The judge who imposed a record $2.25 million fine against Ashland Oil Inc. said the fine would have been larger if the oil company had not acted responsibly following one of the nation's largest inland fuel spills.

U.S. District Judge Gustave Diamond on Thursday said he considered the fine a "gentle sentence" for the negligence he found on Ashland's part in the spill that fouled two rivers in three states last year, threatening to disrupt drinking-water supplies for more than a million people.Ashland's Floreffe Terminal ruptured on Jan. 2, 1988, unleashing 3.8 million gallons of diesel fuel. More than 700,000 gallons escaped a dike and entered the Monongahela River 25 miles south of Pittsburgh.