An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Renewable Fuel Standard Program

Proposed Consent Decree to Complete the Anti-backsliding Study for Renewable Fuel Volumes

EPA has announced a proposed consent decree that would require EPA to complete the “anti-backsliding study” required by Clean Air Act section 211(v)(1) by March 30, 2020. The study will consider whether the renewable fuel volumes required by the Clean Air Act adversely impact air quality as a result of changes in vehicle and engine air pollutant emissions. This proposed consent decree would partially resolve a lawsuit that sought to compel EPA to complete the study. Under the terms of the proposed consent decree, EPA has agreed to postpone further proceedings on a schedule for any follow-up regulatory response until EPA has completed the study. The regulatory response will be either a rulemaking or a decision that rulemaking is unnecessary.

EPA is opening a 30-day comment period for people who are not parties or intervenors to the litigation to comment on the proposed consent decree. EPA or the Department of Justice may withdraw or withhold consent to the proposed partial consent decree if the comments disclose facts or considerations that indicate that such consent is inappropriate, improper, inadequate, or inconsistent with the requirements of the Act. The comment period closes on March 25th, 2019.

Consent Decree to Complete the Anti-backsliding Study for Renewable Fuel Volumes (PDF) (2 pp, 223 K, published February 22, 2019, About PDF)