What to do if your tap water is discoloured

Last updated May 7, 2024
Reading time: 2 min

Is your tap water discoloured? Is it yellow, brown, grey or red (rust-coloured)? Normally this situation won’t last long and it is easy to eliminate by following a few steps before consuming the water.

Discoloured water (yellow, red, brown or grey) is generally caused by iron oxidation, creating rust in the drinking water lines. When equipment is inspected, or repair work is done on the distribution network, rust particles may come loose, causing the water to become discoloured.

Follow these steps

  • Open the cold water tap. If in a house, use the bathtub tap, or if not, then the kitchen sink. If your building (e.g. a store) doesn’t have a bathtub or kitchen sink, use whatever tap is available.
  • If the tap has an aerator, first unscrew the tip to remove it.
  • Let the cold water run until it is clear. Now you can drink it.
  • To prevent staining clothing or damaging an appliance, be sure the water runs clear before doing your laundry or using an appliance that uses water.

Does the discolouring persist?

If the water is still discoloured, call 311

Why is the water discoloured?

Water can become discoloured when work is done on the drinking water network:

  • Opening of fire hydrants or valves
  • Change in direction or speed of water flow in lines
  • Repair, maintenance or construction work

Why is my tap water white?

The water that comes out of your tap looks opaque and whitish because it contains tiny air bubbles.

Air is most soluble in water when it’s cold. When water sits in the pipe for a while, it warms up and the air it contains becomes gaseous again.

You can run the water until it’s cold again, then run it for another minute to get fresh water from the tap.

Would you like to stay informed?

  • View the list of current notices and alerts.
  • Subscribe to the Notices and Alerts system. Choose “Water and water mains” as the type of notice. You can choose notification by e-mail or text.

For any health questions, contact 811.