Coal giant Glencore's carbon capture and storage project was once enthusiastically supported by the previous Morrison Liberal government, and has received millions of dollars in public funding.
But now serious questions are being asked about where this waste carbon dioxide is to be permanently held.
Glencore has long claimed an aquifer in the Great Artesian Basin where it plans to store the captured CO2 is "saline" and "unsuitable" for agriculture but now an alliance of major agriculture producers claim Glencore's own water samples show this is misleading, and valuable groundwater is at risk.
Glencore is one of the world's biggest coal miners, and through its subsidiary Carbon Transport and Storage Corporation (CTSCo), is planning a trial of capturing CO2 from a coal-fired power station in southern Queensland and injecting it deep underground.
CO2 will be captured from the Millmerran power station, turned into a liquid form, and then trucked north to a storage well near the farming town of Moonie, more than 400 kilometres west of Brisbane.
Over the three-year trial, CTSCo plan to inject up to 110,000 tonnes of the waste CO2 each year into the Precipice Sandstone, a groundwater formation in the Great Artesian Basin (GAB), which is about 2,300 metres underground.
"CTSCo has deliberately identified a deep, low-quality aquifer that cannot be used for drinking or agriculture use," general manager Darren Greer said.
In its Environmental Impact Statement (EIS) lodged late last year, CTSCo said the water at the site was "saline, high in iron (long-term), high in fluoride, and high in total dissolved solids, and was unsuitable for aquatic ecosystems, and unsuitable for irrigation water, stock water, and drinking water".
Ken Cameron runs a major pork business on a property less than 10km away. He relies heavily on groundwater and has a licence to extract water from the same aquifer.
"This is a preposterous project that Glencore has got on the table," he said.
"Their proposal is to pump industrial waste into the Great Artesian Basin, and the Great Artesian Basin is the lifeblood of much of regional Australia."
Barb Madden, president of the Australian Lot Feeder's Association (ALFA), the peak body for some of Australia's biggest beef producers, said the proposal was a "major threat" to the GAB.
"Our biggest concern is the detrimental impact this project could have on the existing high-quality water within the aquifer," she said.
However, CTSCo's Darren Greer, maintained that "elevated" minerals "posed a risk of soil degradation" and the water at the site was "unsuitable for agriculture".
The water samples in the CTSCo EIS found that the total dissolved solids (TDS), including salt, in the water at its injection well in the Precipice Sandstone aquifer was about 1,800mg/L – official livestock water quality guidelines state that cattle, pigs and sheep can tolerate between 4,000 and 5,000mg/L of TDS respectively, without adverse effects.
Ned Hamer, a hydrogeologist with close to 30 years of experience, is currently subcontracted by farmer Ken Cameron.
He said calling the water at the site "saline" was "very misleading".
"The term saline makes it sound as though it's very salty and unfit for any use … that's not the case, the water quality there is very good for livestock, there is no doubt about it," he said.
"I don't have a problem with carbon capture and storage. I do have a problem with the injection of CO2 into the GAB," Mr Hamer said.
Elevated fluoride levels
CTSCo said there were other elements in the water at the site that made it unsuitable for livestock.
"The water contains naturally occurring elevated levels of sodium, chloride, fluoride, iron and boron," Mr Greer said.
"Fluoride levels are more than three times above the recommended upper limit for livestock consumption and more than six times above the drinking water limit for humans."
Neighbouring farmer Ken Cameron said the water quality of CTSCo's sample was actually higher quality than the water he was already using for his piggery.
"The fluoride levels and salinity of the water we're currently using of shallower aquifers, they're higher levels than the water in the samples they took … so it's a total nonsense," Mr Cameron said.
While the fluoride levels in the water were higher than livestock drinking water guidelines, hydrogeologist Ned Harmer said elevated levels of the chemical were common in the GAB.
"Fluoride is relatively easily removed from and treated from a groundwater supply if it was needed to be," he said.
For four generations the Cameron family has farmed and operated large-scale piggeries in southern Queensland.
Their Cameron Pastoral Company (CPC) holds a licence to extract water less than 10km from the same aquifer CTSCo is proposing to store waste CO2.
"Simple logic is those contaminants will flow from high pressure to a low-pressure area, it will turn up at our bore," Ken Cameron said.
But CTSCo's Darren Greer said the project was "not expected to impact any future water extraction at these landholdings".
"The two Precipice water licences held by the Cameron Pastoral Company are very small compared to the enormous volumes of water in the aquifer and cover landholdings located 10 kilometres or more from our proposed site," he said.
"As such, any future drilling undertaken by CPC would have negligible impact on the pressure in the Precipice Sandstone.
However in CTSCo's EIS it also states:
Future users should not be allowed to take groundwater supply from the zone impacted by the plume (Precipice Sandstone aquifer). This should include a zone around the impacted area from which water might be extracted by a well installed outside of the immediate residual impact zone. Although it is noted that the Precipice Sandstone is deep at this location and not likely to be used for water supply by regular users.
The Cameron Pastoral Company produces about 3,000 pigs each week and employs about 130 people.
With the water in the shallower aquifers in the area close to fully allocated, Mr Cameron said it made the groundwater in the deeper, harder-to-reach Precipice Sandstone even more valuable.
"That's our future, we've been building towards using that for our future growth," he said.
