Water Quality questions -
Click on the 4 commonly asked questions below to see the answers:
Discoloured water is usually caused by the disturbance of deposits in the water pipes. The disturbance of deposits can happen when a water main is shut off due to essential maintenance or in an emergency. Our website is constantly updated, click Planned work or Emergency work to find out more.
Discoloured water is unlikely to be harmful to health but we wouldn’t expect anyone to drink it when it looks unpleasant. It usually clears fairly quickly after a few minutes of flushing your taps though but it may take around 45 minutes of running the tap before it clears.
Avoid washing clothes until the water is clear but if you have and the discoloured water has stained your washing, please re-wash when the supply has cleared. If the clothes are still stained after re-washing please keep the stained clothes and contact us on 0800 052 0130
If you are concerned and the discolouration hasn’t cleared, please call us on 0800 052 0130
For more information, please see our information sheet Discoloured Water.
This is almost certainly nothing to do with the quality of your water supply.
What you are seeing is a mould that thrives on damp, warm surfaces – just like you’ll find growing on kitchen or bathroom surfaces e.g. on tiles, toilet cisterns or shower curtains. This mould also likes to grow on your taps.
Cleaning with an ordinary detergent may solve the problem temporarily but it won’t fully get rid of the mould. To do this you must kill the mould with a bleach-based disinfectant. We recommend a food grade disinfectant or a sterilising fluid such as that used for baby’s bottles is used on taps used for drinking water.
A useful tip is to use an old toothbrush to give the tap a good clean with the disinfectant, including inside the spout. Then let the tap run for a few minutes to wash away the disinfectant and mould.
For more information, please see our information sheet Slime and Staining.
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 milkyness 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 on 0800 052 0130
For more information, please see our information sheet White Water.
Occasionally customers report that their water doesn’t taste or smell as it usually does. Taste and odour can be described as ‘earthy’, ‘musty’ or a chemical taste although a few other descriptions may also apply.
Here are some useful questions that may help you pinpoint the cause:
Is this a sudden change in the taste, or have I noticed it building up gradually over some time?
Is the unusual taste present all the time – or does it come and go?
Do you have a header tank, which feeds the cold water drinking taps? If you have, then take a look or get a plumber to look to make sure it’s covered. If it isn’t covered something may have fallen into the tank and caused the unusual taste or odour. If this is the case the tank will need cleaning out, disinfecting and a suitable cover fitted. You will need advice from a plumber in order to carry this out.
Have you had any plumbing or building work done recently or have you had a new appliance? This could be a simple as having a washing machine installed or piece of new pipework fitted up to your drinking water tap or a new kettle.
- If a non return valve has not been fitted to the end of your washing machine hose, depending on your plumbing arrangements, water that has been sitting in the hose can sometimes find its way into the water feeding your tap giving the water a phenol or TCP taste. This is may be particularly noticeable when you make a hot drink.
- Short lengths of flexible hose fitted beneath sinks connecting the taps are sometimes the source of taste problems. Check the information that came with the hose to see if it has been approved for use with mains water by a recognised organisation such as Water Regulations Advisory Service (WRAS). If it hasn’t then you should replace it with an approved fitting. We recommend that whenever you undertake plumbing work yourself or ask a plumber to do it for you always check that fittings are approved for use with drinking water e.g. by WRAS.
If you detect a diesel or petrol taste please report it to us immediately as this may be caused by a fuel spill e.g. when someone on your property or neighbouring properties been working on a car or motor cycle and allowed petrol or oil to leak onto the ground. Fuel can work its way through the ground and penetrate plastic water pipes, it can sometimes take several days or weeks for the fuel to reach the water pipe.
If you have made these checks or changes and the problem persists please contact us for further advice on 0800 052 0130
For more information, please see our information sheet Taste and smell (odour) of drinking water.
Click here to view the leaflet looking after water in your home
For more information on drinking water quality click here