The Keystone Pipeline has had at least 3 significant spills in the last 5 years. Here’s what to know.

A small Kansas county became a site of a significant pipeline failure last week as the Keystone Pipeline leaked an estimated 14,000 barrels of crude oil into a creek — the largest spill in its history. Now, officials are scrambling to clean up the mess made by the system, which stretches more than 2,600 miles from Canada to the U.S. 

And it isn’t the first time they’ve had to do so. 

The Keystone Pipeline has had nearly two dozen accidents since it went into service in 2010, according to a report from the U.S. Government Accountability Office, a history similar to other oil pipelines. There are dozens of “significant” oil pipeline incidents every year in the U.S., according to the Pipeline and Hazardous Materials Safety Administration, costing more than $3 billion and leading to the deaths of six people since 2002. More than 719,000 barrels of crude oil have been lost in that time, with each barrel being about 42 gallons. 

It’s not uncommon for smaller-scale oil pipeline breaches to occur in the U.S. But what makes the Keystone Pipeline different, the GAO said, is that its incidents have only gotten worse.

While most of the 22 accidents at the pipeline over the past 12 years resulted in fewer than 50 barrels of oil being released each time, four incidents stand out. In two separate instances in two different states, 400 barrels, or more than 16,000 gallons, of oil spilled out of the pipeline – in Ludden, North Dakota, in 2011 and in Freeman, South Dakota, in 2016.

Then in the past five years, the pipeline has had two larger accidents, aside from the most recent one, that pushed the pipeline’s performance below nationwide averages. Before last week, there were two – one in 2017 and the other in 2019 – that were big enough to affect people or the environment, according to the hazardous materials administration’s standards. 

“Over the last several years, we have taken decisive action to implement measures to strengthen our approach to safety and the integrity of our system and will conduct a full investigation into the root cause of this incident, in cooperation with regulators,” TC Energy said in a statement to CBS News on Monday. “We take every incident very seriously. No incident is ever acceptable to us.”

Here’s what to know. 

November 2017: At least 210,000 gallons spilled 

The Keystone Pipeline was shut down mid-November 2017 after it leaked an initial estimate of 210,000 gallons of crude oil in Amherst, South Dakota, according to the GAO. It was one of the largest on-shore oil spill in the nation since 2010, according to the Associated Press, and months later, it was determined to be nearly twice as big as originally thought. 

A spokesperson for TransCanada Corp., the owner of the pipeline now called TC Energy, said five months after the fact that the pipeline had actually spilled about 407,000 gallons of crude oil into surrounding farmland, with the GAO saying last year that 6,592 barrels of oil were released. Despite taking months to clean up, the pipeline resumed 12 days after the leak began. 

According to the GAO, the leak was caused by a crack in the pipeline’s exterior that was likely caused by a vehicle during installation and “grew to a critical size.” Following the incident, the company used technology to find other cracks in the impacted segment and “excavated several anomalies by September 2018,” GAO said, but no similar issue to what caused the accident was detected. 

October 2019: 383,000 gallons spilled 

Not even two years later, a tiny town of fewer than 200 people became the site of another massive leak nearby. The pipeline sprung a leak near Edinburg, North Dakota, in October 2019, forcing the pipeline to halt the transport of oil. While state regulators initially expected the leak to affect about 22,500 square feet, they later determined it was almost 10 times bigger than that – 209,100 square feet, according to the AP. 

According to the GAO, 4,515 barrels of oil were released in the incident, with officials telling the AP that an estimated 383,000 gallons of oil had been leaked. 

The cause for this particular spill was a pipe that had been manufactured “with an atypical seam,” according to the GAO, that was severe enough to cause a crack. As of 2021, work to detect similar cracks in the area was ongoing. 

December 2022: More than half a million estimated gallons 

The latest major incident started last week, when TC Energy officials announced on Dec. 8 that an estimated 14,000 barrels had been spilled in Washington County, Kansas — more than all the crude oil pipeline spills in 2021 combined, according to federal data. With each barrel being 42 gallons, that would come out to more than half a million gallons of crude oil seeping into the surrounding area. 

And when the pipeline ruptured, it shot oil “the length of a football field” in an area that included farmland that’s over 80 years old, land owner Bill Pannbacker told CBS News. His pasture, where cattle are kept from May through October, was quickly saturated by the oil, much of it turning black. The pipeline ruptured about 15 feet north of his fence line, he said.

“That’s our livelihood out here,” he said of the land hit by the oil, which has been in his family since the 1930s. They also grow corn, soybeans and wheat.  “…Probably an acre, an acre-and-a-half of grasses was totally covered with oil. But that’s on a slope so it would run down, and that’s when it ran down into the creek.” 

Workers rushed to contain the seepage and address its cause, TC Energy officials said, as the Keystone system was once again paused. As of Sunday, more than 250 people were working on the incident and company officials said they were working with Tribal Nations and landowners about what occurred. The regional EPA office said they built a dam about 4 miles downstream to prevent oil from migrating further.

“As always, the health and safety of our onsite staff and personnel, our community neighbors, and mitigating risk to the environment remains our primary focus,” TC Energy said in an online statement. “… We recognize this is concerning to the community and commit that we will continue our response until we have fully remediated the site. … We have not confirmed a timeline for re-start and will only resume service when it is safe to do so, and with the approval of the regulator.”

Pannbacker, who served as a state representative from 2019-2020, told CBS News, “I’m leaving the cleanup and that part of it to those entities and I trust that the government oversight … that they’ll monitor the situation and make sure that it’s done right.” 

Li Cohen

Li Cohen is a social media producer and trending reporter for CBS News, focusing on social justice issues.