WASHINGTON, D.C. — “Big Oil’s” tempestuous relationship with biofuel proponents grew more testy earlier this month as part of a pending lawsuit over the new Renewable Fuel Standard (RFS).

Six biofuel groups filed a motion in federal court on April 6 seeking to intervene on behalf of the U.S. Environmental Protection Agency (EPA) and in support of the new RFS, which mandates the use of at least 13.2 billion gallons of alternative fuels this year, mostly made from corn.

That mandate rises to 36 billion gallons in 10 years, with 21 billion gallons coming from sources other than corn. The American Petroleum Institute (API), along with the American Fuel and Petrochemical Manufacturers (AFPM), filed suit last month challenging the mandate and calling requirements for cellulosic-based ethanol as “unachievable.”

The lawsuit came days before the EPA approved the start of wider manufacture and marketing of an E15 blend of gasoline and ethanol, a move the API and AFPM immediately criticized as premature.

Additional testing on older vehicles already approved for E15 use by the EPA is needed, the groups maintain.

“Unfortunately, the EPA announcement represents yet another in the agency’s unwise, premature and irresponsible series of actions in its rush to force E15 to the marketplace,” said AFPM President Charles T. Drevna. “With a lawsuit by AFPM and other organizations on this critical issue about to be heard, there is no reason for EPA to have rushed to judgment.”

The six groups seeking intervener status in the federal lawsuit, and in support of the EPA, are the Advanced Biofuels Assoc., the American Coalition for Ethanol, the Advanced Ethanol Council, the Biotechnology Industry Organization, Growth Energy and the Renewable Fuels Assoc. (RFA).

Despite criticism from longtime opponents to ethanol mandates, RFA President and CEO Bob Dinneen said during this month’s Indiana Ethanol Forum in Indianapolis that the industry is doing exactly what it set out to do – to lessen America’s dependence on foreign oil.

Seven years ago, he said, the United States was 60 percent dependent on imported fuel. Today, the country’s foreign fuel use is down to 45 percent.

In the groups’ filing for intervener status in the lawsuit, they wrote they “have investments in equipment, research and development, to supply the necessary renewable fuel.” If successful, the API’s move to lower the fuel standards would “deprive” the groups of the significant investments they have made to meet the new standards.

During the Advanced Biofuels Leadership Conference earlier this month in the nation’s capitol, USDA Secretary Tom Vilsack noted the petroleum industry, or Big Oil, is entrenched.

“You’re faced with a very well-financed group of people who don’t necessarily want this industry (biofuel),” he said.