Exxon to repair Pegasus oil pipeline in Missouri DONIPHAN, Mo., May 3 (UPI) -- Federal approval was given for Exxon Mobil to repair part of the Pegasus oil pipeline that leaked about a barrel of oil in Missouri, the company said. Exxon acknowledged about 42 gallons of oil spilled from the Pegasus pipeline in Doniphan, Mo., near the border with Arkansas. Exxon said that it expected to have the pipeline repaired by the weekend and have the site refilled with new soil following approval from the Pipeline Hazardous Materials Safety Administration. Exxon said it was working with federal authorities to investigate the cause of the incident on the pipeline, which was built in the 1940s. Pegasus is out of service following a March oil spill in Mayflower, Ark. About 5,000 barrels of oil spilled from a 22-foot rupture on the pipeline, soiling marshland. The pipeline was carrying a diluted form of tar sands oil from Canada at the time of the March incident. That type of crude oil is heavier than conventional oil and sinks in water, making remediation difficult. Exxon said it had special absorbent materials deployed to soak up the oil. There was no indication of what sort of ecosystem, if any, was soiled by the Missouri incident.