Specifically, EPA proposes 3.71 percent of all US gasoline sold next year be a "renewable fuel." Currently the standard is 2.78 percent of all gasoline sales.
Most of the fuel ethanol made in the United States currently comes from corn, although the White House says it wants to devote government research dollars to other potential feedstocks, including waste paper and landfill trash. Biodiesel is typically made from soybeans.
EPA projected that the pending rules would mean that the nation's petroleum consumption would drop by 3.9 billion gallons per year, with 14 million tons in greenhouse gas emissions reduced annually.
Critics of the program, including some environmental groups, say ethanol fuels do little, if anything, to protect the public from harmful tailpipe emissions.
"Reducing oil imports is a good idea, but it should not come at the expense of reducing public health protections," said Frank O'Donnell, president of the advocacy group Clean Air Watch.
EPA's plan, still subject to public comment, also outlines a credit and trading system that the agency says would allow renewable fuels to be used where they are most economical, while giving fuel suppliers a flexible way to comply with the standard.
Refiners said they still are worried that the new rule may place undue strains on the US fuel shipping system and raise pump prices.
"While EPA was required by statute to develop the implementing regulations, (we) continue to have serious concerns about the wisdom of policies that mandate a prescribed ethanol or biodiesel content in the nation's transportation fuel supply," said Bob Slaughter, president of the National Petrochemical and Refiners Association.
"Consumers will be better served if the market, rather than politics, determines future use of fuel-blending components, including renewables," he added.
