Rethinking the cause of the lead water scare in Hong Kong

Recently, excess lead was fund in the tap water system of several public housing estates in Hong Kong. This has raised public concern about water safety and the effectiveness of the monitoring system for public works in Hong Kong.
According to Hong Kong’s relevant regulations, lead materials are banned from use in the water pipe system. Why could the government officials not discover the use of lead welding and plumbing materials earlier? How long have the lead materials been used in the system? Which groups of people decided to use it? It is necessary to ask these questions not only to find out who is to be blamed but also to learn of the true cause of this incident. Another similar scandal regarding short pilling happened in the Home Ownership Scheme (HOS) project in 2000. 15 years later, black holes still exist in public works which affect public interests.
This article analyses the failures of the system of tendering, public procurement and different tiers of sub-contracting in public works. Available in Chinese language only.

The president of the Professional Teachers' Union, Fung Wai-wah, has accused the Education Bureau of trying to shirk its responsibility in the tainted tap water scandal. 
The bureau at first decided against carrying out water tests for schools, after lead-contaminated water was found in some of them.
But the Chief Secretary Carrie Lam announced on Tuesday that the government would test the tap water in all kindergartens in Hong Kong. She said she expected the tests at the 980 kindergartens to be completed within six months.
Speaking on a radio programme, Fung welcomed the government's U-turn but said it was "too late". He also said the administration should subsidise schools for installing water filters if excessive lead is found in their water supply and carry out blood tests on students if needed.
Excessive levels of lead were first found in the tap water at some public housing estates in July. Initial investigations have found the heavy metal in the soldering materials connecting the water pipes at the estates.
More than 100 people, mostly children and pregnant women, who live at the affected estates were found to have excessive level of lead in their blood. Five of the children have shown signs of slow development but a link to the tainted water has not yet been established.