NEW ORLEANS-If a recent federal appeals court ruling stands, corporate polluters may be less likely to be convicted for violations of the Clean Water Act if they don't have broad knowledge of the crime.

As of last week, U.S. attorneys were still reviewing the language of the ruling and the Justice Department will decide whether to appeal.

The November ruling by a panel of the 5th U.S. Circuit Court of Appeals comes in a case involving a Texas convenience store owner who in 1994 pumped about 4,690 gallons of gasoline into a city storm drain and sewer system. Some of the fuel ended up in a creek that feeds into the San Jacinto River, which feeds into Lake Houston. Gasoline also was found in the city sewage treatment plant.

The owner, Attique Ahmad did not deny discharging gasoline but claimed he intended only to pump out water that had seeped into an underground tank.

A U.S. District Court jury in 1991 sentenced Mr. Ahmad to 21 months in prison for the pollution. In overturning the conviction, the 5th Circuit said the lower court's interpretation of the Clean Water Act was incorrect and jury instructions in the trial were unclear as to what the defendant should have known about the pollution.

"What is significant is that the opinion is somewhat ambiguous as to what is required in the sense of government proof," said Michael Shelby, a Houston-based U.S. attorney who prosecuted the case. "One could argue that the U.S. will now have to prove that a polluter knowingly violated every element of the act."

That could mean proof would be required that, among other things, a defendant not only knowingly discharged a pollutant but also knew the pollutant would make its way to navigable waters, he said.

Mr. Shelby said, however, that he interprets the ruling to mean that only proof that a defendant was aware he was discharging a pollutant is required.

Mr. Ahmad's attorney, David Gerger of Foreman, DeGeurin, Gerger & Nugent in Houston, said the ruling means that "if you discharge a pollutant but didn't know you were discharging a pollutant, it's not a crime."

United States of America vs. Attique Ahmad, 5th U.S. Circuit Court of Appeals; No. 95-20627, Nov. 27, 1996.