testing strip in front of sink
I was curious – could I drink the tap water of Hong Kong safely? What about metal contaminants while swimming in the open water? For the first few years here, I drank from the tap without hesitation and didn’t think twice about it. Then I noticed my downstairs neighbors would order giant crates of water bottles to their front door, while another friend would exclusively drink from plastic water jugs you can buy at the corner stores.

So is the tap water safe to drink?


What do Official Sources Say?

According to the water supplies department, “Hong Kong enjoys one of the safest water supplies in the world” the article continues to describe the treatment process:

“In the water treatment process, raw water (untreated water) is mixed with chemicals and passes to the clarifiers where coagulation and flocculation of the impurities in the water will take place. Clarified water then flows into filters of sand and anthracite for removal of the more finely divided suspensions.”

There’s a list of the chemicals added to treat the water, which include chlorine, fluorine, and lime. Most chemicals are removed during the purifying process with trace amounts of chlorine left to keep the water bacteria-free as it moves through the pipes.

Even though the official sites state clearly that Hong Kong water is safe to drink, I decided to do a check of my own. Once again I went to amazon to order heavy-metals testing strips and some concave slides for the old yet trusty microscope down at Dimsum Labs.


The Experiment

I decided to gather water from the following places:

  • The waterfall at the beginning of the morning trail (featured in the vid)
  • Lincoln house in Quarry Bay
  • Big Wave Bay on Hong Kong Island
  • The public swimming pool in TST
  • Tap water in Sheung Wan
  • Victoria Harbour (featured in the vid)

First, I boiled my water collecting accouterments in distilled water for about ten minutes to kill anything that might have been lurking in them. Next, I made a plan and spread out some time to collect each specimen for testing.


Also, at each testing site, I would test the water for heavy metals using these color strips using this amazon testing kit. The label on this kit says that it tests for Cu+2, Co+2, Zn+2, Cd+2, Ni+2, Hg+2 and it measured in ppb (parts per billion)

Picture of the testing kit ordered from amazon

Here’s a chart of what is considered a dangerous level of heavy metals in mg/L (1 mg/L = 1,000 ppb):

1.3 mg/L

20 mg/L

5 mg/L

0.005 mg/L

0.1 mg/L


I tried to wait and collect the water after a few days of no rain because I didn’t want my samples in some areas to be overly diluted.



My tap water had about 100ppb of heavy metal compared to Lincoln House tap water in Quarry bay which contained 125ppb. The biggest difference between these two taps was the taste; my tap water tastes rather neutral while Quarry Bay’s tasted like it has hundreds of old pennies soaking in it – not pleasant at all. Overall, 2/10 would not drink unless I had to.


I was a bit surprised to find that the waterfall on the morning trail didn’t contain any traces of heavy metals. For some reason, I had it in my mind that there would be some contamination that would have leached into the water, especially from the top of the peak down to the morning trail. In terms of heavy metal, the peak waterfall was the safest to drink! However, I found little critters swimming around under the microscope, even after the sample waited a few days. I only wish my microscope was a bit more high-powered so I could see in detail what they were.


The Big Wave Bay sample also had some organisms in it along with detritus and what I assume to be minuscule sand bits (for lack of a more technical term). This I definitely expected and was kind of cool to see after spending some time looking at the more mundane tap water.

Can confirm that in the tap water, I found no little microorganisms, but I have to stress that my microscope wasn’t incredibly powerful and that I only tested so many slides. Perhaps the trace amounts of chlorine that the HK gov leaves in the treated water have done their job splendidly!


Here’s the chart for what I found.

Chart of water levels at different locations
Chart of water levels at different locations



Thankfully none of the water samples I tested were off the charts in heavy metal contamination. I would like to stress that the dangerous levels of heavy metals chart is in mg/L while the chart directly above is in ppb. The shortcoming of this experiment is that we don’t know which metal is triggering the strip’s color change – if it’s copper then not a problem, however, if the test is registering cadmium then we are in trouble.


Another part of my test for the tap water was the taste – and that varied quite a bit with the worst being the financial building in quarry bay and the most neutral being my flat (probably because I’m used to it). If we are to trust that HK gov properly filters the water from Dongjiang and the collected rainwater, then the variety must be attributed to the buildings and building holding tanks themselves.


Even this government website says “Drinking water quality, however, can be affected by the condition of a building’s inside service. To safeguard tap water quality, property owners and building managers are advised to carry out proper maintenance of inside service and regular cleaning of water storage tanks.

If you are overseas and have never lived in a Hong Kong flat, then I can assure you that many of these apartment buildings are not being maintained to the highest standard. I wouldn’t be surprised if some of the tanks haven’t been cleaned or maintained since the day they were constructed, no telling what kind of chemical buildup or rust can enter into the pipes.

At the end of the day, the water going into the pipes is probably as clean as a whistle, adhering to the strict guidelines that Hong Kong implements. What comes out on the other end? That’s a bit more like playing Russian roulette (with much lower stakes). Time for me to go out and buy myself a filter.


Further Thoughts

My next experiment will be to take the sample that had the heaviest metal contamination (Lincoln House in Quarry Bay) and to test which type of water filters filter it the best and compare that to the bottled water so many people drink here. Because I do wonder about the plastic contamination that comes from drinking water that’s been stored in plastic – especially when being shipped around in the hot Hong Kong sun.

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