A decision on the proposed continued pumping of water from the Yallourn open-cut mine into the Latrobe River is expected this week.
Environment Victoria has raised concerns about the impact of increased river turbidity since TRUenergy was given "emergency discharge approval" by the Environment Protection Authority in June following the collapse of the Morwell River into the mine.
With the current approval due to expire on Saturday, the EPA said it would make an assessment this week on whether TRUenergy's application for a further emergency discharge approval would be allowed.
If allowed, it is likely to extend the "discharge" period by another three months.
An EPA spokesperson said the timelines were "tight" and the EPA Act "requires us to act quickly".
Environment Victoria campaign director Mark Wakeham this week told The Age if another emergency discharge was allowed, it would have been "eight months during which the normal environmental standards for water released into the river will not have applied", which he said was "extraordinary".
Mr Wakeham expressed concern about confirmed increases in river turbidity (cloudiness of the water due to silt) and the impact this "could have on aquatic life".
This week the EPA said an "independent risk assessment" had found there was "low risk of ecological and environmental harm to the Latrobe River and Gippsland Lakes" but added "the situation remains serious and requires ongoing supervision"…
Help stop more coal mining disasters here >
Sign our petition asking the government to withdraw $5.5B compo from big polluters >