THE ADMINISTRATOR OF THE ENVIRONMENTAL PROTECTION AGENCY

The Honorable Darwin St. C lair Jr. Chairman of Eastern Shoshone Tribe P.O. Box 538 Ft. Washakie , Wyoming 82514 Dear Chairman St. Clair: WASHINGTON , D

. C

. 20460


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I would lik e 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 (Jlg/m3) to 12.0 Jl g/ m 3

. Thousands of s cientific studies have linked exposure to these tiny particles- approximately 1/30th 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 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 sources that cou ld 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 Eastern Shoshone Tribe reservation violates the 20 12 standard or contributes to a nearby violation of the standard. As a result, the EPA is designating all of the Eastern Shoshone Tribe reservation " unclassifiable/attainment. " Because air-quality monitoring for 20 14 is nearly com plete, the EPA , at a tribe ' s request, will evaluate the status of an area based on its annual fine-partic le-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 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-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 -particle 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 pollution. Nationwide monitored levels of fine-particle pollution have fallen 34 percent since 2000 when we first began such monitorin g for particles of this size. I am confident this progress will continue as we work toward our shared goal of clean air.

For additional information about these designations , p l ease visit www.epa.gov/pmdesignat i ons. **~** vl/f/IV