UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 10 

1200 Sixth Avenue, Suite 900 

Seaitle, WA 98101-3140 

Stu Clark 

Washington State Department of Ecology 

P. 0. Box 47600 

Olympia, Washington 98504-7600 

Craig Kenworthy 

1904 Third A venue, Suite 105 

Seattle, Washington 9810 

Dear Mr. Clark and Mr. Kenworthy: 

OFFICE OF 

AIR, WASTE AND TOXICS 

Thank you for the opportunity to work so closely with your staff on the technical development of 

the Tacoma-Pierce County Nonattainment Area Emission Inventory. Based on our pre-submittal 

review, we believe the version provided to us on September 10, 2012 would satisfy the emission 

inventory requirements of 40 CFR 51.1008 assuming there are no substantive changes to the 

final version or issues that arise during the state public comment period. The EPA will make a 

final decision based on its 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 

EPA's public process. 

If you have any questions please feel free to contact me at 206-553-1847 or have your staff 

contact either, Debra Suzuki, State and Tribal Air Programs Unit Manager, at 206-553-0985 or 

Jeff Hunt, PM2.5 staff lead, at 206-553-0256. 

Sincerely, 

R chard Albright, Director 

Ollice of Air, Waste, and Taxies 

Q P~lnted o~ Recycled Paper_ 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 10 

1200 Sixth Avenue, Suite 900 

Seattle, WA 98101-3140 

OFFICE OF 

ENVIRONMENTAL ASSESSMENT 

MEMORANDUM 

SUBJECT: 

FROM: 

TO: 

Review of Draft Tacoma-Pierce County PM25 Nonattainment Area Emission 

Inventory 

Robert Kotchenruther, E.;!ii.,~~Z~~~ U~["Pfcol(. 

Jeff Hunt, Tacoma-Pierce County Nonattainment Area PM25 Lead 

State and Tribal Air Programs Unit 

I reviewed the draft Appendix A: Tacoma-Pierce County Nonattainment Area Emission 

Inventory Documentation that Ecology provided to EPA on September 10, 2012. I believe this 

draft would satisfy the emission inventory requirements of 40 CFR 51.1008 assuming there are 

no substantive changes to the final version or issues that arise during the state public comment 

period. Highlights of the draft include: 

• Non-point Sources: according to the emissions inventory, residential wood smoke 

combustion accounts for 74% of the total fine particle winter clay emissions. This 

information supports Washington Department of Ecology and Puget Sound Clean Air 

Agency's general control measure strategy of improving enforcement of burn bans and 

removing uncertified solid fuel devices. 

• Point Somces: for nonattainment areas, the federal regulations define point sources as 

any stationary source having the potential to emit 100 tons per year of a criteria pollutant. 

These sources require Air Operating (Title V) Permits. There are 9 Title V sources in 

Pierce County. These sources account for 2% of winter clay fine particulate emissions. 

• Mobile Sources: onroad and nonroad sources account for 9% and 5% of winter clay fine 

particulate emissions, respectively. Onroad mobile source emissions come from exhaust, 

evaporation, and brake and tire wear and were calculated using EPA's MOVES model. 

Nonroad mobile sources include all off-road vehicles and equipment and include 

locomotives and marine vessels. Due to fleet turnover, on-going clean diesel projects, 

and reduced sulfur content of shipping fuel, EPA expects mobile source emissions to 

remain generally low or diminish over time as a percentage of overall wintertime 

emissions.