Sydney’s remaining “outfalls” – which discharge industrial wastewater, stormwater and sewerage into the ocean – could pose a “very high” risk to our health, according to a report commissioned by Sydney Water.

The independent pollution study, published this month, looked at the last three remaining cliff-facing wastewater outfalls in Sydney, which are located in Vaucluse and Diamond Bay in Sydney’s east. It confirmed they currently discharge “untreated wastewater into the ocean”, collected from 10,500 people living nearby. Visible trails from the sewage outlets were found in the water, its plume “larger than previously understood”.

Next time you take a dip, go scuba diving or fish below the rocky outfalls in these locations, you might come in contact with what can be described as “brown fuzz”. Toilet paper, sanitary products and wet wipes have also been found floating on the water surface.

The “brown fuzz” is a mixture of algae, bacteria and hydroids (a jellyfish-like species), which the report found rated a “very high” risk to people’s health, with the potential to cause gastroenteritis and infections, as well as a “high” risk to the environment.

“The three outfalls are difficult and dangerous to access. As soon as we learned in 2016 that some people were accessing the area for recreational purposes, we worked with NSW Health to distribute a fact sheet to user groups and installed signage near the outfall,” a Sydney Water spokesperson told Broadsheet.

The study reported around 2000 people come into “primary contact” with the sewerage by swimming, spearfishing and scuba diving underneath the ocean outfalls every year. A pollution study found 100 people fish from boats (and consume their catch) in this area on average each month, too. The Bondi to Watson’s Bay ocean-paddle event also sees 100 or so people travel through this particular stretch of water.

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So, where to from here? The community will be consulted in the next month to determine whether the outfalls should be closed, or continue operating.

“We need to review these options and consider new technologies that could reduce impacts on residents, while still delivering a cost-effective solution,” says the spokesperson. One option flagged to manage the discharges from Vaucluse and Diamond Bay was transferring wastewater to Sydney Water’s Bondi Wastewater Treatment Plant to be treated.

In the meantime, other measures have been put in place, including the installation of additional signage near the outfalls to advise the community not to access the area.

The silver lining? The Sydney Water spokesperson confirmed the water quality at nearby swimming beaches (including Bondi) remain “good” or “very good”.

Sydney Water is slated to complete its review by the end of next year.

With additional reporting by Lucy Booth.