A Chinese mining giant is being accused of underestimating the impact a proposed open cut mine will have on groundwater on the New South Wales Liverpool Plains.
The University of New South Wales' Water Research Laboratory conducted a study into the Shenhua Watermark Mine's environmental impact statement (EIS), and in particular its findings around the project's potential effect on water.
The research was commissioned by the Caroona Coal Action Group (CCAG), which is opposed to the project.
The study has found that the modelling used by the mining company was flawed, because it relied upon incorrect data on the storage volume of groundwater aquifers.
"The values used were implausibly high based on our research," Ian Acworth, UNSW Emeritus Professor, said.
Dr Acworth peer-reviewed the UNSW study.
"If you say that the aquifer is capable of producing far more than it really can, then the impacts of any extraction are going to become very much more restrictive," he said.
Dr Acworth said that based on UNSW's study, the capacity of these aquifers is a lot smaller.
"If the ground cannot produce the water locally it has to come from further afield," he said.
The UNSW is confident that its modelling is correct and is not only relevant to mining projects, but any abstraction from a water source.
Environmentalists' concerns that groundwater abstraction will impact upon connected systems, surface water/groundwater connected systems, is [sic] correct," Dr Acworth said.
While the report was commissioned and funded by the CCAG, stakeholders claim it is independent.
Committee member and farmer Graeme Norman said the report was peer-reviewed and the research is accurate.
"It is independent because the Government won't do these reports themselves, it is up to us to fund these reports otherwise they don't get done," he said.
Dr Acworth said the CCAG asked a qualified expert to break down the original data.
"[They] found it a little bit heavy on detail, which is what it ought to be for an international scientific journal, and they just requested basically some further work to explore the impacts," he said.
"This is not new work as such — basically, it's just using the specific storage data and showing what will happen if models don't use the correct data."
Take 'damning' report seriously
The CCAG has been fighting Shenhua's Watermark proposal for more than a decade.
Landholder and CCAG chair Susan Lyle addressed a roomful of people at the Breeza Hall, and said the report confirmed their worst fears.
"We have never expected that mining below the aquifers would result in zero harm for our groundwater."
Fellow committee member and farmer Graeme Norman runs an operation north of the Shenhua mine site, on the Breeza plains.
Mr Norman said the figures in the new report would be detrimental to the underground water supply for households and primary producers.
He said figures suggested that Shenhua had overestimated that there was between 100 to 1,000 times more groundwater in the impact zone than what there actually was.
"Basically it means that the drawdowns in and around Shenhua will be way above the 1.8 metres that they forecast and it also means the impact area will be extended further away," Mr Norman said.
"Add to that the 25,000 tonnes of salt produced by the mine each year that will be entering into the aquifers … the concentration of salt in that groundwater will be significantly higher."
The next step
The research has triggered a call for Shenhua Watermark to reassess the mine's potential impact on water.
"If the EIS has used values of storage which are magic pudding-type values, then the work needs to be redone to see what the true environment impacts were," Dr Acworth said.
"Then society is able to make a better informed judgement about whether any project like this should go ahead."
The CCAG has now sent the report to ministers on both sides of Government.