Campaigners are calling on the federal government to stop Santos from releasing untreated coal seam gas wastewater into a Queensland river that provides critical habitat to two species of threatened “bum-breathing” turtles.
The oil and gas company has approval to dig an additional 6,100 gas wells near Roma, in the state’s south west.
But the federal government ruled last year that the plan to pump resulting wastewater into the Dawson River must be assessed under the Environment Protection and Biodiversity Conservation Act, due to the “unacceptable” risk it could pose to the critically endangered, white-throated snapping turtle and the Fitzroy River turtle, which is listed as vulnerable.
Under its Fairview Water Release Scheme, Santos could release 18 megalitres of “reverse osmosis treated” CSG wastewater into the Dawson every day, as well as an unspecified amount of untreated wastewater during times of heavy flow, which could be up to 52 times a year.
A report by the Independent Expert Scientific Committee on Coal Seam Gas and Large Coal Mining Development (IESC), handed to the government in July, found that the release of untreated water could have “major impacts” upon about 12km of the Dawson River currently untouched by water releases, including directly and indirectly exposing the turtles to contaminants.
“The IESC considers that untreated produced CSG water should not be released into any surface waters, even during high flows, because of the risks of short- and long-term impacts of mixtures of chemical contaminants on downstream aquatic, riparian and shallow subterranean ecosystems,” the report found.
“Downstream legacy impacts of some of these contaminants are unlikely to be resolved merely by dilution, especially as the releases of untreated water are projected to potentially continue until 2066.”
The committee found that Santos had not identified some drilling chemicals which could be present in the released water, such as barium, and “did not fully consider the risk” of others such as the “acutely toxic” tributyl tetradecyl phosphonium chloride (TTPC).
The committee also found that the regular release of treated water could have a range of negative effects on the river, creating conditions that favour invasive species and further disadvantage the already stressed turtles.
Lock the Gate Alliance Queensland spokesperson, Ellie Smith, said the report provided “an opportunity” for the environment minister, Tanya Plibersek, to “show that she means business when it comes to protecting Australia’s environment and its critically endangered species”.
She said the “bum-breathing” turtles were species that practice cloacal respiration, a unique form of breathing that means the turtles, particularly juveniles, were extremely susceptible to changes in water quality.
“The recent state of the environment report showed the devastating decline of our native wildlife numbers and their habitat. This is an opportunity to put threatened species first,” Smith said.
Plibersek’s office referred questions to the federal Environment Department, which said the approval “of any project under the EPBC Act follows a rigorous assessment” and that Santos would require approval under the EPBC Act before it can proceed with its water release plans.
Santos will also be required go through a consultation period and receive public submissions prior to submitting its final assessment documentation.
The department could not say when public consultation would begin.
Ann Hobson, a resident of Theodore which sits on the Dawson River and Wildlife Preservation Society of Queensland member said the health of the river would be “life-giving for generations of communities for centuries to come”, but that “the gasfield was a “cash grab that will only line the pockets of shareholders and executives”.
“The turtles and the aquatic life that depend on the health of this river need our help,” she said. “They must not be sacrificed so Santos can make more money shipping gas off-shore.”
Santos has been contacted for comment.