Review of standards governing seawater

PUBLISHED : Saturday, 26 September, 2009, 12:00am
UPDATED : Saturday, 26 September, 2009, 12:00am

The city's 22-year-old quality objectives for marine water are to be revamped under a review launched by the government yesterday that might lead to different standards for different places, depending on their uses.

The review will explore issues involved in tracking health risks at bathing beaches, the need for separate standards for fish-culture zones or marine parks, and introducing quantitative criteria for toxic water pollutants.

The outcome of the review will also have a bearing on a multibillion-dollar sewage treatment plant planned for Victoria Harbour beyond 2013.

Elvis Au Wai-kwong, assistant director of the Environmental Protection Department, said yesterday the review was needed because of new marine pollution science, technologies and practices and changing use of the seas over the past two decades.

'We have been closely tracking all these developments and it is time we moved on to see what improvements we can achieve,' Au said.

A three-month push to engage the public on the issues would be launched and a public seminar would be held on October 31 to seek opinions. The exercise would be followed by further studies on proposals, decisions on objectives and methods by which to attain them.

The results would be made available for public consultation by the end of next year.

An advisory committee comprising academics, engineers and officials has been formed to steer the review.

According to review documents, Hong Kong has 11 broad categories of water quality guidelines on things such as dissolved oxygen, ammonia and nutrients. Overseas authorities have also begun replacing guidelines on E. coli bacteria with parameters on other bacteria when they measure beach water quality and effects on human health.

These have been incorporated into enforcement guidelines for 10 water quality control zones set up in 1982 that cover the whole city. No discharges into these zones are allowed without a licence.

But compliance with objectives varies greatly between the zones - from full compliance in eastern waters, to just 40 per cent in Deep Bay and 65 per cent in southern waters as at the end of last year.

One of the reasons for the low compliance rate is related to untreated sewage pumped into the sea.

About 450,000 cubic metres of raw sewage is discharged into the harbour every day.

That will continue until 2013 when an expanded sewage collection network is completed.

The Deep Bay area, shared with Shenzhen and adjacent to Mai Po Nature Reserve, is the most stressed water body outside the harbour.

Some of its pollution loads are believed to exceed its carrying capacity.

WWF Hong Kong yesterday welcomed the review but called on the government to clearly outline guidelines that will conform to the most stringent international standards.

'Relentless development and reclamation over the last 15 years on the Shenzhen side of Deep Bay has radically altered the hydrodynamics of the bay,' the WWF said in a statement yesterday.

'Revised objectives based on the current situation are therefore needed to facilitate more meaningful interpretation of the marine conditions on which the biodiversity of the bay depends.'