Pegasus Crude Oil Pipeline

From Global Energy Monitor
This article is part of the Global Fossil Infrastructure Tracker, a project of Global Energy Monitor.

Pegasus Crude Oil Pipeline (also known as the EMPCO Pipeline and the Magnolia Pipeline) is an oil pipeline in the United States.[1]


The pipeline runs from the Patoka Oil Terminal Hub, Illinois, to Nederland, Texas.

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Project Details

  • Operator: ExxonMobil[1]
  • Current capacity: 90,000 barrels per day
  • Proposed capacity:
  • Length: 1,380 kilometers (858 miles)
  • Status: Retired[2][3][4]
  • Start Year: 1947


Pegasus is a 20-inch pipeline that delivered crude from the Patoka Oil Terminal Hub in Patoka, Illinois to refineries in Texas, with a capacity of 90,000 barrels per day. It was owned by ExxonMobil.[1] The pipeline is buried an average of 24 inches below ground.[5]

The pipeline 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.[6]

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.[7]

The pipeline was out of service since the Mayflower oil spill, and later transferred to Energy Partners and now is known as Permian Express Oil Pipeline.[4]

2013 Mayflower oil spill

The 2013 Mayflower oil spill occurred on March 29, 2013, when the Pegasus Pipeline, carrying Canadian Wabasca heavy crude from the Athabasca oil sands, ruptured in Mayflower, Arkansas, about 25 miles (40 km) northwest of Little Rock, releasing about 3,190 barrels (134,000 US gal; 507 m3) of oil. Approximately 12,000 barrels (500,000 US gal; 1,900 m3) of oil and water mix was recovered. Twenty-two homes were evacuated.[8] The United States Environmental Protection Agency (EPA) classified the leak as a major spill.[9]

A Material Safety Data Sheet confirmed the spilled oil was bitumen mixed with hydrocarbon diluents.[10][11]

On April 2, 2013, the Pipeline and Hazardous Materials Safety Administration (PHMSA), the federal pipeline regulator, issued a corrective action order until repairs were completed and all safety concerns addressed.[12]


Several problems with the pipe seam were identified as the cause of the failure. Hook cracks, extremely low impact toughness, and elongation properties were named for the pipe tested.[13][14][15]

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.[16]


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.[8]

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 4,500 barrels (190,000 US gal; 720 m3) of oil and water mix had been recovered. The following day the company said 12,000 barrels (500,000 US gal; 1,900 m3) 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 5,000 barrels (210,000 US gal; 790 m3) 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.[17] Before determination of the penalties for the violations of federal and state environmental laws, the estimated amount was corrected to 3,190 barrels (134,000 US gal; 507 m3).[18]

On April 1, 2013, the Federal Aviation Administration announced it was closing the airspace from the ground to 1,000 feet (300 m) over the disaster area; the restriction spanned a 5-mile (8.0 km) radius.[19] The Arkansas Democrat-Gazette reported that the FAA's restriction stated "only relief aircraft operations under direction of Tom Suhrhoff" were permitted to enter the designated airspace. Surhrhoff was identified as an "aviation advisor" to ExxonMobil.[20] On April 3 the FAA changed the restriction level to allow media access stating the media should not have been restricted from this type of incident, also claiming FAA was responsible for the error.[21] The flight restrictions over Mayflower were cancelled on April 5.[22][23]

On April 2, PHMSA issued a corrective action order to ExxonMobil Pipeline Co. preventing ExxonMobil from restarting operations on the affected segment of the pipeline until it is satisfied with repairs and all safety concerns have been addressed. According to the order: "continued operation of the Pegasus Pipeline would be hazardous to life, property, and the environment." Arkansas' Attorney General Dustin McDaniel promised a state investigation into the cause and impact of the spill. In a letter to ExxonMobil McDaniel stated: "There are many questions and concerns remaining as to the long-term impacts, environmental or otherwise, from this spill," He asked ExxonMobil to preserve records pending his investigation.[12]

For several days after the spill, local residents complained about the "horrible smell" of the diluted bitumen.[24] Air quality monitoring has been conducted by the EPA and ExxonMobil and posted online by the Arkansas Department of Environmental Quality. According to Fox 16 News, the air quality readings have been reviewed by the Arkansas Department of Health and are below levels that will cause health effects for the general population except in cleanup areas where emergency responders are working.[25]

On April 10, Attorney General McDaniel hired disaster management firm Witt O'Brien's to analyze the cleanup process.[26]



Since the spill on March 29, there have been conflicting reports as to whether the oil sands oil has reached Lake Conway. Official reports have indicated that there is no oil in Lake Conway, but an independent study claims to have samples showing oil in the water column. Scott Smith of Opflex, an oil clean-up company, states that official samples are of surface water only: “Exxon and the EPA are taking instantaneous water samples, grab samples from the surface. Obviously if the contaminants in oil sands oil, and chemicals, are in the water column beneath the surface you’re not going to get any of those molecules to test.” Keith Stephens of Arkansas Game and Fish has countered these findings, pointing out that there have been no dead fish or other wildlife that would indicate that there is oil in the main body of the lake.[27]

Air quality

While initial reports of air quality by the Arkansas Department of Health did not reveal levels that were of concern for health effects, monitoring by a citizens group has revealed significant readings of toxic chemicals. According to a representative of the Sierra Club: "Total toxic hydrocarbons were detected at more than 88,000 parts per billion in the ambient air."[28] Exxon reported detecting benzene and other harmful chemicals in early sampling at Mayflower but said air and water quality was within safe limits. However, the report, released by the Faulkner Citizens Advisory Group, said residents were still showing symptoms of exposure to harmful chemicals, including benzene and toluene, more than four weeks after the spill.[28]

Legal action

Residents of Mayflower are seeking payment from ExxonMobil for the environmental damage caused by the spill. By initiating action, they've forced the state and federal governments to file a lawsuit against the company. According to Arkansas Attorney General Dustin McDaniel, the lawsuit came quickly—within three months after the spill—but he said that the governments were forced to act. Citizens may file suits in lieu of the government, if the government won't act. A threatened lawsuit from displaced residents forced the state and federal government to file suit, or lose the opportunity. "We had 60 days to either resolve our claims or be masters of our own ship and, certainly, I think that the Department of Justice and the State Attorney General’s office have a responsibility to litigate on behalf of the governments of the state and the federal government rather than abdicating that to private lawyers," McDaniel said. Commenting about ExxonMobil, McDaneil added: "I think that they have done a really good job with response and cleanup, but then they break the law when they store the stuff that they removed from the site." The company had stored materials, including soil, water, concrete and wood chips, in large barrels at a company-owned site nearby. Arkansas officials had not granted permission to store hazardous material and have ordered the company to stop immediately.[29]

According to Fox 16 News, local residents banded together on April 5, 2013 and April 8, 2013 at a "Mayflower Oil Spill Town Meeting hosted by Johnson & Vines Attorneys" to discuss their legal rights.[30] Since that time, in addition to the State action file by the Attorney General, a mass action has been filed by two law firms in Arkansas state court in Faulkner County, Arkansas: Johnson & Vines[31] (member of the American Injury Attorney Group)[32] and partnering firm, Hare, Wynn, Newell & Newton.[33]

In 2015, ExxonMobil settled charges that it violated the federal Clean Water Act and state environmental laws, for $5.07 million, including $4.19 million in civil penalties. It did not admit liability.[34]

Articles and resources


  1. 1.0 1.1 1.2 Pegasus Crude Oil Pipeline, A Barrel Full, accessed September 2017
  2. Bohannon, Tad (2020). "Pegasus reborn?".{{cite web}}: CS1 maint: url-status (link)
  3. Herzog, Rachel (2020). "Part of oil pipeline closed since it burst in Central Arkansas in 2013 being tested".{{cite web}}: CS1 maint: url-status (link)
  4. 4.0 4.1 Parris Kane. "Testing underway to get pipeline back online 8 years after Mayflower oil spill". KATV. Retrieved 2023-03-27.
  5. Arkansas Department of Environmental Quality (March 30, 2013). Mayflower oil Spill Response: Key facts. Retrieved on: 2013-04-13.
  6. Douglass, Elizabeth (2013-11-14). "Exxon Overlooked, Masked Safety Threats in Years Before Pegasus Pipeline Burst". InsideClimate News. Retrieved 2016-08-19.
  7. "Archived copy" (PDF). Archived from the original (PDF) on April 8, 2016. Retrieved 2016-03-30. {{cite web}}: Unknown parameter |deadurl= ignored (help)CS1 maint: archived copy as title (link)
  8. 8.0 8.1 Kristen Hays and Matthew Robinson (March 31, 2013) Exxon cleans up Arkansas oil spill; Keystone plan assailed. Reuters. Retrieved on: 2013-04-07.
  9. Michael Schwirtz (March 30, 2013). Oil Pipeline Ruptures in Arkansas. The New York Times. Retrieved on: 2013-04-07.
  10. Gallucci, Maria (April 18, 2013). Dilbit or Not? Wabasca Crude Is the Question. InsideClimate News. Retrieved on: 2013-06-05.
  11. Cenovus Energy Inc. (April 10, 2013). Material Safety Data Sheet - Heavy Crude Oil/Diluent Mix. Retrieved on: 2013-06-05.
  12. 12.0 12.1 Nuss, J. (April 2, 2013). Arkansas Oil Spill Investigation: State Attorney General To Look Into ExxonMobil Pipeline Rupture. Huffington Post. Retrieved on: 2013-05-06.
  13. "Archived copy". Archived from the original on July 11, 2013. Retrieved 2013-07-12. {{cite web}}: Unknown parameter |deadurl= ignored (help)CS1 maint: archived copy as title (link)
  14. "Archived copy" (PDF). Archived from the original (PDF) on November 2, 2013. Retrieved 2013-07-12. {{cite web}}: Unknown parameter |deadurl= ignored (help)CS1 maint: archived copy as title (link)
  15. "Archived copy" (PDF). Archived from the original (PDF) on March 4, 2016. Retrieved 2016-01-18. {{cite web}}: Unknown parameter |deadurl= ignored (help)CS1 maint: archived copy as title (link)
  16. "PHMSA - Advisory Bulletins". Retrieved 2016-08-19.
  17. United Press International (April 10, 2013). Exxon faces deadline for oil spill. Retrieved on: 2013-04-13.
  18. "Correction: Oil Leak-Arkansas story". CNS News. Associated Press. 2015-04-23. Retrieved 2016-04-17.
  19. "Archived copy". Archived from the original on April 5, 2013. Retrieved 2013-04-07. {{cite web}}: Unknown parameter |deadurl= ignored (help)CS1 maint: archived copy as title (link)
  20. Gavin Lesnick (April 3, 2013). No-fly zone in place over Mayflower oil spill. Arkansas Democrat-GazetteArkansasOnline. Retrieved on: 2013-04-07.
  21. Sims, Scarlet (2013-04-03). "FAA amends no-fly order | - Conway, Arkansas". Retrieved 2016-08-19.
  22. "FAA Cancels Flight Restrictions over Mayflower Dilbit Spill | Aviation Impact Reform". 2013-04-06. Retrieved 2016-08-19.
  23. Federal Aviation Administration NOTAM Search. NOTAM 3/8699 was cancelled by NOTAM 3/9343, which, in turn was cancelled on April 5, 2013 at 18:22.
  24. Peeples, L. April 10, 2013. Arkansas Oil Spill Health Complaints Emerge In Mayflower. Retrieved on: 2013-05-28.
  25. Fox 16 News (April 4, 2013). Air Quality Information for Mayflower Area Now Online. KLRT-TV, Little Rock AR. Retrieved on: 2013-04-09.
  26. Hays, Kristen (April 12, 2013). "Exxon working to remove damaged part of Arkansas oil pipeline". Chicago Tribune. Retrieved April 14, 2013.
  27. Kauffman, J. (April 23, 2013). Tar Sands Oil in Lake Conway? KUAR Public Radio. Retrieved on: 2013-05-06.
  28. 28.0 28.1 (April 30, 2013). "Citizen group sees 'toxic' oil soup in Arkansas". United Press International. Retrieved on: 2013-05-05.
  29. Curwood, Steve (June 27, 2013). U.S., state officials file lawsuit against ExxonMobil over Arkansas oil spill. Public Radio InternationalI "Living on Earth." Retrieved: 20132-06-27.
  30. Manley, Marci (April 5, 2013). Little Rock Attorneys Plan Town Meeting for Mayflower Residents. Retrieved on: 2013-04-05.
  31. "Personal Injury Attorney | Little Rock, AR Injury Lawyers". 2016-08-11. Retrieved 2016-08-19.
  32. "Personal Injury Lawyers Who Fight For Justice". Attorney Group. Retrieved 2016-08-19.
  33. "Lawyers Helping People - Since 1890 | AL, AR, KY | Personal Injury Lawyers – Birmingham Alabama | Little Rock Arkansas | Fayetteville Arkansas | Lexington Kentucky". Retrieved 2016-08-19.
  34. Stempel, Jonathan (2015-08-12). "Judge approves Exxon Mobil settlement over 2013 Arkansas spill". Reuters. Retrieved 2016-01-09.

Related articles

External resources

External articles

Wikipedia also has an article on Pegasus Crude Oil Pipeline. This article may use content from the Wikipedia article under the terms of the GFDL.