Experts: Predicting CO2 pipeline rupture threats can be extremely costly

Chris Ruhl, who oversees accident investigations for the Pipeline and Hazardous Materials Safety Administration, said advanced plume modeling is being evaluated and tweaked. (Jared Strong/Iowa Capital Dispatch)

DES MOINES — A carbon dioxide plume modeling software did not anticipate the threat a pipeline break in 2020 posed to a small Mississippi town, largely because it did not take land topography into account.

That break near Satartia, Mississippi, resulted in emergency responders scrambling to save people from a "green gas" and "rotten egg smell" with no preparation and no immediate notification from the pipeline company about what had occurred, according to a federal Pipeline and Hazardous Materials Safety Administration report.

"We didn't know there was a CO2 pipeline running through my county," Jack Willingham, director of Yazoo County's emergency management and who oversaw the response, recounted Thursday.

His comments were part of a two-day meeting PHMSA hosted to discuss carbon dioxide pipeline safety and potential regulatory changes to help prevent a similar incident as Satartia.

The incident exposed a lapse in anticipation of and preparation for such a rupture. About 200 people were evacuated from the area — including the town of Satartia's 50 residents. Three people nearly died, Willingham said, and a total of 45 sought hospital treatment.

Predicting where a carbon dioxide release from a pipeline will go can be a costly, time-consuming venture, according to a panel of experts assembled by PHMSA to discuss what is called "dispersion modeling" on Thursday in Des Moines.

That's because of all the factors that can affect the heavier-than-air gas, which, in the case of the Satartia incident, pooled near the break and eventually migrated northwest toward the town. The surrounding air had been very still at the time.

Those carbon dioxide plumes can be affected by air temperature, wind strength and direction, the lay of the land, the size of the pipe rupture — even whether there is standing corn in nearby fields.

"The fact that under the current regulations and the current standards, the fact that (the pipeline operator) did not identify Satartia as potentially being impacted by a failure on that pipeline says volumes," said Bill Caram, executive director of the Pipeline Safety Trust.

His comments were part of a two-day meeting PHMSA hosted to discuss carbon dioxide pipeline safety and potential regulatory changes to help prevent a similar incident as Satartia.

The agency plans to propose new rules in early 2024 with the potential to have them finalized by the end of that year.

Because those rule changes are pending, pipeline opponents say states should halt their issuances of new permits to construct the pipelines. There are three pending proposals in Iowa, and one of them could get a final permit hearing yet this year.

PHMSA does not determine where the pipelines can be built but oversees their construction and operation.

There is more sophisticated plume modeling software than what was initially used to evaluate the risks near Satartia, but it can require tremendous computational capacity.

Simon Gant, who studies fluid dynamics for a British regulatory agency, said he estimated that a comprehensive evaluation of a 100-kilometer pipeline could take 44 years for his equipment to complete.

Jeremy Fontenault, of RPS Group, who has experience with the different modeling software, estimated that it could cost hundreds of thousands of dollars just to evaluate one location along a pipeline for all of the potential variables.

"When you start applying that along the entire pipeline — hundreds of locations — it just raises exponentially," he said.

Max Kieba, director of program development for PHMSA who moderated the talk, said that changes to modeling requirements are under consideration but that the costs of the modeling must be weighed against its benefits.

PHMSA is sponsoring university research to develop a computational fluid dynamics modeling system that would improve threat identifications and be cost effective, but it might not be complete for years.

Dean Kluss, a Wright County supervisor, said it is "absurd" not to require pipeline companies to use the advanced modeling techniques to ensure the safety of residents.

"If we know what's best, why don't we do the modeling?" he said. "Figure it out. If we can send a man to the moon, we can figure this out."

Gant said real world pipeline leak simulations are also needed to verify whether the modeling software is accurate and to determine how much the gas can penetrate different types of dwellings.

In a separate discussion Thursday, the emergency management director of Cedar County said rural counties such as hers will struggle to prepare for a large pipeline leak because of the specialized equipment and training required.

Emergency responders in Satartia, for example, relied on breathing apparatus that cost more than $6,000 apiece that allowed them to rescue people from the carbon dioxide plume. Willingham said one rescuer who did not use apparatus eventually collapsed from breathing too much of the gas.

That is an unaffordable cost for most rural volunteer fire departments, said Jodi Freet, the emergency management director of Cedar County.

"So, what happens if there's a CO2 emergency?" Freet said. "I can't send my firefighters or my (emergency medical) people to respond. I have to call in a specialized hazardous materials team."

She said that team comes from a different county and is a 45-minute drive away.

This article first appeared in the Iowa Capital Dispatch, a sister site of the Nebraska Examiner in the States Newsroom network.

by Jared Strong, Nebraska Examiner June 2, 2023

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Senior reporter Jared Strong has written about Iowans and the important issues that affect them for more than 15 years, previously for the Carroll Times Herald and the Des Moines Register. His investigative work exposing police misconduct has notched several state and national awards. He is a longtime trustee of the Iowa Freedom of Information Council, which fights for open records and open government. He is a lifelong Iowan and has lived mostly in rural western parts of the state.