The sales pitch on new tar sands pipelines is like a song stuck on repeat: our pipeline is the safest, most state-of-the-art way to get oil from point A to point B. Companies seeking to win approval from states and the federal government make all kinds of estimates and promises about how safe their new pipelines will be: they’ll hardly ever leak, the leaks will be small, our detection technology will catch spills as soon as they happen!
The beleaguered Keystone tar sands pipeline pipeline with its alarming history of spills, provides a far more truthful view of reality. When the Pipeline and Hazardous Materials Safety Administration (PHMSA) provided a special permit for TransCanada’s Keystone pipeline back in 2007, they gave the company the right to push oil through at pressures equivalent to 80% of the stress level the pipeline could tolerate before deformation or failure. Regulations typically limit this stress level to 72%, but PHMSA felt at the time that its operating conditions would “provide for more inspections and oversight than would occur on pipelines installed under existing regulation.” This special dispensation meant that TransCanada could operate the Keystone pipeline at 591,000 bpd, instead of the 435,000 bpd nominal capacity that the pipeline was designed to operate at if a special permit hadn’t been granted.
But the last eight years have provided every indication that PHMSA made the wrong decision. When TransCanada presented its tar sands pipeline to state and federal regulators back in 2006, it claimed that a leak of more than 50 barrels (2,100 gallons) would only happen once every 11 years for the entire length of the pipeline, and once every 41 years in South Dakota. Poor South Dakota. On November 16, the second large spill from Keystone took place within the state, just eight years into the pipeline’s operation. And while the pipelines' previous major spills—one in South Dakota, one in North Dakota—were large and caused more than $11 million in property damage, they were more than 12 times smaller than last month’s 5,000 barrel (210,000 gallon) spill.
So, what’s going on with the Keystone tar sands pipeline? In May 2011, after being in operation for about a year, the pipeline experienced two spills: a 400 barrel (16,800 gallons) spill and a 10 barrel (420 gallon) spill, taking place at two different pump stations in North Dakota and then in Kansas. The cause? Overtightening of a pipeline component during construction. The larger spill was first reported by a local landowner who spotted oil in a field. In April 2016, another local landowner, this time in South Dakota, reported seeing oil in a field. The spill was once again estimated to be 400 barrels—a fact that makes the amount of oil spilled alarming, as it was found that the pipeline was leaking at the rate of only two drops per minute. The cause here? A welding anomaly, or in plainer English, another likely construction error, given TransCanada’s lackluster history with welds. In 11 other instances reported to PHMSA since 2010, Keystone has leaked, though fortunately the largest of those was 15 barrels. 
Even as the Keystone pipeline has experienced spills far beyond what TransCanada assured people wouldn’t happen, other problems have plagued the pipeline. In October 2012, after just two years of operation, TransCanada shut down the whole Keystone system for immediate repairs due to safety issues that were not immediately disclosed. Years later, documents obtained via the Freedom of Information Act (FOIA) showed that Keystone was suffering severe external corrosion, with portions of its nearly brand-new pipeline already whittled down to the thickness of a fingernail. As with the prevalence for major leaks, this kind of issue wasn’t supposed to happen and opened up a whole slew of new concerns over the safety of operating tar sands pipelines at high pressures.
Which brings us to Keystone’s most recent spill and a host of new details that have emerged now that PHMSA has issued a corrective action order. Three things in PHMSA's order stand out as cause for major alarm in this latest, and, by far, largest spill for the Keystone pipeline:
- The amount of oil. Last month’s incident was 12.5 times larger than previous major spills experienced by the Keystone pipeline, and has been estimated at 210,000 gallons.
- The potential size of the rupture. TransCanada detected the spill via its pipeline monitoring system at 5:33am and began shutting down the line at 5:36am. That means the pressure differentials in the pipeline varied so much so quickly that TransCanada was sure they had a leak on their hands (in previous instances, for example, TransCanada did not detect the leak and a passerby’s reports led to the pipeline being shut down). This suggests a major pipeline failure, not the kind of pinprick leak that the pipeline experienced just over a year ago.
- A major design flaw. Initial observations suggest that the cause of the latest Keystone rupture was damage to the pipeline during construction. This damage was caused from the installation of weights that were used to keep the pipeline underground in areas where it passes through heavily saturated soil (local landowners reported remembering that TransCanada had a hard time keeping Keystone from floating back to the surface when they were building the pipeline).
The Keystone pipeline spill came at a particularly charged moment for tar sands pipelines and TransCanada—the company that is also hoping to build Keystone XL. Four days after spilling 210,000 gallons of tar sands oil into a wet field in South Dakota, Nebraska rejected TransCanada’s preferred route across the state and instead approved an alternative route that TransCanada had deemed “infeasible” in testimony to regulators. Then three days later, a federal court allowed a challenge of TransCanada’s cross-border permit—the Trump administration’s infamous reversal that brought Keystone XL back from the dead—to move forward. It wasn’t a good week for the company, to say the least.
But the Keystone spill may prove to be even worse for TransCanada than people think. South Dakota regulators are considering pulling permits that allow TransCanada to operate the Keystone pipeline within their state. Their interest and concern with the issue suggests that the permits TransCanada holds for Keystone XL in South Dakota might also be looked at with a fresher eye. Which makes sense. Claims of safety and estimates of spill incidence on a pipeline that is essentially a bulked-up twin of the existing Keystone pipeline need more careful scrutiny. Keystone XL crosses numerous water bodies, travels through areas with aquifers incredibly close to the surface, and carries a substance that should never come anywhere near water. If tar sands oil cannot be moved safely by pipeline, the public needs to know and regulators need to start taking a look under the hood of these projects to fully comprehend the level of risk they pose to our communities and our environment.
 Accidental releases from hazardous liquids pipelines are compiled in downloadable files by PHMSA. Data related to TransCanada’s Keystone pipeline is available here: https://www.phmsa.dot.gov/data-and-statistics/pipeline/distribution-transmission-gathering-lng-and-liquid-accident-and-incident-data