Toward a healthier harbour: Secretary for the Environment, Transport & Works Dr Sarah Liao says HATS Stage 2 is necessary to improve water quality - and re-open Tsuen Wan beaches.

Secretary for the Environment, Transport & Works Dr. Sarah Liao has announced a four-month public consultation exercise for the Harbour Area Treatment Scheme (HATS) Stage 2.

HATS Stage 1 is now treating 75% of the sewage generated from both sides of  Victoria Harbour while the remaining 25% is still being discharged into the Harbour almost untreated. "This is not sustainable environmentally. We need to implement HATS Stage 2," Dr Liao said. 

Stage II will comprise:

* Extension of the deep tunnel network to collect and convey sewage from the remaining parts of Hong Kong Island for proper treatment;

* Expansion of the existing chemical treatment capacity from the present design level of 1.7 million cubic metres daily to 2.8 million cubic metres

* provision of disinfection to all HATS treated effluent before the effluent is discharged into the Habour; and

* Upgrading to biological treatment for all HATS flows.

To improve the harbour as early as possible, the bureau recommends implementing Stage 2 in two phases, completing Stage 2A at the earliest possible time.

This stage will see the extension of the deep tunnel network, expansion of the existing chemical treatment capacity and provision of disinfection - and will cost $8.4 billion to construct and $440 million a year to operate.

Sewage treatment facility upgrade slated for completion by 2012

The Government hopes to complete the upgrading of the sewage treatment facilities by 2011/12.  The more challenging tunneling works are expected to be completed by 2013/14, Dr Liao said.

"By completing Stage 2A, we will be able to achieve most of our water quality criteria in the majority of the harbour area, leading to a healthier marine environment. This will enable us to re-open and sustain the public enjoyment of all the Tsuen Wan beaches as well as to conduct ad hoc events such as cross-harbour swims," she added

Stage 2B is necessary to cope with population growth and sewage flow build-up. The Administration intends to build biological treatment facilities at a site near Stonecutters Island Sewage Treatment Works. The proposed facilities would be built underground to allow for other uses or co-development on top. Stage 2B will cost $11.1 billion to construct and $720 million to operate.

Planning of second stage shouldn't interfere with earlier one

"The Government is fully committed to Stage 2B even though we propose to implement it when the actual need arises. To demonstrate our commitment, we will not only closely monitor the actual sewage flow build-up and harbour water quality monitoring results, but also make preparations for Stage 2B in parallel with implementation of Stage 2A," Dr Liao said. 

"The biological treatment facilities under Stage 2B are both complex and costly and we need to find extra space for them. It is therefore prudent and important to allow ourselves more time to plan them carefully so that we can build the right system in a cost-effective manner to serve the long term needs of Hong Kong. An equally important consideration is that we do not wish to let the planning of Stage 2B hold up the commencement of Stage 2A, thereby delaying the improvement to our harbour water quality."

HATS Stage 1 is now collecting and treating the sewage collected from the entire Kowloon, Tseung Kwan O and part of Hong Kong Island including Chai Wan and Shau Kei Wan. Stonecutters Island works is one of the most efficient chemical treatment plants in the world, with an organic pollutant removal rate above  70%.  It is now treating 1.4 million cubic meters of sewage and effectively stopping 600 tonnes of sludge from entering the harbour every day.

Initial steps have improved harbour water quality significantly

Since the full implementation of HATS Stage 1 in December 2001, the harbour water quality has improved significantly. The compliance for the dissolved oxygen water quality objective in the harbour area has increased from an average of 55% in 1992-2001 to 97% in 2002-2003.

The level of pollutants in the harbour has also decreased significantly. Toxic ammonia levels fell 25% and the E.coli level - an indicator of disease-causing bacteria - fell 50% overall.

In 2000, the Government invited an International Review Panel to carry out a review of further stages of HATS. The panel proposed four options for siting the sewage treatment facilities, assuming different degrees of decentralisation, and recommended the Government carry out a series of trials and studies to determine the way forward. 

Of the four options, the Government prefers Option A, to transfer all the sewage to the Stonecutters Island for centralised treatment because it is the most cost-effective, technically sound, socially acceptable and environmentally friendly.

Positive impact reaches as far as Shek O beach

Although Stage 1 has brought about significant water quality improvements in the harbour area and its positive impact has reached as far as Shek O beach, the beaches at Tsuen Wan are still being affected by local discharges and un-disinfected effluent, rendering them not suitable for swimming.

To alleviate the problem, the Administration proposes to speed up part of the disinfection facilities of Stage 2A for completion by 2008/09 to enable the early re-opening of the Tsuen Wan beaches.

Dr Liao stressed that sewage treatment was always costly and a fair cost-sharing arrangement in line with the Polluter-Pays principle would need to be worked out at a later stage.There is a need to forge a general consensus within the community and the public is encouraged to give their views and comments on the way forward for HATS.

Consultation period ends on October 20

The four-month public consultation exercise on HATS Stage 2 will last until October 20. In-depth briefings will be provided to key stakeholders such as green groups, academics, professional bodies and community representatives. The bureau will also hold a public hearing to collect the views of the public directly on the proposed way forward for HATS Stage 2.