A bipartisan group of 37 Senators is calling on the Environmental Protection Agency to strengthen the Renewable Fuel Standard. In a letter to EPA Administrator Gina McCarthy the Senators said, “The RFS has already proven to be an effective driver of alternative fuels and economic development.

The biofuels volume requirements for 2014 and beyond have serious implications for our economy and energy security. We encourage you to ensure a final proposal continues to work toward achieving the RFS’s long-term economic and renewable energy goals.” The letter was organized by Sens. Amy Klobuchar (D-MN), Chuck Grassley (R-IA), Dick Durbin (D-IL), John Thune (R-SD), Al Franken (D-MN), and Mark Kirk (R-IL). The EPA has indicated it plans to propose RFS volume requirements by June 1 for 2015 and 2016, and re-proposes requirements for 2014.