Harbour Area Treatment Scheme

The Harbour Area Treatment Scheme is collecting and treating the sewage on both sides of Victoria Harbour. Here you can learn about why the scheme was implemented, its phases and what the polluter pays principle is doing to help improve the water quality of our world renowned harbour.

The Situation

As the water quality in Victoria Harbour affects many people in Hong Kong, the Government initiated the Harbour Area Treatment Scheme. The scheme coordinates the overall sewage collection on both sides of the harbour, which is no easy task given the size of the catchment area. So implementation has been split into stages, with the first stage beginning operations at the end of 2001.

Frequently asked questions about the Harbour Area Treatment Scheme

Stage 1 and its Accomplishments

Stage 1 of the Harbour Area Treatment Scheme treats 75% of the sewage discharged into Victoria Harbour. The infrastructure includes a 23.6 kilometre-long system of deep underground tunnels, with the capacity to move up to 1.7 million tones of sewage from Kowloon and the northeastern part of Hong Kong Island to Stonecutters Island. The treatment facility at Stonecutters is one of the largest of its type in the world. With Stage 1 fully commissioned in December 2001, the overall harbour water quality has substantially improved, which means that you can enjoy a cleaner harbour.

Sludge treatment facility at Stonecutters Island Sewage Treatment Works

More on Stage 1 of the Harbour Area Treatment Scheme

Stage 2A

However, some 25% of the sewage entering the harbour is still not adequately treated. After a period of public consultation, the Government developed a programme at an estimated cost of 17.5 billion to treat all sewage from the northern and southwestern areas of Hong Kong Island. Under Stage 2A of the Harbour Area Treatment Scheme, the preliminary treatment works on the northern, western and southwestern shores of Hong Kong Island are being upgraded. Construction of a tunnel system to move the currently preliminary-treated sewage to Stonecutters Island, where the existing chemical treatment process would be expanded and new disinfection facilities added. The Stage 2A construction works commenced in 2009, and the relevant facilities were commissioned in 2015.

Map showing the scopes of HATS Stage 1 and Stage 2A

General information on Stage 2A of the Harbour Area Treatment SchemeMore details on Stage 2A of the Harbour Area Treatment Scheme

Stage 2B

The Government has completed a review of the implementation of HATS Stage 2B (the Review) which is to provide for an underground biological treatment facility adjacent to the existing SCISTW.  The Review reveals that HATS Stage 2A has already provided adequate capacity to handle the projected sewage flow and the bulk of Victoria Harbour will be in compliance with the Water Quality Objectives (WQOs) upon its commissioning.  The Review thus concludes that in terms of WQOs compliance, the implementation of HATS Stage 2B at this stage is not critical.  Meanwhile, the implementation of HATS Stage 2B will be kept under review taking into account the water quality situation and the latest technological development in biological treatment.

The Polluter Pays Principle

The Harbour Area Treatment Scheme and other sewerage facilities require a significant amount of resources for daily operation in order to sustain our efforts for protecting the marine environment. In accordance with the polluter pays principle, those who create waste have a responsibility for helping to pay to clean it up. We have been applying this principle in the provision of sewage services through implementation of the Sewage Services Charging Scheme, under which we currently recover only part of the operating cost through collection of sewage charge and trade effluent surcharge. The deficits are subsidised by the Government.

More on the polluter pays principleMore on sewage treatment and charges
Last revision date: March 2016