THE ADMINISTRATOR OF THE ENVIRONMENTAL PROTECTION AGENCY

The Honorable Diane Enos President of Salt River Pima

Maricopa Indian Commun ity I 0005 East Osbourne Road Scottsdale, Arizona 85256 Dear President Enos: WASHINGTON, D

. C

. 20460


## LDEC 1

I would like to summarize the U.S. Environmental Protection Agency ' s recent action to address fineparticle pollution on your reservation. As required by the Clean Air Act, the EPA has determined which areas are meeting the national ambient-air-quality standards for fine-particle pollution and which areas must take steps to reduce emiss ions that contribute to violations of the standard. The EPA on December 14 , 2012 , strengthened the annual, health-based fine-particle standard from 15.0 micrograms per cubic meter ( J..L g/ m3 ) to 12.0 J..Lg/m3

. Thousands of s cientific studies have linked exposure to these tiny particles

- approximately 1130th the size of a human hair

- with serious health problems including premature death in peop le with heart and lung disease, nonfatal heart attacks and increased hospital admiss ions and doctor and emergency-room vi sits for respiratory and cardiovascu lar disease. I appreciate the information you and your staff have shared with the EPA throughout this process to assess fine-particle-pollution levels in communities across your reservation and the impact of emission source s that could be contributing to unhealthy air. After considering your recommendations, reviewing the most recent certified fine-particle air-quality data for your reservation and evaluating factors to assess contribution to nearby levels of fine-particle pollution, I have determined that no area within the Salt River Pima Maricopa Indian Community reservat ion violates the 20 12 standard or contributes to a nearby violation of the standard. As a result, the EPA is designating all of the Salt River Pima Maricopa Indian Community reservation " unclassifiable/attainment." Because air-quality monitoring for 2014 i s nearly complete, the EPA, at a tribe's request, will evaluate the status of an area based on its annual fine-particle-monitoring data for 2012-14. If you would like the EPA to re-evaluate any areas within your reservation , please submit complete , quality-assured and certified air-quality data for 2014 to the EPA by February 27 , 2015. I reco gnize that the EPA shares responsibility with the states and tribes for managing particle-pollution levels. Efforts by states and tribes to attain the 1997 and 2006 fine-particle-pollution standards are already working 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 ensure steady reductions of fine -p article pollution and will protect public health in communities across the nation.

This paper is printed with vegetable·oil·based inks and is 100-percent postconsumer recycled material chlorine-free-processed and recyclable

.Together we have made considerable progress in reducing fine-particle pollut i on. Nationwide monitored levels of fine - particle pollution have fallen 34 percent s ince 2000 when we first began such monitoring for particl es of this size. I am confident this progres s will continue as we work toward our shared goal of clean air.

For additiona l i nformation about th ese designations , please visit www.epa.gov/pmdesignations.