Cancer-linked chemical found at five times safe level in drinking water reservoir

Cancer-linked chemicals have been discovered at five times the incoming safe level in a reservoir used to top up the tap water supply in the upmarket tourist haven of Leura in the Blue Mountains.

On Monday, Sydney Water confirmed to the Herald it had drained two drinking water reservoirs in recent weeks after discovering the so-called “forever chemicals”, also known as PFAS, at levels exceeding proposed new safety guidelines.

Unsafe levels of PFAS have been found in a drinking water reservoir in the tourist village of Leura. The testing was conducted after pressure by community campaigner Jon Dee.Credit: Sitthixay Ditthavong

The agency said drinking water from the reservoirs was “rarely used”, and when it did provide “very limited supply”, it was blended with water from elsewhere, meaning tap water samples were safe.

Sydney Water carried out widespread testing of its reservoirs in the Blue Mountains in April, following demands by community campaigner Jon Dee. The agency has known for nearly 12 months that the region is a contamination hotspot. 

Dee was shocked to discover on Monday that the testing he called for had taken place and that the results had been quietly published on Sydney Water’s website.

“I’ve had to stumble on it myself. Nobody has been told,” said Dee, who convenes the local STOP PFAS action group.

Dee raised concerns with authorities in March that monitoring did not appear to have taken place in Sydney Water’s distribution network, which pipes treated drinking water from filtration plants to a series of storage reservoirs and then onto homes.

Dee said the levels in Leura reservoir were alarming and even higher than those that had mobilised a multimillion-dollar government response at the nearby Cascade Water Filtration Plant last year.

“Why has Sydney Water only started this wider testing now?” he asked. “What is Sydney Water doing to make sure that there is no PFAS residue left in these reservoirs?”

The two affected reservoirs are the Jamieson Reservoir on Cousins Lane at Leura and the Shipley Reservoir, near Blackheath.

The forever chemical perfluorooctanesulfonic acid (PFOS), deemed a probable carcinogen by the US EPA, was five times the incoming safe level at Jamieson Reservoir and twice the incoming safe level at Shipley Reservoir.

Jamieson Reservoir at Leura, where forever chemicals have been found at five times the incoming safe level. Credit: Sitthixay Ditthavong

Leura is a tourism magnet in cooler months. Travellers venture to the picturesque village to bathe at its day spas and dine at upmarket eateries.

A Sydney Water spokeswoman would not directly answer when asked how many residents were affected.

She said all the garden taps and all but two of the reservoirs sampled as part of its detailed monitoring program had met current and proposed Australian drinking water guidelines.

“Jamieson and Shipley reservoirs are rarely used, and provide very limited supply to customers, and returned results meeting the current guidelines but exceeding the proposed guidelines for PFOS,” she said.

“Jamieson Reservoir has only contributed to supply once in the last year.”

The spokeswoman said that when water had been supplied from the two reservoirs, it had been blended with treated water from the Cascade Water Filtration Plant, where a $3.4 million filtration unit was installed last year.

“This is why the garden tap results are within future guidelines,” she said.

“Even though this is the case, Sydney Water has implemented measures to reduce the presence of PFOS in these two reservoirs.

“This includes emptying the reservoirs and replenishing them with water supplied from Cascade Water Filtration Plant.”