THE ADMINISTRATOR OF THE ENVIRONMENTAL PROTECTION AGENCY

The Honorable Ruben Barrios Chairperson of Santa Rosa Rancheria

Tachi - Yok u t Tribe P.O. Box 8 Le m oo re, Calif ornia 93245 Dear C ha irp erso n B arrios: WASHINGTON , D . C . 20460

I would like to summarize the U.S. Environmenta l Protection Agency's recent action to address fineparticle pollution o n your re se rv ation . As required by the Clean A ir Act, the EPA has determined which areas are meeting the nationa l ambie nt -air-quality standards for fme-particle pollution and which areas must take steps to reduce emiss io n s that contribute to violations of the standard. The EP A o n D ecember 14 ,20 12, stre ngthened the annu al , health - bas e d fine-particle s tandard from 1 5.0 micrograms per cu bi c m e ter

**~t g/m**  **)** to 12.0

**~g/m**

**.** Thousan d s of scientific stu dies have linked exposu r e to th ese tiny particles - approximately l/30th the s i ze of a human hair - with se rious 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 cardiovascu lar d isease. I appreciate the information you and your staff have s hared w i th the EPA throughout thi s process to assess fine - particle-pollution levels in communities across your reservation and the impact of emiss ion sou r ces that could be contri buting to unhe a lth y a i r. After reviewing the most rece nt certifie d fineparticle air-quality data for th e s tat e of Calif o rni a and evaluating factors to assess co ntribution to nearby leve ls of fine particle polluti o n , I have d e termined that some areas in California do not meet the 20 12 annua l fine particle standard or they contribute to a nearby vio l ation of the standard. The EPA i s designating those areas "no nattainment." Some of these areas al so include areas oflndi an country, including the reservati on of the Santa Rosa Ranch er i a Tachi - Yo kut Tribe . Nonattainment areas will be requi red to take action to reduce fine -particle poll uti on and meet the standard no later than 202 1 . As required by the Clean Air Act, those actions may include st ri cter controls on indu st rial facil it ies and additional planning requ irements for transportation-related sources. While tribes are not requ ired to take actions, the EPA wi ll work w ith tribes to d eve l op plans as neces sary or appropriate to ensure tribal areas m ee t th e stan dard no late r tha n 202 1. Because air- qual i ty monitoring fo r 20 1 4 is nearly complete, the EPA, at a tribe 's request, w ill evalu ate the status of an area based on its annual fine-partic le-moni toring data for 20 12-14. If you would like th e EPA to re-evaluate any areas wi thin your reservation , please submit complete , qua li ty-assured and certified air- quality data for 20 14 to the EPA by February 27, 2015. I recognize that the EPA shares respons ibili ty with the states and tribes for managing particle-pollution leve ls. Eff orts by states a nd tribes to attain the 1 997 and 2006 fine-particle-pollution s tand ards are This paper is printed with vegetable-oil-based inks and is 100-percent postconsumer recycled material , chlorine-free-processed and recyclable .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 f u e ls will ensure steady reductions of fine-particle pollution and will protect public h ea lth in communities across the nation. Together we have made considerable progress in reducing fine-particle pollution. Nationwide monitored level s of fine-particle pollution have f allen 34 percent since 2000 when we first began such monitoring

for particles of this size. I am confident this progress will continue as we work toward our shared goa l of clean air.

For additional information about these designation s, please v i s it www.epa.gov / pmdesignat ion s. cerely , 0:AV