UNITED STATES ENV I RONMENTAL PROTECTION AGE N C Y WASHINGTON, D.C. 20460

The H onorab le J eremi ah W. (Jay) Nixon Governor of M issouri P.O. Box 720 Jeffer son City, M issouri 65102
Dear Governor N ixon : 

# m:c 1 

# a 2014

THE ADMIN I STRATOR

I am writ ing to summa rize the U.S. Environmen t al Protection Agency's recent action t o address fine particle pollutio n in your state. As required by the C lean A ir Act , the EPA has determ ined which areas are meeting the national ambient a ir quality standa rd s for fine particle pollution and whic h areas mu st take steps to reduce emissions th at contribute to violations of th e standard. On December 14 , 2012, the EPA strengthened the annual , health-based fine particle standard from 15.0 microgram s pe r cubic me ter ( ll g/m 3 ) to 12.0 ll g/ m 3

. Thousand s o f sc ientific s tudi es have linked expo s ure to these tiny pa rticles

- a ppro ximately 1/ 30th the s ize of a huma n hair

- with seri o us human health problems including premature death in people with h eart and lung d i sease, nonfatal heart attacks, and increased hospital admis sion s and doctor and emerge ncy room visits for respiratory and cardiovascular disease.
I apprec iate the in formation you and your staff have shared with the EPA throughout this process to assess fi ne particle po llution levels in communities across your state and the impact of emission sources that could be contribu ting to unhealthy air. After considering your recommendations , reviewing the most recent certified fin e particl e air quality data for your state and eval uating factors to asses s contributi o n to nearby le ve ls of fine particl e pollution, I have de t ermi ned that most areas within Missouri do not violate the 2012 standard or contribute to a nearby v iolation of the standard. As a re sult, co n sistent with mo s t of your area recommendat ions , the EPA is designating mos t of the s tate " unclassifiable/ attainment. " As we have been discussing with your staff, the EPA identified data quality iss ues ea rli er thi s year th at invalidated tine particle poll ution monitoring data for the state of Illinois. Because of these data issues, the E PA cannot de tennin e at th is time whether the Illinois portion of the St. Loui s, MO -IL area is meeti ng the s tandard. As a result, even though the monitors in the Missouri portion ofthe St. Loui s, MO -I L area are showing attainment, the EPA doe s not have s ufficient information to determine whether these Missouri co u nties do or d o not contribute to a nearby v iolation in Illinois. Along with the s tate of Illinois , the EPA is designating the Missouri counties in that area " unclassifiabl e
. " The enc losed table li sts the area a nd c ounti es in Missouri that the EPA is designating unclassifiable. The EPA will work closely with Illin o is to ensure that identified problems with air quality monitoring data are correc ted. The agency intends to reassess levels of fine particle pollution in the St. Louis , MO-I L area once s ufficie nt complete air monitoring data are available.

Internet Address (URL) • hllp :// www

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. gov Recycled/Recyclab l e • Printed with Vegetable Ott Based Inks on 100% Postconsumer, Process Chlori ne Free Recyc l ed PaperBecause air quality monitoring for 2014 is nearly complete, if a state or tribe requests it, the EPA will evaluate the status of an area based on its annual fine particle monitoring data for 2012
- 2014. If you would like the EPA to re-evaluate any areas within your state, p l ease submit to the EPA, complete , quality-assured and certified air quality data for 2014 by Feb ru a r y 27,20 1 5. The EPA shares responsibility w i th the s t a t es and tr i bes for managing particle pollut i on leve l s . Effo r t s b y s tates and tribes to attain the 1997 a n d 2006 fine particle po ll ution standards are already working to r e duc e unhealthy level s of fine particle pollution. In add ition , current and upcomi n g federa l standard s and safe guards , inc l uding pollution reduction rules for power plants , vehicles and fuels will assure s teady reductions of fin e particle pollution and will protect public health in communities across the country. Together , we h ave made considerable p r ogress to reduce fine particle pollution. Nat i o n w id e, mon it ored l evels of tin e p art i cle pollu ti on have fa llen 3 4 percent s i nce 2 00 0 whe n we first began na ti onwide monito r ing fo r part i cles of this size. I am confiden t this progress w ill continue as we wor k t oge t her towards our shared goa l of c l ean air. For addi t iona l information about these de s ignations, please visit our website at: w · w, . v.e pa. gm / pmdesignations .

If yo u have questions or concerns, please contact m e or your sta f f may contact Mark Rupp , Deputy Associate Administrator for Inte r governmental Relations , at rupp . markrm epa.gov or at (202) 564-7178 . . E nclosure

### Enclosure- Initial U nclassifiable Area Designations for the 2012 Annual Fine Particle Standard, Missouri

Statefferritory Area Name 2014 EPA Designated Unclassifiable Counties St. Lo ui s , MO St. Loui s City , MO MO St. Louis , MO-IL St. Charles , MO Jeffer so n , MO Franklin , MO