In Hong Kong, the major water source relies on the East River in Guangdong province and only 30 per cent of daily consumable water comes from natural local supplies. With proper treatment and stringent quality monitoring and control by Water Supplies Department (WSD), we enjoy one of the safest and wholesome water supplies in the world that conforms strictly to the Guidelines for Drinking-water Quality recommended by World Health Organization (WHO).
Nevertheless, it may be a different story when water runs further down the pipelines. Investigations found dozens of different contaminants in drinking water, including E. Coli bacteria, disinfectants such as bleach and products of the pipe system such as lead and copper. Such phenomena may be blamed to the condition of inside plumbing due to the presence of iron from rusty pipes or contaminants leak in from cracked pipes that may be 30-50 years old or even pre-war. Other than that, high rises means more pipes and more potential for contamination and water tanks in buildings over six-storey may get dirty and contaminate the water further.
Boiling water is the most traditional remedy as viruses and bacteria could be killed but contaminants like rust and heavy metal particles will still remain in the boiled water and some sediment on the bottom of the kettle. Drinking distilled water is also a common choice, however, many started to aware that drinking distilled water is not healthy and may cause mineral lost. Besides, some of the bottled water suppliers in the market claim that they provide spring water or mineralized water. However, excessive levels of calcium in mineral water may lead to formation of kidney stones, while high sodium content is believed to lead to high blood pressure.
Fortunately, there is something you can do to minimize the problems of contamination. One of the possible solutions is to install water filters under the kitchen sink. Although normal carbon filters can reduce unpleasant odors, tastes and some of the chlorine, there is no significant effect on heavy metals or bacteria. Reverse osmosis filters may be effective as it can remove many dissolved metals and virtually all bacteria, pesticides and insecticides.