The 2013 Mayflower oil spill occurred on March 29, 2013, when the Pegasus Pipeline, owned by ExxonMobil and carrying Canadian Wabasca heavy crude from the Athabasca oil sands, ruptured in Mayflower, Arkansas, about northwest of Little Rock releasing about of oil. Approximately of oil and water mix was recovered. Twenty-two homes were evacuated. The United States Environmental Protection Agency (EPA) classified the leak as a major spill.
Exxon's Pegasus pipeline carries of crude a distance of from Patoka, Illinois to Nederland, Texas. On April 2, 2013, PHMSA, the federal pipeline regulator, issued a corrective action order until repairs have been completed and all safety concerns addressed.
Pegasus Pipeline
The Pegasus Pipeline, (a/k/a, EMPCO Pipeline, and the Magnolia Pipeline) is , and runs from Patoka IL to the Texas Gulf Coast. It was built in two segments between 1947-1954 as an oil pipeline, which shipped products from Corsicana Texas, both north for industrial uses, and south to Gulf Coast refineries.
The flow of the southern section was reversed in 1995, and again in 2002. The northern section was abandoned in 2002, before being re-commissioned in 2005-2006 and reversed to carry diluted bitumen from Alberta Tar Sands to refiners in Texas.
The pipeline sheet metal was manufactured by Youngstown Sheet & Tube Co, using a manufacturing process called LF-ERW (Low-Frequency Electric Resistance Welds). This process has been known to have latent defects which eventually leads to failures. Pipeline and Hazardous Materials Safety Administration issued advisory bulletins in 1988 and 1989 to alert operators of factors contributing to failures of pipelines constructed with ERW pipe.
Substance spilled
There has been some controversy over the exact nature of the substance spilled in Mayflower. On April 5, the Environmental Protection Agency sent a request for more information about Wabasca Heavy—the oil that spilled on the Pegasus line on March 29. The EPA's question was: "Can the oil accurately be described as oil sands oil, or a type of diluted bitumen (dilbit)?" In his response on April 10, Richard Byrne, Exxon's assistant chief attorney of environmental and safety law stated: "Canadian producers report their production of Wabasca Heavy as bitumen." This contradicts statements by company officials that the substance spilled was simply "heavy oil," not oil sands bitumen. However, the Material Safety Data Sheet for the product confirms that the Wabasca Heavy is bitumen mixed with hydrocarbon diluents.
Response
Early images from local media showed crude oil running along a suburban street and across lawns. The pipeline was shut after the leak was discovered on March 29. Twenty-two homes were evacuated. The oil flowed into storm drains leading to nearby Lake Conway, a fishing lake. First responders, including fire fighters, city employees, county road crews and police built dikes to block culverts and stop the crude from fouling the lake. ExxonMobil deployed 3,600 feet (1,100 m) of containment boom around the lake. ExxonMobil said that by early morning on March 30 there was no more oil spilling from the pipeline and trucks were there to assist with the cleanup. Residents of the homes evacuated were allowed to temporarily return to their homes escorted by police to retrieve personal items. ExxonMobil set up a claims hotline for affected residents. Officials from the EPA and the Pipeline and Hazardous Materials Safety Administration (PHMSA) initiated an investigation of the spill.
There have been varying estimates of how much crude spilled. Initially ExxonMobil did not state an exact amount. On March 30, the company reported that of oil and water mix had been recovered. The following day the company said of oil and water had been recovered. The company was unable to estimate how much of the total was oil and how much water. On April 10, UPI reported that around of oil were spilled but quoted Exxon as saying that the final volume would not be known until after the pipeline was repaired and refilled. Before determination of the penalties for the violations of federal and state environmental laws, the estimated amount was corrected to .