Digging into an Eyre Peninsula desalination plant to boost mining
A $15m government-funded business case for an Eyre Peninsula desalination plant is primarily aimed at delivering water to expand mining in remote areas and revisits an earlier plan abandoned by BHP.
BHP Billiton's Olympic Dam mine
On Wednesday the federal and state governments announced funding for a business case looking into the Northern Water Supply project.
The announcement flagged that the plan to consider a desalination plant and lengthy pipeline aimed to reduce pressure on the Great Artesian Basin and the River Murray, while supporting the hydrogen, mining, horticulture, pastoral and agriculture sectors.
Tender documents issued last year however indicate the Northern Water Supply project primarily sought to “underpin new resources development” with barely any mention of farming needs.
An Infrastructure Priority List document in the tender files defined the “problem” to be addressed solely as “water supply constraints [on] the expansion of mining activity” along with associated environmental impacts.
The document highlighted that the SA Government’s Copper Strategy proposes to triple copper production to a million tonnes per year by 2030.
A separate specification document noted that “there is unlikely to be any significant new or expanded minerals production in the Gawler Craton without a new water source. There is already growing community and investor pressure for mining companies to continue to limit their extraction of ground water.”
The tender proposal envisages bringing water to the Gawler Craton region in the Far North of the state, and potentially the Upper Spencer Gulf, via pipelines from a desalination plant near Whyalla.
The South Australian government on Wednesday announced it had entered into a MOU with SA Water, BHP and Oz Minerals to progress the business case to examine the desalination plant and alternatives.
“To be able to partner with some of South Australia’s biggest companies to decrease reliance on our finite water resources and future-proof our state in a changing climate is really pleasing,” said Premier Steven Marshall.
The state government has committed $10 million to the business case, with the federal government offering an additional $5 million.
The project could support up to 8000 construction jobs and up to 6000 ongoing jobs once operating, the state government claims.
The Northern Water Supply proposal echoes a BHP plan abandoned a decade ago to develop a Eyre Peninsula desalination plant and pipeline as part of a major expansion of the company’s Olympic Dam mine.
The copper, gold and uranium mine near Roxby Downs draws roughly 35 million litres a day of water from the Great Artesian Basin.
The BHP-funded expansion, which like the state government proposal considered Point Lowly as a site for the desalination plant, was abandoned by the mining giant over cost concerns.
In 2006 the BHP desalination plant and pipeline plan was estimated to cost $700 million — which equates to just over a billion dollars in 2022 terms.
The desalination plant would have required 35Mw of power and a further 22Mw to pump the water along a 320km pipeline to the mine site — or enough energy to power over 22,000 homes.
The tender documents for the new proposal also highlight Oz Minerals’ Prominent Hill Mine, which is a further 150km north-west of Olympic Dam, indicating a pipeline longer than 470km would be needed.
Long-running efforts to build a desalination plant on the Eyre Peninsula have been met with sustained local resistance.
Last November the South Australian government suspended plans for a desalination plant at Billy Lights Point in Boston Bay at Port Lincoln, following objections from the seafood industry and environmentalists.
Conservation Council of SA Chief Executive Craig Wilkins said desalination has significant environmental impacts.
“We are surprised that the Upper Spencer Gulf (USG) has already been identified as the preferred location, given the enormous environmental, social and community concerns raised last time this option was proposed,” he said of the latest proposal.
“Scientists and marine experts have previously raised concerns about the level of ocean flushing in the USG, and the flow-on impact that would occur to marine life, including iconic events like the Giant Australian Cuttlefish aggregation if salinity levels were to rise.”