Unitywater Acting Executive Manager Sustainable Infrastructure Solutions, Ivan Beirne, said the wastewater network is designed to take minor additional flows from wet weather, but too much can lead to overflows, posing a risk to public health and the environment.
“This program was designed to minimise the volume of stormwater that enters the wastewater network during heavy rain to help reduce the risk of overflows on private property and in the environment,” he said.
The program, which began in July 2021, has seen 38,000 properties investigated, with eight percent of these found to have plumbing defects including incorrectly installed or poorly maintained Overflow Relief Gullies (ORG) and illegally connected downpipes.
“Our smoke testing program has been an effective way to mitigate stormwater inflow and infiltration into our wastewater network and with 81% of the private plumbing defects now rectified, we’ve seen an annual reduction of 18% – the equivalent of 548 million litres reduced,” Mr Beirne said.
“The testing identifies any defects in Unitywater’s wastewater maintenance holes as well, which we can then fix. We have already inspected 12,700 of our maintenance holes which can have tree roots intrude them or come loose, allowing excess water to flow into them.”
The tests involve blowing a non-toxic, non-flammable, artificial smoke through the pipes which emerges at select vents, or through breaks or cracks which alerts crews to a problem.
“A purpose-built analytical tool that evaluates the performance of each wastewater pump station during rainfall events determined which suburbs would undergo these investigations,” Mr Beirne said.
He said residents didn’t need to be home for the investigation but could expect a notification card in their mailbox two weeks prior. If a defect is identified, Unitywater will then communicate the findings and request customers take reasonable steps to address the issues.
“Most people aren’t aware they have any issues with their plumbing connections and are happy to fix them for their own benefit as well as their neighbours and the broader community,” he said.
Unitywater has contracted Regional Australian Infiltration Network (R.A.I.N) to carry out these tests, which will be completed this December, in the following suburbs:
- Bokarina
- Buddina
- Caloundra West
- Clontarf
- Everton Hills
- Ferny Hills
- Golden Beach
- Little Mountain
- Meridan Plains
- Minyama
- Moffat Beach
- Mountain Creek
- Parrearra
- Pelican Waters
- Warana
Residents can learn more about Unitywater’s smoke testing program at www.unitywater.com/sewer-network-testing
