Carbon Dioxide Pipelines Planned for Minnesota Fall into Regulatory Black Hole

February 07, 2022

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by Mike Hughlett (Star Tribune) ... Right now, the CO2 pipelines don't require approval from the Minnesota Public Utilities Commission (PUC). But the PUC in December opened a proceeding on whether it should change state regulations to deem CO2 pipelines as hazardous. The Minnesota Departments of Transportation, Agriculture, Commerce and Natural Resources (DNR) all favor such a change.

"A developing body of research has raised concerns about the safety and environmental effects of pipelines transporting CO2," the DNR said in a PUC filing Monday. "Leaks or breaks in a pipeline can cause CO2 to accumulate in low-lying areas [including basements of area residences and building], thereby displacing oxygen."

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There are about 5,000 miles of U.S. carbon dioxide pipelines — a fraction of the nation's 2.6 million miles of natural gas, oil and petroleum products pipelines.

The worst accident on CO2 line appears to have occurred in 2020 near Satartia, Miss. A 24-inch pipeline owned by an oil and gas company ruptured, leading to the evacuation of more than 300 people. Forty-six were treated for injuries at local hospitals.

Law enforcement officers told the Jackson (Miss.) Clarion Ledger that some people overtaken by the gas were walking around like "zombies" while others were "foaming at the mouth."

The Mississippi rupture also released hydrogen sulfide, a dangerous gas often lurking in naturally occurring CO2 deposits. It wouldn't be present, however, in the purer CO2 stream from ethanol plants, Summit and Navigator say. Also, the diameter of the CO2 pipes in Minnesota would be relatively small — primarily 6 to 8 inches.

Still, CO2 leaks alone can cause breathing difficulties, rapid heartbeat, vomiting, headaches and impaired thinking. The Great Plains Institute said in a PUC filing that there has not been a fatality in the history of CO2 pipeline operations. But death by suffocation is possible if CO2 concentrations are high enough, including for wildlife and livestock near a pipeline rupture.

CO2 flowing through pipelines is pressurized. It has the density of a liquid and the viscosity of gas — both good traits for transport. But in a rupture, CO2 rapidly depressurizes and returns to a pure gas phase, raising the risk of "ductile fractures," said the Pipeline Safety Trust's Caram.

"If there is a ductile fracture, it can rip the line like a zipper and it can be miles long," he said.

Natural gas pipelines are primarily overseen by the federal government. In Minnesota, the PUC issues permits for pipelines carrying hazardous liquids including oil, petroleum-derived products and ammonia.

The PUC has been fielding comments on whether to include carbon dioxide on that list. For now, the C02 pipelines would need only county permits.

The PUC acted soon after Minnesota-based Clean Up the Riverfront Environment (CURE) petitioned for a state environmental review of the CO2 pipelines. CURE says an "environmental assessment worksheet" is required by law.

Both pipeline companies have since said they will voluntarily conduct the assessment. But both are against the PUC deeming CO2 a hazardous liquid for their pipelines.

Along with branches of Gov. Tim Walz's administration, the Upper Sioux Community, two labor unions, CURE and several citizens have filed comments with the PUC asking that CO2 pipelines be regulated as hazardous. READ MORE

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‘A stark warning’: Louisiana carbon dioxide leak raises concerns about safety, regulation (Des Moines Register)

Excerpt from Des Moines Register: It wasn’t the wail of a siren or the buzz of an emergency phone alert that warned Tanya Richard a pipeline near her home was spewing poison gas. The first hint that something was wrong came from her cats, a motley collection of free-roaming felines that fled her property as the dense cloud of carbon dioxide rolled over a rural stretch of southwest Louisiana on April 3.

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As it turned out, a 2-foot diameter pipeline at a CO2 pump station about a half mile from Richard’s house had ruptured, releasing about 107,000 gallons of the gas, which can cause drowsiness, suffocation and sometimes death. Colorless, odorless, and heavier than air, carbon dioxide can travel undetected and at lethal concentrations over large distances.

The CO2 pipeline network is undergoing rapid expansion as companies invest in the booming carbon capture and sequestration market. With this growth come worries that emergency communities may not be prepared or even aware of the potential for dangerous leaks.

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In the outskirts of Sulphur, local police and firefighters could do little more than set up roadblocks and wait for the pipeline’s owner, ExxonMobil subsidiary Denbury Inc., to send repair specialists.

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Calcasieu Parish issued a shelter-in-place advisory, urging everyone within a quarter mile of the pump station to close doors and windows and turn off air conditioners, but officials relied mostly on social media to convey the warning. The parish narrowed its emergency alert system to phone numbers listed for addresses within a quarter mile of the station. That amounted to about eight homes ― four of which were likely unoccupied, according to parish officials.

The pump station and pipeline aren’t equipped with alarms or other methods of alerting the nearby residents when leaks or other accidents occur.

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Local firefighters alerted Exxon about the April 3 leak shortly after it was first reported at around 6 p.m. The company’s Texas-based repair crew arrived an hour and a half later. Wearing masks and air tanks, the crew stopped the leak just before 8:30 p.m. ― nearly two and a half hours after it was first reported, according to records from the Ward Six Fire Protection District in Calcasieu Parish. The shelter-in-place advisory was lifted at 9:15 p.m.

No injuries or serious illnesses were reported, parish officials said.

Exxon is still investigating the leak’s cause. In a statement, the company promised to “learn from this.”

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The pipeline has had several accidental releases, including a 1,000-gallon CO2 leak at the same location in 2011, according to the Pipeline and Hazardous Materials Safety Administration.

In 2020, the pipeline had two large-scale leaks in the small Mississippi community of Satartia, about 30 miles from Jackson, the capital. One rupture, caused by a mudslide after a hard rain, forced about 200 Satartia residents to evacuate and hospitalized at least 45 people. Emergency responders found people passed out or disoriented and struggling to breathe. READ MORE