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Oklahoma-based refiner Citgo Petroleum Corp. may face a $197 million fine for the 2006 oil spill at its refinery in Lake Charles, La., if a federal judge approves the request by the Justice Department, according to local newspaper The Advocate.

The department stated that the Citgo oil spill was one of the most serious and among the largest oil spills in the history of the United States. It is seeking a penalty of at least $197 million for the violation of the federal Clean Water Act, with the maximum penalty for such cases standing at approximately $232 million.

In June 2006 heavy rains caused two oil tanks at the Lake Charles refinery to overflow, resulting in the spill of an estimated 54,000 to 76,800 barrels of oily wastewater mixed with other pollutants, which flowed into the Calcasieu River and other waterways nearby.

Even though the case went to trial in 2011, it is back in court after the 5th U.S. Circuit Court of Appeals last year instructed U.S. District Judge Richard Haik to consider changing the $6 million penalty he ordered last year. He was urged to take into account Citgo's past violations of environmental laws, as well as the company's decision to delay recommended upgrades to the refinery with regard to environmental law compliance that could have prevented the spill, The Advocate reported.