LAKE CHARLES (AP) — Citgo Petroleum Corporation pleaded guilty Wednesday in federal court to oil spill violations. The oil spill, which occurred in June 2006 at Citgo’s Lake Charles refinery, closed 20 miles of the Calcasieu Ship channel for weeks. Citgo was fined $13 million and given a mandatory special assessment of $125 million. The refinery must also implement a comprehensive environmental compliance program and it will be placed on one year unsupervised probation to implement the program.