Samples of potable water in Hong Kong were found to contain excessive levels of heavy metals including lead, nickel and cadmium in 2015. Such discoveries of contamination caused widespread crisis within the city.
The scandal began in June 2015 when the Democratic Party announced that testing of drinking water at Kai Ching Estate in Kowloon revealed lead contamination. The Hong Kong Housing Authority subsequently confirmed that the levels of lead exceeded the standard established by the World Health Organization. Since the initial discovery at Kai Tak, lead contamination of drinking water has been found at numerous other housing estates, schools, and public buildings across Hong Kong.
Heavy metal content in domestically used water
Potable water that is used in Hong Kong indicated high levels of heavy metal when it was tested. The heavy metals include lead and nickel. The discovery was made in 2015 when the Democratic Party undertook the responsibility of testing the water that was used at Kai Ching Estate. Hong Kong Housing Authority also discovered the presence of heavy metal in the water that was used was higher in comparison to the World Health Organization standards. Since lead water pipes have been used in the past there are certain acceptable limits of lead occurrence in drinking water where Hong Kong standard limit is at 10 micrograms of lead per litre. Helena Wong who is a member of the Democratic Party led to the exposure of the presence of high levels beyond the set standard of lead occurrence in domestic used water in an estate in Kowloon City. The source that resulted to high level of lead in the water was the illegal welding at the joints of the water pipes. After the discovery was made the government tried to shift the blame to the contractor but the contractor rejected the blame. The contractor claimed that his organisation was responsible for the installation of outside pipes thus didn't undertake the mandate to install the pipes inside the building.
Lead standards
Lead is a toxicant that can cause serious and irreversible health damage. Children are especially vulnerable to its effects. Due to the historic usage of lead water pipes, many jurisdictions have legal limits on safety levels of lead content in drinking water. Hong Kong standards limit the acceptable lead content of drinking water to 10 micrograms of lead per litre, the same standard as Europe, Australia, Taiwan, Japan and Singapore. For comparison, the United States allows 15 micrograms while Mainland China allows 10 micrograms per litre.
Discovery and cause
On 5 July 2015, Democratic Party legislator Helena Wong exposed the lead contamination in tap water at Kai Ching Estate, a newly constructed public housing estate in Kowloon City. Samples had been sent for testing at one of the six laboratories authorised by the government. According to the Water Supplies Department, the public monopoly supplier of potable water, the contamination was caused by illegal soldering at the joints of water pipes. Government officials attempted to pass the blame onto a building contractor. The contractor in turn rejected the accusation, saying that he had installed outside piping and had no role in installing pipes inside the building to each apartment. He asserted that materials used by his firm were approved by the housing authorities, and suggested the government may have not diligently checked the presence of prefabricated materials used in constructing other parts of the public housing projects. On 13 July 2015, after being identified by the WSD as being accountable for pipe work of Kai Ching Estate, licensed plumber Lam Tak-sum refuted HA's accusation, saying he was only responsible for the pipes connecting the water mains to water tanks of blocks, and that his scope excluded pipe work inside the flats and testing of water quality. However, Leung Chung-lap, assistant director of WSD, rebutted Lam's claim and said records showed that LP was also responsible for the pipelines into flats.