THE ADMINISTRATOR OF THE ENVIRONMENTAL PROTECTION AGENCY

The Honorable Keeny Escalanti President of Quechan Indian Tribe P.O. Box 1899 Yuma, Arizona 85366 Dear President Escalanti: WASHINGTON , D
. C
. 20460 

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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 C lean Air Act, the EPA has determined whi ch areas are meeting the national ambient-air-quality standards for fine-particle pollution and which areas must take steps to reduce emissions that contribute to violations ofthe standard
. The EPA on December 14,2012, strengthened the annual, heal t h-based fine-particle standard from 15.0 micrograms per cubic meter (f.lg/m 3 ) to 12.0 f.1g/m 3

. Thousands of scientific studies have li nked expos ure to these tiny particles

- approximately !/30th the size of a human hair

- with serious health problems including premature death in people with heart and lung disease, nonfatal heart attacks and increased hospital admissions and doctor and emergency -room visits for respiratory and cardiovascular di sease. I appreciate the information you and your staffhave shared w ith the EPA throughout this process to assess fine-particle -p oHution levels in communities across your reservation and the impact of emission sources 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 Quechan Indian Tribe reservation violates the 2012 standard or contributes to a nearby violation ofthe standard. As a result, the EPA is designating all of the Quechan Ind ian Tribe 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 fo r 2012-14. If you would like the EPA to re -eval uate any areas within your reservation, please submit complete, qualit y-assured and certified air-quality data for 2014 to the E PA by February 27,2015. I recognize 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 -particl e 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 -particle pollution and will protect public health in communities across the nation.

This paper is printed with vegetab l e- o i l- based i nks and i s 100·percent postco n s u mer recycled mate ria l , chlorine-free-processed and recyc l able
.Together we have made considerable progress in reducing fine - particle pollution. Nationwide mon i tored levels of fine-particle pollution have fallen 34 percent since 2000 when we first began such monitoring for particles of t his size. I am confid e nt this progress will continue as we work t oward our shared goal of clean air.

For additional information about these designations, please visit www . epa.gov / pmdesignations.