ENG-1993 — Page 461

THE ENVIRONMENT

The asbestos waste action plan, introduced in 1990, has been replaced by statutory control under the Waste Disposal (Chemical Waste) Regulation, ensuring that waste producers and disposal contractors follow safety guidelines in the code of practice on asbestos waste.

Under a five-year trial programme, treated sludge from the waterworks and sewage treatment processes at Sha Tin are disposed of at sea some 15 kilometres east of Waglan Island. Approximately 40 000 cubic metres of sludge is dispersed every month at the spoil ground, which was selected after detailed study. Monitoring of the water, marine sediment quality and biotic community at the spoil ground is continuing, to provide an early indication of any adverse effects on the environment.

A study of the long-term arrangements for the disposal of waterworks and sewage sludge looked into both new and well-established technologies, including energy recovery. It recommended that sludge be dehydrated, dried, and buried in landfills.

In view of the unsatisfactory disposal arrangements for clinical waste, animal carcasses and some security waste, a central incinerator is planned to dispose of such waste. A consultancy study is underway and the tender for constructing the facility is expected to be called in late 1994.

The government has appointed a contractor to collect livestock waste that would otherwise be indiscriminately dumped into streams and rivers in the New Territories. In 1993, some 2000 tonnes of solid livestock waste were collected and sent to the government-operated composting plant at Sha Ling for recycling.

Monitoring and Investigations

The assessment of progress towards policy goals is one of the key activities of the Environmental Protection Department. Its routine monitoring and special investigations form the basis for the strategic planning, provision of facilities and statutory controls that aim to improve the environment.

The department has a new marine pollution investigation vessel, the Dr Catherine Lam, which is used to monitor water quality in all 10 existing and proposed water control zones. It has a network of nearly 100 monitoring points in inland waters, and keeps 42 publicly-managed bathing beaches under surveillance. The results of this monitoring, which goes back to 1972, form a comprehensive record of the chemical, physical and microbiological quality of Hong Kong's waters.

All the data are published regularly, and can be made available to scientists and engineers on computer disks or tapes to contribute to their work. Members of the public are usually most interested in the summary reports of bathing water quality, which are issued to the media every two weeks during summer.

Standards and objectives for water quality draw heavily on the results of water quality monitoring and a number of special investigations that the department carries out. During 1993, work continued to analyse the results of a third phase of a long-term investigation to quantify the link between the pollution of bathing waters and health risks. This study was conducted in co-operation with the Chinese University of Hong Kong.

Mathematical models are used in much of the department's water quality assessment work. The department also provides a service to other government departments whose activities might have a major impact on the flow and quality of sea water around Hong Kong.

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