‘There will be contamination’: Water scientist joins farmers in concern over wastewater pipeline

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Lithgow’s Centennial plant has always had a problem: what to do with the millions of litres of contaminated wastewater generated by its longwall coal mining operation.

Up to 350,000 litres of treated wastewater is being discharged each day into the Sydney water catchment under an Environment Protection Authority licence.

But an ambitious long-term solution for this water has caused angst for scientists and Central West farmers.

The plan, developed by Regis Resources, involves the construction of a 90-kilometre pipeline, which would ship the water from the coal mine to the state’s west.

Regis McPhillamys’ gold mine at Blayney, not far from Orange, is in negotiations to take the water from Centennial Coal over an 11-year agreement, across 112 aquifers and waterways.

The mine would bring jobs to the town as well as investment in infrastructure and the community.

Regis argues the water is “stock quality”, and that its transportation poses minimal risk to the surrounding farmland.

A pool of stagnant orange coloured water A pool of stagnant orange coloured water
Wastewater pools at Blackman’s Flat, at the entrance to Centennial Coal’s Springvale Coal Services in Lithgow.(ABC Central West: Luke Wong)

But Dr Wright, who has studied the water slated to travel through the pipeline, disputes this and said the risk was too great.

“It’s a 80 to 90-kilometre pipeline so it transits a lot of country and there are big elevations involved, which means that there’ll be some high-pressure plumbing. I’ve worked in the water industry; all pipes and pumps at some point fail,” he said.

“And when you’ve got such hazardous levels of metals, even a one to 100 dilution, the sort of nickel-zinc levels in here could be really dangerous to aquatic life and could build up in the soil.”

In a statement, Centennial Coal told the ABC that a water offtake agreement was close to being finalised with Regis Resources, using water extracted during the mining process that was surplus to requirements.

A pool of stagnant water A pool of stagnant water
Water pooling at Blackman’s Flat in Lithgow, at the entrance to Centennial Coal’s Springvale Coal Services.(ABC Central West: Luke Wong)

A dam on the headwaters

The Regis McPhillamys proposal includes a plan to build a tailings dam on the Belubula River’s headwaters.

A graphics slide showing a mining operation A graphics slide showing a mining operation
An overview of the proposed Regis McPhillamys gold mine, near Blayney in central west NSW. The tailings dam can be seen sitting over the Belubula River headwaters.(ABC: Landline)

Tailings are a by-product of gold mining and are created when rock is pulverised to separate valuable gold from rock.

Chemicals — such as cyanide — are added to the ground rock to assist in the separation.

The gold is then removed and the finely crushed rock and chemical slurry left over is dumped in a tailings dam.

Rebecca and David Price farm downstream of the proposed Regis McPhillamys operation, on the banks of the Belubla River.

They said the proposed tailings dam location and the proposed pipeline could threaten their farming operation and the wider river system.

“There are two reasons it’s going to leak into the system,” Ms Price said.

“The first reason is that they actually designed the tailings storage facility to leech under the wall, albeit at a very slow rate, but they have designed it to do so.

“The second is that there are over 25 springs under the tailings storage facility – that’s where the majority of the springs that feed this river lie.

“The risk of the springs being contaminated and them not being able to monitor that is a very real risk for us.”

Regis declined an interview with the ABC but in a statement said extensive investigations had been undertaken around the mine operation site, and that the design of the McPhillamys tailings dam had been peer reviewed by international experts.

Regis said it was confident the tailings dam design met best practice and was being engineered to the highest dam safety criteria.

But that’s not enough to convince Dr Wright.

“There are just so many questions here about the leakage from the site, there will be contamination, I’ve never seen a mine site that doesn’t lead to some form of contamination,” he said.

“There are serious issues about how this will affect plant growth and also livestock.

Water allocation a ‘game of musical chairs’

The Regis McPhillamys development proposal was lodged in 2016, in the middle of an unprecedented drought in NSW.

That drought, and the project’s water demands, have kept it on Minister for Planning Rob Stokes’ desk for five years and a decision is not due until 2022.

“Water is one of the major concerns that’s been raised by the community — and it’s also a concern for the regulator to make sure those impacts on water into the longer term are properly addressed,” Mr Stokes said.

An aerial shot of a riverAn aerial shot of a river
The Belubula River snaking through the Prices’ property in Blayney, Central West NSW.(ABC Central West: Luke Wong)

Regis is currently in talks with the NSW government to bolster the project’s water supplies via a large surface water licence — meaning accessing water that normally flows into the Belubula River during rain events.

It comes at a time when the NSW government data shows rivers in NSW are on a drying trend.

“We’re playing a game of musical chairs here,” Mr Stokes said.

“Every time the music stops, there’s one less chair — we’re dealing with less water over time.

“The good news is there’s a lot we can do to increase water use efficiency. But there’s not a lot we can do to increase the amount of water.”

Mining’s legacy

In a statement, Regis told the ABC that “mining and farming have coexisted in the NSW Central West since the mid-1880s, including the Kings Plains area where gold was first discovered in 1851”.

They pointed out that “the McPhillamys’ site includes a number of old [mine] workings”.

An aerial picture of subsidence caused by mining.An aerial picture of subsidence caused by mining.
A drone reveals subsidence occurring in mine-owned farmland at the Newcrest Cadia goldmine.(Supplied: Max Phillips)

But for families that had farmed the region as long as it had been mined, that legacy was what concerned them the most.

For David Price, neighbouring goldmine Newcrest Cadia was a living example of how fraught farming alongside a mining operation could be.

“You’ve only got to look — Cadia’s wall broke two years ago,” Mr Price said.

A neighbouring mine

Stuart and Gem Green’s beef and lamb grazing operation is in a neighbouring valley to the Prices, 35km from the proposed Regis gold mine at Blayney.

The Greens have farmed alongside the Newcrest Cadia goldmine — one of the biggest gold mines in the world — in relative harmony for 20 years until Newcrest Cadia’s tailings dam wall failed in 2018.

Two people sit side by side in an interviewTwo people sit side by side in an interview
Stu and Gem Green farm alongside the Newcrest Cadia goldmine, near Orange in Central West NSW.(ABC Central West: Luke Wong)

Their property was routinely covered in tailings dust as a result and the Greens were concerned about the long-term environmental effects of the wall fail.

“This dust that’s coming across is called a PM 2.5, which is that fine it’s dissolvable and can pass through membrane walls,” Mr Green said.

“And to be very clear — we’re not talking about red dust that blows in from the west during drought events. This is a material that blows off the surface of a tailings dam that’s created as a by-product of a chemical reaction in the process of extracting gold from ore.

“It’s not dirt.”

March 2021 dust lift CadiaMarch 2021 dust lift Cadia
Tailings dust lifts off the surface of Newcrest’s Cadia Valley Operations on March 18, 2021.(Supplied: Gem Green)

In a statement, Newcrest Cadia told the ABC they “don’t take their position in the community for granted and continually strive towards improving ways in which they can work with their neighbours to successfully and positively coexist”.

The company said it “appreciates that mining and agriculture have a long intertwined history”, and that they “want to play their part in … shaping the future of the region”.

Less margin for error

The Greens said the changing climate complicated the relationship between mining and agriculture and that there was simply less margin for error.

“I think resources are limited,” Stu Green said.

“Climate modelling has it that it is going to get dry, so these resources and particularly water are going to become more scarce and more valuable.”

Current mining methods had Stu Green and Rebecca Price concerned there was no longer enough to go around.

“That mine over there carries on whether it’s the worst drought or the wettest year, their production doesn’t alter,” Mr Green said.

“How long can that go on for?”

An aerial shot of cattle crossing a riverAn aerial shot of cattle crossing a river
The Prices’ beef cattle cross the Belubula River.(ABC Central West: Luke Wong)

Mining, said Rob Stokes, was not going away.

But he agreed the nation’s already compromised natural resources would require more scrutiny for planning proposals in the future.

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