UNITED STATES ENVIRONMENTAL PROTECTION AGENC Y WASHINGTON, D.C. 20460

The Honorable Terry Branstad Governor of Iowa 1

007 East Grand Avenue Des Moines, Iowa 50319 Dear Governor Branstad: 

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**201~** THE ADMINISTRATOR

I am writing to summarize the U.S. Environmental Protection Agency's recent action to address fine particle pollution in your state. As required by the C lean Air Act, the EPA has determined which areas are meeting the national amb ient air quality standards for fine particle pollution and which areas must take steps to reduce emissions that contribute to violations of the standard. On December 14,2012 , the EPA strengthened the annual, health

-based fine particle standard from 15.0 micrograms per cubic meter

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**)** to 12.0

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**.** T housands of scientific stud ies have linked exposure to these tiny particles-approximately 1130th the s ize of a human hair

- with serious human health prob lems including premature death in people wit h heart and lung disease , nonfatal heart attacks, and increased hospital admissions and doctor and emergency room visits for respiratory and cardiovascular disease. I app reciate the information you and your staff have shared with the EPA throughout this process to assess fine particle pollution levels in communities across your state and the impact ofemission sources that could be contributing to unhealthy air. After considering your recommendations , reviewing the most rece nt certified fine particle air quali ty data for your state and evaluating factors to assess contribution to nearby levels of fine particle poll ut ion, I have determined that no area with in Iowa violates the 2012 standard or contributes to a nearby vio lation of the standard. As a result, the EPA is des ign ating a ll of lowa " unclassifiable/attainment. " Because air quality monitoring for 2014 is nearly complete , if a state or tribe requests it, the EPA w ill evaluate the status of an area based on its annual fine particle monitoring data for 2012 -2014. I f you would like the EPA to re-evaluate any areas within your state, please submit to the EPA, complete , quality-assured and certified air quality data for 2014 by February 27 , 2015. The EPA sha res responsibility with the states and tribes for manag ing particle po ll ution level s. Efforts by states and tribes to attain the 1997 and 2006 fine particle pollution standards are a lready work in g to reduce unhealthy levels of fine particle pollution. In addition, current and upcoming federal standards and safeguards , including pollution reduction rules for power plants , vehicles and fuels will assure steady reductions of fine particle pollution and will protect public health in communities across the country.

I n ternet Address (URL) • hllp ://www

. epa . gov Recycled/Recyclable • Printed with Vegetable Oil Based Inks on 100% Poslconsumer, Process Chlorine Free Recycled PaperTogether, we have made considerable progress to reduce fine part icle pollution. Nationwide, monitored le vels of fine particle pollution fell 34 percent since 2000 when we first began nationwide monitoring for particles of this size. I am confident this progress will accelerate as tog et her we continue to work towards our s har ed goal of clean air. For additional information about these designations, please visit our website at: www.epa.gov / pmdesignations .

If you have questions or concerns, please contact me or your staff may contact Mark Rupp, Deputy Associate Administrator for Intergovernmental Relations , at rupp.mark(a),epa.gov or at (202) 564-7178.