The US Supreme Court declined to hear a lawsuit seeking to overturn California’s Low Carbon Fuel Standard, which requires fuel producers to reduce the “carbon intensity” of their products by 10 percent by 2020.

In its Monday decision, the high court let stand a 2013 decision by the 9th US Circuit Court of Appeals upholding the state’s low-carbon fuel standard, the Sacramento Bee reports. The oil industry and Midwest farmers and ethanol producers have fought the standard in court.

Policies including California’s LCFS have put California is ahead of the biodiesel curve, according to an August 2013 study by E2 and Environmental Defense Fund. Growing production in the state shows California companies have started capitalizing on this low-carbon fuel.