TOPEKA, Kan. (AP) – Consumers across the U.S. still will be able to buy higher-ethanol blend E15 gasoline this summer, the Environmental Protection Agency announced April 28, saving them a little money at the pump but frustrating environmentalists who believe the move potentially harms the air and water.

The emergency waiver issued by the EPA prevents retailers in most states from having to stop selling E15 gasoline on May 1. While the waiver remains in effect only through May 20, EPA Administrator Lee Zeldin signaled that he plans to keep issuing waivers through Sept. 15, the date when the federal government typically would allow E15 sales in all states again.

Most gasoline sold across the U.S. is blended with 10 percent ethanol, but 15 percent blends are becoming increasingly common, particularly in the Midwest, where most of the nation’s corn is grown. E15 gasoline generally costs at least 10 cents less a gallon than E10 gasoline, but the EPA had previously prohibited its sale during the summer over concerns that its use during the summer driving season could increase smog.

But the EPA has relaxed restrictions on E15, granting a series of short-term waivers in 2022, 2023 and 2024 to allow its sale nationwide through the summer. And last year, the EPA issued a rule allowing year-round sales in eight Midwestern states – Iowa, usually the nation’s top corn producer, as well as Illinois, Minnesota, Missouri, Nebraska, Ohio, South Dakota and Wisconsin.

Trump administration officials said the action will lower consumers’ costs and give them more choices at the pump while also increasing the demand for corn. They also described it as reducing America’s reliance on imported energy.

The biofuels industry and politicians in both major parties argue that ethanol helps farmers, lowers prices at the pump and reduces greenhouse gas because the fuel burns more cleanly than straight gasoline.

But ethanol consumes about 40 percent of the nation’s corn crop, and environmentalists argue that higher corn production leads to higher use of fertilizers that are a leading source of water pollution.