Planned water discharge from rehabilitated mine pit raises concerns

Posted 26 July 2018

LakeWith the decommissioned Hazelwood mine pit set to become a lake, environmentalists are concerned the rehabilitation process is not being managed appropriately following an emergency discharge licence application from the managing utility. 

Multinational energy utility ENGIE applied for an emergency discharge licence to take pressure off the Hazelwood Pondage dam wall, aiming to avoid damage to the 50-year-old structure.

The Environment Protection Authority (EPA) gave ENGIE permission to double the amount of water being discharged out of the pondage, from 150 to 300ML a day for up to 60 days.

Environment Victoria Campaigns Manager Dr Nicholas Aberle told La Trobe Valley Express he is concerned PFAS levels in the pondage could have serious public health impacts for local communities.

"PFAS could be the next asbestos. We won't find out the effects of these chemicals until further down the road, and until then, we should apply precautionary principles to manage exposure," Aberle said.

"How confident are we that these levels are genuinely safe? What are the long-term effects of low-grade exposure to this chemical? We may not know for the next 20 years."

The EPA advised that PFAS levels were below the 95% level required for ecosystem protection standards, arguing that additional flow would result in increased salt concentration, but with no ecological impacts. 

Aberele said that although the EPA and ENGIE are required to ensure discharges do not have negative effects on public health or the environment, he believes it is necessary for the authority to produce proof. 

"I assume that ENGIE and the EPA will make sure that whatever water is being discharged, there will be no impacts downstream. Let's get the evidence there will be no impact," Aberele said.

Aberle said it was concerning that ENGIE had allowed the dam wall to get to a state of emergency and he is unconvinced the utility could manage the full-pit lake in the Hazelwood mine void.

"ENGIE has a big challenge in the rehabilitation of the mine pit and people need confidence. If ENGIE cannot look after a wall in a dam, how will they look after an entire pit of water?” he said. 
"Why have pondage conditions become so frail that they need to have an emergency discharge? Why hasn't ENGIE been managing the wall for the past decade to ensure it is stable?"

An ENGIE spokesman said the company monitors water quality discharges from the pondage on a weekly basis as required by its EPA license.

"ENGIE Hazelwood continues to meet its regulatory obligations and is working with regulators, as required, on the final void rehabilitation," they said.

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