United Christian Hospital provides its patients with clean drinking water from its taps - and has a gold certificate to prove it. It was the first hospital to receive the recognition, awarded in a Water Supplies Department project to make sure the tap water of participating organisations is constantly monitored and meets World Health Organisation standards. 'The government ensures water in reservoirs is up to standard,' hospital chief executive Luk Che-chung said. 'But for water quality in buildings, the responsibility lies with property owners or maintenance staff.' Since joining the voluntary Quality Water Recognition Scheme in 2002, the hospital has passed the qualifications for five consecutive years - the minimum requirement for getting gold. Under the scheme, pipes have to be inspected by licensed plumbers, and water tanks must be cleaned every three months. Samples are collected from taps at the end of the year to be checked for their pH and iron content, micro-organisms and other criteria. Participating organisations undergo regular quality checks. As of last month, more than 2,230 buildings had been certified. Tap water in most buildings in the city is not safeguarded. Drinking water contaminated with coliform bacteria may cause diarrhoea. Pipes that were not properly maintained could be oxidised, and iron would make water turn yellow, senior hospital engineer Alan Ho Chiu-hung said. Boiling water would kill most bacteria, but not remove any iron content. 'Heavy metal will remain even if the water is boiled,' Mr Ho said. 'Long-term accumulation may cause harm to health, especially for children.' Dr Luk said that while food poisoning could be traced to certain restaurants, it would be difficult to identify the source if bacteria entered tap water. 'As a public body, our hospital would like to be a leader and initiate action. It would be more negative if we acted only after an accident.'