Two more public housing estates were found to have lead pollution in their water supply system on Tuesday as concerns over water safety in Hong Kong grow. This comes after excessive lead levels were found in tap water samples from Kai Ching Estate.

The two estates were Kwai Luen Estate in Kwai Tsing District and Shui Chuen O Estate in Sha Tin District. Five out of the 44 water samples from two buildings - Luen Yat House and Luen Yuet House - of the Kwai Luen Estate were confirmed to have lead levels beyond what the World Health Organization finds acceptable.

Of the 43 water samples from Shui Chuen O Estate, one was also found to be contaminated. As the tainted sample was drawn from a vacant flat, the government said a follow-up survey will be conducted in the building.

Speaking at a press conference, Secretary for Transport and Housing Anthony Cheung Bing-leung said preliminary investigation suggested the excessive lead levels found in the tap water samples of the estates came from soldering material.

A veteran plumber, who refused to be identified, told China Daily that the government should conduct a step-by-step elimination process on different sections of the pipelines - instead of only checking water samples inside households - in order to find out the source of the lead.

Discussing the suggestion that plumber Lam Tak-shum is responsible for the use of lead in soldering water pipes, the industry source said plumbers only use materials provided by their company.

The tainted water issue surfaced a week ago when water samples from all six blocks of Kai Ching Estate were found to have excessive levels of lead. The new findings on Tuesday have brought the number of households affected from 5,000 to more than 6,400.

Blood tests will be conducted for members of the five new households found to have tainted water.

Meanwhile, the authorities will duct water directly from the rooftop water tanks of the six buildings of Kai Ching Estate to every floor as an alternative remedy. The necessary construction work is expected to be completed within three weeks.

A makeshift water supply station will also be set up at Kwai Luen Estate. Work on temporary pipelines from the government's two water tanks, and a water truck for each block, was expected to be finished in two to three days, Director of Water Supplies Enoch Lam Tin-sing said.

Contact the writer through stushadow@chinadailyhk.com

Residents collect and stock up on water from a temporary water station at Kai Ching Estate on Tuesday. Parker Zheng / China Daily

(HK Edition 07/15/2015 page7)