Great Artesian Basin carbon capture plans branded ‘madness’

James Nason, February 22, 2023

A depiction of Surat Basin groundwater systems in the CTSCo Environmental Impact Statement, sourced from Queensland’s Office of Groundwater Impact Assessment.


A MINING company’s plans to inject waste carbon dioxide captured from a power station into a Great Artesian Basin aquifer has been labelled as “madness” by representatives of the many existing users who already depend on the groundwater resource.

The controversial carbon capture and underground storage project was publicly announced in November, and is currently being reviewed by the Queensland Government.

The window for public submissions closes tomorrow, but existing users of the aquifer say the consultation period has not been long enough and are calling for the deadline to be extended to ensure potential impacts on a critical underground water resource are given adequate consideration.

Three-year carbon capture and storage trial

Behind the project is Carbon Transport and Storage Corporation (CTSCo), a subsidiary of coal-mining giant Glencore.

CTSCo has advanced plans to undertake a three-year trial which aims to demonstrate the effective permanent storage of captured carbon dioxide (CO2).

The project entails capturing waste CO2 from the Millmerran Power Station in Southern Queensland and compressing the gas into liquid form, before transporting it 260km further west to Moonie.

There CTSCo plans to inject 110,000 tonnes of the waste liquid per year over three years into the Precipice Sandstone aquifer at a depth of about 2300 metres, via a well west of Moonie it has already drilled and tested.

Disputes over quality of water in aquifer

CTSCo states that it has deliberately identified “a very deep, 2.3 kilometre, low-quality sandstone aquifer 50km from the nearest bore used for agricultural purposes, and where water quality is low and cannot be used for drinking or agricultural use”.  It says water quality is low because it contains naturally elevated levels of sodium, chloride, fluoride, iron and boron (see Glencore’s full response to Beef Central below).

However, numerous users with regulated existing entitlements already rely on different parts of the same large-scale aquifer to provide water including dozens of intensive livestock enterprises, in addition to regional councils with active and inactive entitlements acquired but set aside for town water supply. If treated through processes such as Reverse Osmosis, the water is suitable for human consumption.

The GAB Strategic Management Plan shows that at least 30 different businesses have intensive water entitlements (some on multiple properties) in the Precipice Sandstone aquifer, with a further 180 businesses accessing the resource for stock and domestic purposes.

At least one agricultural user is understood to have an existing development permit in place for a deep bore within 10km of the CTSCo injection site.

Existing users say claims that water in the Precipice Sandstone aquifer is of low value are contradicted by test results contained within CTSCo’s own Environmental Impact Statement.

Test data from CTSCo’s West Moonie injection well detailed in the EIS show that the water at the site in the Precipice Sandstone aquifer has Totalled Dissolved Solids including salt of 1,850mg/L.

That falls well within the safe range for livestock according to official drinking water quality guidelines, which stipulate that beef and dairy cattle, sheep, horses and pigs can consume water with total dissolved solids of up to 4000mg/L with no adverse effects expected. (link here)

In written comments in response to Beef Central’s questions,  Darren Greer, General Manager of Glencore’s CTSCo Project, pointed to flouride levels as a key concern with water quality in that section of the aquifer: “This Precipice aquifer contains brackish water with fluoride levels that are six times above the drinking water standard for human consumption and three times over the maximum level for stock consumption.  Fluoride can only be removed by processes such as reverse osmosis purification, which is very costly and energy intensive.” (See Glencore’s full response further down in article).

Poor water quality claims ‘misleading’

Hydrogeologist Ned Hamer, principal of groundwater consulting practice Earth Search, told Beef Central that claims that water at the site is highly saline are “quite misleading”.

Mr Hamer said the permeability and quality of the water in the Precipice was good even at depths of 2300m.

“The quality as tested by themselves (CTSCo) is very good and well below the stock drinking water guidelines.

“The way they have presented the data and the findings in the EIS is quite misleading.

“They are saying that it is not fit for livestock, it is not fit for any use, it has no environmental value etc, which really isn’t true.”

Mr Hamer is the geologist in charge of a bore currently being drilled into the Precipice Sandstone aquifer for Western Downs Regional Council for town water supply.

“I would be ecstatic if we get the same quality as what they have there (at Moonie).”

In response to the mining company pointing to flouride levels as a reason why it regards water quality at that part of the aquifer as not suitable livestock, Mr Hamer said fluoride above the stock guideline level is very common within GAB aquifers.

Mr Hamer said this did not mean that the water was unsuitable for livestock, and said there had been no known health effects from flouride on stock in the basin from his experience with many of the large intensive prodcuers in the region.

“The guidelines are very conservative based on assumed high fluoride intake in food and no other water source for the animals life.” Additionally, the guidelines were not intended as an absolute cutoff, rather, they served as a trigger to observe animal health and check with nutritionist if needed.

The flouride issue was “easily managed” through fluoride levels in feed and “could easily be reduced in water by blending, amendment and treatment etc”, but none of that has been needed in the region.

Why injecting CO2 into an aquifer would be problematic

Asked what he believed the problem with injecting waste CO2 captured from a power plant into an aquifer would be, Mr Hamer nominated two distinct issues.

The first is that the aim of the project is to put CO2 deep underground and have it stay there”.

Mr Hamer believes the CTSCo EIS overlooks the potential for other bores in close proximity to prevent this from happening.

In layman’s terms, he said, the idea of the project is to keep the compressed gas in liquid form deep under pressure to hold it in solution and stop it going back into a gas.

If someone pumps from nearby in the same aquifer – such as the owner of the existing agriculture development permit with an entitlement to build a bore within 10km – that dissolved CO2 could “degas” and go back up a nearby bore into the atmosphere where it came from, which would defeat the intent of the project.

Increased acidity

Another issue is that liquified waste CO2 is very acidic with a PH of around 4, according to their CTSCo EIS.

Mr Hamer said acid changes the equilibrium of water quality and what is dissolved in it.

Increases in acidity would lead to metals such arsenic and lead being leached from the rock aquifer into the groundwater.

“They stay this in their EIS, so you will end up with very acidic water in the aquifer moving with groundwater.”

Mr Hamer said the CO2 project would create a “plume” containing corrosive, dissolved heavy metals around the injection point in the aquifer.

Other pumping from the same aquifer would influence and move that plume towards the pumping bore, because CO2 as a liquid would flow from a point of high-pressure to a point low-pressure.

He said the EIS suggests this plume will remain in one spot due to the stagnant nature of the underground aquifer.

But he said the EIS had not modelled the influence of pumping which would “completely change that static situation” and make it quite dynamic, he said, with water moving from the injection bore towards the pumping bore quite quickly, “much faster than ground water normally flows in the Great Artesian Basin”.

Nor would the water quality continue to be fit for livestock.

“Anybody else who wants to drill a bore in that vicinity in the future, it kind of sterilises or locks out a portion of the water resource from future users, and I guess that is why the ag sector is quite upset about that.”

Additionally, anyone pumping nearby the acidic water would likely corrode the normal steel casing of their water bore, he said.

CO2 wells are required to use a special higher grade of casing to handle the greater corrosiveness.

Value of the Precipice

The Precipice is the deepest of all of Surat Basin aquifers utilised for various purposes including stock and domestic and intensive water use.

A lot of the shallower aquifers are fully allocated or even over allocated, and current GAB water plans do not allow for any more water to be taken from new licenses.

This underlines the value of the deeper Precipice aquifer to users with existing entitlements.

It is more expensive to access (both in drilling costs and the $10,000-$15,000 per megalitre annual licence fees required to use the water) but this also means fewer users and greater stability of supply for those users with existing entitlements.

Pumping into viable water aquifers makes no sense: ACC

Australian Country Choice is among the existing users of water from the Precipice Sandstone aquifer.

The livestock processing, lot feeding and cattle producing company has a number of water entitlements in the aquifer to support tens of millions of dollars in existing feedlot infrastructure, in addition to inactive entitlements held for future development plans.

ACC CEO Anthony Lee. Picture: Nigel Hallett

CEO Anthony Lee said the company was not opposed to projects which explored ways to reduce carbon emissions, but the idea of pumping toxic substances into viable water aquifers relied upon by many existing users made no sense.

“This project should be injecting into a geological formation that does not have the ability to support rural Industry and in an area remote from the Great Artesian Basin,” he said.

“If it progresses this trial sets a precedent for all water bearing aquifers within the GAB footprint and must be rejected in the strongest terms to ensure the security of water for current users and rural industry into the future.

“There would be complete uproar if such a project was placed in the vicinity of the Roma town water supply bores which source from the GAB, a real consideration if carbon injection into the GAB is allowed to proceed.”

Mr Lee said the short comment period has meant little time for investigation and consultation and the window for comment should be extended beyond the deadline of Thursday, February 23.

“I’d like to see the project rejected outright but at the very least the timeline extended to allow adequate due diligence to occur.”

Contamination risk means extension needed: AgForce

Agriculture organisation AgForce has also thrown its weight behind calls for the public notification period to be extended.

CEO Mike Guerin said the GAB is a unique pristine underground storage system providing water to more than 120 communities as well as food and fibre producers.

Contamination of the water supply would have significant impacts for human drinking water as well as impacting on general urban and industrial uses, including agriculture and the future expansion of food and fibre production.

“The issues that could well be overlooked without an extension and further consideration are potentially significant and permanent, and cross community, environment, social and economic dimensions,” he said.

AgForce is also seeking an urgent meeting with the State Government to provide more detail relating to the concerns.

In a recent speech to Parliament MP Colin Boyce described the proposal to store waste CO2 in the Great Artesian Basin as “unthinkable madness”.

Glencore comments on CTSCo Project

Darren Greer, General Manager of Glencore’s CTSCo Project, said the Environmental Impact Statement (EIS) public consultation period is set by the Queensland Government and CTSCo Project has a 12-week public consultation period.

Glencore was not opposed to extending this by a couple of weeks to enable additional stakeholders to comment, Mr Greer said.

In written comments to Beef Central, Mr Greer said CTSCo has specifically targeted “a very deep aquifer, 2.3 kilometres below surface, containing water unsuitable for human or livestock consumption, or crop irrigation.

“We take our guidance on water quality and use from Australian standards and guidelines. This Precipice aquifer contains brackish water with fluoride levels that are six times above the drinking water standard for human consumption and three times over the maximum level for stock consumption.  Fluoride can only be removed by processes such as reverse osmosis purification, which is very costly and energy intensive.

“We take water management very seriously and the proposed CTSCo injection test will not impact the shallower potable water sources used by communities and agriculture across the region.

“There are no agricultural water extraction bores accessing the Precipice aquifer within 50 kilometres of the proposed CTSCo injection site.  CTSCo has proposed that no future water extraction bores be drilled within the area extending approximately 300 metres from the injection well.

“Carbon Capture and Storage is a proven technology, with about 41 projects in operation and construction around the world including in Australia, and is cited by the International Energy Agency and the UN Intergovernmental Panel on Climate Change as an important technology if the world is to meet ambitious emission reduction goals.”

Background on project

Background information also provided by Glencore on the project said the Surat Basin was first identified as being potentially suitable for large scale CO2 storage more than 13 years ago (by a 2009 National Carbon Storage Taskforce report and also the Queensland Government CO2 Storage Atlas).

Glencore received a greenhouse gas storage exploration permit from the Queensland Government in 2019, and said it assessed and selected its proposed CO2 storage site following extensive environmental and geological studies, which indicated its suitability for permanently and safely storing CO2.

It said the proposed storage site “is geographically isolated from the much shallower aquifers used by the agricultural community” and too saline for crop irrigation.

The company said its proposed injection testing project included “extensive monitoring to ensure the stored CO2 remains in place”.

“The injection testing project proposed by CTSCo is a short duration, limited volume carbon dioxide storage project aiming to demonstrate safe permanent geological storage and monitoring techniques required and to collect sufficient data to allow for a future informed decision on potential large-scale CCS in Queensland.”


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  1. Norm McCleary, March 10, 2023

    Most of the above is ill-informed drivel. What you need to understand is that the gas over a period of time (2-5 years) will, with the help of the high salinity water, actually become mineralised. That is, it will become a carbonate and will remain in place with no ill effects to anyone or any thing.

  2. Rob Moore, February 25, 2023

    It’s madness. Ever tried pumping up a blown-out tyre with an air compressor?

  3. David Dwyer, February 22, 2023

    CTSTo needs to put up a bond to cover impacts to users in the affected area during the trial if it progresses; to cover economic loss and potential remediation. I would think this would need to be in the hundreds of millions of dollars.

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