Environment Victoria has criticised Victoria's environmental regulator for allowing TRUenergy to continue pumping muddy water into the Latrobe River in the state's south-east.
The Environment Protection Authority (EPA) has given TRUenergy permission to discharge water from its flooded Yallourn open-cut mine for another four months.
The EPA says the discharged water poses a low risk to fish, the river ecology and the Gippsland Lakes.
However, Mark Wakeham from Environment Victoria says pollution levels in the discharged water will increase as the mine is drained.
He says the EPA is looking after the business interests of TRUenergy rather than protecting farmers and the environment.
"The EPA should be trying to eliminate risks, not accept low risks to the environment, when the major issue that the EPA seems to be addressing is trying to restore business as usual at Yallourn rather than trying to protect the health of the river and downstream environment," he said.
"The risk will increase over time as the water is discharged and what's left in the pit is of increasingly poor quality, and also as the flows decrease in the Latrobe River and the proportion of discharge in the river increases as we move from spring into summer."
TRUenergy says it will comply with water quality and water volume limits set by the EPA.
It says there is still about 40,000 megalitres of water in the mine but it intends to leave about 10,000 megalitres there…