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THE ENVIRONMENT
programme, and the collection service for the whole area began in July. It covers some 80 farms with 11 collection points.
To complement the government's efforts in stepping up regulatory control of the disposal of chemical waste, a centralised chemical waste treatment facility is being planned. Consultants have been commissioned to conduct a detailed feasibility study and to advise the government on the economic, financial and contractual aspects of the project. A codisposal facility is being planned at Junk Bay Landfill whereby chemical wastes which do not require prior treatment will be codisposed with municipal refuse. Both the treatment plant and the codisposal facility are expected to be commissioned in 1990, to coincide with the implementation of regulatory controls.
Refuse floating in the sea, although representing a very small proportion of the total waste arising, is a disproportionately conspicuous pollution problem. The Marine Depart- ment is responsible for harbour cleansing and operates a fleet of one harbour sweeper and six Water Witches that collect an average of 10 tonnes of floating refuse per day. In addition, the department collects about four tonnes of refuse each day from ocean going vessels moored in Victoria Harbour and dwelling boats in typhoon shelters. To combat oil pollution, the department operates a purpose-built pollution control vessel and has stocks of low toxicity chemical dispersants, and more than 2 400 metres of large and medium size oil containment booms.
Monitoring and Investigations
There has always been a commitment to value for money in the government's environ- mental protection programmes. This means that any controls or facilities have to be demon- strably right for the prevailing circumstances in Hong Kong, and not merely measures adopted uncritically from other countries. Accordingly, the Environmental Protection Department operates a comprehensive monitoring scheme and undertakes investigations to establish an objective basis for local action.
The department has established an advanced network of six continuous air quality monitoring stations to obtain data on background air pollution levels in urban areas and two stations to monitor pollution arising from vehicular emissions. In line with the declaration of the Tsuen Wan-Kwai Chung Air Control Zone, work has started to establish two air quality monitoring stations in Tsuen Wan and Kwai Chung.
The background stations are linked through a telemetry system to the EPD's computer and this has greatly improved the operational efficiency of the air quality monitoring network. The vehicular emission monitoring stations are now being incorporated into the telemetry network.
Results from the air quality monitoring network during 1987 show that the overall levels of sulphur dioxide remained low in most urban areas, but in Causeway Bay the short term air quality objective was exceeded a few times. High levels of nitrogen dioxide were measured at Kwun Tong, Central-Western and Junk Bay monitoring stations. The concentration exceeded the short term criteria of the relevant objectives, and the level in Kwun Tong exceeded the annual criterion too. Levels of photochemical oxidant were lower than last year. High levels of total and respirable suspended particulates were measured at all monitoring stations and all, except Junk Bay, exceeded the objectives. Moreover, high levels of rainwater acidity and sulphate deposition rate in rain were recorded on several occasions during the year.
As a supplement to the fixed-site monitoring network, a mobile air quality laboratory was deployed for short term studies in a number of areas. The mobile laboratory allows