Discoloured water

Find out what may be causing a change in the colour of your water.

The water in your tap should appear as clear and colourless as it does leaving the water treatment plant. On some occasions the water in your tap may appear discoloured.

Cloudy or white water

To find out what is causing your drinking water to be white or cloudy in appearance, you can try this simple test. Fill a glass of water from the cold tap in the kitchen of your home and leave to stand for a few minutes. Then check it for the following:

  • Air bubbles: If the water clears from the bottom of the glass upwards then air bubbles are causing the cloudiness. The bubbles clear as they rise upwards from the bottom of the glass.
  • Limescale: If the water clears from the top of the glass downwards, the cloudiness or white colour may be due to limescale. This is found in areas of hard water.

Is it safe to drink?

Hard water and air bubbles do not affect the quality of drinking water. If the colour of your water clears after a few minutes, the water is safe to drink. If the white or cloudy appearance does not clear, please contact us on 1800 278 278 and we will ensure it is promptly investigated.

How to clear it

Trapped air bubbles in your water supply should clear within a short period of time. If limescale is causing the discolouration, find out how you can prevent the build up of limescale caused by hard water.

What to do if your water appears white or cloudy

Brown or orange water

The following can cause brown or orange water.

Ageing pipework

Your drinking water may pass through several kilometres of pipework before it reaches your home. Some of this pipework may be constructed from cast iron and depending on the area can be up to 100 years old. Old cast iron mains typically suffer from corrosion and as a result sediment from these pipes can be dislodged as water passes through them.

Changes in flow, pressure or direction

Most of the time, the drinking water passes over this sediment unchanged. However changes in flow, pressure or direction can dislodge this sediment and carry it through to your tap. This can cause your water to appear as brown or orange in colour. This discolouration is more likely to occur when repair or maintenance works are being carried out on the pipes.

Preventing sediment issues

In order to prevent sediment build-up, we regularly flush our water mains especially in old areas of the network. Under our mains rehabilitation programme, we are prioritising the replacement of old cast iron mains where these issues are most likely to occur.

Is it safe to drink?

Drinking water should be clear and colourless in appearance. If your water has suddenly changed in colour to orange or brown, we would encourage you to run your tap for a number of minutes to see if it returns to a clear colour.  If running your tap does not restore the clear colour, please contact us on 1800 278 278 and we will ensure it is promptly investigated. In the meantime, we would advise that you should not drink the water until we have investigated the matter.

How to clear it

Discoloured water can usually be cleared by running the cold water tap in the kitchen for a few minutes until the water runs clear. If running your tap does not restore the clear colour, please contact us on 1800 278 278 and we will ensure it is promptly investigated.

What to do if your water appears brown

Black or black particles in water

The following can cause black or black particles in water water.

Domestic water filters

Domestic water filters (e.g. jug filters) can contain activated carbon that can leak black particles into the water. Compare a glass of water from the cold tap with a glass of water from the jug filter. If black particles only appear in water from the jug filter then you may need to check the manufacturer’s instructions.

Tap washers

A disintegrating tap washer can leave large black particles that can be held between your fingers. This may indicate that the tap washer should be changed.

Manganese

If your water is black or contains tiny black particles, it may be due to manganese deposits. Manganese can occur naturally in certain water sources and if not removed can gather as sediment deposits in the water network.

Changes in flow, pressure or direction can dislodge sediment and carry it through to your tap. This can cause black particles in your water or your water to appear partly discoloured. This discolouration is more likely to occur when repair or maintenance works are being carried out on the pipes.

Is it safe to drink?

Manganese in drinking water is generally not harmful but it is best to wait until it has cleared as the taste may differ. We would encourage you to run your tap for a number of minutes to see if it returns to a clear colour. 

If running your tap does not restore the clear colour, please contact us on 1800 278 278 and we will ensure it is promptly investigated. In the meantime, we would advise that you should not drink the water.