Plans to dump up to 15m tonnes of salt and other waste near a creek in drought-stricken Queensland carry a “considerable” risk of water contamination, a new study has found.

Approved plans to expand a dump near the town of Chinchilla allow salt waste from coal seam gas operations to be stored fewer than 100 metres from Stockyard Creek, in the headwaters of the Murray-Darling Basin.

The expansion was signed off by the Queensland government and the Western Downs regional council last year.

How can you force a company to manage beyond the lifespan of the people who run the company? Professor Stuart Khan

Local graziers, community groups and environmentalists are now pushing for the federal environment minister to assess the project, under the provisions of the Environment Protection and Biodiversity Conservation Act.

Stuart Khan, an environmental engineering professor at the University of New South Wales, has completed a study for the NSW Environmental Defender’s Office that concludes there is considerable risk of water contamination.

“From a water quality management perspective, I would consider an operation such as this to be a high-risk operation,” the report says.

“The likelihood of contaminating groundwater and surface water over the long term is considerable. The responsibility for managing these risks over the long term will likely be inherited by future generations.”

Khan told Guardian Australia salt “does not biodegrade in the environment and has an infinite environmental residence time”. He said the stockpile in close proximity to Stockyard Creek would “need a management plan that runs for centuries”.

“How can you force a company to manage beyond the lifespan of the people who run the company?” he said.

Need for federal assessment

Proponents are responsible for referring their own projects to the federal environment minister if they are likely to have a significant impact on matters of national environmental significance, such as water resources.

The company that runs the dump, We Kando, has not yet sought an assessment under the EPBC act.

Guardian Australia understands the federal Department of Environment and Energy has recently written to the company “to ensure they were aware of their obligations”.

The Lock the Gate Alliance argues the plan meets the “water trigger” that requires assessment of mining or coal seam gas developments, including associated waste management, likely to have a significant impact on a water resource.

The national coordinator of Lock the Gate, Carmel Flint, said the government had the power to initiate an assessment in those circumstances.

“We believe it’s incredibly high-risk to locate this kind of facility so close to a creek that runs into the Murray-Darling Basin. We would expect the highest level of scrutiny on such a project.”

Flint says the approval of the salt dump is typical of state and federal approaches to coal seam gas development.

“The big problem with the coal seam gas industry is they’ve never had a viable plan to deal with their waste, yet they were approved to proceed without that.

“Now farmers … end up with this salt dump proposal next door to them. What’s needed now is an urgent review of waste management by the coal seam gas industry in Queensland.”

‘We don’t want another Linc Energy situation’

About 20km from the dump is the site of Queensland’s worst environmental disaster, the failed Linc Energy underground coal gasification plant, which earlier this year was hit with record criminal fines for contaminating nearby farmland.

Glen Beasley draws stock water from the creek about 5km from the We Kando site.

“We just don’t trust government or industry to reliably monitor or enforce any compliance whatsoever following Linc Energy,” Beasley says.

“When I market livestock I sign a national vender declaration that declares my product is safe for human consumption. I don’t know how I can continue to do that [given the risks outlined in Khan’s report].”

“Why do governments continue to allow these sorts of circumstances to unfold? Blind Freddy can see those risk are real.”

Flint says there are too many examples of mining and associated projects closing, leaving damaging environmental legacies, to leave “serious question marks” about the long-term management of the site.

“The Chinchilla region really has been treated with contempt in the way these industries have been forced on them, and they’ll have to live with the consequences,” Flint said.



We Kando was contacted and offered the opportunity to comment.

A spokesperson for the company last year told Fairfax Media that salt would be stored in fully contained mono-cells, with full monitoring and leachate detection.