The RFS and Ethanol Production: Lack of Proven Impacts to Land and Water

This report was prepared by Ramboll for Growth Energy in anticipation of the United States Environmental Protection Agency (EPA) issuing proposed rulemaking on the Renewable Fuel Standard (RFS), commonly referred to as the “RFS Reset.” One of the factors that EPA must consider in resetting renewable fuel volumes in the program is potential environmental impacts.

The key conclusion of this report is that there are no proven adverse impacts to land and water associated with increased corn ethanol production under the RFS. Accordingly, EPA could decide to reset renewable volumes in a manner that would incentivize greater production and consumption of conventional corn ethanol in US transportation fuel without discernible adverse environmental impacts to land and water, to the extent any exist. The major factors supporting this conclusion are that continued improvements in agricultural practices and technology indicate that increased demand for corn grown for ethanol in the United States can be met without the need for additional acres of corn planted, while at the same time, reducing potential impacts to water quality or water supplies.

Our review focused on analyses concerning water quantity and quality; as well as ecosystems, wetlands, and wildlife. Analyses concerning ecosystems, wetlands, and wildlife were presented primarily as part of the body of literature addressing land use change (LUC) and conversion of land from non-agricultural to agricultural uses in the United States. We focused particular attention on EPA’s recent environmental review of the RFS, Biofuels and the Environment: Second Triennial Report to Congress (EPA 2018a), and studies relied upon by the agency therein. Ramboll also reviewed other key publications pre- and post-dating EPA (2018a). A full list of refences cited in this report is presented in Section 8.

We also reviewed a recent paper by Hill et al. (2019) investigating the air quality-related health impacts of growing corn. Finally, we provide a brief overview of certain environmental impacts of oil and gas exploration and production and gasoline refining, in response to EPA’s (2018a) acknowledgement that its assessment is not fully comprehensive because it does not consider a comparative assessment of the impacts of biofuels relative to petroleum derived fuels.