The New South Wales government will stop dumping sewage into ocean just north of Bondi Beach.

Premier Gladys Berejiklian on Sunday announced the three last ocean outfalls in the state would be cut, months after a Sydney Water report revealed they posed a “very high risk” to about 2000 people a year.

The pipes in Vaucluse and Diamond Bay spit out four million litres of untreated waste from 10,500 people each day, as well as toilet paper, sanitary products and wet wipes.

It’s expected to take up to 10 years to reverse the impacts to the environment, Sydney Water said in its March report.

The sewage will be diverted to a treatment plant in Bondi, at a cost of $86 million.

A spokesperson for Utilities Minister Don Harwin said work would start in 2019 and finish in 2020.

The outfalls dump four million litres of waste in the ocean each day. Photo: Recreational Fishing Alliance of NSW/ Facebook

“These outfalls are a legacy from Sydney’s early wastewater network. While there’s no easy way to fix them, we take our responsibility to protect the environment and public healthy very seriously,” Ms Berejiklian said in a statement on Sunday.

The Sydney Water report in March said about 2000 people a year swim, fish and scuba dive near the outfalls.

Those people were found to be at a “very high” risk, with “significant risk of high levels of illness transmission”.

The aquatic ecosystem in the immediate vicinity was at a high risk.

A “visible plume” of sewage sometimes extends 100 metres out into the ocean.

“As the discharge wastewater is not treated, there is no capture of solid materials (eg toilet paper, sanitary products, wet wipes). These can be visible on the water surface and in the water column,” the report found.

There is no indication of any impact on beaches from the outfalls, built between 1916 and 1936.

Beachwatch last month rated nearby Bondi Beach as having good water quality.

The waste from residents in Watsons Bay, Vaucluse, Diamond Bay, Rose Bay North and part of Dover Heights represents 0.3 per cent of Sydney Water’s total waste discharges.

Environment Minister and local member Gabrielle Upton said the problem had “sat for too long in the too-hard basket”.

“This is something my local community and I have been campaigning about for years and I am proud as local member to help deliver this outcome,” she said.

The outfalls were built in 1916 and 1936. Photo: Sydney Water