UNITYWATER may face State Government penalties after its Murumba Downs Sewage Treatment Plant dumped 11.5 million litres of raw sewage into the Pine River on a fine day in late May.
The release, the largest since Unitywater began operating the system, prompted a review of all its sewage treatment plants including those on the Sunshine Coast.
A Department of Environment and Heritage Protection spokesperson said improvements to all plants have been implemented.
The release was caused by operator error and comes as the company is reducing staff across its operations.
The spill occurred on May 29-30 with the department notified on May 30. However there was no broader release of information to the public.
Environmental services consultant and SEQ Healthy Waterways Report Card architect Trevor Lloyd said the discharge would have broken down over a number of days.
He warned it was a symptom of a system that was struggling and a need to invest more in maintenance and new infrastructure before any plans were made to accommodate "pie in the sky growth projects that are being bandied about".
Infrastructure Minister Jackie Trad has indicated the review of the SEQ Regional Plan will determine how it can accommodate an additional 2.2 million.
The department spokesperson said it was still considering enforcement options as a result of the release.
"The department has a range of available enforcement options including warning notices, statutory orders or prosecution."
Unitywater said yesterday it had conducted a review and enhancement of the associated work instruction for the maintenance task across all treatment plants to ensure a similar event does not happen again.
Glen Babington of Unitywater said the review of alarm testing at all STP sites had been completed and complementary back-up alarm systems were being installed.
"This incident was temporary in nature and localised in an area where there was no easy public access," he said.
The spill occurred because of human error during a preventative maintenance task and alarm setting procedure.
"There is no evidence that the cause of the incident was a result of Unitywater failing to provide the necessary training and equipment to undertake the maintenance work,'' he said.
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