Government announces latest Hong Kong Drinking Water Standards

     The Government announced today (April 22) the latest Hong Kong Drinking Water Standards (HKDWS).

     Hong Kong has adopted the respective guideline values/provisional guideline values in the World Health Organization (WHO)'s Guidelines for Drinking-water Quality as the HKDWS since September 2017. With reference to the WHO's advocacy, the Government commissioned an expert consultant earlier on to conduct a review, including making reference to international practices, to establish a set of drinking water standards suitable for adoption in the local context. Based on the expert consultant's findings and recommendations, the Government has formulated the latest HKDWS which has been deliberated and agreed by the Drinking Water Safety Advisory Committee (DWSAC).

     The number of water quality parameters in the latest HKDWS is revised from 92 to 60, which includes the addition of two new parameters, namely perchlorate and total trihalomethanes, and the exclusion of 34 irrelevant parameters.

     The newly added parameters have been established in accordance with the latest WHO Guidelines. As for the excluded parameters, they have all along been found undetectable under the routine water quality monitoring programme of the Water Supplies Department (WSD), indicating that their levels were negligible, if not nil, in the drinking water of Hong Kong, which were far below a level that would cause an adverse health risk. Nevertheless, the WSD will continue the surveillance of these excluded parameters in the drinking water. In addition, with reference to the WHO Guidelines, the Government has adopted more stringent standards for chlorate and dichloroacetate in the latest HKDWS.

     The latest HKDWS are detailed at Annex I, while the excluded parameters are detailed at Annex II.
     With reference to the monitoring practices on drinking water quality adopted by international organisations and overseas countries, the expert consultant also recommended additional water samples for monitoring residual chlorine and E. coli be collected through the current Enhanced Water Quality Monitoring Programme (Enhanced Programme). The recommendation has also been deliberated and agreed by the DWSAC.

     The WSD has implemented the Enhanced Programme since 2017 to randomly select about 670 premises each year from water accounts over the territory for collecting drinking water samples from their taps to test for six metals viz. antimony, cadmium, chromium, copper, lead and nickel. Starting from next month, the WSD will extend the scope of the Enhanced Programme to cover the testing of residual chlorine and E. coli in drinking water samples.

     The public may visit the WSD website ( for updated information on the Enhanced Programme.

Ends/Thursday, April 22, 2021
Issued at HKT 11:57