Farm state lawmakers, led by Iowa Sens. Charles Grassley and Joni Ernst, vowed last week to keep the heat on the Environmental Protection Agency (EPA) to prevent any backtracking on biofuel volume requirements in the Renewable Fuel Standard (RFS).

A bipartisan group of 38 senators sent a letter to EPA Administrator Scott Pruitt calling for him to follow congressional intent on the RFS and scrap a proposal that would reduce volumes.

Grassley, who called President Donald Trump to ...