Special Report

The US Oil Pipeline With the Worst Spill Record

Polina-Petrenko / iStock via Getty Images

Following a serious rupture of the Keystone pipeline in Kansas this past December, the Federal government last month announced that stricter regulations were on the way, targeting Canada’s TC Energy Corp., the operator of the infamous pipeline.  The rupture this past winter dumped 14,000 barrels of heavy crude, some of it into a creek, in the largest U.S. oil spill in nearly a decade. The new regulations would require TC Energy to reduce the pipeline’s operating pressure. 

The temporary shutdown resulting from the December rupture interrupted the flow of this critical artery through which 622,000 barrels of heavy crude oil flows daily from Alberta, Canada, to U.S. refineries and oil farms as far south as Houston. (Also see, cities with the most land flagged for hazardous waste cleanup.)

The rupture, caused by faulty welding and stress fatigue on the pipe, was of the biggest spill in the company’s 71-year history. The 2,600-mile pipeline has had 22 accidents since its first phase went online in 2010, according to a report last year from the U.S. Government Accountability Office.

Unfortunately, Keystone’s track record is actually about on par for the industry, which  experiences dozens of “significant” oil pipeline incidents every year, according to data collected by the U.S. Pipeline and Hazardous Materials Safety Administration.

To determine the U.S.-based pipelines that have leaked the most oil since 2010, 24/7 Wall St. examined press coverage from Bloomberg and other local and national news sources. Revenue and profit figures for the publicly listed companies operating the leakiest oil pipelines in the U.S. were taken from 2021 annual regulatory filings.

Many of these spills are relatively small, but some are significant enough to cause property and environmental damage as well as, occasionally, the loss of life. Of Keystone’s 22 accidents reported by the GAO, six were large enough to impact people and the environment.

The Kansas spill helped put the Keystone Pipeline at the top of the list of the five leakiest crude oil arteries in the country. The five based pipelines listed have spilled nearly 92,000 barrels (3.8 million gallons) of crude in various incidents since 2010.

Owners of these pipelines include Marathon Petroleum Corp., which has owned the Tesoro High Plains Pipeline since 2018; Canadian pipeline and energy company Enbridge Inc.; and Houston-based Enterprise Products. (Find out which is the country that has the most oil.)

Here are the U.S. pipelines that have spilled the most crude oil since 2010.

5. Enterprise Chico Station
> Barrels spilled since 2010: 12,200
> Owner: Enterprise Products Partners
> Company revenue, 2021: $40.8 billion

Enterprise Products Partners is a major Houston-based natural gas and crude oil pipeline company. According to preliminary data from the Pipeline and Hazardous Materials Administration, the company has spilled more than 12,000 barrels of oil since 2010. In one 2011 incident, several thousands of barrels of crude oil spilled out of a tank at an Enterprise gathering station near Chico, Texas. That spill was contained by a dike. Later that year, Enterprise Products reported a spill from one of its discharge pipes at one of its facilities in Cushing, Oklahoma.


Source: Maxim Trukhin / Getty Images

4. Belle Fourche Bicentennial
> Barrels spilled since 2010: 12,600
> Owner: True Companies (Truecos)
> Company revenue: N/A (private)

Earlier this year, the United States and North Dakota filed a complaint against two Truecos pipeline concerns, including Belle Fourche Pipeline Company, which owns and operates the Bicentennial Pipeline. The lawsuit blames the company for being negligent and causing the Ash Coulee Spill that dumped 14,400 barrels of crude in Billing County in 2016. Belle Fourche Pipeline Company is a subsidiary of Casper, Wyoming-based Truecos.

Source: ntsb / Flickr

3. Enbridge Line 6B
> Barrels spilled since 2010: 20,100
> Owner: Enbridge Inc.
> Company revenue, 2021: CDN $47.1 billion ~USD $34.5 billion

Pipeline giant Enbridge of Calgary, Alberta, Canada claims it transports about 30% of crude oil produced in North America, at more than 3 million barrels of crude and other petroleum liquids every day. Its Enbridge Line 6B is one of the leakiest in the country, however. In the summer of 2010, the line ruptured in Marshall, Michigan, regurgitating more than 3 million liters (792,516 gallons) of oil sands into the Kalamazoo River and surrounding wetlands over 17 hours.

The National Transportation Safety Board said the prolonged release caused “pervasive organizational failures at Enbridge.” The company reported CDN $6.3 billion in profit last year or about $4.6 billion in U.S. dollars.

2. Tesoro High Plains Pipeline
> Barrels spilled since 2010: 20,700
> Owner: Marathon Petroleum Corp.
> Company revenue, 2021: $120 billion

The Tesoro High Plains pipeline system in North Dakota and Montana gathers oil from the massive Bakken formation and delivers it to a Tesoro refinery and to another pipeline owned by Enbridge Inc. In 2013, the pipeline spilled thousands of barrels of crude into a Dakota wheat field. At the time it was considered the biggest spill in the state since it became a major U.S. producer, according to Reuters. Marathon Petroleum Corp., the Ohio-based major petroleum refining and oil transportation company, has owned the pipeline since its 2018 acquisition of Andeavor (formerly Tesoro Corp.)


1. TC Energy Keystone Pipeline
> Barrels spilled since 2010: 26,000
> Owner: TC Energy Corp.
> Company revenue, 2021: CDN $13.4 billion ~USD $9.8 billion

Canadian energy company TC Energy owns the 2,600-mile North American oil pipeline system that has experienced 22 accidents since it went online in 2010. Six of these accidents met the U.S. government’s criteria for spills “impacting people of the environment,” according to the U.S. Government Accountability Office report from last year, including major spills in North and South Dakota in 2011 and 2016, respectively. The Kansas spill in early December 2022 is the third significant Keystone pipeline rupture in the past five years, according to CBS News.

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