An irregular source of the water supplied to Hong Kong – Shawen River – has been polluted with domestic waste, Secretary for Development Paul Chan Mo-po has said.
Chan said water from the river, which lies to the north of the Shenzhen Reservoir, only flows into the reservoir when its water level rises steeply as a result of heavy rainstorms during the flood season. The mechanism was rolled out after the completion of the Shawan Interception Point in 2003.
The water supply for Hong Kong passes through the reservoir before reaching the city.
According to the regular monitoring work of the Water Supplies Department, the Dongjiang water supplied to Hong Kong is of a consistently good quality. But certain water quality indicators occasionally deviate from standards, such as the emergency floodwater discharge at the Shawan Interception Point, Chan added.
Alerts and remediation
He said that the Guangdong and Hong Kong authorities have put in place a notification mechanism for floodwater discharge from the Shawan Interception Point, so that the Water Supplies Department can receive an early alert, in order to step up monitoring and adjust chemical dosages.
“This will ensure that all the raw water – including the Dongjiang water – will become fully compliant with the World Health Organisation guidelines in respect of chemical, microbial and radiological quality after treatment at the Water Supplies Department’s water treatment works,” he said.
Chan said the Shenzhen authorities have also launched a remediation project for the Shawan River Basin environment to reduce direct discharge of effluent to the river, and to reduce the risk of contamination of the Shenzhen Reservoir by floodwater discharge. The whole project will take two to three years to complete.
Lawmaker Claudia Mo Man-ching voiced criticism, saying that Hong Kong spent around HK$5 billion each year buying water but a large amount was wasted as it was not utilised.
“We will sign a three-year agreement with Guangdong authorities at the end of year… in the next negotiation, can we discuss buying only the amount that we need?” she said.
In response, Chan said he understood the concerns over the pricing mechanism, saying that the government will raise the point of only buying a necessary amount in future negotiations.