THE ENVIRONMENT
of exposure to asbestos. The permit system was reviewed to allow smooth transition to the future regulatory regime under the Waste Disposal Ordinance.
In addition to the above, an investigation was initiated to review the interim and long-term strategy for the disposal of waterworks and sewage sludges.
A survey on clinical waste arisings and current disposal practice was completed by the EPD and initial planning has commenced for the establishment of the first centralised incineration facilities for clinical wastes in Hong Kong.
Monitoring and Investigations Water Quality
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The Environmental Protection Department is responsible for water quality monitoring in the sea, at beaches, and in rivers and streams. It operates a comprehensive monitoring programme which involves 69 general marine monitoring stations, 54 seabed sediment stations, 23 typhoon shelter stations, 118 sampling points at beaches, and 60 manual and six automatic sampling points on 10 priority rivers. The results of the monitoring programme are used to detect water pollution problems and to assess the water quality against a series of quality objectives.
Generally, water quality in Hong Kong's open marine waters is good. However, pollution problems, exemplified in the form of either oxygen depletion, high bacterial counts or algal bloom exist in some parts of Victoria Harbour (Kowloon Bay, North-west Kowloon and Rambler Channel near Tsuen Wan), the inner parts of embayments (Tolo Harbour, Port Shelter, Junk Bay and Deep Bay), and typhoon shelters. Trends of water quality deterioration have been found in some of these blackspots, in particular Victoria Harbour and Tolo Harbour.
The monitoring results show that many rivers and streams are heavily contaminated with livestock waste, sewage and industrial effluents. In some cases, high bacteria numbers in the river estuaries cause concern. Yet during the year, slight improvements were detected in some watercourses such as Lam Tsuen, Tai Po, Fo Tan, and Shing Mun rivers, mainly as a result of the implementation of the WPCO in the Water Control Zones, clearing of squatter areas and the interception of sewage from villages.
The microbial water quality at many of Hong Kong's beaches has been declining for a number of years. The deterioration was caused mainly by livestock waste and raw or partially-treated sewage entering the sea at or close to the beaches. The increasingly-large number of faecal bacteria in these discharges contaminated the water at many beaches, posing a health risk to swimmers.
In order to assess the risk of swimming at Hong Kong beaches, a ranking system was developed based on the expected rates of gastroenteritis and skin diseases associated with different degrees of faecal pollution of beach water. The degree of faecal pollution is assessed by regular monitoring of the abundance of indicator bacteria in the beach water, and the rankings are determined by examining the results for each beach averaged over the whole swimming season. Under the systems, beaches are classified as good, meaning that the expected gastroenteritis and skin symptom rate is zero; acceptable, meaning that the rate is less than 10 per thousand swimmers; barely acceptable, meaning that the rate is up to fifteen per thousand; and unacceptable, meaning that the risk rate is higher than this. In 1990, the number of bathing beaches classified as good was 22; acceptable 26; barely acceptable six, and unacceptable, two.
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