Water Pollution Control Ordinance
The Water Pollution Control Ordinance (Cap 358) enacted in 1980 is the principal law for managing water quality. The Ordinance establishes Water Quality Objectives (WQOs) for the beneficial uses of water bodies and defines Water Control Zones (WCZs) for Hong Kong waters within which discharges of effluents are subject to licensing control.
The WQOs set for all WCZs specify that toxic substances in the water should not attain such levels as to produce significant toxic, mutagenic, carcinogenic or teratogenic effects in humans, fish or any other aquatic organisms, with due regard to biologically cumulative effects in food chains and to interactions of toxic substances with each other. The standards for effluents discharged into the various WCZs are specified in the Technical Memorandum on Standards for Effluents Discharged into Drainage and Sewerage Systems, Inland and Coastal Waters.
Details of Cap 358 and its subsidiary regulations can be found at the "Hong Kong e-Legislation" website of the Department of Justice.