Monday, May 25, 2020

Concerns about drinking tap water in a residential home in Singapore


Hi Mr Chen,

I've been reading your blog after stumbling across it while trying to find out more about water quality in Singapore.

I’ve always drank tap water neat, since childhood and never had any issues but ever since having a kid of my own, I've always questioned somewhat the quality of drinking water in my home. Perhaps because my other mummy friends are using fancy water dispensers with filters themselves and over time, that has made me question my own practice at home.

At the moment I’m using cooled water from a thermal pot (that boils fresh water and keeps it at 98C) for my daughter’s drinking needs. Apart from that, cooking etc i use tap water neat.

I recently dug up some old concern of mine (not sure why) - my toilet tap water intermittently tastes like soap..sometimes even smell like soap. IT disappears after a while, and then recurs perhaps a few months later for a short period of time. I’m not quite sure. The other water taps in my home doesn’t carry that taste/smell.

As such, I've asked PUB for help and they’ve taken water samples for testing and I’ve not heard back yet.
Before they left, the plumber did ask me if i boiled water for my daughter before use and when i said i did, he advised to continue doing so.
This made me think - is our tap water not safe then?

I know you have written articles about our excellent quality of tap water here in Singapore but I’m wondering if the piping used during construction works/ old pipes leading out from the original source itself - could they leach particles/chemicals/trace metals that over time, may be accumulated in the body and start causing harm?

I’m not sure also if any plastic pipes are used at all and over time, BPA/BPS/other endocrine disrupting chemicals could potentially be a concern too?

I”d love to hear your thoughts on this.

Thank you very much!

Jennifer


Hi Jennifer,

I was very occupied in the past few weeks, hence the late reply. 
  1. There are concerns about keeping water heated continually. As some chemical reactions are more likely to occur given the continual supply of energy. These reactions include those that form trihalomethanes (THM), a class of suspected carcinogens. There is of course still controversy over these concerns. Personally, I boil my water once and keep it hot in a thermal flask with no further heating.
  2. As for your intermittent soapy taste/smell from a single tap in your house, are you the only one who notices it? Do other family members experience this soapy taste/smell? If no, can it be due to a medical condition in you?
  3. PUB is obligated to test your tap water if there are complains. However, it never shares its test results, except to tell you whether the tap water is safe or not. In your case, since there is no further reply from PUB, then the water ought to be safe.
  4. You may want to read one of my previous posts - Ok, water from the water treatment plant is clean... do I still need water filters?. In short, PUB is not the only entity responsible for your tap water. Depending on your type of residence, the town council or building management committee may come into play. Depending on how they do their maintenance and accounting for unforeseen events e.g. dead maid in the water tank, there is a chance that your tap water may not be as clean as you like. Perhaps, your plumber was addressing this point when he made that remark.
  5. Properly certified for drinking water and/or food, plastics (including those in piping) should not contain BPA, BPB, plasticisers. But of course, if you are referring to plastics from decades ago, then it is anybody's guess whether these chemicals are present. Then again, if plastics are so old, they should be replaced anyway.
  6. Finally, yes, some chemicals can accumulate in your body and cause harm when a certain threshold has been reached e.g. lead, mercury. Google up on "bioaccumulation" for more information. 
Good luck!

https://www.worldatlas.com/r/w1200-h701-c1200x701/upload/ea/29/fc/shutterstock-373503418.jpg
Figure: Mercury/ quicksilver/ hydragyrum (Latin). Its chemical symbol is Hg which came from it Latin word. Mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury), by inhalation of mercury vapor, or by ingesting any form of mercury.

1 comment:

eiji said...

(( ..might anyone else who uses that bathroom have the habit of soaping over the tap head/handle/knob down after/while washing their hands especially if they're really soiled/otherwise dirty, perhaps..? throwing water over the thing to rinse said soap off only cursorily might've left some residue alongbthe length of and near the head of the spout, as might backsplash upward from rigorous washing/scrubbing laundry etc in the sink itself, especially if the sink is sorta small or the tap's water flow has been turned down to conserve water (like my parents did at our place. the behavioural effect has been that washing movements (of hands, snagging water while soaping up or scrubbing out laundry smalls, cupping a mouthful of water for teethbrushing et al) are way regularly brought possibly too close to the tap a awful lot; i've begun wondering if my compulsion to particularly and properly flush off the entire tap after each soap-generating usage (so no one ever winds up gargling with traces of laundry detergent for example) isn't using even more water than just letting the water flow normally the distance the tap's design intended, haha x_x";;; ))