THE operator of the Goodna Sewage Treatment Plant has apologised to residents and business owners for mistakenly releasing more than 60,000 litres of sewage into the Brisbane River.
Queensland Urban Utilities issued the apology on Saturday, six days after the spill and just one day after the company confirmed the incident had actually happened.
The release was caused by a valve fault during plant commissioning, a QUU spokesperson said.
The spokesperson said the fault "led to a combination of 63,000 litres of partly and fully treated sewage being released for approximately five minutes into the Brisbane River".
Ipswich councillor Paul Tully said QUU should notify the community of any future incidents as they happened.
"It's good they've apologised, but they should ensure they notify people of issues immediately in the future," Cr Tully said.
"I think people realise accidents do happen, but if people are told (of accidents), they can take precautions.
"People swim in the river a kilometre away and they should've been informed."
The QUU spokesperson said the company adhered to environmental guidelines.
"At the time of the incident, the Department of Environment and Heritage Protection was notified and sampling of the outflow and waterway took place."
Department test results showed minimal impact to the waterway due to a speedy shut-off, QUU said. The spokesperson confirmed the water quality of the Brisbane River remained at a suitable level for recreational activities including boating and fishing.
Thiess is conducting a major upgrade of the plant.
The spill followed a project update in The Queensland Times last week, in which QUU chief executive Louise Dudley said the upgrade would reduce the plant's environmental impact on the river.
Ms Dudley said the upgrade would increase the plant's capacity by about 40%, allowing it to cater for population growth.