Pennzoil-Quaker State remained the defendant in the case even after it sold the refinery to Calumet Lubricants Co. in 2001. At that time,the facilityhad capacity to produce 5,900 barrels per day of paraffinic base oil and 2,700 b/d of naphthenic base oil. Shell assumed responsibility for Pennzoil-Quaker States defense when it bought the automotive consumer products marketer last fall. Shell officials could not be reached for comment.

The Shreveport refinery had a permit regulating its discharge of industrial wastewater into the Brush Bayou. According to the suit, the facility exceeded permitted concentrations of sulfates, suspended solids, or oil and grease for seven consecutive months during 1997 and again in January 1998 and April 1999. In some cases, the actual concentration exceeded the permitted level by more than 400 percent.

The refinery also had a permit regulating discharge of sulfur dioxide from its sulfur recovery unit. The permit was based on Pennzoil-Quaker States stipulation that the unit had capacity to process 19.9 long tons of sulfur per day, just belowthe 20-ton-per-day level that would have brought the facility under more stringent controls.

When the EPA discovered that the unit had processed 20.5 tons of sulfur one day in July 1998, the agency concluded that the unit should have fallen under the more stringent controls and had therefore been in violation since its construction two years earlier. Investigators also cited a valve that was missing a cap required to prevent emissions leaks.

The hazardous waste charges were based on failures to include manifest numbers and material identification numbers on several loads taken to landfills.