Prudhoe Bay oil spill

The Prudhoe Bay oil spill (2006 Alaskan oil spill) was an oil spill that was discovered on March 2, 2006, at a pipeline owned by BP Exploration, Alaska (BPXA) in western Prudhoe Bay, Alaska. Initial estimates of the five-day leak said that up to 267,000 US gallons (6,400 bbl) were spilled over 1.9 acres (7,700 m²), making it the largest oil spill on Alaska's north slope to date.^[1] Alaska's unified command ratified the volume of crude oil spilled as 212,252 US gallons (5,053.6 bbl) in March 2008.^[2] The spill originated from a 0.25-inch (0.64 cm) hole in a 34-inch (86 cm) diameter pipeline. The pipeline was decommissioned and later replaced with a 20-inch (51 cm) diameter pipeline with its own pipeline inspection gauge (pig) launch and recovery sites for easier inspection.^[2]

In November 2007, BPXA pleaded guilty to negligent discharge of oil, which prosecutors said was the result of BP's knowing neglect of corroding pipelines, a misdemeanor under the federal Clean Water Act, and was fined US$20 million.^[3] In July 2011, BPXA paid a $25 million civil penalty, the largest per-barrel penalty at that time for an oil spill, and agreed to take measures to significantly improve inspection and maintenance of its pipeline infrastructure on the North Slope to reduce the threat of additional oil spills. In November 2012, it was announced that the U.S. state of Alaska would collect $255 million related to BP Plc's pipeline leaks and a resulting shutdown in 2006. BP's share was $66 million since it would pay the award and then be reimbursed by partners, including Exxon Mobil Corp and ConocoPhillips, based on their proportionate share of ownership.