	Introduction

Established by Congress as an amendment to the Clean Air Act, the Renewable Fuel Standard (RFS) mandates that U.S. transportation fuels contain a minimum volume of biofuel. It is also uncertain how the program will fare once EPA implements the "reset" provision of the statute, which allows the agency to modify the volumes required for future years (starting in 2016) if certain conditions are met. They also have questioned whether to amend or repeal the RFS or whether to maintain the status quo. The Statute

The Renewable Fuel Standard (RFS) was established by the Energy Policy Act of 2005 ( P.L. 109-58 ; EPAct05) and expanded in 2007 by the Energy Independence and Security Act ( P.L. 110-140 ; EISA). The RFS mandate requires that transportation fuels sold or introduced into commerce in the United States contain an increasing volume of a predetermined suite of renewable fuels. The statute required 4.0 billion gallons of renewable fuel in 2006, ascending to 36.0 billion gallons required in 2022, with EPA determining the volume amounts after 2022 in future rulemakings. The total renewable fuel requirement under the RFS is met with the combination of fuels from two renewable fuel categories: conventional biofuel and advanced biofuel. Statutory Compliance

EPA regulates compliance with the RFS using a tradable credit system. EPA reduced the statutory targets for both advanced biofuel and total renewable by the same amount as the reduction for the cellulosic biofuel (i.e., 8.08 billion gallons). Administering Agency

EPA administers the RFS. This responsibility includes evaluating renewable fuel pathways eligible for the RFS. For several years following the 2010 issuance of the amended RFS final rule, EPA has had difficulty projecting certain volume requirements (e.g., cellulosic biofuels) which have led EPA to use its waiver authority to set annual volume requirements for cellulosic biofuel, total advanced biofuel, and total renewable fuel different from what was stated in the statute. EPA reports that it will issue a rulemaking in early 2019 that proposes to reset the cellulosic biofuel, advanced biofuel, and total renewable fuel volume targets for the years 2020-2022. Likewise, the environmental impact of the RFS could be challenged, as the advanced biofuel component of the RFS—set to yield greater greenhouse gas emission reduction benefits—has missed the statutory targets by a large margin.
The Renewable Fuel Standard (RFS) requires U.S. transportation fuel to contain a minimum volume of renewable fuel. The RFS—established by the Energy Policy Act of 2005 (P.L. 109-58; EPAct05) and expanded in 2007 by the Energy Independence and Security Act (P.L. 110-140; EISA)—began with 4 billion gallons of renewable fuel in 2006 and aims to ascend to 36 billion gallons in 2022. The Environmental Protection Agency (EPA) has statutory authority to determine the volume amounts after 2022.
The total renewable fuel statutory target consists of both conventional biofuel and advanced biofuel. Since 2014, the total renewable fuel statutory target has not been met, with the advanced biofuel portion falling below the statutory target by a large margin since 2015. Going forward, it is unlikely that the United States will meet the total renewable fuel target as outlined in statute.
EPA administers the RFS and is responsible for several tasks. For instance, within statutory criteria EPA evaluates which renewable fuels are eligible for the RFS program. Also, EPA establishes the amount of renewable fuel that will be required for the coming year based on fuel supply and other conditions although waiver authority in the statute allows the EPA Administrator to reduce the statutory volumes if necessary. Further, the statute requires that the EPA Administrator "reset" the RFS—whereby the fuel volumes required for future years are modified by the Administrator if certain conditions are met. EPA monitors compliance for the RFS using a system of tradable credits referred to as renewable identification numbers (RINs).
Congress has expressed ongoing interest in the RFS, particularly as the mandate relates to other legislative efforts (e.g., Reid Vapor Pressure requirements for ethanol-gasoline fuel blends containing greater than 10% ethanol, a national octane standard) and about oversight of the RIN market, among other things. Some assert it is time to amend or repeal the RFS, while others contend the best course of action is to maintain the status quo. For instance, some Members contend the RFS hurts consumers by creating an artificial market for ethanol. Others see ethanol as a part of a competitive energy strategy.
Congress may also express interest in how the EPA Administrator applies the RFS "reset" authority. EPA reports that in early 2019 it will issue a rulemaking that proposes to modify—or "reset"—the cellulosic biofuel, advanced biofuel, and total renewable fuel volume targets for the years 2020-2022.