HOUSTON (AP) — The U.S. Environmental Protection Agency has launched an investigation into a 41-day benzene release at BP's Texas City refinery, the site of a massive explosion in 2005 that killed 15 workers.
The EPA's investigation, announced late Thursday, is the latest blow to the oil giant, still struggling to deal with the outcome of the massive Gulf of Mexico oil spill.
The refinery incident under investigation began April 6 when a fire occurred in a hydrogen compressor. As a result, gases were rerouted to the facility's flare — a flame at the top of many refineries used to burn off toxic gases — until the compressor could be fixed and restarted on May 16. The EPA is investigating whether the fire or the release violated the federal Clean Air Act.
Texas environmental regulators have said the company released more than 500,000 pounds of toxic air pollutants, including cancer-causing benzene, during that time.
The EPA's regional director Al Armendariz said the agency is trying to ensure "disclosure of all information by BP."
"It is important the EPA, state officials and public know what happened at the plant, and that BP is held accountable to prevent incidents like these from happening in the future," Armendariz said in a statement.
The EPA declined to comment further because the investigation is active.
BP said in a statement that it would cooperate with the EPA investigation. Previously, Scott Dean, a BP spokesman, denied there were elevated readings during the spring incident.
The EPA launched its probe after Texas filed suit against BP in August, arguing the company illegally emitted nearly 500,000 pounds (227,000 kilograms) of toxic air pollutants.
The Texas Commission on Environmental Quality has accused the company of having a pattern of poor operation and maintenance practices at the Texas City facility. It turned over its findings to the state's attorney general. BP could be fined up to $25,000 per day for each violation.
BP recently paid a $50 million fine imposed by the U.S. Occupational Safety and Health Administration, which found a litany of recurring problems at the plant years after the company was supposed to address issues that led to the 2005 explosion. The total fine was $87 million and OSHA has said it is trying to collect the remainder.
Also in August, hundreds of Texas City residents joined a class-action suit against BP for the April-May incident. The residents are seeking $10 billion of damages for being exposed to toxic chemicals that could be harmful to health.
In a letter addressed to BP on Thursday, the EPA demanded all "information regarding the fire that occurred" on April 6. It said the oil giant must hand over all related documents, even if BP believes them to be "a trade secret or confidential business information." The EPA gave BP 30 days to hand over the material, though the company can file for an extension.
The fire occurred in the refinery's ultracracker unit, which helps convert petroleum products, similar to diesel fuel, into high-octane gasoline. Texas environmental regulators have reported five other problems in the unit in the past year. In its lawsuit, the state accuses BP of continuing to use the equipment without the damaged compressor so productivity would not decrease. This caused the release, Texas said in its lawsuit.