More than 600 million litres of under-treated sewage was released into Tasmania’s waterways in 2024-25, newly compiled data shows, including millions of litres upstream from one of the state’s most popular swimming spots.
The figures were compiled by Environment Tasmania, which has launched an interactive map called ‘Map the Crap’ using TasWater’s own records.
The data shows TasWater released more than 47 billion litres of wastewater into Tasmanian waterways over the year.
Of that, 635,793,000 litres was under-treated sewage released during so-called bypass events.
During a bypass event, sewage skips secondary treatment, a critical step that helps make it safer before release.
Bypasses typically happen during heavy rainfall or when equipment fails.
Environment Tasmania freshwater campaigner Lucy Tremain said the volumes were alarming, particularly from the Prospect Vale plant above Launceston’s Cataract Gorge.
“Over 27 million litres of under-treated sewage was dumped above Launceston’s key tourist destination, Cataract Gorge, putting locals and over 400,000 tourists at risk of exposure to harmful pathogens and toxins,” Tremain said.
The Cameron Bay plant discharged about 36 million litres, clouding waters near MONA in Hobart’s north, while the Ti Tree Bend plant released more than 338 million litres into the Tamar River.
The group has launched a petition calling on the state government to fund real-time monitoring equipment at all plants, which would alert the public to bypass events.
“Under-treated sewage from bypass events poses a real risk to human health, while also devastating Tasmania’s precious waterways,” Tremain said.
“All Tasmanians have the right to make informed decisions about their health, including if they are being exposed to this under-treated sewage.”
Deputy Premier Guy Barnett said the issue was a concern, but ultimately one for TasWater.
“There are clear guidelines and clear rules that apply to protecting our environment here in Tasmania and TasWater is subject to those requirements,” Barnett said.
He said the Launceston City Council monitored water quality at the Gorge over summer, which he welcomed as a regular swimmer there.
“TasWater must comply in every respect and Tasmanians could and should be confident of that going forward,” Barnett said.
TasWater plans to invest more than $1 billion over the coming years to improve its ageing sewage network.
The utility’s general manager of sustainable infrastructure services, Matt Derbyshire, said reducing bypass events was a key priority.
“While nobody wants to see them happen, they are an important safeguard that helps protect the wider sewerage network and reduce the risk of more serious environmental or public health impacts, including blockages that can impact private plumbing,” he said.
“We know Tasmanians expect better outcomes for their waterways and so do we.”
He also pointed to more than $314 million spent on the Selfs Point Sewer Transformation and $140.7 million on the Tamar Estuary river health action plan.
“We will continue to work closely with environmental and public health authorities and remain committed to delivering long-term infrastructure upgrades for Tasmania,” Derbyshire said.
