Hong Kong Water: Worthy or Worrisome?

Anyone unfortunate enough to have experienced the gurgling gush of copper-brown discharge from one of Hong Kong’s kitchen sinks can now rest a little easier; it turns out that tap water in Hong Kong isn’t nearly as foul as it sometimes appears. In the majority of cases, having unclean looking water is a result of living in a high-rise building.

Raw water from one of the twenty one treatment works in Hong Kong first has to be dosed with chemicals such as alum and hydrated lime to achieve coagulation and flocculation in order to remove impurities. The water then goes through several processes to remove fine particles, chlorine is added to disinfect the supply and finally fluoride is used to prevent dental decay. That small amount of residual chlorine you can sometimes taste is maintained in treated water to prevent contamination, but be assured that any hint or taste is minimal, and can be removed simply by boiling the water.

After this treatment the now clarified water travels up through a roof tank before arriving in your sink. Because it has to journey through the pipes around the building, any remaining water left behind after use usually stagnantes until the tap is turned on again. This is the main cause behind discoloured water from a tap, which can sometimes be very alarming. The issue can be simply overcome by running the tap for a few seconds, ejecting any still water in the pipes and getting the fresher supply running.

Although it is common practice among locals to boil all tap water intended for drinking or cooking, HK residents can still consume unboiled tap water on the condition that the management of the building maintains high standards.

If dirty tap water is a consistent issue however, it usually means a continued use of ageing pipes or an unmaintained header tank. The HK Water Services Department have released maintenance standards that need to be kept by all buildings, otherwise they run the risk of a contaminated water supply. This includes ensuring water tanks are regularly cleaned and that damaged or rusty water tank covers are promptly replaced.

Only about 20-30 percent of Hong Kong’s fresh water comes from local catchments and reservoirs. Compare that with the 70-80 percent of fresh water coming directly from Dongjiang and it easy to come across concerns that the quality might be questionable, due to its origin and a general mistrust of Mainland service and health standards. The truth is however that all tap water in Hong Kong is well within acceptance standards from the World Health Organisation’s guidelines for drinking-water quality. Extensive research has also proven that the risk of getting cancer from drinking tap water in Hong Kong is almost zero.

Should I install a filter?
You may sometimes wonder why small bits of sediment can be found in an electric kettle; but these are harmless minerals, mostly calcium salts. Filters can help reduce the chance of these sediments building up in kettles and also help overcome that ‘brown’ aesthetic from some taps. Filters aren’t necessary, especially if all water consumed is boiled first, but the peace of mind is sometimes worthwhile.

Should I replace my pipes?
Since 1995 unlined galvanized pipes for water transportation have been prohibited. To avoid corrosion of pipes, other pipe materials such as lined galvanized steel pipes, copper pipes, stainless steel pipes and polyethylene pipes are recommended by the Water Services Department.

Should I convert to bottled water?
Mineral and distilled water, both local and imported brands, are readily available from all supermarkets and convenience stores. Hong Kong reportedly sold more than 275 million litres of bottled water, generating HK$2.68 billion in revenue. To put that into practical terms, bottled water costs roughly 1,000 times more than tap water.

Residents concerned with the impact to the environment are recommended to boil tap water and carry it in a reusable bottle. The real appeal for bottled water should remain purely as a convenience, rather than an alternative to tap water because of concerns for health.

All of Hong Kong’s fresh water supply is treated and tested to well above WHO’s standards, and is actually among the safest in the world.