoring method 

Section 5- Emission Inventory- includes historical information on the most significant PM 10 

emission categories from the original maintenance plan and an updated inventory on these 

categories 

Section 6- Control Measures - lists the measures and rules that were in place in the original 

maintenance plan and the current rules that maintain and enforce these measures 

Section 7- Contingency Measures - describes the provisions that are in place in rules and will be 

taken, if the PM 10 standard is violated 

11 
Section 8- Commitment to Continued Monitoring and Verification of Continued Attainmentdescribes how monitoring will be continued and how compliance will be confirmed 

Section 9- Summary of Maintenance Plan Commitments- outlines commitments of this plan 

Section 10- Completion of Required Plans- states that this document fulfills federal planning 

requirements 

2. Background 

Geographic Area 

EPA analysis- a portion ofthe Tacoma maintenance area is within the Puyallup Indian Reservation. 

In 1991, the Puyallup Indian Tribe and PSCAA entered into an agreement to cooperatively manage 

air quality in the overall airshed, including PSCAA providing technical assistance when appropriate. 

The technical demonstrations contained in this plan for meeting Clean Air Act 175A maintenance 

plan requirements such as the demonstration of attainment, the calculation of motor vehicle 

regional emissions, the quantification of inventories, and the assurance of adequate monitoring 

cover the entire geographic span of the Tacoma maintenance area, including all Tribal lands. The 

only exception is the set of state and local control measures cited in this plan which are not 

approved to apply on trust lands within the exterior boundaries of the Puyallup Indian Reservation, 

in accordance with the Puyallup Tribe of Indians Settlement Act of 1989, 25 U.S.C. 1773. 

The EPA and the Puyallup Tribe of Indians are responsible for control measures on trust lands as 

discussed in the final rule Federal Implementation Plans Under the Clean Air Act for Indian 

Reservations in Idaho, Oregon and Washington, also called the FARR (April 8, 2005,70 FR 18074). 

reviewed the FARRand determined that the existing control measures on trust land are adequate 

to ensure continued maintenance of the PM10 standard and satisfy the remaining Clean Air Act 

175A requirements. The EPA sent an offer for consultation on review of the Kent, Seattle, and 

Tacoma PM 10 plan on October 18, 2013. 

Unlike ozone nonattainment areas which tend to have a large geographic scale due to the nature of 

ozone secondary formation, the boundaries of the Kent and Seattle PM10 maintenance areas are 

more localized and do not include other federally recognized Tribal reservations. 

The Kent PM10 maintenance area is located on the eastern side of the Green River Valley between the 

Cities of Tukwila and Auburn. The PM 10 sources in this region come from residential wood burning, light 

industry, and mobile sources. The valley floor is roughly two to three miles in width and is bound by hills 

which rise 300-400 ft. in elevation. These hills act to trap pollutants under stable meteorological 

conditions (inversions). These conditions exist most frequently during the late fall and winter and are 

associated with the majority of particulate matter violations. 

12 
Figure 2.1, below, shows the Kent PM 10 maintenance area boundary and the location of the monitoring 

site. 

The Seattle PM 10 maintenance area is comprised of the Duwamish industrial and commercial area 

immediately south of the downtown district and includes the Port of Seattle. The monitoring site has 

been in place since 1971 and is located in the center of the Duwamish industrial valley near the Port of 

Seattle. The site is a neighborhood scale site that is representative of South Seattle neighborhoods and 

ambient exposure in the industrial valley. The site is influenced by a very complex mixture of mobile 

sources, port and marine sources, industrial sources, winter home heating wood smoke, and other 

pollution sources. The site is 80 meters west of E. Marginal Way, which is a main arterial for many large 

haul trucks, as well as service vehicles and personal automobiles. Figure 2.2 shows the Seattle 

maintenance area boundary, the areas of the Port of Seattle that lie within the maintenance area, and 

the air monitoring station. 

The Tacoma PM10 maintenance area is comprised of the industrial area of Tacoma, including the Port of 

Tacoma, a Kraft pulp mill and other industrial operations. The monitoring site has been in place since 

1987 in the industrial area near the Port of Tacoma. The site is neighborhood scale located near several 

industrial air pollution sources. The sources that impact the area are a mixture of mobile sources, port 

and marine sources, industrial sources, and winter home heating from wood burning. The site is also 

within the Puyallup Indian Reservation, as well as the 2006 PM4.5 Tacoma-Pierce County nonattainment 

area. Figure 2.3 shows the Tacoma maintenance area boundary, the Port of Tacoma, and the location of 

the monitoring site. 

13 
Figure 2.1: The Kent, WA PMto Maintenance Area 

! l 

4 t • • i . 

Kent PM10 Maintenance Area #/ ·t ·-~ 

[ 

I 

\ •.. ,...-, I 

I 

I 

( 

* AJr Monitoring Station 

0 lndustnal Registered Sources Repcrnng PM:: 1n 2011 

Highways and MaJor Roads 

MaJor Freeways 

···-··• Rail 

c:::::::J F't.h Maintenance Area 

14 

' 

·' I t ;I 

+ 

~ 

.1 

~ l 

i 

r 

~ .:, 

1 

~ 

~ ~ 

i ' 

0 0.2 0.4 

- -

0 

~ p s cleanai r. org Puget $ound · ~) ;;.: Ag·HIC\' 

0.8 1.2 

Miles 
Figure 2.2: The Seattle, WA PMto Maintenance area 

/ 

Seattle PM16':Maintenance Area '<,~·, -. ., . "' 

,,/ 

L 

* Air Momtonng Station 

0 Industrial Registered Sources Reporting P!Vkin 2011 

Highways and Ma1or Roads 

Major Free'h ays 

............. , Ra1l 

EZ23 Port 

CJ Pf'lhMa111tenance Area 

15 

• 

~ o .;_ 

' 

~"------ pscleandir.org 

Puga: Sc.undC:t::' .... i· .;.~enc y 

2 I,. 

Miles .. 
Figure 2.3: The Tacoma, WA PM10 maintenance area 

Tacoma PM10 Maintenance Area 

* Air Monitonng Stat1on 

0 Industrial Registered Sources Reporbng Pf\'hin 2011 

Highways and MaJor Roads 

Major Freeway s 

·-'·······+ Ra1l 

CZJ Pcrt 

Puya l up Indian ReseNation 

CJ Pf\'kMaintenanceArea 

16 

'7 

''"...:_. ___ j 

---~~ psc:leandi r.org P1.19c: Soun~ .:h::' ."':i · .:O.;JEncr 

~ o .:.. 0.8 1.6 I Miles 
Compliance History 

EPA analysis- this historical summary is consistent with our records. 

On August 7, 1987, EPA identified Kent and the industrial areas of Seattle and Tacoma as having greater 

than 95% probability of violating the 24-hour PM 10 average standard. By operation of law, all three areas 

were designated moderate PM 10 nonattainment areas upon enactment of the CAA on November 15, 

1990. 

State Implementation Plan (SIP) submittals addressing PM10 nonattainment in Kent and Seattle were 

submitted by Ecology to EPA in November 1990, followed by the submittal for Tacoma one year later. 

The principal control strategies included in the PM10 attainment plans for the three areas included a 

residential wood smoke control program, a fugitive dust control program, and a prohibition on outdoor 

burning. 

The PM10 attainment plan for Kent was fully approved by EPA on July 27, 1993 (58 FR 40059) and the 

plans for Tacoma and Seattle were fully approved by EPA on October 25, 1995 and October 26, 1995, 

respectively (60 FR 54599 and 60 FR 54812). The maintenance plan and request for redesignation from 

nonattainment to maintenance for Kent, Seattle, and Tacoma were approved on March 13, 2001 (66 FR 

14492). 

This plan is the Second 10-Year Limited Maintenance Plan for PM10 in Kent, Seattle, and Tacoma and is 

the last maintenance plan for these areas. This maintenance plan revision ensures compliance through 

2020 and fulfills the second 10-year planning requirement of CAA Section 175A (b). 

3. Limited Maintenance Plan Option 

EPA analysis- early in the process PSCAA worked with the EPA and Ecology to review 

preliminary data and discuss the qualification criteria . As a result of those discussions, the EPA 

recommended the limited maintenance plan option. 

In consultation with Ecology and EPA, PSCAA chose to follow the EPA's Limited Maintenance Plan (LMP) 

option for the second PM 10 maintenance plan for the Kent, Seattle, and Tacoma maintenance areas. The 

EPA developed the Limited Maintenance Plan (LMP) option for areas with little risk of re-violating the 

PM10 standard. EPA allows states to use this policy to prepare the required second 10-year maintenance 

plans, if the area meets the qualification criteria in the EPA LMP Option Guidance (LMP Guidance) 1

. The 

LMP option for moderate PM10 nonattainment areas requires an area to meet certain applicability 

criteria in order to qualify for the LPM option. The first criterion is that an area should be attaining the 

1 Limited Maintena nce Plan Option for Moderate PMlO Nonattainment Areas 

17 
National Ambient Air Quality Standard (NAAQS), the second that the average PM10 design value based 

on the most recent 5 years of air quality data should be at or below 981Jg/m3 for the 24-hour PM 10 

NAAQS2

• The third criterion is that the area should expect only limited growth in on-road motor vehicle 

emissions and pass a motor vehicle regional emissions analysis test. The Kent, Seattle, and Tacoma 

maintenance areas meet these criteria as described below; supporting information can be found in 

Appendix A. 

NAAQS Qualification Criterion 

EPA Analysis- Robert Kotchenruther worked closely with PSCAA in developing the attainment 

analysis and PM10 concentration estimates described below. All three areas are well below the 

24-hour NAAQS of 150 1Jg/m3 with estimated PM10 concentrations of 44±3 1Jg/m3 for Kent, 49±4 

1Jg/m3 for Seattle, and 55±5 1Jg/m3 for Tacoma. 

To qualify for the LMP option, the area must be attaining the 24-hour NAAQS, 150 1Jg/m3

. Monitoring 

data shows that Kent, Seattle, and Tacoma have been in attainment of the standard since 1987, 1990, 

and 1989 respectively. The areas were reclassified to attainment for the 24-hour PM10 standard in March 

2001 when EPA approved the first 10-year maintenance plan for Kent, Seattle, and Tacoma. Table 3.1 

below shows the 3-year design values are well below the 24-hour NAAQS of 150 1Jg/m3 for all three PM10 

maintenance areas. 

Table 3.1: Three-year design values calculated using the most recent three years of 

estimated PM1o concentrations 

Site YEARS NO. DATA TABLE LOOK- STATISTICAL 

POINTS UP,I-lg/m3 FIT, l-lg/m3 

Kent 2010-2012 1017 44 44±3 

Seattle 2010 - 2012 1068 48 49±4 

Tacoma 2010 - 2012 1030 59 55±5 

2 Limited Maintenance Plan Option for Moderate PMlO Nonattainment Areas, pp 3 

18 
Design Value Criterion 

EPA analysis- the general approach of this plan is consistent with PM 10 estimation 

methodology recently approved in the Thurston County PM10 action. The methodology is 

technically sound and the estimated five-year PM 10 concentrations are well below the 

limited maintenance plan qualification threshold of 98 11g/m3

. For the 2008 to 2012 

period, estimated PM10 concentrations were 46±3 11g/m3 for Kent, 50±5 11g/m3 for 

Seattle, and 58±8 11g/m3 for Tacoma. (Note: PSCAA made a minor typographical error in 

the narrative of this section. The correct 2008 to 2012 value for Seattle should be '50±5 

11g/m3 rather than 48±5 11g/m3 to match Table 3.3. Since this is a minor typographical 

error, PSCAA will probably correct this prior to final submission to the EPA). 

To qualify for the LMP option, the average 24-hour PM10 design value for the area based upon the most 

recent five years of data should not exceed 98 11g/m3

. A design value is the statistic based on monitoring 

data that determines an area's compliance status. The LMP Guidance directs the design value be based 

on the most recent five years of data. The design values for Kent, Seattle, and Tacoma based on Federal 

Equivalence Method (FEM) 24-hour PM 10 monitoring data from 2003 through 2007 are 57±3 11g/m3

, 

68±41-lg/m3

, and 72±9 11g/m3. The most recent design values estimated based on an alternative 

method, using 2008 to 2012 values, are 46±3 11g/m3

, 48±5 11g/m3, and 58±8 11g/m3 respectively. All of 

these values are below the 98 11g/m3 value stipulated in the LMP Guidance. 

The PM10 SIP Development Guideline3 (SIP Guideline) outlines the following four approaches to 

determine the PM10 design value: a table look-up procedure; fitting a statistical distribution to several 

years of data; a graphical estimation technique; and the use of a conditional probability approach. This 

analysis uses both the table look-up method and a statistical fit to calculate the PM10 design values. The 

graphical estimation and the conditional analysis were considered for this analysis however the table 

look-up method and the statistical fit were the most appropriate for the Kent, Seattle, and Tacoma 

monitoring datasets. The graphical estimation technique was not used in this analysis due to insufficient 

data in some cases. Where there was insufficient data the concentration that corresponds to a 

frequency of 1/365 could not be read directly off a graph of the distribution at each of the sites for all of 

the 5-year time periods. The conditional probability approach is used in cases where individual years of 

data should be treated separately. Preliminary analysis of the conditional probability approach showed 

that values for individual years did not vary significantly from year to year. Calculating the design value 

using the table look-up method and the statistical fit method allows for the most conservative design 

value to be selected. 

The table look-up procedure is outlined in the PM 10 SIP development guide4

. The PM10 SIP development 

guide states that the design concentration for PM 10 is the concentration that corresponds to a frequency 

3 PM-10 SIP Development Guideline, publication EPA 450/2 86-001 4 PM-10 SIP Development Guideline, publication EPA 450/2 86-001, Table 6-1, pp.6-5 

19 
of 1/365 on an empirical frequency distribution.4 Table 3.2 below is used to estimate which point on 

the empirical frequency distribution corresponds to a frequency of 1/365. 

Table 3.2: Tabular Estimation ofPM10 Design Values4 

Number of Values Data Point to be Used 

1 -347 Highest Value 

348-695 Second Highest Value 

696 - 1042 Third Highest Value 

1043 - 1390 Fourth Highest Value 

The statistical fit is calculated according to the approach is outlined on pages 18-20 of the Ozone 

guideline5

. The design value is calculated by solving for the concentration of PM 10 that is equal to a 

probabil ity of 1/3654. The 95% confidence interval is reported with the statistical fit design value. The 

design values calculated using with the table look-up method all fall within the range of the 95% 

confidence interval of the statistical fit design values. 

Design values for the most recent 5 years of monitoring data are shown in bold in Table 3.3 alongside 

design values calculated using estimated PM10 concentrations. Monitoring data is discussed in Section 

4.1 and PM 10 estimates are discussed in Section 4.2. 

Table 3.3: Five-Year Design Values for Kent, Seattle, and Tacoma 

5-VEAR 5-VEAR 5-VEAR 5-VEAR 

PERIOD DESIGN VALUE DESIGN VALUE 

Site YEARS NO. DATA TABLE LOOK- STATISTICAL 

POINTS UP, 11g/m3 FIT, 11g/m3 

Kent 2003-2007 1149 58 57±3 

Kent 2008-2012 1762 43 46±3 

Seattle 2003-2007 1318 69 68±4 

Seattle 2008-2012 1311 so 50±5 

5 Guideline fo r the Interpretation of Ozone Air Quality Standards, EPA-450/4-79-003 

20 
Tacoma 2001-2007* 900 68 72±9 

Tacoma 2008 - 2012 1725 54 58±8 

*2004 was excluded because more than 75% of the data was missing 

Motor Vehicle Regional Analysis Criterion 

EPA analysis- estimated growth in on-road motor vehicle PM 10 emissions is very small during the 

ten year period. Total estimated growth is shown in the equations below as VMTp; x DVmv, and 

calculates to 1.5 11g/m3 for Kent, 2.7 11g/m3 for Seattle, and 2.9 11g/m3 for Tacoma over the entire 

ten-year period. All three areas easily meet the margin of safety of 98 11g/m3

, with Kent= 61.5 

11g/m3

, Seattle= 74.7 11g/m3

, and Tacoma= 83.9 11g/m3 . 

To qualify for the PM10 LMP option, an area should expect only limited growth in on-road motor vehicle 

PM 10 emissions (including fugitive dust) and pass a motor vehicle regional emissions analysis test, found 

in Appendix B of the LMP Guidance. The results of the analysis must be less than 98 11g/m3, the Margin 

of Safety (MOS) value for the 24-hour PM 10 standard. The Kent, Seattle, and Tacoma maintenance areas 

meet both these criteria, as described below and in Appendix A. 

The following methodology was used to determine whether increased emissions from on-road mobile 

sources could, in the next 10 years, increase concentrations in the maintenance areas and threaten the 

assumption of maintenance that underlies the LMP Guidance. 

DV + (VMTp; x DVmvl < MOS 

Where: 

DV =the area's design value based on the most recent 5 years of data in 11g/m3 

VMTp; =the projected percent increase in vehicle miles traveled (VMT) over the next 10 years 

DVmv = motor vehicle design value based on on-road mobile portion of the attainment year inventory in 

11g/m3 

MOS =margin of safety for the relevant PM10 standard for a given area: 40 11g/m3 for the annual 

standard or 98 11g/m3 for the 24-hour standard 

Qualification for the LMP approach is demonstrated when the motor vehicle regional 

a value less than the MOS of98J.1.g/m3 for the 24-hour PMto standard. The variables and 

equation for each of the three maintenance areas are shown in 

21 
Table 3.4. The results of the calculation is less than the MOS of 98 1-1g/m3 and therefore demonstrates 

that the Kent, Seattle, and Tacoma PM10 maintenance areas pass the motor vehicle regional analysis and 

qualify for the LMP approach. 

Table 3.4: Margin of Safety Comparison 

Kent Seattle Tacoma 

DV (llg/m3 ) 60 72 81 

VMTp; 9% 11% 12% 

DV mv (llg/m3

} 16.8 24.5 24.3 

DV + (VMTp; x DVmv) 61.5 74.7 83.9 

MOS (llg/m3 ) 98 98 98 

LMP Qualification 

EPA analysis -- The EPA concurs with PSCAA/Ecology's demonstration that the three areas meet 

the qualification criteria outlined in the limited maintenance plan memo. The EPA is also 

proposing to approve the monitoring system modification, using PM2.5 monitoring data to 

estimate PM10 concentrations, under 40 CFR 58.14(c) for the second 10-year maintenance plan 

period similar to the previously approved Thurston County PM10 action. PSCAA has demonstrated 

that this estimation method is a reproducible approach to representing air quality in all three 

maintenance areas, and all three areas continue to meet the applicable Appendix D requirements 

evaluated as part of the annual network approval process. 

The Kent, Seattle, and Tacoma PM10 maintenance areas meet the LMP qualification criteria and qualify 

for the LMP option. As described above and in Appendix A, these areas are in compliance with the 24-

hour NAAQS for PM 10, the five year design values are well below 981-lg/m3 and the growth in PM10 

emissions from motor vehicles will not threaten compliance with the standard. 

PSCAA provided its analysis to Ecology and EPA Region 10 office. EPA Region 10 and Ecology mutually 

agreed to the LMP approach. We have discussed the alternative approach for PM10 estimation, outlined 

in Section 4.2, with Ecology and EPA. With this submittal, we request approval for the alternative 

approach for PM 10 estimation. PSCAA will calculate the 3-year and 5-year PM10 design value estimates 

and provide them to Ecology annually. Ecology will include a statement that the area continues to 

qualify for the LMP option in the annual monitoring network report. The report can be found at 

https: //fortress. wa .gov I ecy/pu b I icatio ns/U I Pages/Home .aspx 

22 
4. Particulate Matter Monitoring 

EPA analysis- t~is section outlines the monitoring history and technical basis for the 

PM2.

5 and PM10 correlation. This analysis was thoroughly reviewed by EPA Region 10. 

4.1. PMto Concentrations 

Kent Maintenance Area 

The daily (midnight to midnight) concentrations of PM 10 and PM2.5 are shown in Figure 4.1.1. PM 10 

monitored values are shown from 1987 through 2007 (blue circles), PM2.5 monitored values are shown 

from 1999 through 2012 (green plus), and estimated PM10 values based on PM2.5 monitored values are 

shown from 1999 through 2012 (black dots). Monitored concentrations have never exceeded the 

NAAQS since monitoring began in 1987. The maximum 24-hour concentration recorded during the last 

five years of PM 10 FEM monitoring was 69 11g/m3 in 2006. Estimated PM 10 concentrations are shown in 

black, the highest estimated PM 10 concentration is 144 11g/m3

, this value occurred on July 4, 2009. 

Estimated concentrations of PM 10 are shown in the figure below (black dots). Model development is 

described in Section 4.3. 

Figure 4.1.1: Kent Historical PM to Concentrations 

Kent 24-hour PM10 Concentrations 

250r----~----,-----,----~--~==~======~ 

200 

150 0 

0 

0 

23 

o PM10 

"' PM2.5 

• Estimated PM10 

--NAAQS 
Kent Monitoring 

The Kent PM 10 maintenance area is shown in Figure 4.1.1. PSCAA monitored PM10 at James Street and 

Central Avenue using a Federal Reference Method (FRM) between 1988 and 2003 and a Federal 

Equivalent Method (FEM) from July 2004 through December 2007. The area has been in compliance 

with the standard since 1987. Federal Equivalent Method (FEM) PM10 values were low enough that the 

FEM monitor was removed with EPA approval at the end of 2007. Excerpts from this report are included 

as Appendix B. Since then, continuous monitoring of PM2.5 has been conducted in Kent with a TEOM, 

which has been correlated with a co-located PM10 monitor to provide estimated PM 10 values. 

Figure 4.1.2 shows the dates and monitors located at the Central and James Street monitoring site from 

1988-2007. All of the data used to develop the relationship between PM10 and PM2.5 relied exclusively 

on data downloaded from EPA's Air Quality System (AQS). The data downloaded from AQS was collected 

using the monitors show in Figure SS. The model described in section 4.2 was developed using data from 

the time period where PM10 and PM2.5 measurements are co-located {1999-2003). For the period 2008-

present the PM 10 concentrations are estimated using PM2.5 concentrations measured with the 

instruments in Figure 4.1.3. Details on the PM10 and PM2.5 relationship are described in section 4.2. 

Figure 4.1.2: PM10 and PMz.s data used to develop the PMto to PMz.s relationship 

Kent PM2.5 • Pa rtisol R&P 

Model2025 

Kent PM10 ·Hi Voi/GMW· 

1200 

Kent PM 10 • R&P TEOM 

1400 

1/1/1985 1/1/1988 1/1/1991 1/1/1994 1/1/1997 1/2/2000 1/1/2003 1/1/2006 

24 
Figure 4.1.3: PMz.s monitoring data used to estimate PM1o concentrations from 2008-present 

Kent PM2.5- R&P TEOM 

FEM 

Kent PM2.5- R&P TEOM 

FDMS_STP 

Kent PM2.5- R&P TEOM 

1400 

1/1/2008 12/31/2008 12/31/2009 12/31/2010 1/1/2012 12/31/2012 12/31/2013 

25 
Seattle Maintenance Area 

The 24-hour concentrations of PM 10 and PM2.

5 are shown in Figure 4.1.4 below. PM w monitored values 

are shown from 1985 through 2007 (blue circles), PM2.5 monitored values are shown from 1999 through 

2012 (green plus), and estimated PM10 values based on PM2.5 monitored values are shown from 1999 

through 2012 (black dots). Monitored concentrations have not exceeded the NAAQS since 1990. The 

maximum 24-hour concentration recorded during the last five years of FEM monitoring was 80 11g/m3 in 

2006. 

Seattle Monitoring 

Figure 4.1.4: Seattle Historical PMto Concentrations 

0 

0 

0 0 

Jan90 

Seattle 24·hour PM10 Concentrations 

0 

II 

Jan95 

0 

0 

0 

0 

o PM10 

.- PM ~ 

Estimated PM10 

- NAAQS 

Jan15 

The Seattle PM10 maintenance area is shown in Figure 2.2. PSCAA monitored PM10 at both 4401 and 

4752 East Marginal Way South using an FRM between June 1988 and December 2003 and an FEM from 

October 2004 through 2007. The area has been in compliance with the standard since 1990. Federal 

Equivalent Method (FEM) PM 10 values were low enough that the monitor was removed with EPA 

approval at the end of 2007. Excerpts from this report are included as Appendix B. Since then, 

continuous, reference and non-reference method monitoring of PM2.5 has been conducted at the Seattle 

monitoring site and correlated with a co-located PM10 monitor to provide estimated PM10 values .. 

Figure 4.1.5 shows the dates and monitors located at the 4401 and 4752 East Marginal Way South 

monitoring site from 1985-2007. All of the data used to develop the relationship between PM10 and 

PM 2.5 relied exclusively on data downloaded from EPA's Air Quality System (AQS). The data downloaded 

from AQS was collected using the monitors show in Figure 4.1.5. The model described in section 4.2 was 

developed using data from the time period where PM10 and PM2.5 measurements are co-located (1999-

2007). For the period 2008- present the PM 10 concentrations are estimated using PM2.5 concentrations 

measured with the instruments in Figure 4.1.6. Details on the PM 10 and PM 2.5 relationship are described 

in section 4.2. 

26 
Figure 4.1.5: PMto and PMz.s data used to develop the PMto to PMz.s relationship 

Seattle PM2.S- R&P Model 202S 

Seattle PM10- Hi Vol SA321A 

Seattle PM10- Hi Voi/GMW-1200 

Seattle PM 10- R&P TEOM 1400 

1/1/198S 1/1/1988 1/1/1991 1/1/1994 1/1/1997 1/2/2000 1/1/2003 1/1/2006 

Figure 4.1.6: PMz.s monitoring data used to estimate PM1o concentrations from 2008-present 

Seattle PM2.S- R&P 

Model2025 

Seattle PM2.5 - STP 

Thermo Scientific 1400a 

& SSOOCFDMS 

Seattle PM2.5- FEM 

Thermo Scientific 1400a 

& 8500C FDMS 

·· ·························---

1/1/2008 12/31/2008 1/1/2010 

l 

1/1/2011 1/2/2012 1/1/2013 

27 
Tacoma Maintenance Area 

The 24-hour concentrations of PM10 and PM2.5 are shown in Figure 4.1.7 below. PM10 monitored values 

are shown from 1987 through 2007 (blue circles), PM2.5 monitored values are shown from 1999 through 

2012 (green plus), and estimated PM 10 values based on PM2.

5 monitored values are shown from 1999 

through 2012 (black dots). Monitored concentrations have not exceeded the NAAQS since 1988. The 

maximum 24-hour concentration recorded during the last five years of FEM monitoring was 69 11g/m3 in 

2006. 

250 

0 

200 

150 0 

Figure 4.1.7: Tacoma Historical PMto Concentrations 

Tacoma 24-hour PM10 Concentrations 

o PM10 

* PM2.5 

Estimated PM10 

--NAAQS 

M 0 0 

E 0 Cl 

:I 

100 

Jan15 

Tacoma Monitoring 

The Tacoma PM10 maintenance area is shown in Error! Reference source not found .. PSCAA monitored 

M10 at 2301 Alexander Avenue site in Tacoma, Washington . The area has been in compliance with the 

standard since 1990. Federal Equivalent Method (FEM) PM10 values were low enough that the monitor 

was removed with EPA approval at the end of 2007. Excerpts from this report are included as Appendix 

B. Since then continuous monitoring of PM2.5 has been conducted at the Tacoma monitoring site and 

correlated with a co-located PM10 monitor to provide estimated PM10 values. Figure 4.1.8 shows the 

dates and monitors located at the 2301 Alexander Avenue monitoring site from 1988-2007. All of the 

data used to develop the relationship between PM10 and PM 2.5 rel ied exclusively on data downloaded 

from EPA's Air Quality System (AQS). The data downloaded from AQS was collected using the monitors 

show in Figure 4.1.8. The model described in section 4.2 was developed using data from the time period 

where PM 10 and PM2.s measurements are co-located (1999-2003). For the period 2008- present the 

PM 10 concentrations are estimated directly from a correlated nephelometer. The nephelometer is the 

only instrument presently reporting PM2.5 concentrations at the Alexander Avenue monitoring site. 

28 
Nephelometers have been used to monitor particulate matter light scatter in the maintenance areas for 

decades. A nephelometer measures light scatter (bscat) and, when correlated with a Federal Reference 

Method (FRM) instrument, accurately represents particulate matter levels. Because of the high 

correlation between nephelometer readings and FRM and Federal Equivalent Method (FEM) monitors, 

Ecology and PSCAA conclude that PM2.5 values calculated directly from a nephelometer are sufficiently 

reliable and reproducible. Nephelometer measurements began in the maintenance areas in 1999 and 

measurements continue in those areas today. Each of the monitoring stations in the three maintenance 

areas measure PM2.

5 with a nephelometer. The Seattle and Kent monitoring stations currently both use 

a FEM method and a nephelometer. PM2.5 measurements reported using the FEM monitoring and the 

nephelometer the Seattle and Kent maintenance areas are well correlated. 

Details on the PM10 and PM2.5 relationship are described in Section 4.2. 

Figure 4.1.8: Tacoma monitoring data used to calculate the PM10 PMz.s relationship 

Tacoma PM2.5- R&P 

Model2025 

Tacoma PM2.5- STP 

Thermo Scientific 1400a 

& 8500CFOMS 

Tacoma PM10- Hi 

Voi/GMW-1200 

Tacoma PM10- R&P 

TEOM 1400 

1/1/1985 1/1/1988 1/1/1991 1/1/1994 1/1/1997 1/2/2000 1/1/2003 1/1/2006 

29 
4.2. Model Development 

EPA analysis- this modeling methodology is technically sound and Region 10 concurs with the 

approach. 

Monitoring for PM10 concentrations was discontinued with EPA approval at all three monitoring stations 

in late 2007 because PM10 levels were so low and continued attainment of the NAAQS could be ensured 

through correlation with PM 2.s monitoring. PM 10 concentrations from 2008 to the present are calculated 

using a relationship between PM10 and PM2.5. PM2.5 measurements collected from 1999- 2007 were 

correlated to PM10 measurements collected in the same period. Many of the sources of PM10 are 

independent of season; however, residential wood burning in all three maintenance areas occurs 

primarily in the winter months, October-March. Due to the difference in emission sources in the winter 

months compared to the summer months, the relationship was calculated separately for summer 

months, April- September, and winter months, October- March. 

The relationship between PM 2.5 and PM 10 was calculated using a robust regression technique. The 

standard ordinary least squares (OLS) regression technique, which uses a Pearson correlation, is not 

suitable for data with outliers or uncertainty in the independent variable. For weaker correlations, an 

OLS regression will result in a slope with a significant low bias. A robust regression technique reduces 

the low bias on the slope6

·

1 and is less sensitive to outliers6

·

2

. For our analysis, the OLS approach resulted 

in a slope with a low bias for some of the maintenance areas, which underestimated the PM 10 

concentrations. Instead, we used an iteratively re-weighted least squares algorithm (with a bi-square 

weighting function) to calculate the slope and intercept of the PM10 to PM2.

5 relationship. This 

relationship was then used to estimate PM10 concentrations using measurements of PM 2_5• 

Kent 

The correlation between PM10 and PM2.5 is strongest in the winter months, October- March. This is 

expected because residential wood burning accounts for most of the winter time PM10 and PM2.

5 

emissions in Kent. For the winter time period, the PM 10 to PM2.5 relationship can be described similarly 

using and OLS regression or a robust regression. The summer months, April- September, have lower 

concentrations and a weaker relationship. Since the summer relationship has a lower correlation than 

the winter relationship, the robust regression technique produces a steeper slope for the PM10 to PM2.

5 

relationship than the OLS technique. For consistency we use the robust regression technique to 

calculate the slope and intercept to describe the relationship for both the winter and summer months. 

The relationships for PM 10 to PM2.5 in the summer and winter months are shown in Figure 4.2.1. 

The estimated PM10 values are calculated using measured PM2.5 and the equation of the line for summer 

or winter depending on the date ofthe PM2.5 measurement. In other words, all PM 10 concentrations 

6

'

1 Ayers, G. P. (2001), Comment on regression analysis of air quality data, Atmos. Environ., 35(13), 2423-2425, 

doi:10.1016/S1352-2310(00)00527-6 6

'

2 Huber, P. J. Robust Statistics. Hoboken, NJ : John Wiley & Sons, Inc., 1981. 

30 
estimated for dates from April through September use the summer slope and intercept as the PM 10 

model. As a check for the model, PM 10 concentrations were estimated over the period 1999-2007 and 

plotted against PM10 measurements from the same period. The results are shown in 

31 
Figure 4.2.2. 

Figure 4.2.1: 

Winter PM10 

1999-2007 

Monitoring 100 

80 

60 

0 

Kent Summer (April • Septemberl1999-2007 

,/ 

/ 

.,., 

·~r 40 D. ./· .··· .... ....... ·· 

M 

~ 

" 0 

:{ 

D. 

, .. n>::: .. ·• 

20 

~ 

..... -r., · 'A • • 

. .p·" 

0 / 

0 R2 : 0.66 

robust regression 2.07x+0.29 

ordinary LS 1.4x+5.6 

0 

100 

80 

60 

40 

20 

0 

0 

10 20 30 40 50 

Kent Winter (October-Marchl1999-2007 

o&_......~ ......... 

0 

., ...... ,k ..... 

-~~ 

0 .... ~ .. 0 

0 _ ........ 

o o o cs· <b r--o-R_2_=_0-.7-6---------, 

o o ~ • .!lt\o';;d>o o .Wei" robust regression 1.22x+3.09 

ordinary LS 1.2x+4.3 

10 20 40 50 

32 

60 

60 

Summer and 

to PMz.s from 

at the Kent 

Site 
Seattle 

Figure 4.2.2: Estimated PM1o to Measured PM1o for the years 1999-2007 

80 

70 

60 

50 

al 

a; 40 "CC 

e 

0 30 ::t 

IL 

20 

10 

Kent Estimated PM10 

b. R2 = 0.71 

• ordinary LS 0.87x+1 .9 

- - robust regression 1.0x-0.03 

'1 o~-----:"1o=----2~o----=J'='o __ ..J.4o=----s~o---6.L..o--"='7o __ __,so 

PM10 measured 

The relationship between PM1o and PMz.s in Seattle is similar in both seasons. Because this 

characterized by emissions from industry and the Port of Seattle, PM1o and PMz.s emissions 

more uniform throughout the year. Higher wintertime concentrations are likely a result of 

inversion and stagnation events which trap pollutants near the surface. Although the OLS 

produces a slightly steeper slope than the robust regression technique, the PM1o model for 

maintenance area will use the relationship described by the robust regression technique for 

with the Kent and Tacoma maintenance areas. The relationships for PM1o to PMz.s in the 

winter months are shown in 

Figure 4.2.3 

The estimated PM 10 values are calculated using measured PM2.5 concentrations and the equation of the 

line for summer or winter depending on the date of the PM2.

5 measurement. In other words, all PM10 

concentrations estimated for dates from April through September were estimated using the 

summertime slope and intercept from the PM 10 model. As a check for the model, PM 10 concentrations 

were estimated over the period 1999-2007 and plotted against PM 10 measurements from the same 

period. The results are shown in Figure 4.2.4. 

33 
Figure 4.2.3: Summer and Winter PMto to PMz.s from 1999-2007 at the Seattle Monitoring 

Site 

100 

80 

M 

~ 60 

:I 

0 

-=:~ 40 IL 

20 

10 

Seattle Summer (April. September) 1999-2007 

.-, R2 = 0.70 

--robust regression 1.83x+4.7 

ordinary LS 2x+3.9 

30 40 

PM2.

5 ug/m3 

50 60 70 

Seattle Winter (October-March) 1999-2007 

20 

0 

0 

0 

0 0 

0 R2 = 0.64 

.. .. · .. · ~"" 

- robust regression 1.26x+8.30 

ordinary LS 1.4x+ 7.8 

30 40 

PM2.

5 ug/m3 

34 

50 60 70 
Tacoma 

Figure 4.2.4: Estimated PM1o to Measured PM1o for the years 1999-2007 

"0 

~ 

90 

80 

70 

60 

~ 50 

0 

E 

= 40 .,... 2 

c.. 30 

Seattle Estimated PM10 

6 R2 : 0.67 

• ordinary LS 0.69x+6.7 

-.robust regression 0.99x+1.1 

o~---1~0----2~0----3~o----~4o----~5~0----6~0----7~0----8~o--~go 

PM10 measured 

In the Tacoma maintenance area the winter correlation between PM10 and PM2.5 is stronger than the 

summer months. This may be explained by the residential wood smoke emissions in the Tacoma region 

as well as decreased road dust emissions in the wintertime. For the winter time period, the PM10 to 

PM2.

5 relationship can be described similarly using and OLS regression or a robust regression. The 

summer months, April- September, have higher PM10 concentrations and a weaker relationship. It is 

likely this is a reflection of the difference in PM10 and PM2.

5 emission sources in the summer' months. The 

PM10 model for the Tacoma maintenance area uses the relationship described by the robust regression 

technique. The relationships for PM10 to PM2.s in the summer and winter months are shown in Figure 

4.2.5 

The estimated PM10 values are calculated using measured PM2.5 and the equation of the line for summer 

or winter depending on the date of the PM2.5 measurement. In other words, all PM10 concentrations 

estimated for dates from April through September the summer slope and intercept are used as the PM10 

model. As a check for the model, PM10 concentrations were estimated over the period 1999-2007 and 

plotted against PM10 measurements from the same period. The results are shown in Figure 4.2.6. 

35 
Figure 4.2.5: Summer and Winter PMto to PMz.s from 1999-2007 at the Tacoma Monitoring 

Site 

100 

80 

M~ 60 

"' 0 

£ 40 IL 

100 

80 

.,~ 60 

"' 0 

-:r 40 IL 

0 10 

Tacoma Summer (April - Septemberj1999-2007 

20 30 

" R2 = 0.43 

40 

robust regression 2.44x+0.26 

ordinary LS 1.9x+6.4 

50 60 70 

Tacoma Winter (October-Marchj1999-2007 

R2 = 0.84 

Figure 4.2.6: Estimated PM10 to Measured PMto for the years 1999-2007 

., 

.. 

Oi 

., 

e 

0 

100 

90 

80 

70 

60 

50 

f 40 

30 

20 

Tacoma Estimated PM10 

• ordinary LS 0.68x+6.5 

--robust regression 0.997x+0.01 

PM10 measured 

36 

..... ···· .. 

........ ··· ..... ··· 

90 100 
PM1o Violation Unlikely 

EPA analysis- this demonstration shows that the more stringent 35 11g/m3 24-hour PM2.

5 standard 

would be violated well before a possible exceedance of the 24-hour PM10 standard of 1501lg/m3 in 

these three maintenance areas. 

Compliance with the 2006 24-hour PM2.5 standard of 35 11g/m3 will help assure continued compliance 

with the 1987 PM1o standard. PSCAA ran collocated FRM/ FEM PM 10 and FRM/FEM PM2.

5 monitors from 

1999 through 2007. Using the relationships described in the model development section above, we can 

estimate the measured PM2.5 concentrations that would suggest an exceedance of the 24-hour PM 10 

standard of 1501lg/m3 in the summer and winter seasons. PM2.5 concentrations that would be required 

to exceed the 24-hour PM10 standard are summarized in Table 4.2.1. 

Table 4.2.1 PMz.s concentrations corresponding to a PM to concentration of 150 ~gjm3 

Summer PMz.s Max Summer Winter PMz.s Max Winter 

Concentration (1J.g/m3

) PMz.s (1J.g/m3

)* Concentration (1J.g/m3

) PMz.s (1J.g/m3

) 

since 2008 since 2008 

Kent 75 71* 122 33 

Seattle 79 28 113 34 

Tacoma 62 35 114 53 

*Maximum value was observed on July 4

1

h, 2009. The second highest value at Kent from 2008-2012 is 281lg/m3 

The maximum summer and winter PM2.5 concentrations observed at each of the monitoring sites from 

2008-2012 are listed in Table 4.4.1. Using the relationship between PM 10 and PM2.5, 24-hour PM2.5 

levels would have to exceed, at a minimum, 62 11g/m3

, in summer or at least 113 11g/m3 in the winter to 

exceed the PM 10 standard at any of the three maintenance area monitoring sites. Because of the form 

of the PM 10 standard, the PM2.5 level would have to be exceeded more than once a year, over a three 

year average, to violate the PM 10 standard. For example the 711lg/m3

, recorded at Kent on July 4, 2009, 

corresponds to a PM10 concentration of 142 11g/m3

. While 142 11g/m3 is near the NAAQS of 150 11g/m3

, it 

is not an exceedance. However, the PM2.5 concentration of 7lllg/m3 is well above the NAAQS of 35 

11g/m3

. This demonstrates that PM2.5 is the controlling standard. The maximum observed PM2.s 

concentrations in table 4.4.1 demonstrate that an exceedance of the PM 10 NAAQS is highly unlikely. 

37 
4.3. Current PMto and PMz.s Data Availability 

EPA analysis- this approach is similar to the recently approved Thurston County action. Data 

and summary results are readily available to the public on the website links below, and are 

submitted to the EPA annually in accordance with the limited maintenance plan option memo. 

PM10 concentrations calculated from the PM 10 model described above are available from PSCAA and can 

be provided to EPA and the public on request. Both the 3-year and 5-year design values will be included 

in Ecology's annual monitoring network report to EPA, this report is available to the public at 

https://fortress.wa.gov/ecy/publications/UIPages/Home.aspx The PM2.

5 monitored concentrations used 

to calculate the PM 10 concentrations are available from the PSCAA website, www.pscleanair.org. 

38 
5. Emission Inventory 

EPA analysis- due to the steadily declining PM10 levels and emission sources, this emissions 

inventory is generally straightforward and noncontroversial. In order to address any potential 

questions or issues related to locomotive transport of coal, PSCAA worked closely with Robert 

Kotchenruther to include estimated fugitive dust emissions for the locomotive sector along with 

the more traditional diesel emission impacts reported as part of the National Emissions Inventory. 

Total locomotive emissions represent a small proportion of the overall PM10 inventory (Kent= 6%, 

Seattle= 5%, and Tacoma = 2%) and are unlikely to interfere with continued maintenance given 

the current low levels of PM10 monitored in the area. As shown by the maintenance area maps, 

all three monitors are located close to major rail lines. Therefore, continued monitoring of 

attainment and qualification under the limited maintenance plan option will be easy to verify over 

time. For more information on development of the inventory and the inventory preparation plan 

developed with the EPA and Ecology, please see Appendices C and D of the PSCAA submission. 

This section presents the emissions inventory for this second 10-year maintenance plan and briefly 

describes its development. The LMP Guidance requires the maintenance plan include an attainment 

inventory-that is, an inventory with emission levels consistent with attainment ofthe PM 10 standard. 

EPA develops a triennial national emission inventory based on EPA and state inputs. EPA issued the Air 

Emissions Reporting Rule (AERR) to clarify state reporting requirements. EPA and Ecology agreed on 

developing the attainment inventory from available triennial inventory information and annual reported 

industrial emissions. Appendix C provides details on the emission inventory development. 

Emission years and categories 

EPA approved the Inventory Preparation Plan (IPP) prepared by Ecology that proposed use of readily 

available information. This plan is provided as Appendix D. Emission estimates in this maintenance plan 

inventory are from Ecology's draft 2011 triennial emissions inventor/ (2011 El} and the annual 2011 

industrial emissions reported to PSCAA and Ecology. 

The original seven significant emission categories are reorganized in seven new categories in this 

attainment inventory as listed in Table 5.1. County values from the seven most significant categories 

have been temporally and spatially allocated to their respective maintenance areas. These seven 

emissions categories were chosen based on a review of the emission sources in the original 

maintenance plan. 

7 Draft Excerpts of the Washington State Base Year 2011 County Inventories, Wash ington State Department of Ecology Air 

Quality Program, Sally Otterson, 2013. 

39 
Table 5.1: Emission Categories used in this LMP 

1994 Emissions Categories 2011 Emission Categories 

Gasoline Exhaust On-road Mobile 

Diesel Exhaust Port and Marine, On-road Mobile 

Ships Port and Marine 

Locomotives Locomotives (including fugitive dust) 

Wood Burning Residential Wood Combustion 

Road Dust Paved Road Dust, Unpaved Road Dust 

Allowable Industrial Industrial 

Emission inventory geography 

The emission inventory is an estimate of the total PMlO tons boundaries shown in the Figure 2.1, Figure 

2.2, and Figure 2.3. 

40 
Significant source categories 

The most significant sources of PM10 listed in the original maintenance plan for the Seattle and Tacoma 

Maintenance Areas was industrial emissions. For the Kent Maintenance Area, the major source of 

emission was from Residential Wood Combustion, and to a lesser extent diesel and gas vehicle exhaust. 

Fugitive dust emissions from coal trains were estimated and are included in the total locomotive 

emissions, see Appendix C. 

Other sources are deemed insignificant, including outdoor burning, construction dust, aircraft emissions, 

wildfires, cigarette smoke, commercial charbroiling, and secondary particulate matter. Outdoor burning 

is prohibited in the three maintenance areas, so emissions would be minimal. Neither Ecology nor 

PSCAA have local information on emissions for construction dust, cigarette smoke, or commercial 

charbroiling, but is assumed to be minimal in these areas. Smoke from wildfires in Puget Sound is rare 

and was considered negligible. Some of these values are included in the 2011 NEI, however the 

emission estimates have large uncertainties because the data was collected nationally and was not 

developed specifically for local areas, or for sub-county regions like the Seattle, Tacoma, and Kent 

Maintenance Areas. 

41 
Maintenance Plan Inventory 

Emissions for these seven emission categories are shown in Table 5.2 below. Washington State's 2011 El 

is the most recent, complete, readily available emission inventory for King and Pierce County. 

Table 5.2: Seattle, Tacoma, and Kent Maintenance Area Annual and Winter Day PM1o 

Emissions 

Seattle Duwamish Tacoma Tideflats Kent 

<II > > IJ n:J n:J ... ... ~ "C Ill :::J n:J ... ... <II 0 <II ·;: ... > <II ... > <II ... > II) > > n:J ..... > n:J ..... > n:J 0 ~ t ........ ~ c:: ........ ~ c:: ........ ~ tl.O Ill ... '§: Ill ... '§: Ill ... <II 0 0 c:: <II c:: <II c:: <II ..... ..... c. 0 ..... ........ 0 ..... ........ 0 ..... n:J c:: <II ..... c:: Ill ..... c:: Ill ..... c:: u <II a:: '§: c:: '§: c:: '§: c:: > n:J 0 n:J 0 n:J 0 c:: c:: :::J ........ ..... :::J ........ ..... :::J ........ - 0 ·u; c:: Ill c:: Ill c:: Ill 

c:: ·u; c:: n:J c:: n:J c:: • !!! 0 Ill c:: 0 ..... c:: 0 ..... c:: 0 <( 0 <( 0 <( E ·u; ·e 1- ..... 1- ..... 1- w Ill 

·e w - - 0 0 

w '* '* 

On-road Mobile 2011 El 2011 100.8 0.29 12% 59.9 0.17 11% 21.7 0.06 

Port and Marine 2011 El 2011 122.2 0.33 14% 77.0 0.21 14% 0.0 0.00 

Locomotives 

(including fugitive 2011 El 2011 43.5 0.12 5% 13.4 0.04 2% 13.8 0.04 

dust) 

Residential Wood 

2011 El 2011 

Combustion 

17.0 0.13 5% 6.6 0.05 3% 34.8 0.26 

Paved Road Dust 2011 El 2011 190.1 0.53 22% 104.6 0.29 19% 40.9 0.11 

Unpaved Road Dust 2011 El 2011 133.6 0.65 27% 23.3 0.11 7% 28.7 0.14 

Industrial 

PSCAA, 

Ecology 

2011 127.3 0.35 15% 243.4 0.67 43% 0.5 0.00 

Total -- 2011 734.5 2.40 -- 140. 528.2 1.53 -- 0.61 

4 

42 

> 

n:J 

~ 

... 

<II 

..... 

c:: 

'§: 

........ Ill 

c:: 

0 

..... 

-

n:J 

..... 

0 

..... 

-

0 

'* 

10% 

0% 

6% 

42% 

18% 

23% 

0% 

--
6. Control Measures 

EPA analysis- the suite of control measures that brought the three areas into attainment 

continue to remain in place in accordance with the limited maintenance plan option memo. 

Additionally, due to efforts to address the more stringent PM2.5 standard, many of these 

control measures have strengthened over time, such as the residential wood combustion 

regulations and diesel programs. 

PSCAA and Ecology relied upon Reasonably Available Control Measures (RACM) for residential wood 

combustion and fugitive dust to return the three maintenance areas to compliance with the 1987 PM10 

standard. In addition to the RACM for wood smoke and fugitive dust, PSCAA and Ecology have 

enforceable and permanent control measures for industrial sources and outdoor burning. Improved 

federal standards for diesel emissions have also helped to control emissions. 

PSCAA and Ecology continue to implement the control measures included in the attainment plan and 

the first maintenance plan. 

Federal, PSCAA, and Ecology rules provide the legal authority to implement, maintain, and enforce the 

control measures in this plan. Control measures are listed below, with further explanation and 

references following: 

Wood Smoke Curtailment 

• Mandatory curtailment and enforcement program during impaired air quality (PSCAA Regulation 

1, Article 13.05) 

• Opacity limits (PSCAA Regulation 1, Article 13.03) 

• Fuel restrictions (PSCAA Regulation 1, Article 13.04) 

• Prohibition and sale of uncertified wood stoves (PSCAA Regulation 1, Article 13.07) 

• Allow woodstoves to be prohibited entirely as a SIP contingency measure (PSCAA Regulation 1, 

Article 13.07 (b)) 

• Certification of new woodstoves (PSCAA Regulation 1, Article 13.02) 

• Rules that govern the sale and transfer of uncertified stoves (PSCAA Regulation 1, Article 13.06) 

Fugitive Dust Control Measures 

• Prevent spillage and track out of dirt and mud on to public roadways (PSCAA Regulation 1, 

Article 9.15(a)(4)) 

• Improved industrial hygiene (PSCAA Regulation 1, Article 9.1S(a)) 

Industrial Source Program 

• Modifications of existing major sources 

• Boiler replacement 

• Facility Shutdown 

• Monitoring opacity of emissions (PSCAA Regulation 1, Article 9.04) 

• Emissions standards in PSCAA Regulation I- Article 9 and Chapter 173-400 WAC 

43 
• PSCAA Orders of Approval and Ecology Regulatory Orders for Simpson Tacoma Kraft 

Diesel Programs 

• Emissions have been reduced as a result of federal regulations on the sulfur content of diesel 

fuel and the particulate emissions of new vehicles. 

• Chapter 173-422A WAC requires heavy duty vehicles registered in Kent, Seattle, and Tacoma to 

pass a vehicle inspection and pass specific emissions standards. 

Outdoor Burning Restrictions 

• Land clearing is prohibited in King and Pierce Counties (PSCAA Regulation 1, Article 8.13) 

• Residential yard waste burning is prohibited in urban growth areas in King and Pierce Counties 

(PSCAA Regulation 1, Article 8.9 and 8.10) 

Emission Reduction Program.s 

The following programs are believed to be responsible for the region maintaining compliance with the 

ambient air quality standard. Where applicable, we have also included voluntary measures that reduce 

emissions under the appropriate category (explicitly noted voluntary). Unless noted voluntary, the 

emission reductions listed below are considered permanent and enforceable. 

Wood Smoke Curtailment 

PSCAA successfully implements the curtailment program in the Kent, Seattle, and Tacoma PM10 

maintenance areas. Mandatory curtailment and enforcement of solid fuel burning devices is outlined in 

PSCAA Regulation I, Article 13.05. When wood smoke pollution is forecasted to impair air quality, PSCAA 

restricts wood burning. When PSCAA calls burn bans for the area, wood stove use and outdoor burning 

are restricted or prohibited. Burn bans do not apply to homes without another source of adequate 

heat. 

PSCAA calls burn bans in two stages. A Stage 1 ban prohibits all uncertified wood heating devices when 

pollution approaches unhealthful levels. A Stage 2 ban prohibits all wood heating when pollution 

reaches a specified higher level. Unhealthful levels are defined as follows: a Stage 1 burn ban (First 

Stage of Impaired Air Quality) is declared when meteorological conditions are forecast to cause fine 

particulate levels to exceed 35 11g/m3 within 48 hours, when measured on a 24 hour average basis (or 

30ug/m3 within 72 hours in counties with a PM2.5 nonattainment area- this includes Pierce County). A 

Stage 2 burn ban (Second Stage of Impaired Air Quality) is declared when a first stage of impaired air 

quality has been in force and has not been sufficient to reduce the increasing fine particulate pollution 

trend. Under certain circumstances a Stage 2 ban may be declared without calling a Stage 1 ban first. 

Since Stage 1 and Stage 2 burn bans are designed to maintain the more stringent 2006 PM2.5 standard, 

PSCAA's burn ban rules are more protective of the PM10 standard than the state burn ban rules 

44 
supporting the attainment and first 10-year maintenance plan for Kent, Seattle, and Tacoma PM10 

maintenance areas. 

Fugitive Dust 

Spillage and track out of dirt and mud onto public roadways is regulated in section 9.15(a) of Regulation 

I in the PSCAA rules. The PSCAA fugitive dust program has been determined by EPA to meet the RACM 

requirements in CAA Section 189(a)(1)(C). The emission reductions from this program are considered 

both permanent and enforceable. 

Industrial Sources 

Reductions in actual and allowable emissions from industrial sources have occurred as a result of 

facilities permanently shutting down as well as new federal regulations for specific stationary sources. 

The National Emission Standards for Hazardous Air Pollutants (NESHAPS) are stationary source 

standards for hazardous air pollutants (40 CFR Part 61 and 40 CFR Part 63). Particulate matter is 

regulated in NESHAPs found in 40 CFR Part 63. Section 111 of the Clean Air Act authorized the EPA to 

develop technology based standards which apply to specific categories of stationary sources. These 

standards are referred to as New Source Performance Standards (NSPS) and are found in 40 CFR Part 60. 

The NSPS apply to new, modified and reconstructed affected facilities in specific source categories such 

as manufacturers of glass, cement, rubber tires and wool fiberglass.

8 The NSPS apply to industrial 

sources in the Tacoma and Seattle PM 10 maintenance areas. Emission standards contained in Article 9 of 

PSCAA Regulation I and Chapter 173-400 WAC as well as PSCAA Orders of Approval and the Ecology 

Regulatory Orders for Simpson Tacoma Kraft have been determined by EPA to be permanent and 

enforceable. 

Diesel Emissions 

National diesel fuel standards have significantly reduced sulfur content in diesel fuel since 1997. The 

diesel program regulations are located in 40 CFR Part 80 subpart I. A 15 parts per million (ppm) sulfur 

specification, known as Ultra Low Sulfur Diesel (ULSD), was phased in for highway diesel fuel from 2006-

2010. Diesel engines equipped with advanced emission control devices (general ly, 2007 and later model 

year engines and vehicles) must use highway ULSD fuel. Exhaust emissions from t hese engines will 

decrease by more than 90%.

9 Low sulfur (500 ppm) and Ultra Low Sulfur Diesel (ULSD) fuel wil l be 

phased in for non-road, locomotive, and marine (NRLM) engines from 2007-2014. These fuel 

requirements, coupled with advanced em ission control technologies, will decrease emissions from these 

engines by more than 90%.9 EPA adopted changes to the diesel fuel program to allow for t he production 

and sale of diesel fuel with up to 1,000 ppm sulfur for use in Category 3 marine vessels. The regulations 

generally forbid production and sale of fuels with more than 1,000 ppm sulfur for use in most U.S. 

waters, unless operators achieve equivalent em ission reductions in other ways9. 

8 New Source Performance Standa rds and State implementation Pla ns 

http://www.epa .gov/compliance/moni.toring/programs/caa/newsource.html 9 EPA Diesel Fuel Page http://epa.gov/otaq/fuels/dieselfuels/index.htm 

45 
In 2010, the International Maritime Organization designated specific portions of U.S. waters as an 

Emission Control Area (ECA). In our region, the ECA extends out to approximately 200 nautical miles 

west of the West Coast. The ECA became enforceable in August 2012, but the most stringent fuel sulfur 

reductions will come into effect in January 2015. 

The ECA will reduce the sulfur content in fuels from an average of about 2.7% sulfur to 0.1% sulfur by 

January 2015. This cleaner fuel will result in decreases in both sulfur oxides and PM 10 pollution in the 

Tacoma and Seattle Maintenance Areas. It should reduce emissions from ocean-going ships of sulfur 

oxides by approximately 95% and PM 10 pollution by approximately 60 to 80%. 

Voluntary diesel emissions reductions: 

Strategies for reducing diesel emissions in the Kent, Seattle, and Tacoma PM10 maintenance areas 

have been achieved through the PSCAA Diesel Solutions Program as well as the Northwest Ports 

Clean Air Strategy. These programs target emissions in four transportation sectors: off-road 

equipment, on-road vehicles, maritime vessels and equipment, and rail. 

Off-road: Off-road diesel emissions include construction equipment, aircraft-support equipment, 

and cargo handling equipment used at seaports and rail yards. Voluntary strategies to reduce 

diesel emissions in the off-road sector include cleaner fuels, retrofit technologies and vehicle 

replacement. Through the voluntary programs, cargo handling equipment has been retrofitted 

and replaced in the Seattle and the Tacoma PM10 maintenance areas. 

On-road and School Buses: Voluntary strategies to reduce diesel emissions from the on-road 

sector include cleaner fuels, retrofit technologies and vehicle replacements. Between 2003 and 

2008 PSCAA retrofitted school busses through the Puget Sound region with diesel oxidation 

catalysts and crankcase filters. As part of the Puget Sound Clean Cities Petroleum Reduction 

Project, waste hauling fleets are reimbursed for the cost difference between a conventional diesel 

truck and a natural gas or hydraulic-hybrid natural gas truc_k 

Ports: Since both The Port of Tacoma and The Port of Seattle fall within two of the maintenance 

areas, diesel reduction projects at the ports have contributed to reducing emissions. Public and 

private fleets in The Port of Seattle were replaced with new trucks and diesel oxidation catalysts 

as part of the Diesel Solutions Program between November 2009 and January 2011. Through the 

voluntary programs, cargo handling equipment has been retrofitted and replaced in both the 

Seattle and the Tacoma PM10 maintenance areas. As part of the Puget Sound Clean Cities 

Petroleum Reduction Project, waste hauling fleets are reimbursed for the cost difference between 

a conventional diesel truck and a natural gas or hydraulic-hybrid natural gas truck. 

46 
Outdoor burning . 

While not considered a significant contributor to high PM 10 concentrations on stagnant winter days, 

outdoor burning of land clearing debris and yard waste has potential for causing violations of the PM 10 

standard. In 2000 and 2008 Article 8 of Regulation I was amended to prohibit residential yard burning in 

the King and Pierce County urban growth areas as well as the former ca rbon monoxide non-attainment 

area (Seattle/Tacoma/Everett urban areas, as defined by the Washington State Department of 

Transportation, 1983 version, urban area maps). Article 13 of Regulation 1 prohibits land clearing 

burning completely in King and Pierce counties. PSCAA continues to encourage development of 

alternatives to outdoor burning such as chipping, composting and yard waste collection programs. 

Control Measures in PSCAA Rules 

Washington State's Clean Air Act grants the authority for and outlines the conditions under which PSCAA 

may adopt its own rules. PSCAA has jurisdiction over the Kent, Seattle, and Tacoma PM 10 maintenance 

areas and relies upon its rules to maintain and enforce the PM10 standard. 

The PSCAA rules as listed in Table 6.1, Table 6.2, and Table 6.3 are included in the federally approved 

SIP. 

Table 6.1: PSCAA Regulation I -Article 8: Outdoor Burning 

Regulation I -Article 8: Outdoor Burning State Adoption EPA Effective 

Date 

8.04 General Cond itions for Outdoor Burning 11/9/2000 9/30/2004 

8.05 Agricultural Burning Permits 11/9/2000 9/30/2004 

8.06 Outdoor Burning Ozone Contingency Measure 12/19/2002 9/7/2004 

8.09 Description of the King County No-Burn Area 11/9/2000 9/30/2004 

8.10 Description of the Pierce County No-Burn Area 11/9/2000 9/30/2004 

8.11 Description of the Snohomish County No-Burn Area 11/9/2000 9/30/2004 

8.12 Description of the Kitsap County No-Burn Area 10/24/2002 9/30/2004 

Table 6.2: PSCAA Regulation I- Article 9: Emission Standards 

Regulation I -Article 9: Emission Standards State Adoption EPA Effective 

Date 

9.03 Emission of Air Contaminant: Visual Standard 3/11/1999 9/30/2004 

9.04 Opacity Standard for Equipment with Continuous Opacity 4/9/1998 9/30/2004 

Monitoring Systems 

9.05 Refuse Burning 12/9/1993 6/29/1995 

9.08 Fuel Oil Standards 4/14/1994 6/29/1995 

9.09 Particulate Matter Emission Standards · 4/9/1998 9/30/2004 

9.15 Fugitive Dust Control Measures 3/11/1999 9/30/2004 

9.16 Spray-Coating Operations 7/12/2001 9/30/2004 

9.20 Maintenance of Equipment 6/9/1988 10/28/1994 

47 
Table 6.3: PSCAA Regulation I- Article 13: Solid Fuel Burning Device Standards 

Regulation I -Article 13: Solid Fuel Burning Device Standards State Adoption EPA Effective 

Date 

13.03 Opacity Standards 10/25/2012 6/28/2013 

13.04 Allowed and Prohibited Fuel Types 10/ 25/2012 6/ 28/2013 

13.05 Restrictions on Operation of Solid Fuel Burning Devices 10/25/2012 6/28/2013 

13.06 Emission Performance Standards 10/25/2012 6/28/2013 

13.07 Prohibitions on Wood Stoves that are not Certified 10/25/2012 6/28/2013 

Wood Stoves 

48 
7. Contingency Measures 

EPA analysis-- PSCAA's Regulation 1-Article 13.07 (b) remains in place and is part of the 

approved, federally enforceable SIP codified in 40 CFR 52, Subpart WW. 

CAA Section 175(A) requires a maintenance plan include contingency measures necessary to ensure 

prompt correction of any violation of the standard that may occur after redesignation. PSCAA's 

Regulation 1- Article 13.07 (b) provides for prohibition of the use of uncertified woodstoves for the sole 

purpose of meeting CAA requirements for contingency measures. To implement this provision, the rule 

requires that the EPA, in consultation with Ecology and PSCAA, must make written findings that: 

(1) The area has failed to maintain a national ambient air quality standard 

(2) Emissions from solid fuel burning devices from a particular geographic area are a contributing 

factor to such failure to make reasonable further progress or attain or maintain a national ambient air 

quality standard 

Contingency Measure Trigger 

The contingency measure will be triggered if a violation of the PM10 standard occurs at the maintenance 

area monitor based on nephelometer and/or FRM monitoring. A violation of the PM10 standard will be 

determined by the procedures outlined in 40 CFR Part 50. 

49 
8. Commitment to Continued Monitoring and Verification of Continued 

Attainment 

EPA analysis- this section is consistent with the previously approved Thurston County PM10 

plan. 

Emissions in the Kent, Seattle, and Tacoma PM10 maintenance areas are not expected to grow to 

threaten compliance with the standard as discussed in Section 3 of this plan. 

PSCAA makes a commitment to continue operation of PM2.5 monitors in the Kent, Seattle, and Tacoma 

PM 10 maintenance areas through 2020, the end of the maintenance period. The PM2.

5 measurements 

will be used to calculate PM10 levels in the maintenance areas. In the unlikely event that after 

exceptional events are taken into account (using EPA guidance), the calculated design value for PM10 

exceeds the LMP threshold of 98!1g/m3

, PSCAA will reestablish PM10 monitoring as part of the annual 

network monitoring report process. PM10 concentrations calculated from the PM 10 model described in 

section 4.3 are available from PSCAA and can be provided to EPA and the public on request. The PM2.

5 

monitored concentrations used to calculate the PM10 concentrations are available from the PSCAA 

website, www.pscleanair.org. Both 3-year and 5-year design values will be provided annually to Ecology 

for the annual monitoring network report. The network review is available at 

https ://fortress. wa .gov I ecy/p u bl icatio ns/U I Pages/Home .a spx 

PSCAA will calculate 3-year and 5-year PM10 design value estimates annually for the Kent, Seattle, and 

Tacoma maintenance areas through 2020 to confirm the areas continue to meet the PM10 NAAQS. A 3-

year PM 10 design value estimate of or below 150 11g/m3 demonstrates continued compliance with the 

PM10 NAAQS. Ecology will include a statement in the annual network report to inform EPA of continued 

attainment for the Kent, Seattle, and Tacoma PM10 maintenance areas based on calculated PM10 values. 

50 
9. Summary of Maintenance Plan Commitments 

EPA analysis- this section details work sharing between Ecology and PSCAA. In the unlikely 

event PSCAA cannot fulfill the obligations below, Ecology as the Governor's designee will be 

responsible for fulfilling these commitments. 

Commitments made in this maintenance plan are summarized in Table 9.1. 

Table 9.1: Second 10-Year LMP Commitments 

Section Commitment Responsible 

Agency 

3 Annual calculation ofthe Kent, Seattle, and Tacoma PM10 5-year PSCAA 

design values through 2020 to show continued qualification for 

the LMP option. 

3 Reporting to EPA on continued qualification for the LMP option in Ecology 

the annual monitoring network report 

7 Implementation of the contingency measure if the Kent, Seattle, PSCAA 

or Tacoma maintenance area violates the PM 10 standard based on 

PM 2.s monitoring 

8 Continued monitoring of PM 2.5 in the Kent, Seattle, and Tacoma PSCAA 

maintenance areas through 2020 

9 Annual calculation of the 3-year PM 10 design values for the Kent, PSCAA 

Seattle, and Tacoma maintenance areas through 2020 to assess 

compliance with the PM 10 standard 

9 Reporting to EPA on continued PM 10 attainment in the annual Ecology 

monitoring network report 

The PM10 attainment plan for Kent was fully approved by EPA on July 27, 1993 {58 FR 40059) and the 

plans for Tacoma and Seattle were fully approved by EPA on October 25, 1995 and October 26, 1995, 

respectively {60 FR 54599 and 60 FR 54812). EPA approved the first 10-year maintenance plan on March 

13, 2001 {66 FR 14492). This plan ensures compliance through 2020 and fulfills the final requirement for 

maintenance plans specified by the CAA. 

51 

Attachment B -- the following sample proposed Federal Register notice is intended to identify 

key issues in review of PSCAA I Ecology's draft. Upon receipt of a final SIP revision, the EPA 

will review any changes to the SIP submittal as a result of local and state public comment 

processes or any relevant EPA policy changes to adapt this sample proposed Federal Register 

notice as appropriate. 

6560-50-P 

ENVIRONMENTAL PROTECTION AGENCY 

40 CFR Part 52 

[Docket#: EPA-R10-0AR-2013-0713; FRLApproval and Promulgation of Implementation Plans; \Vashington: Kent, Seattle, and 

Tacoma Second 10-Year PM10 Limited Maintenance Plan 

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: The EPA is proposing to approve a limited maintenance plan submitted by the 

State of Washington on XXXX, 2013, for the Kent, Seattle, and Tacoma maintenance areas for 

particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers 

(PM10). A limited maintenance plan is used to meet Clean Air Act requirements for formerly 

designated nonattainrnent areas with little risk of violating the PM10 National Ambient Air 

Quality Standard (PM10 NAAQS) again. All three areas currently have monitored PM10 levels 

that are roughly one-third of the PM10 NAAQS, with steady declines in PM10 levels since the 

areas were first identified as potentially violating the PM10 NAAQS in 1987. 

DATES: Comments must be received on or before [INSERT DATE 30 DAYS FROM THE 

DATE OF PUBLICATION IN THE FEDERAL REGISTER]. 
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-RlO-OAR-2013-0713, 

by any of the following methods: 

A. www.regulations.gov: Follow the on-line instructions for submitting comments. 

B. Mail: JeffHunt, EPA Region 10, Office of Air, Waste and Toxics (AWT-107), 1200 

Sixth Avenue, Suite 900, Seattle W A, 98101 

C. E-mail: RIO-Public Comments@.epa.gov 

D. Hand Delivery: EPA Region 10 Mailroom, 9th Floor, 1200 Sixth Avenue, Suite 900, 

Seattle WA, 98101. Attention: JeffHunt, Office of Air, Waste and Toxics, AWT1 07. Such deliveries are only accepted during normal hours of operation, and special 

arrangements should be made for deliveries of boxed information 

Instructions: Direct your comments to Docket ID No. EPA-RlO-OAR-2013-0713. The EPA's 

policy is that all comments received will be included in the public docket without change and 

may be made available online at www.regulations.gov, including any personal information 

provided, unless the comment includes information claimed to be Confidential Business 

Information (CBI) or other information the disclosure of which is restricted by statute. Do not 

submit information that you consider to be CBI or otherwise protected through 

www.regulations.gov or e-mail. The www.regulations.gov website is an "anonymous access" 

system, which means the EPA will not know your identity or contact information unless you 

provide it in the body of your comment. If you send an e-mail comment directly to the EPA 

without going through www.regulations.gov your e-mail address will be automatically captured 

and included as part of the comment that is placed in the public docket and made available on the 

Intemet. If you submit an electronic comment, the EPA recommends that you include your 

2 
name and other contact information in the body of your comment and with any disk or CD-ROM 

you submit. If the EPA cannot read your comment due to technical difficulties and cmmot 

contact you for clarification, the EPA may not be able to consider your comment. Electronic 

files should avoid the use of special characters, any fonn of encryption, and be free of any 

defects or viruses. 

Docket: All documents in the electronic docket are listed in the www.regulations.gov index. 

Although listed in the index, some information is not publicly available, i.e., CBI or other 

infonnation the disclosure of which is restricted by statute. Certain other material, such as 

copyrighted material, is not placed on the Internet and will be publicly available only in hard 

copy form. Publicly available docket materials are available either electronically in 

www.re2:ulations.gov or in hard copy during normal business hours at the Office of Air, Waste 

and Toxics, EPA Region 10, 1200 Sixth A venue, Seattle W A, 98101. 

FOR FURTHER INFORMATION CONTACT: Jeff Hunt at (206) 553-0256, 

hunt.jeft@epa.gov, or by using the above EPA, Region 10 address. 

SUPPLEMENTARY INFORMATION: Throughout this document wherever "we", ''us" or 

"our" are used, it is intended to refer to the EPA. 

Table of Contents 

I. This Action 

II. Background 

III. Public and Stakeholder Involvement in Rulemaking Process 

IV. The Limited Maintenance Plan Option for PM10 Areas 

A. Requirements for the Limited Maintenance Plan Option 

B. Conformity under the Limited Maintenance Plan Option 

V. Review ofthe State's Submittal 

A. Has the State Demonstrated that the Maintenance Areas Qualify for the Limited 

Maintenance Plan Option? 

B. Does the State Have an Approved Attaimnent Emissions Inventory? 

C. Does the Limited Maintenance Plan Include an Assurance of Continued Operation of 

3 
an Appropriate EPA-Approved Air Quality Monitoring Network, in Accordance with 

40 CFR Part 58? 

D. Does the Plan Meet the Clean Air Act Requirements for Contingency Provisions? 

E. Has the State Met Conformity Requirements? 

VI. Proposed Action 

VII. Statutory and Executive Order Reviews 

I. This Action 

The EPA is proposing to approve the limited maintenance plan submitted by the State of 

Washington (Washington or the State) on XXXX, 2013, for the Kent, Seattle, and Tacoma PM10 

maintenance areas, including approval of a monitoring system modification for the area. If 

finalized, the EPA's approval of this limited maintenance plan will satisfy the section 175A 

Clean Air Act requirements for all three areas, including the portion of the Puyallup Indian 

Reservation that falls within the Tacoma PM10 maintenance area. 

II. Background 

On August 7, 1987, the EPA identified portions of Kent, Seattle, and Tacoma as "Group 

I" areas of concern for having a greater than 95% probability of violating the 24-hour PM 10 

NAAQS (52 FR 29383). On November 15, 1990, the Group I areas of Kent, Seattle, and 

Tacoma were designated as nonattainment for PM 10 by operation of law upon enactment of the 

Clean Air Act Amendments. The Washington Department of Ecology (Ecology) and the Puget 

Sound Clean Air Agency (PSCAA) worked with the communities to establish PM10 pollution 

control strategies. Primary control strategies for the three areas included a residential wood 

·smoke control program, a fugitive dust program, a prohibition on open burning, and industrial 

emission controls. These control measures were highly successful with monitoring data showing 

Kent, Seattle, and Tacoma meeting the PM10 NAAQS since 1987, 1990, and 1989, respectively, 

with continuing declines in PM10 levels ever since. 

4 
The EPA fully approved the PM10 attainment plans for Kent, Seattle, and Tacoma on July 

27, 1993, October 26, 1995, and October 25, 1995, respectively (58 FR 40059,60 FR 54812, and 

60 FR 54599). The EPA then approved a 1 0-year maintenance plan redesignating all three areas 

from nonattainment to attainment, making them maintenance areas effective May 14, 2001 (66 

FR 14492, published March 13, 2001). The purpose of the current limited maintenance plan is to 

fulfill the second 10-year planning requirement, section 175A (b) of the Clean Air Act, to ensure 

compliance through 2020. 

III. Public and Stakeholder Involvement in Rulemaking Process 

Section 110(a)(2) ofthe Clean Air Act requires that each State Implementation Plan (SIP) 

revision offer a reasonable opportunity for notice and public hearing. The State provided notice 

and an opportunity for public comment beginning September 27, 2013, and ending November 4, 

2013. Under the requirements of 40 CFR 51.102(a), the State held a public hearing at 6:30pm 

on October 30, 2013 in the Mill Creek Room of the Kent Commons, 525 Fourth Avenue N, 

Kent, Washington. No comments were received. (confinn) This SIP revision was submitted by 

the Governor's designee and was received by the EPA on XXX .. '(, 2013. The EPA evaluated 

Ecology's submittal and detennined that the State met the requirements for reasonable notice and 

public hearing under section 11 0( a)(2). 

IV. The Limited Maintenance Plan Option for PM10 Areas 

A. Requirements for the Limited Maintenance Plan Option 

On August 9, 2001 , the EPA issued guidance on streamlined maintenance plan provisions 

for certain moderate PM10 nonattainment areas. See memo from Lydia Wegman, Director, Air 

Quality Standards and Strategies Division, entitled "Limited Maintenance Plan Option for 

5 
Moderate PM10 Nonattainment Areas" (limited maintenance plan option memo). The limited 

maintenance plan option memo contains a statistical demonstration that areas meeting certain air 

quality criteria will, with a high degree of probability, maintain the standard ten years into the 

future. Thus, the EPA provided the maintenance demonstration for areas meeting the criteria 

outlined in the memo. It follows that future year emission inventories for these areas, and some 

of the standard analyses to determine transportation conformity with the SIP, are no longer 

necessary. 

To qualify for the limited maintenance plan option the State must demonstrate the area 

meets the criteria described below. First, the area should have attained the PM10 NAAQS. 

Second, the most recent five years of air quality data at all monitors in tpe area, called the 24-

hour average design value, should be at or below 98 11g/m3

. Third, the State should expect only 

limited growth in on-road motor vehicle PM10 emissions (including fugitive dust) and should 

have passed a motor vehicle regional emissions analysis test. Lastly, the memo identifies core 

provisions that must be included in all limited maintenance plans. These provisions include an 

attainment year emissions inventory, assurance of continued operation of an EPA-approved air 

quality monitoring network, and contingency provisions. 

B. Conformity under the Limited Maintenance Plan Option 

The transportation conformity rule and the general conformity rule ( 40 CFR parts 51 and 

93) apply to nonattainment areas and maintenance areas covered by an approved maintenance 

plan. Under either conformity rule, an acceptable method of demonstrating a Federal action 

confonns to the applicable SIP is to demonstrate that expected emissions from the planned action 

are consistent with the emissions budget for the area. 

6 
While qualification for the limited maintenance plan option does not exempt an area from 

the need to affirm conformity, conformity may be demonstrated without submitting an emissions 

budget. Under the limited maintenance plan option, emissions budgets are treated as essentially 

not constraining for the length of the maintenance period because it is unreasonable to expect 

that the qualifying areas would experience so much growth in that period that a violation of the 

PM1o NAAQS would result. For transportation conformity purposes, the EPA would conclude 

that emissions in these areas need not be capped for the maintenance period and therefore a 

regional emissions analysis would not be required. Similarly, Federal actions subject to the 

general conformity rule could be considered to satisfy the "budget test" specified in 40 CFR 

93.158 (a)(S)(i)(A) for the same reasons that the budgets are essentially considered to be 

unlimited. 

V. Review of the State's Submittal 

A. Has the State Demonstrated that the Maintenance Areas Qualify for the Limited 

Maintenance Plan Option? 

As discussed above, the limited maintenance plan option memo outlines the requirements 

for an area to qualify. First, the area should be attaining the PM10 NAAQS. Monitoring data 

shows that all three areas attained the PM1o AAQS by 1990, with declining levels ofPM, oever 

since. The EPA formally redesignated the areas from nonattaimnent to attaimnent, making them 

maintenance areas effective May 14, 2001 (66 FR 14492, published March 13, 2001). 

Second, the average design value for the past five years of monitoring data must be at or 

below the critical design value of98 ~L g/ 3 for the 24-hour PM10 NAAQS. The critical design 

value is a margin of safety in which an area has a one in ten probability of exceeding the 

7 
NAAQS. The design values for Kent, Seattle, and Tacoma based on 24-hour PM10 monitoring 

data from 2003 through 2007 are 57±3 Jlgl m3

, 68±4 ~Lg , and 72±9 ~tg . As discussed later 

in this proposal, in these three areas PM 10 levels can be estimated with a high degree of accuracy 

using fine particulate matter (PM2.5) concentrations. In 2007, the EPA approved the State's 

request to shift from PM10 specific monitoring in Kent, Seattle, and Tacoma to rely on the more 

stringent and environmentally relevant PM2.5 NAAQS monitoring effort. PM 10 design values 

estimated using PM2.s concentration levels from 2008 to 2012 are 46±3 Jlgl m3

, 50±5 Jlglm3, and 

58±8 ~tg , respectively. The EPA reviewed the data and methodology provided by the State 

and finds that all three areas meet the design value criteria of98 Jlg/m3 outlined in the limited 

maintenance plan option memo. 

Third, the area must meet the motor vehicle regional emissions analysis test described in 

Attachment B of the limited maintenance plan option memo. The State submitted an analysis 

showing that growth in on-road mobile PM10 emissions sources was minimal and would not 

threaten the assumption of maintenance that underlies the limited maintenance plan policy. 

Using the EPA's methodology, the State calculated total growth in on-road motor vehicle PM10 

emissions over the ten-year period for Kent, Seattle, and Tacoma of 1.5 Jlg/m3

, 2. 7 Jlg/m3

, and 

2.9 Jlg/m3

, respectively. This calculation is derived using Attachment B of the EPA's limited 

maintenance plan memo, where the projected percentage increase in vehicle miles traveled over 

the next ten years (VMTpi) is multipled by the on-road mobile portion of the attainment year 

inventory (DYmv), including both primary and secondary PM10 emissions andre-entrained road 

dust. The EPA reviewed the calculations in the State's limited maintenance plan submittal and 

concurs with the determination that all three areas meet the motor vehicle regional emissions 

8 
analysis test. This test is met when (VMT pi x DYmv) plus the design value for the most recent 

five years of quality assured data is below the limited maintenance plan threshold of 98 11g/m3. 

The results for Kent, Seattle, and Tacoma were 61.5 11g/m3

, 7 4. 7 11g/m3

, and 83.9 11g!m3

, 

respectively. Please see Appendix A of the State's submission for the full analysis. 

Lastly, the limited maintenance plan option memo requires all controls relied on to 

demonstrate attainment remain in place for the areas to qualify. The EPA confirmed that the 

underlying control measures for Kent, Seattle, and Tacoma remain in place, thus qualifying for 

the limited maintenance plan option. 

As described above, the Kent, Seattle, and Tacoma maintenance areas meet the 

qualification criteria set forth in the limited maintenance plan option memo. Under the limited 

maintenance plan option, the State will be expected to determine on an annual basis that the 

criteria are still being met. If the State determines that the limited maintenance plan criteria are 

not being met, it should take action to reduce PM10 concentrations enough to requalify. One 

possible approach the State could take is to implement contingency measures. Section V. I. 

provides a description of contingency provisions submitted as part of the limited maintenance 

plan submittal. To ensure this requirement is met, the State commits to reporting to the EPA on 

continued qualification for the limited maintenance plan option in the annual monitoring network 

report. 

B. Does the State Have an Approved Attainment Emissions Inventory? 

Pursuant to the limited maintenance plan option memo, the State's submission should 

include an emissions inventory which can be used to demonstrate attainment of the NAAQS. 

The inventory should represent emissions during the same five-year period associated with air 

9 
quality data used to determine whether the area meets the applicability requirements of the 

limited maintenance plan option. 

The limited maintenance plan submittal includes an emissions inventory based on the 

State's draft 2011 Triermial Emissions Inventory. This inventory is prepared as part of the 2011 

National Emissions Inventory under the EPA's Air Emissions Reporting Rule (73 FR 76539, 

December 17, 2008). The information was supplemented with annual 2011 industrial emissions 

reported to PSCAA and Ecology. The 2011 base years represent the most recent emissions 

inventory data available and is consistent with the data used to detennine applicability of the 

limited maintenance plan option (i.e., having no violations of the PM10 NAAQS). The emissions 

inventory focused on seven significant source categories chosen based on a review of the original 

maintenance plan. The 2011 emission categories are shown along with source categories from 

the original maintenance plan in parentheses. These categories are: on-road mobile (gasoline 

exhaust); port and marine, on-road mobile (diesel exhaust); port and marine (ships); locomotives, 

including fugitive dust (locomotives); residential wood combustion (wood burning); paved road 

dust, unpaved road dust (road dust); and industrial (allowable industrial). Other source 

categories, including outdoor burning, construction dust, aircraft emissions, wild±ires, cigarette 

smoke, commercial charbroiling, and secondary particulate matter, are insignificant. The EPA 

reviewed and is proposing to approve the emissions inventory and methodology. The emissions 

inventory data supporis the State's conclusion that the existing control measures in place will 

continue to protect and maintain the PM 10 NAAQS. 

C. Does the Limited Maintenance Plan Include an Assurance of Continued 

Operation of an Appropriate EPA-Approved Air Quality Monitoring Network, in 

10 
Accordance with 40 CFR Part 58? 

PM10 monitoring was established in the Kent, Seattle, and Tacoma areas between 1985 

and 1987, with many changes to the monitoring technology and requirements since. Beginning 

in 1999, the State collocated PM2.5 monitors with the existing PM10 Federal Equivalent Method 

(FEM) monitors to establish correlation data and confirm that PM10 levels could be accurately 

predicted using PM:u concentrations for the areas. Due to the high level of correlation between 

the PM2.5 and PM10 monitors, the State requested discontinuing the PM10 specific monitors as 

part of the 2007 ammal network monitoring report under 40 CFR part 58. The EPA approved 

this request in a letter dated November 16, 2007, included in the docket for this action. 

A full description of the correlation data and the estimation model is included in the 

limited maintenance plan· submittal. The EPA is proposing to approve this monitoring system 

modification, using PM2.5 monitoring data to estimate PM 10 concentrations, under 40 CFR I 

58.14(c) for the second 1 0-year maintenance plan period. This estimation method is a 

reproducible approach to representing air quality in all three maintenance areas, and all three 

areas continue to meet the applicable Appendix D requirements evaluated as part of the annual 

network approval process. As detailed in the limited maintenance plan, the State will calculate 

the PM10 design value estimate annually from PM2.5 monitoring data through 2020 to confirm the 

area continues to meet the PM10 NAAQS. The State also makes a commitment to continue 

operation of PM2.

5 monitoring in the three maintenance areas through the 2020, the end of the 

maintenance period, to detennine PM10 levels. In the unlikely event that after exceptional events 

are taken into account, the calculated design value for PM10 exceeds the limited maintenance 

plan threshold of98 )..lg/m3

, the State will re-establish PM10 monitoring. 

11 
D. Does the Plan Meet the Clean Air Act Requirements for Contingency 

Provisions? 

Clean Air Act section 175A states that a maintenance plan must include contingency 

provisions, as necessary, to ensure prompt correction of any violation of the NAAQS which may 

occur after redesignation of the area to attaim11ent. Puget Sound Clean Air Agency's Regulation 

I- Article 13.07 (b) provides for prohibition of the use of uncertified woodstoves for the sole 

purpose of meeting Clean Air Act requirements for contingency measures. The EPA approved 

Article 13.07 (b) as a contingency measure for all three areas on March 13, 2001 (66 FR 14492). 

Regulation I- Article 13.07 (b) remains in effect today and the entire Article 13 was re-approved 

by the EPA on May 29,2013 (78 FR 32131). 

E. Has the State Met Conformity Requirements? 

(1) Transportation Confonnity 

Under the limited maintenance plan option, emissions budgets are treated as essentially 

not constraining for the maintenance period because it is unreasonable to expect that qualifying 

areas would experience so much growth in that period that a NAAQS violation would result. 

While areas with maintenance plans approved under the limited maintenance plan option are not 

subject to the budget test, the areas remain subject to the other transportation confonnity 

requirements of 40 CFR part 93, subpart A. Thus, the metropolitan planning organization (MPO) 

in the area or the State must document and ensure that: 

(a) transportation plans and projects provide for timely implementation of SIP transportation 

control measures (TCMs) in accordance with 40 CFR 93 .113 ; 

(b) transportation plans and projects comply with the fiscal constraint element as set forth in 40 

12 
CFR 93.108; 

(c) the MPO's interagency consultation procedures meet the applicable requirements of 40 CFR 

93.105; 

(d) conformity of transportation plans is determined no less frequently than every four years, 

and conformity of plan amendments and transportation projects is demonstrated in accordance 

wit~ the timing requirements specified in 40 CFR 93.1 04; 

(e) the latest planning assumptions and emissions model are used as set forth in 40 CFR 93 .110 

and 40 CFR 93.111; 

(f) projects do not cause or contribute to any new localized carbon monoxide or particulate 

matter violations, in accordance with procedures specified in 40 CFR 93.123; and 

(g) project sponsors and/or operators provide written commitments as specified in 40 CFR 

93.125. 

Upon approval of the limited maintenance plan for the Kent, Seattle, and Tacoma areas, 

the three PM10 maintenance areas are exempt from perfonning a regional emissions analysis, but 

must meet project-level confonnity analyses as well as the transportation conformity criteria 

mentioned above. 

(2) General Confonnity 

For Federal actions required to address the specific requirements of the general 

confonnity rule, one set of requirements applies particularly to ensuring that emissions from the 

action will not cause or contribute to new violations of the NAAQS, exacerbate current 

violations, or delay timely attaimnent. One way that this requirement can be met is to 

demonstrate that "the total of direct and indirect emissions from the action (or portion thereof) is 

13 
determined and documented by the state agency primarily responsible for the applicable SIP to 

result in a level of emissions which, together with all other emissions in the nonattaimnent area, 

would not exceed the emissions budgets specified in the applicable SIP" (40 CFR 

93.l58(a)(5)(i)(A)). 

The decision about whether to include specific allocations of allowable emissions 

increases to sources is one made by the state air quality agencies. These emissions budgets are 

different than those used in transportation confonnity. Emissions budgets in transportation 

conformity are required to limit and restrain emissions. Emissions budgets in general conformity 

allow increases in emissions up to specified levels. The State has not chosen to include specific 

emissions allocations for Federal projects that would be subject to the provisions of general 

confonnity. 

VI. Proposed Action 

The EPA is proposing to approve the limited maintenance plan submitted by the State of 

Washington on XXXX, 2013, for the Kent, Seattle, and Tacoma PM10 maintenance areas, 

including approval of a monitoring system modification for the area. If finalized, the EPA's 

approval of this limited maintenance plan will satisfy the section 175A Clean Air Act 

requirements for all three areas, including the portion of the Puyallup Indian Reservation that 

falls within the Tacoma PM10 maintenance area. 

VII. Statutory and Executive Order Reviews 

Under the Clean Air Act, the Administrator is required to approve a SIP submission that 

complies with the provisions of the Act and applicable Federal regulations. 42 U.S.C. 741 O(k); 

40 CFR 52.02(a). Thus, in reviewing SIP submissions, the EPA's role is to approve state 

14 
choices, provided that they meet the criteria of the Clean Air Act. Accordingly, this action 

merely approves state law as meeting Federal requirements and does not impose additional 

requirements beyond those imposed by state law. For that reason, this action: 

• is not a "significant regulatory action" subject to review by the Office of Management 

and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993); 

• does not impose an infonnation collection burden under the provisions of the Paperwork 

Reduction Act (44 U.S.C. 3501 et seq.); 

• is certified as not having a significant economic impact on a substantial number of small 

entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.); 

• does not contain any unfunded mandate or significantly or uniquely affect small 

governments, as described in the Unfunded Mandates Reform Act of 1995 (Public Law 

104-4); 

• does not have Federalism implications as specified in Executive Order 13132 (64 FR 

43255, August 10, 1999); 

• is not an economically significant regulatory action based on health or safety risks subject 

to Executive Order 13045 (62 FR 19885, April23 , 1997); 

• is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, 

May 22, 2001); 

• is not subject to the requirements of Section 12(d) of the National Technology Transfer 

and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those 

requirements would be inconsistent with the Clean Air Act; and 

15 
• does not provide the EPA with the discretionary authority to address, as appropriate, 

disproportionate human health or environmental effects, using practicable and legally 

permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994). 

In addition, this rule does not have tribal implications as specified by Executive Order 

13175 (65 FR 67249, November 9, 2000), because it will not impose substantial direct costs on 

tribal governments or preempt tribal law. The SIP is not approved to apply in Indian country 

located in the State, except for non-trust land within the exterior boundaries of the Puyallup 

Indian Reservation, also known as the 1873 Survey Area. Under the Puyallup Tribe of Indians 

Settlement Act of 1989, 25 U.S.C. 1773, Congress explicitly provided state and local agencies in 

Washington authority over activities on non-trust lands within the 1873 Survey Area and the 

EPA is therefore approving this SIP on such lands. Consistent with EPA policy, the EPA 

nonetheless provided a consultation opportunity to the Puyallup Tribe in a letter dated October 

18, 2013. The EPA did not receive a request for consultation {Confitmj . 

16 
List of Subjects in 40 CFR Part 52 

Environmental protection, Air pollution control, Particulate matter, and Reporting and 

recordkeeping requirements. 

Authority: 42 U.S.C. 7401 et seq. 

Dated: -------

17 

Dennis J. McLerran 

Regional Administrator 

Region 10