THE ENVIRONMENT
penalty is being paid in adverse ecological changes, a heavy but usually hidden financial burden on the community, and great risks to community health.
The government's pollution control strategy aims not to harm industry and commerce, but to work in partnership with firms so that all may benefit from a better environment. There are often direct economic benefits to be gained from activities that benefit the environment, such as recycling and the introduction of pollution prevention in manu- facturing. These methods are better than pollution control techniques, that have to be applied after a waste material has become a potential pollutant.
The government would prefer industry and commerce to recognise the benefits of waste minimisation and pollution prevention, but it is inevitable that this cannot be an entirely voluntary process. Nowhere is this more apparent than in the case of the Water Pollution Control Ordinance, which first came into effective operation in 1987, and has been gradually extended to a series of water control zones. These zones do not yet cover the most heavily industrialised areas.
The North Western Water Control Zone came into being in April 1992, bringing the number of zones in operation to seven, covering 92 per cent of the territory. Three zones remain to be declared. The Eastern and Western Buffer Zones should be declared in mid 1993, when polluting discharges from some of the main industrial and developed areas around Victoria Harbour will come under control.
Every trade effluent in a water control zone needs a licence, which will specify the maximum amount of pollutants that may be emitted. The standards vary from place to place in accordance with the conservation goals and water quality objectives for the receiving water body. Licence standards usually follow a set of published guidelines.
Considerable efforts are made to ensure that effluents meet the standards set in licences. In 1992, Environmental Protection Department inspectors took more than 4 500 effluent samples and made over 12 000 laboratory tests.
This activity has had great success. For example, in Tolo Harbour, the first water control zone, more than 100 expedient connections were rectified. The organic pollution load on the harbour has been reduced by 75 per cent. Concentrations of heavy metals in the digested sludge of the Sha Tin sewage treatment works have been reduced to such an extent that the sludge now meets the stringent standards that apply to marine disposal. In the Southern Water Control Zone, over 90 per cent of private sewage treatment plants are now operating satisfactorily and the water quality of many popular bathing beaches has improved as a result.
In the Deep Bay Water Control Zone, the Environmental Protection Department has managed to divert about 7 000 m3/day of industrial effluents from the storm drains to the foul sewerage system. This is equivalent to the organic pollution load from a population of 50 000 people. For those recently declared zones, such as north-western waters, the reduction in pollution is comparatively low as the controls have been in force for a short time only. In the established zones of Port Shelter and Junk Bay, the reduction is as much as 70 and 50 per cent of the organic pollution load respectively. Over all control zones, the department estimates that so far it has achieved an average of about 50 per cent reduction in the target pollution load by enforcing the Water Pollution Control Ordinance. The reduction is expected to increase further when the controls have been fully implemented.
Pollution of the once notorious Ho Chung River, 'the black river of Sai Kung', has improved dramatically due to effective control of the major industrial polluters. An
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