Narrow pipes installed with materials welded together with lead could be responsible for excessive levels of the heavy metal found in Hong Kong water, a member of the task force set up to investigate the scandal said. Dr Chan Hon-fai, chairman of the Advisory Committee on Water Resources and Quality of Water Supplies and a member of the task force probing the water scare in public housing estates, believed the lead may have dissolved into the water through narrow pipes which connect water meters and taps inside flats. Such pipes, which are particularly narrow, have a larger contact area with water and would keep water for a longer period of time, he explained. Therefore the heavy metal would have a higher chance to contaminate the water should pipes have been installed with materials which contained lead for welding, he said. The task force would put forward its first report by the middle of this month, Chan said. In the meantime, a total of 100 components, collected from three water supply chains in Hong Ching House at Kai Ching Estate in Kowloon City and Kwai Luen Estate (Phase Two) in Kwai Chung had been taken for laboratory tests. Results would be announced soon, he said. Separately, education minister Eddie Ng Hak-kim said some 919 kindergartens and 67 out of the 80 government-funded newly built primary and secondary schools completed after 2005 would join the government scheme in testing the lead level in water. The kindergartens, alongside five boarding schools for pupils with special needs, would be prioritised, he added. Officials made a U-turn last week to launch the tests after excessive levels of lead in tap water were discovered at two schools.