Blue Water Discolouration

Seeing blue water run out of your tap is a once-in-a-blue-moon occurrence! (Couldn’t resist that pun) Blue water does happen in Singapore but on a much smaller scale than the yellow-brown water discolouration.

Never heard of yellow-brown water discolouration? You can read more about that here: Brown Water Coming From Hot Water Heater

What causes the discolouration?

Blue water is the result of corrosion of copper pipes or copper fittings. Below is an image of blue or cyan copper crystals. Spot the similarity in colour? A high copper content gives the water a blue tint. Prolonged periods of low usage or stagnant water in copper pipes of new buildings can make the colour more pronounced. If there is an even larger concentration of copper in the water, you may experience a metallic taste in addition to the wacky neon colour. Don’t drink it!

By Crystal Titan [CC BY-SA 4.0], from Wikimedia Commons

The video above was recorded by a new homeowner of a BTO estate. Now that’s pretty close to home; it could well happen to any one of us! Though blue water seems to come out from only the hot water side, it is not limited only to the hot water track. You need to locate the source of the corroded copper and this is highly likely to be a fitting or pipe. Water heaters have much lower (or in some cases, no) copper content so if you have installed a new heater recently, it probably isn’t the issue.

Is blue water dangerous?

Drinking water with copper in it may have health implications, especially for infants and the elderly. Treat the issue immediately and avoid usage till the colour has cleared out completely.

How do I get rid of blue water?

Running the tap at full blast for one minute can flush the plumbing system and clear out the corrosion. In most cases, this is all you need to do.

If the colour persists, it means you need to start hunting for a much larger starting source of the copper corrosion. Time to get the experts or a plumber in to help with the detection!

Closing notes, how to prevent this?

Blue water is an issue that occurs worldwide and the standing consensus is to try not to let warm water sit stagnant in copper pipes for too long. With our climate, this may be hard to avoid especially in a new development so to keep things practical, let’s practice some awareness of the quality and colour of the water we use!



Amanda is an education specialist at AOS Bath. She enjoys building a trusted network by sharing knowledge. Making difficult concepts simple and engaging is rewarding, on both ends.