Central Highlands Water and the privately-owned Canadian multinational McCain are refusing to answer questions about the nature of the discharge and any penalties imposed.

CHW has also declined to answer questions about the frequency of unauthorised sewerage discharges by Ballarat’s biggest companies.

CHW chairman Jeremy Johnson confirmed the incident happened in September when “non-compliant” waste from McCain was received at the Ballarat North treatment plant.

Mr Johnson said the waste, received through the sewerage system in September, was diverted into an offline holding basin after being detected.

He said CHW requested McCain to collect the material and dispose of it off-site according to environmental guidelines.

Mr Johnson’s remarks followed those of a CHW public affairs spokesman who dismissed the incident last year, saying it was nothing unusual.

But a list of questions from The Courier to CHW’s public affairs section last week remain unanswered.

These included:

What caused the discharge of unauthorised material into the city’s sewerage system by McCain?

What was the material discharged? How much was there?

How long did it take for the situation to be rectified?

What was the cost to CHW? Were these costs passed onto McCain?

CHW even declined to confirm whether McCain was its biggest commercial client.

Part of a statement issued by the water authority said the incident posed no threat to public health or environmental standards.

The unauthorised discharge was managed as part of “normal standard operational procedures”, the statement said.

A statement from McCain was also short on detail.

“McCain Foods has an agreement with Central Highlands Water to treat discharge from the Ballarat plant,” it said.

“All waste has been managed within the guidelines set out by the Environment Protection Agency.

“At no time has McCain Foods been fined.”