Iowa Attorney General Tom Miller and attorneys general from seven other states are siding with the biofuels industry in a brief filed with the U.S. Supreme Court.

On April 27, the court will hear arguments over how the E.P.A. has granted waivers from the ethanol mandate to the oil industry. Monte Shaw with the Iowa Renewable Fuels Association said his takeaway from the brief is the attorneys general are simply asking the Supreme Court to uphold the Renewable Fuel Standard.

“The process is laid out. These exemptions were supposed to be for a short period of time to help people transition into the RFS,” Shaw said, “and that was 13 years ago.”

The attorneys general argue in their brief that overturning an appellate court’s decision would be a devastating financial hit to many rural communities.

At the Capitol in Des Moines, an Iowa House committee has made changes to the governor’s proposed biofuels mandate. A coalition of gas stations and convenience stores argued the initial plan would have cost their industry as much as a billion dollars to install new fuel pumps. The House Ways and Means Committee would let retailers have multiple pumps offering “no alcohol” gasoline — the governor’s plan would have allowed just one — but the committee’s bill still calls for all stations to start selling gas with 15% ethanol by 2028 and includes provisions to boost use of soybean-based biodiesel as well.

(By Iowa Public Radio’s Katie Peikes; Radio Iowa’s O. Kay Henderson also contributed to this story.)