Milky water

Milky water is usually caused by air getting into the system. Tiny air bubbles can form in the water as it’s drawn from the tap giving it the milky or cloudy appearance you are seeing. Water with air bubbles is perfectly safe to drink.

Here’s a glass test you can do to see if the milky appearance is due to air bubbles:

  • Fill a glass of cold water from the tap.
  • See if it clears from the bottom to the top.
  • If it does, this indicates the milkiness is due to air bubbles and that the water is fine to drink.


Air can get into water pipes in various ways – sometimes it can happen when we’ve been working on the water mains in the street. The appearance of air in water can also be caused by internal plumbing, the most common cause is when cold water pipes sit too close to hot water or central heating pipes. Warm water holds less dissolved air than cold water so when the cold water is warmed in the pipe air bubbles will form which results in the water appearing milky. This milky appearance should clear if you flush the tap until the water runs cold and you can prevent it from happening by insulating the pipes to stop the cold water warming up.

If your water doesn’t clear in the glass test above and the milky water is persistent, affecting all your taps and not affecting neighbours, then please contact us for further advice.