CD S?. 

PRO

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY


WASHINGTON, D.C. 20460

OFFICE OF


The Honorable Charles A. Gonzalez AFR AND RADIATION 

U.S. House of Representatives 

Washington, D.C. 205 15-4320 

Dear Congressman Gonzalez: 

Thank you for your letter of July 26, 2011, in which you shared your concerns about the U.S. 

Environmental Protection Agency's "Tier 3" light-duty vehicle emissions and gasoline standards and the 

timing of the anti-backsliding study. Specifically, you expressed concern that the Tier 3 standards be 

supported by adequate analysis and that the public has an opportunity to provide comment on the 

underlying research and data. 

First, let me assure you that the EPA is absolutely committed to developing a robust and transparent 

analysis to support the Tier 3 vehicle and fuel standards. We are conducting the anti-backsliding study 

required by Clean Air Act section 211(v) (as amended by the Energy Independence and Security Act 

(EISA) of 2007), and we are planning to release the draft as part of the broader regulatory analysis 

accompanying the Tier 3 proposal in December 2011. 

As part of the Tier 3 rulemaking development, the EPA is in the process of conducting a thorough 

analysis of the emissions and air quality impacts of light-duty vehicles, and the environmental and health 

benefits of stronger vehicle and fuel standards. An important aspect of that analysis involves the air 

quality impacts of renewable fuels, which is also the subject of the anti-backsliding provisions. As a 

result, we are including the anti-backsliding study as part of our comprehensive analysis related to Tier 3 

vehicle and fuel standards. 

The EPA is developing new Tier 3 standards for light-duty vehicles and their fuels in order to reduce 

their contribution to the poor air quality and adverse health effects that millions of Americans currently 

experience. The EPA has acknowledged for several years the importance of reducing vehicle emissions 

in order to attain the nation's air quality standards, and state air agencies are continuing to call for 

increased federal measures to reduce vehicle emissions. 

We believe that by issuing and seeking comment on the draft study as part of the rulemaking process, 

we are maximizing opportunity for public review and input. The rulemaking process ensures visibility 

and accessibility, and all supporting materials related to the study—as well as all public comments on 

the study—will be accessible as part of the rulemaking docket. Further, there will be a public hearing on 

the proposal that will offer the public an additional opportunity to provide input on the anti-backsliding 

study, and on broader issues associated with the Tier 3 standards. 

Internet Address (URL) . http I/wwwepa gov


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The anti-backsliding analysis is the culmination of several years of vehicle testing, data analysis, and 

emissions modeling that the EPA has been conducting since the Energy Policy Act of 2005 and EISA 

were enacted. We used preliminary results from this emissions testing and modeling in the regulatory 

analysis of the Renewable Fuel Standard program (RFS2) that was finalized in March 2010. That air 

quality analysis, which examined only the incremental effects of RFS2's increase in renewable volumes 

as compared to RES 1, predicted increases in population-weighted annual average ambient 

concentrations of ozone and particulate matter that would lead to up to 245 cases of adult premature 

mortality. The anti-backsliding study required by Clean Air Act section 211 (v)( 1) will examine the 

impacts of the full RFS program, not just the increment from RFS1 to RFS2. 

In summary, I want to assure you that the EPA is conducting the anti-backsliding study and will release 

the draft for public comment. By releasing the draft study as part of the Tier 3 proposal, the research and 

data underlying the study will be easily accessible to the public and available for consideration along 

with the broader context of the regulatory analysis. 

Again, thank you for your letter. If you have further questions, please contact me or your staff may call 

Diann Frantz in EPA's Office of Congressional and Intergovernmental Relations at 202-564-3668. 

Sincerely, 

(3c(_c 

Gina McCarthy 

Assistant Administrator