In response to press enquiries on whether the quality of Dongjiang water would be adversely affected by the effluent from a factory at Huizhou, a spokesman for the Water Supplies Department (WSD) said today (October 4) that stringent daily monitoring of water was carried out at Muk Wu Pumping Station (MWPS), where Dongjiang water is received in Hong Kong, to ensure the water received is up to standard.
"The sampling tests at MWPS in the last 6 months consistently show that the concentrations of cadmium, chromium and zinc in the raw water from Guangdong were less than 0.001 mg/L, 0.002mg/L and 0.01mg/L respectively," the spokesman said.
"The levels of concentration are well within the Environmental Quality Standards for Surface Water - GB3838-88 Type 2 Standard which are less than 0.005mg/L, 0.05mg/L and 1.0mg/L respectively," he said.
"This National Standard is specified in the raw water supply agreement between Guangdong and Hong Kong. Nevertheless, we will step up our monitoring if we detect a rise in the concentration of any heavy metals.
"The metal in subject - cadmium is also monitored by the Environmental Protection Bureau of Guangdong Province at the Dongjiang main stream outside Taiyuan Pumping Station where Donjiang water is abstracted and the monitoring results are also available at WSD's websites - https://www.wsd.gov.hk/. The results also indicate that the Dongjiang water quality meets the requirements of the above National Standard."
The drinking water supplied by the Water Supplies Department complies with the World Health Organisation (WHO) Guidelines for Drinking Water Quality (1993). The concentration of metals including chromium, cadmium, etc are well below the guideline values for drinking water. The drinking water quality data are available for viewing at WSD's website.
"There is a dilution and self-purification effect when Dongjiang water flows along Dongjiang and the Dongshen aqueduct. The detention of Dongjiang water in Shenzhen Reservoir is also a self-purification process, " the spokesman explained.
"WSD has urgently approached the Guangdong authorities to seek for a better understanding of the issue, particularly as to whether the effluent from the factory will adversely affect the quality of Dongjiang water," he said.
"Both HK and Guangdong authorities attach great importance to the quality of Dongjiang water supplied to Hong Kong. A lot of efforts and resources have been made and spent to ensure the quality of water, for example, the construction work of the Dongshen closed aqueduct was completed in June 2003," he added.
Ends/Monday, October 4, 2004