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Renewable Fuel Standard Program

Anti-Backsliding Determination and Study

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Rule Summary

Clean Air Act Section 211(v) requires EPA to complete an “anti-backsliding study” to determine whether the renewable fuel volumes required in the Act adversely impact air quality as a result of changes in vehicle and engine emissions. After considering the results of the study, EPA is required to either (1) promulgate fuel regulations to implement appropriate measures to mitigate, to the greatest extent achievable, any adverse impacts on air quality; or (2) determine that no such measures are necessary.

On January 6, 2021, EPA determined that no additional measures are necessary pursuant to Clean Air Act (CAA) section 211(v) to mitigate the adverse air quality impacts of the renewable fuel volumes required under CAA section 211(o). Since 2017, EPA has been implementing the Tier 3 Motor Vehicle Emissions and Fuel Standards which are more stringent and reduce concentrations of ozone, PM2.5, NO2, and air toxics now and in the future.  In making this determination, EPA considered the analyses performed for the Tier 3 rulemaking, as well as the anti-backsliding study.

EPA provided a 30-day comment period for the public to comment on the proposed determination. The comment period closed on July 8, 2020.

Additional Resources