THE ENVIRONMENT
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for the area. A major study into the water pollution problems of Victoria Harbour and its surrounding areas will lead to the production of a suite of mathematical models which will enable the impact of future urban development on the water quality of the harbour to be predicted. Thus, such studies will allow the government to plan the reclamation needed for urban growth and develop cost-effective sewage disposal infrastructure to meet environ- mental objectives.
An action plan has been developed to arrest the serious decline in water quality of Tolo Harbour. The plan recommends, inter alia, the export of effluent from Sha Tin sewage treatment works out of the Tolo catchment, and an engineering feasibility study on a scheme to divert it by tunnel to Diamond Hill is in progress. This scheme would have the additional benefit of flushing pollutants out of Kai Tak Nullah, until the East Kowloon sewerage master plan is fully implemented. Many other sewage disposal schemes are under investigation and design.
Solid waste arisings are expected to double in the next 15 years. The strategy developed for their disposal over the past few years, with the aid of a computerised Waste Management Model, involves a move away from incineration and small local landfills to a system of transfer stations feeding a small number of very large landfills. Planning work is proceeding for two of the major long-term disposal facilities, the West New Territories Landfill and North-east New Territories Landfill. Environmental impact assessments have been carried out on both these projects. These two landfills will provide sufficient disposal capacity for 20 to 30 years.
Proposals have been developed for Hong Kong's first refuse transfer station in East Kowloon, supported by the new landfills, to replace Jordan Valley Landfill and Lai Chi Kok Incinerator. This transfer station is expected to start operation in 1990. Consultants are also examining the feasibility of upgrading Chai Wan Composting Plant to a refuse transfer station to ensure that disposal facilities exist on Hong Kong Island to cater for increased quantities of waste. To reduce smoke nuisance from urban incinerators, electro- static precipitators have been fitted to the Kennedy Town Incinerator and will be fitted to the Lai Chi Kok Incinerator 'A' Plant by July 1988.
One of Hong Kong's most serious waste disposal problems is caused by livestock keeping, the wastes from which are a major polluter of rivers and streams throughout the New Territories. In Hong Kong, there are about 500 000 pigs and 7 000 000 chickens on almost 6 000 farms. They generate some 2 000 tonnes of raw manure a day. Most of the excreta is hosed untreated into rivers and streams. In 1982, under the Clean Hong Kong Campaign, a pilot livestock waste collection service was set up in Pat Heung, Yuen Long, Pai Min Kok and Sai Kung areas. This scheme was expanded in 1987 to cover a total of 266 farms, collecting about 11 tonnes of solid dung each day from 53 collection points. The collected waste is delivered to the Ngau Tam Mei Composting Plant. During 1987 a total of 601 tonnes of this compost was sold, or used by government departments, for landscaping or market gardening.
Government-subsidised collection services will be provided as part of the 10-Year Livestock Waste Control Scheme. The subsidy will taper off as the control scheme expands during the three phases of implementation. Collection services will be provided for livestock farmers in each control area, commencing six months before the implementation of control. Preparatory work for the collection service in the Tolo Harbour and Channel Area and the River Indus Area has already begun. The work includes setting up collection points, improving access roads and appointing service contractors. A pilot collection service was set up in the Lam Tsuen River Valley in advance of Phase One of the proposed control