A carbon dioxide pipeline rupture in the US which hospitalised nearly 50 people has sparked safety fears about plans for a similar pipe across Scotland.
Residents of the small Mississippi town of Satartia were reportedly left unconscious and foaming at the mouth after being exposed to a cloud of carbon dioxide (CO2) which was released when a nearby pipeline burst in February 2020.
Emergency services arriving at the scene described finding disoriented victims of the leak “wandering around like zombies”.
More than 300 people in Satartia and the surrounding area had to be evacuated and some of those affected have claimed to be experiencing lasting health effects, including lung problems, years later.
Despite the incident and another recent leak in the US, a Scottish carbon capture and storage (CCS) project is working on plans to pipe industrial CO2 from the central belt past major towns to Aberdeenshire, where it will then be stored deep under the North Sea.
Backers of the scheme – including Shell and the Scottish Government – say it is vital to Scotland’s industrial future and for reaching climate targets.
The CCS sector maintains that CO2 pipelines have an “excellent safety record” and advocates have previously described fears about safety as “overblown” and claimed the Satartia incident was an anomaly.
But campaigners argue it is proof that piping CO2 can be “extremely dangerous” and called for precautions to be put in place to make sure communities are prepared in the case of a leak.
One US charity raised particular concerns over plans in Scotland to transport CO2 through an old natural gas pipeline which, it claims, could increase the chance of a rupture.
However the company which owns the pipeline that could be reused told The Ferret it would “never take forward a project if there was a risk to public safety”.
Repurposing concerns
Both the Scottish and UK governments have committed to scaling up CCS to reduce the country’s contribution to the climate crisis.
CCS involves capturing CO2 produced from industrial processes at sites like oil refineries, cement plants and power stations. The captured CO2 is then transported to locations where it can be safely stored, usually deep underground. This stops it entering the atmosphere where it causes global warming.
On a visit to the north east last week, first minister John Swinney pledged £2m to a study by gas transmission company, National Gas, which will assess the “feasibility” of converting one of the firm’s unused natural gas pipelines to transport CO2.
The pipe could be key to Scotland’s CCS plans and would transport CO2 from pollution hotspots in the central belt like Grangemouth to the St Fergus gas plant near Peterhead, where the Acorn Project is based.
The Acorn Project – considered the backbone of Scotland’s budding CCS industry – will then transport the CO2 from St Fergus through offshore pipes to permanent storage in rock formations under the North Sea.
The pipeline project is still at the design stage and any construction work is unlikely to happen for a number of years and is dependent on further government support.
The prospect of reusing the old onshore gas pipeline – which passes close to Stirling, Dunblane, Perth and Forfar – has alarmed an American charity called the Pipeline Safety Trust.
It has been at the forefront of the campaign for better regulation of CO2 pipelines in the US and said it is “very concerned” about plans to repurpose natural gas pipes.
Studies have suggested that reusing natural gas pipes for CO2 could be problematic.
CO2 is usually piped at high pressures and very low temperatures, which requires pipelines suited to those conditions. It can also corrode steel pipes if it is contaminated with water, increasing the risk of a rupture.
“Prior to moving CO2 through a pipeline, operators and safety regulators must take into account contaminant risks and have a plan to mitigate their potential negative impacts,” the Pipeline Safety Trust’s policy manager, Amanda McKay, told The Ferret.
She continued: “Pipeline failures in the US have shaken communities, decimated ecosystems, and stolen the lives of far too many people.
“The CO2 pipeline failure in Satartia continues to have lasting impacts on the community with many individuals still facing ongoing health issues and trauma.”
A spokesperson for National Gas said: “Safety and technical feasibility have been critical considerations throughout our joint work with our partners on this project, which aims to design a carbon dioxide transport and storage network to cut carbon emissions.
“We would never take forward a project if there was a risk to public safety and this initiative will only progress after the necessary approvals from the safety and environmental regulators.”
Safety debate
The Satartia blowout has prompted a growing debate about CO2 pipeline safety in the US, where there are plans to massively expand the pipeline network to accommodate the CCS industry.
In the state of South Dakota, for example, a referendum has been called on the same day as this year’s US presidential election on laws relating to the approval of a CO2 pipeline which will snake its way through the state. Possible safety issues with the pipe are expected to be a talking point in the campaign.
That debate is not yet happening publicly in Scotland, though, despite the fact CCS is also key to climate strategy here.
Carbon dioxide is an asphyxiant and in gas form is heavier than air. When large quantities of it are released all at once, CO2 can hug the ground and displace oxygen, making it difficult to breathe.
Depending on the concentration of CO2 in the air – and how long a person is exposed to it – exposure can cause symptoms ranging from coughing and dizziness to coma and even death.
Exposure to CO2 also has an intoxicating effect which can cause confusion and make people feel as if they are drunk.
Some residents in Satartia were found unconscious in their cars because their engines had shut off. CO2 concentrations in the air were so high that there was not enough oxygen for the car’s internal combustion engine to ignite. This also hampered the ability of first responders to evacuate affected communities.
Another obstacle to the emergency response in Satartia was the fact that emergency services did not immediately recognise that victims’ symptoms were caused by a CO2 leak.
Pure CO2 is both odourless and colourless which makes it difficult to detect when in the air.
This – allied to the fact that large amounts of pressurised CO2 can be released at the same time when a pipeline carrying it bursts – can “dramatically increase the size and scope of the impacted area in the case of a rupture”, according to Amanda McKay.
It is “imperative” that Scottish communities near the pipeline are as “prepared as possible”, including by having specific emergency training and resources along the route of the pipe, McKay argued.
Scottish environmental campaigners have long questioned the role of CCS in Scotland’s transition to a cleaner future.
One of those is Alex Lee, who campaigns on climate issues at Friends of the Earth Scotland. They claimed the Scottish and UK governments are “gung-ho” for CCS despite what they branded “decades of expensive failure and abject underperformance” in reducing emissions.
Lee argued the real reason for the promotion of CCS is to “greenwash” the oil industry’s plans to “keep going with fossil fuels”.
The Acorn Project is a joint venture between a number of parties including oil drilling companies Shell and Harbour Energy. As well as existing polluters in the central belt, Acorn could in future store CO2 shipped from elsewhere in Europe and from a proposed new gas power plant at Peterhead which will be equipped with CCS technology.
The Peterhead plan has been vigorously opposed by environmental groups who fear it will keep Scotland “locked into drilling and burning fossil fuels for decades to come” and point out that no CCS technology will capture 100 per cent of emissions produced.
Lee called on the government to reject plans for the Peterhead plant and told The Ferret: “The climate and environmental risks of relying on carbon capture have been well documented but this explosion in Mississippi shows there could also be serious risks to public safety.
“The experience from the USA shows that there are very real risks to piping high pressure carbon dioxide across large distances and the industry will be proceeding with a trial-and-error approach in the UK.”
The Acorn Project declined to comment on this story. In a section on health and safety in a 2021 technical report, the project said emergency plans would be “developed prior to any construction activity” and said personnel would be “trained and competent to deal with any incidents”.
The report continued: “The natural behaviour of CO2 upon release and the potential for it to stall combustion engine vehicles will require careful consideration and adjustment in emergency response.
“There will need to be wider consultation with emergency services and the public to address emergency response methods in relation to CO2 events.”
The Scottish Government said the cash it gave to Acorn would allow it to examine the “technical feasibility and viability” of repurposing a natural gas pipeline to carry CO2 and would “explore a range of areas including pipeline safety requirements”.
Proponents of CCS have previously accused activists of scaremongering.
“All an opponent has to say is ‘don’t do CCS, or you’re going to have people walking around like zombies foaming at the mouth like they did in Satartia,” one executive claimed at an industry conference in Canada last year. “You scare people. You share this information and they’ll be against it.”
The Health and Safety Executive, which is responsible for pipeline safety across the UK, said it would continue updating regulatory frameworks as the roll out of CO2 pipelines continued.
It added that it was working on two projects with external companies to understand and address CO2 pipeline safety issues.
Cover image credit: iStock/MikeMareen
Thanks for publishing this article on CO2 pipelines. It is important to be aware of the specific safety issues around CO2 pipelines. However, this needs to be put in context with the huge web of natural gas pipelines which cover our land. Natural gas is inherently very dangerous and yet we are all very used to these gas pipelines large and small and take then for granted.