LCQ5: Contamination of water in the Shenzhen Reservoir

Following is a question by the Hon Chan Kam-lam and a reply by the Secretary for Development, Mrs Carrie Lam, in the Legislative Council today (April 29):


It has been reported in the press that water in the Shenzhen Reservoir, which stores potable water for supply to Hong Kong, was found in recent months to have been seriously contaminated by the waste materials from waste collection stations and residents' domestic waste water in the vicinity.  In this connection, will the Government inform this Council whether the authorities:

(a)  have stepped up the sample tests conducted on the quality of potable water supplied to Hong Kong after they learnt of the aforesaid press report; if they have, of the results of the sample tests;

(b)  will adopt new measures to ensure that the quality of potable water supplied to Hong Kong meets the quality standard for drinking water; if they will, of the details of the new measures; if not, the reasons for that; and

(c)  will send staff to discuss with the Shenzhen authorities to ensure that the Shenzhen Reservoir will not be contaminated again; if they will, of the details; if not, the reasons for that?



On the supply of Dongjiang (DJ) water to Hong Kong, the Water Supplies Department (WSD) of Hong Kong and the Guangdong authorities keep close contact and established liaison and notification mechanisms.  On March 19, after receiving phone enquiries from the media on the incident of contamination of Shenzhen Reservoir, WSD immediately contacted the Guangdong authorities under the established mechanisms to understand the situation.  On the following day, an Assistant Director and a Senior Engineer of WSD, accompanied by officials of the Department of Water Resources of Guangdong Province and Shenzhen City, visited Shenzhen Reservoir.  We noted that the incident happened at Dawang Village near Wutongshan River, which is some 500 metres upstream of the Reservoir.  The polluting facilities were small in scale, and the authorities concerned promptly removed the facilities on March 19 to ensure no contamination of DJ water.

My reply to the three parts of the question is as follows:

(a)  WSD has set up the Water Quality Monitoring System at Muk Wu Pumping Station where Hong Kong receives DJ water.   The System regularly takes and tests DJ water samples to closely monitor round the clock the quality of DJ water supplied to Hong Kong.  Shortly after the contamination incident, WSD deployed officers to Shenzhen to understand the actual situation and on the same day on March 19 increased the frequency of sampling and testing from twice a day to six times a day (that is once every four hours).  This lasted until March 24. Test results of the 32 samples collected in this period showed that the quality of DJ water supplied to Hong Kong had not been affected by the contamination incident, and the water quality parameters of all the samples showed no unusual change from those recorded before the incident.  The water quality, as reflected in all the data, met the national standard for Type II waters (applicable for the abstraction for human consumption in class I protection area) under the "Environmental Quality Standards for Surface Water, GB 3838-2002".

(b)  Guangdong and Hong Kong attach great importance to the quality of DJ water.  For many years, both sides have discussed actively DJ water issues.  The Guangdong authorities have also implemented a series of measures and works to mitigate water pollution so as to further enhance the water quality at source.  These measures include:

* enforcing more strictly the environmental legislations, regulating the pollution emitters along DJ, as well as strengthening the supervision and monitoring of wastewater discharge points along the river;

* stepping up control over land use planning and polluting activities;

* improving progressively the water resource management and real-time monitoring system;

* implementing wastewater interception schemes around Shenzhen Reservoir to ensure no contamination of the reservoir; and

* purifying DJ water at the Shenzhen Reservoir Bio-nitrification Plant to enhance its quality.

For serious incidents that could affect the quality of DJ water supplied to Hong Kong, WSD has drawn up a series of contingency measures.  They include the immediate upgrading of various surveillance measures, close liaison with the Guangdong authorities to reduce or suspend the supply of DJ water to Hong Kong, or temporarily substituting the water supply from DJ with local sources.  All raw water, including DJ water, has to undergo rigorous treatment and sterilisation processes at the treatment works of WSD to ensure that the quality of the potable water after treatment complies with all relevant standards stipulated by the World Health Organisation.

(c)  On the supply of DJ water to Hong Kong, WSD has maintained close liaison with the Department of Water Resources of Guangdong Province through the Dongjiang-Shenzhen Water Supply Works Operation and Management Technical Sub-Group.  At the same time, WSD exchanges views with the Environmental Protection Bureau of Guangdong Province on various water quality monitoring works and mitigation measures to prevent pollution of DJ water at source through the Dongjiang Water Quality Protection Special Panel under the Hong Kong-Guangdong Joint Working Group on Sustainable Development and Environmental Protection.  At the meeting of the Special Panel on April 23, we requested the Guangdong authorities to step up inspection and regulation of the pollution emitters along DJ to ensure that Shenzhen Reservoir is not contaminated.  In addition to the two standing committees, WSD handles special issues under the existing liaison and notification mechanisms.  Indeed, as mentioned above, an Assistant Director and a Senior Engineer of WSD conducted a site visit and discussed with the Guangdong authorities at Shenzhen on March 20.

     Over the years, the Guangdong authorities have arranged annually for members of the Hong Kong Advisory Committee on the Quality of Water Supplies to inspect and better understand the implementation of various pollution prevention and control measures along DJ.  The inspection last year was conducted in November.  The Advisory Committee was satisfied with what they inspected.  Guangdong and Hong Kong will continue to co-operate closely so as to reduce pollution at source and continuously enhance the quality of DJ water.

Ends/Wednesday, April 29, 2009
Issued at HKT 16:02