HollyFrontier Cheyenne Refining, LLC v. Renewable Fuels Association

In 2021, the U.S. Supreme Court reviewed whether a small refinery that had previously received a hardship exemption under the Renewable Fuel Standard could later apply for an extension even if its exemption lapsed. HollyFrontier and other refiners sought extensions; the Tenth Circuit held that the Clean Air Act only allowed extensions for refiners whose exemptions had been continuously maintained. The Supreme Court reversed 6-3, holding that the statutory term "extension" does not require an unbroken chain of prior exemptions. The decision broadened eligibility for small refinery exemptions, affecting renewable fuel blending obligations nationwide.

The Supreme Court reversed the Tenth Circuit, holding that a small refinery need not have continuously received an exemption to apply for an extension; remanded for further proceedings.

Whether the Clean Air Act's small refinery exemption provision requires a refinery to have continuously received exemptions in prior years to qualify for an "extension."

Expanded the pool of small refineries eligible for hardship relief from Renewable Fuel Standard blending requirements, potentially reducing demand for ethanol and biodiesel; drew criticism from biofuel advocates and praise from refining industry; prompted regulatory uncertainty and future EPA guidance.