Separate state and federal civil lawsuits were filed against BP Exploration (Alaska) Inc. over two spills at the nation''s largest oil field in 2006, reported by the Associated Press. The lawsuits were filed two years after the company pleaded guilty to federal violations of the Clean Water Act for one of the spills and agreed to pay a $20 million fine. The federal government filed its lawsuit in U.S. District Court in Anchorage alleging violations of federal clean air and water laws for the spills at Prudhoe Bay, on Alaska''s North Slope. It asks the court to order BP Alaska to take actions to prevent spills in the future and impose stiff penalties. The state of Alaska followed with its own lawsuit in state Superior Court, alleging violations of state environmental laws and loss of revenue for the state. The state is seeking penalties and restitution for revenue lost between 2006 and 2008 as production was first slowed because of the spills and then for reconstruction of the pipeline system. Steven Mulder, chief assistant attorney general of the state Department of Law''s environmental section, estimated there was a production shortfall of at least 35 million barrels of oil over the three-year period. About 90 percent of Alaska''s state revenue comes from oil taxes and royalties. Both lawsuits contend some of the penalties could be quadrupled if negligence was found to be a factor. The federal lawsuit was filed by the Justice Department on behalf of the Department of Transportation-Pipeline and Hazardous Materials Safety Administration and the Environmental Protection Agency.