Heavy metal levels in samples taken from the river that provides most of Hong Kong's drinking water were between eight and 3,000 times higher than the mainland safety standard, Greenpeace says.
The environmental group took a sample on November 28 at the Taiyuan pumping station on the Dongjiang, or East River, and another six were taken on December 7 and 8 when the station was closed for maintenance.
The maximum lead level recorded in the samples was eight times higher than the mainland standard, while the maximum mercury level was 3,000 times higher. The maximum level of phenols, a cancer-causing chemical, was 200 times higher.
Greenpeace campaigner Dr Howard Liu Hong-to said water from the Shima River - which also serves as a channel carrying supplies to Hong Kong - could be polluting the Dongjiang. The junction of the Shima and Dongjiang is 150 metres downstream from the pumping station where water is tapped for Hong Kong.
'When the pumping station is closed for maintenance, pollutants from the Shima River will flow directly into the Dongjiang river,' Dr Liu said. 'During high tide, the pollutants would be carried upstream and taken in by the pumping station.'
Dr Liu said he expected the Shima, which also carries sewage, to be decommissioned as a channel for Hong Kong's water supply and restored to a natural river after the completion in 2003 of a $4.9 billion closed aquaduct. But he still thought there was no guarantee that the water quality would then improve.
