ENG-1983 — Page 311

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THE ENVIRONMENT

A new air quality monitoring station was established by the EPA during the year at a site above Central and Western Districts. The station is equipped to monitor continuously the levels of sulphur dioxide, particulates, oxides of nitrogen, and ozone, as well as local meteorological conditions. It joins a network of three other air quality monitoring stations operated by the EPA and is supplemented by semi-continuous measurements of sulphur dioxide and particulates from the Labour Department's Air Pollution Control Division and by continuous sulphur dioxide monitors provided and operated by the Hong Kong Electric Company and the China Light and Power Company under a collaborative programme with the government. Measurements so far show that air pollution in Hong Kong is characterised by a high level of particulates everywhere and sporadic high levels of sulphur dioxide near sources of emission. It appears, however, that Hong Kong does not experience the widespread and persistent high levels of sulphur dioxide that occur in some urban areas in more developed countries.

Major investigations of lead in dust and kerbside põllution levels were completed by the EPA during the year. These showed that lead-in-dust, lead-in-air, carbon monoxide, nitrogen dioxide and benz-a-pyrene levels were within internationally accepted levels and were lower than in many conurbations elsewhere in the world; but again, particulate levels were found to be high.

Several government departments contribute to water quality monitoring. Regular sampling and field measurements were carried out by the Pollution Control (Liquid and Solid Wastes) Division of the Engineering Development Department at 60 general water quality stations, 22 seawall sewage outfalls, 18 submarine sewage outfalls, 29 bottom sediment stations, 56 beach stations, 27 seawater intakes and 17 typhoon shelters, covering virtually all territorial marine waters likely to be affected by sewage discharges. Laboratories at the various sewage treatment works operated by the department carry out constant tests to ensure that the quality of the effluent is within acceptable standards. Properties measured include pH, salinity, turbidity, temperature, dissolved oxygen, BOD, suspended solids, nutrients, chlorophyl-a and faecal and total coliform counts. The bacterial quality of the water is also monitored at 38 gazetted beaches and nine ungazetted beaches by the Urban Services Department. In addition, surveys are carried out by the EPA as part of the preparation for various water control zones and the water quality objectives for these zones, and to provide data for validating water quality models under development.

On the whole, marine water quality is good, bearing in mind the pressures on water adjacent to densely developed urban areas. There are, however, black spots such as Kowloon Bay, various typhoon shelters and some beaches to the west of Kowloon. Certain larger but semi-enclosed areas of water, such as Tolo Harbour, are seen as threatened. The unsightly appearance of floating refuse remains a widespread problem and the EPA initiated an investigation during the year to work out the sources, pathways and sinks of flotsam appearing in Hong Kong water as a basis for action to reduce the problem.

Extensive monitoring of solid and semi-solid wastes has been carried out to assist in forecasting the amount and nature of municipal and commercial wastes - as well as toxic, difficult and hazardous wastes - and in planning collection and disposal facilities. It is estimated that general waste will increase from the present level of over 6000 tonnes per day to as much as 13 000 tonnes per day by the end of the decade. The most recent survey shows that in 1982 the main components of municipal waste were paper (27 per cent by weight), putrescibles (20 per cent), plastics (14 per cent) and rags and cotton (six per cent), whereas industrial waste comprised mainly paper (16 per cent), putrescibles (10 per cent), plastics (16 per cent), rags and cotton (19 per cent) and