Following is a question by the Hon Wong Kwok-hing and a written reply by the Secretary for Development, Mr Paul Chan, in the Legislative Council today (March 20):
Question:
It has been reported that on the Mainland in recent years, various types of hazardous chemical substances have been found in some rivers, lakes, coastal waters and even in the bodies of wild animals and human beings, and the drinking water in many places has been contaminated. It has also been reported that the Ministry of Environmental Protection has recently acknowledged for the first time the existence of hundreds of cancer villages on the Mainland. There are 25 such villages in Guangdong Province, and two of them are even in Huizhou, which is situated along the riverbank of Dongjiang - the main source of water supply for Hong Kong. In this connection, will the Government inform this Council:
(a) as Hong Kong has adopted the Guidelines for Drinking-water Quality (the Guidelines) published by the World Health Organization as the water-quality standard for treated drinking water, whether the Guidelines have been updated in recent years in response to the environmental pollution problems which have emerged worldwide one after another; and whether the authorities have devised any new and corresponding strategies for monitoring water quality;
(b) of the items which failed to meet the relevant water quality standards in the outcome of tests of the quality of Dongjiang raw water supplied to Hong Kong in each of the past three years; and whether drinking such substandard water is harmful to health; if it is, of the details;
(c) given the worsening environmental pollution problems on the Mainland in recent years, whether the authorities have discussed with the relevant Guangdong Provincial authorities the implementation of measures to further improve the quality of Dongjiang raw water, including reducing the pollution to the source of Dongjiang water, with a view to reducing the use of chemicals for purifying drinking water; if they have, of the details; if not, the reasons for that; and
(d) given the frequent droughts and revelation of pollution problems on the Mainland in recent years, whether the authorities have formulated any contingency measures to deal with the situations in which Dongjiang water cannot be supplied to Hong Kong or is unsafe to drink due to unexpected incidents, so as to ensure a steady supply of safe drinking water to Hong Kong; if they have, of the details; if not, the reasons for that, and whether the authorities will consider seriously formulating such contingency measures?
Reply:
President,
Since the 1960s, Hong Kong has begun to import raw water from Guangdong Province to meet the growing demand. At present, rainwater collected locally can only meet 20% to 30% of the water consumption in Hong Kong. The remaining 70% to 80% has to be imported from the Dongjiang of Guangdong Province. The Water Supplies Department (WSD) and the Guangdong authorities have kept a close surveillance over the Dongjiang water quality. Under the current water supply agreement, the Guangdong authorities would maintain that the quality of Dongjiang water supplied to Hong Kong complies with the latest national standard, i.e. the standard for Type II waters (applicable for the abstraction for human consumption in first class protection area) in the Environmental Quality Standards for Surface Water (GB3838-2002). It would also strive to step up its efforts in protecting the water resources. At present, the quality of Dongjiang water supplied to Hong Kong is steady and in compliance with the relevant standards. Raw water, both imported from Dongjiang and collected locally, undergoes suitable treatment and stringent disinfection process at WSD's water treatment works before being distributed for public consumption. The quality of treated water is in full compliance with the requirements stipulated in the Guidelines for Drinking-water Quality (the Guidelines) published by the World Health Organization (WHO) and is safe for consumption.
My reply to the four parts of the question is as follows:
(a) The WSD has kept abreast with the latest developments and revisions of the Guidelines published by the WHO and updated the standards for drinking water in Hong Kong accordingly. Currently, WSD is monitoring the quality of drinking water in Hong Kong in accordance with the latest WHO's Guidelines published in 2011.
The WSD has formulated and implemented a Water Safety Plan in accordance with the WHO's Guidelines. The Plan is based on preventive risk management principles and a multiple-barrier approach to monitor and control water quality from water sources, through treatment processes at water treatment works, to water supply and distribution systems for assuring that the water quality is in compliance with the relevant standards.
WSD collects water samples from water gathering grounds, pumping station for receiving Dongjiang water supply, impounding reservoirs, water treatment works, service reservoirs, water distribution system, and consumers' taps to ensure that the water quality is in full compliance with the WHO's Guidelines and is safe for public consumption.
(b) WSD closely monitors the quality of Dongjiang water through the on-line water quality monitoring system set up at Muk Wu Pumping Station around the clock and takes Dongjiang water samples for tests regularly. The routine water quality monitoring results of WSD in the past three years show that the quality of Dongjiang water supplied to Hong Kong is of consistently good quality. The average values of individual monitoring data, including biological oxygen demand, faecal coliforms, various minerals and compounds, are in compliance with the national standards for Type II waters in the "Environmental Quality Standards for Surface Water (GB3838-2002)" (applicable for the abstraction for human consumption in first class protection area). Please refer to the Annex for the monitoring results of the quality of Dongjiang water supplied to Hong Kong over the past three years.
The WSD publishes and updates regularly the information on the quality of Dongjiang water received at Muk Wu Pumping Station and drinking water supply after treatment on its website. The public may access the information at the following link : www.wsd.gov.hk/en/water_resources/water_quality/water_quality_monitoring_data/index.html
(c) Both Guangdong and Hong Kong attached great importance to the quality of Dongjiang water. Both sides have kept in close contact and communication through regular meetings to discuss, follow up and implement various measures to reduce the pollution of Dongjiang water at sources. To safeguard the quality of Dongjiang water supplied to Hong Kong, the Guangdong authorities have implemented a series of prevention and control measures and projects in recent years. These include moving the intake points of Dongjiang water supplied to Hong Kong to a location of better quality water; building a bio-nitrification plant at the Shenzhen Reservoir; and conveying Dongjiang water direct from Tai Yuen Pumping Station to Shenzhen reservoir through a dedicated aqueduct. Various sewage interception and diversion projects have also been undertaken. Video monitoring points are also set up in the periphery of the Shenzhen Reservoir to monitor its water body, the surrounding ecological environment and the operations of key facilities. These measures help the authorities monitor the surrounding environment of the reservoir and facilitate control over untoward incidents that affect water quality. Furthermore, to improve the monitoring facilities for quantity and quality of Dongjiang, the Guangdong authorities are undertaking the construction of the "Dongjiang Water Quantity and Quality Monitoring and Control system", which includes real-time monitoring of the water quality of Dongjiang. Through implementing the above measures and projects, the quality of the Dongjiang water has been maintained steady and of good quality in recent years. As such, there is no significant increase in the use of chemicals for the potable water treatment.
(d) In case of any anomaly in the quality of Dongjiang water, the WSD will immediately step up monitoring and liaise with the Guangdong authorities concerned to carry out appropriate measures, including stepping up the monitoring of various water quality parameters at Muk Wu Pumping Station. The WSD will also maintain close liaison with the Guangdong authorities and consider reducing or suspending the supply of Dongjiang water in the light of its actual quality conditions. Where necessary, all the Dongjiang water already received may be discharged at Muk Wu Pumping Station. Local water resources may then be redeployed to supply the treatment works. In general, the storage in the impounding reservoirs of Hong Kong is adequate to meet our needs for four to six months. We will also discuss with the Guangdong authorities concerned to plan for further responsive actions.
There is also an established notification mechanism manned by designated liaison officers of both Hong Kong and Guangdong authorities. In case of major contamination incidents affecting the quality of Dongjiang water supplied to Hong Kong, the Guangdong authorities would immediately notify the WSD over the telephone followed by supplementary detailed information.
Attachment:
Ends/Wednesday, March 20, 2013
Issued at HKT 16:58
NNNN