Coliban Water said it would respect the process and would work with the EPA as required.

"We acknowledge the concern the release has caused and we are focused on improving plant performance and protecting Campaspe River," managing director Damian Wells said.

"We have commenced upgrades at the Kyneton Water Reclamation Plant and we will bring the plant into a sustainable operating position."

Coliban Water said the charges related to the operation of its Kyneton Water Reclamation Plant from July 2018 to August 2019.

Earlier

Victoria's environmental watchdog has laid 11 charges against Coliban Water regarding the release of treated effluent to the Campaspe River.

The charges relate to discharges in May and August.

The Environment Protection Authority alleges the discharges caused an environmental hazard, polluted waters, and resulted in non-compliance with license conditions during 2018 and 2019.

Breaching licence conditions, causing an environmental hazard and pollution of waters are criminal offences under sections s27, s27A and s39 of the Environment Protection Act 1970.

Coliban Water said in April there was no sign it would be forced to discharge water of a "diminished quality" from the plant in 2019.

In early June, the water corporation advised it was likely to release treated trade waste water from the Kyneton Water Reclamation Plant.

The EPA subsequently cautioned residents not to drink the Campaspe River's water or use it for stock and domestic purposes downstream of the Kyneton Water Reclamation Plant.

The warning was lifted in July.

That month, Coliban Water said it was hopeful upgrades to its Kyneton plant would prevent releases of water of a diminished quality in future.

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