In a case of strange bedfellows, the California Trucking Association is vowing to help defend the Environmental Protection Agency against an expected lawsuit from the National Petrochemical and Refiners Association.

The refinery group announced this month that it plans to sue the EPA over regulations issued by the Clinton administration that would lower the sulfur content in diesel fuel to 15 parts per million by 2006.

The group claims that the air-quality regulation would be too costly, putting refiners out of business and jeopardizing the reliability of the nation’s diesel fuel supply, and wants a less-stringent standard.

But the CTA, whose members already are forced to buy cleaner diesel fuel than truckers elsewhere because of the state’s tough air-quality standards, says it needs the 15 ppm standard to regain competitiveness.

“We are going to be helping the EPA. It is very bizarre, but we want a nationwide fuel standard,” said Stephanie Williams, the CTA’s spokeswoman.

The CTA also contends that a 50 ppm sulfur standard proposed by the refinery group would lead to greater failures of new engines and soot traps that truckers must buy under a companion EPA regulation.

The refinery group announced Feb. 2 that it has filed what is called a petition for review in the U.S. Court of Appeals, a necessary step before it can file a lawsuit.

“Given current concerns about energy supplies, we must find a responsible path to diesel sulfur reduction one that doesn’t encourage refinery closures,” NPRA President Urvan Sternfels said in a news release.

Further clouding the issue is that the sulfur regulations might be rolled back under a review that President Bush ordered of all environmental regulations issued during the last 60 days of the Clinton administration.

That review is not yet complete.