Deep Water Bay on Hong Kong Island after Typhoon Mangkhut. Photo: Facebook/Lifeguards Union

Raw sewage has been flowing into the sea near Deep Water Bay and Shek O on Hong Kong Island after typhoon Mangkhut damaged sewage treatment facilities.

The government said sewage treatment facilities in Sai Kung in the New Territories and Deep Water Bay on Hong Kong Island had been damaged by typhoon Mangkhut and would take time to repair.

Pipes and secondary treatment facilities at the Sai Kung Sewage Treatment Works were damaged, meaning the facility could only maintain primary sewage treatment, according to a joint release by the Drainage Service Department and Environmental Protection Department on Thursday.

An additional disinfection process had been arranged before discharging wastewater near the shore. However, an inspection revealed it may take weeks to fix the damaged facilities.

The Leisure and Cultural Services Department announced that three beaches in the Sai Kung area – Kiu Tsui Beach, Trio Beach and Hap Mun Bay Beach – as well as Deep Water Bay Beach and Shek O Beach, would be temporarily closed until further notice to clean up the debris after the typhoon and repair the shark prevention nets.

In Deep Water Bay, sand was washed onshore and buried the entire changing room and shower room. The lifeguard towers on Shek O beach collapsed, while floating platforms ended up on the beach, Headline Daily reported.

Shek O on Hong Kong Island. Photo: Facebook/Lifeguards Union

The Environment Department collected seawater sample at three Sai Kung beaches, Deep Water Bay Beach and Shek O Beach for testing to check the water quality.

As the sewage bypass and overflow may lead to temporary deterioration of seawater quality in the vicinity, people were being urged not to swim, fish or engage in any water sports in these areas.