THE ENVIRONMENT
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After extensive trials, three mechanical refuse collection vessels were delivered to the unit in 1981 as part of the overall mechanisation plan scheduled for completion in late 1982. This will substantially replace the manual collection services currently undertaken in Victoria and Aberdeen harbours, and introduce mechanised services at Cheung Chau, Tuen Mun and Sha Tin.
The effects of water pollution on the stocks and quality of fish and shellfish around Hong Kong are investigated by the Marine Pollution Research Section of the Agriculture and Fisheries Department. It has also made studies of phytoplankton ecology in water bodies which could be enriched by nutrients thereby possibly producing algal blooms, including red tides, and causing fishkills. Although large catches of commercial fish are not taken from adjacent waters, Hong Kong does have an important mariculture industry based on floating cages and the industry is considered capable of expansion if water quality can be maintained. Funds have been approved for a new marine pollution research vessel to facilitate these aspects of research.
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There is considerable water pollution in some of Hong Kong's low-lying areas where streams and rivers cross agricultural land, often through nullahs in villages and towns, to enter the sea. In addition to large quantities of domestic waste, the streams receive agricultural waste emanating from about half-a-million pigs and seven million chickens in the New Territories. Pilot schemes to collect or divert these wastes are in operation. However, the scale and complexity of the problem is such that it may prove economically feasible to deal only with selected areas in the near future.
Waste Disposal
The enactment of the Waste Disposal Ordinance in 1980 provided the Directors of Public Works, Agriculture and Fisheries, Urban Services and New Territories Services with statutory powers over waste collection and disposal.
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Of the 2.3 million tonnes of solid waste generated in the territory during the year, about per cent was disposed of at controlled tips. There are limits on extending this method of disposal, however, due to the competing demands for land use in Hong Kong. As a means of greatly helping to reduce this problem, consideration is now being given to the use of controlled tipping to create development land.
Incineration, which handled some 797 000 tonnes of waste disposal over the year, is considered less desirable than controlled tipping because of higher costs and the associated problems of air pollution. The composting plant at Chai Wan processed about 90 500 tonnes of waste which was disposed of primarily at controlled tips.
The New Territories Services Department continued with its experimental farm wastes collection schemes in Ta Kwu Ling and Hung Shui Kiu where the concentration of pig and poultry breeding has caused serious water course pollution. During the year, some 4 400 tonnes of agricultural waste was collected for disposal. Various other proposals for the treatment and utilisation of agricultural waste are still being considered.
Noise Pollution
Under the Summary Offences Ordinance it is an offence to make noise calculated to disturb public tranquillity between 11 p.m. and 6 a.m. This legislation also provides for the control of construction noise between 7 p.m. and 7 a.m. every day, and all day on Sundays and public holidays.
The Director of Public Works is authorised, under the Summary Offences (Permitted Work) Regulations, to issue and renew permitted work permits to allow contractors to use