WaterFuture - Get into water

Have you got discoloured water?

The cause of the discolouration will depend on what colour your water is now. 


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Orange, brown or yellow White or cloudy Green Blue Bits in water Black or dark brown

Orange, brown or yellow water

Why is my water orange, brown or yellow?

Orange, brown or yellow coloured water can sometimes be caused by the disturbance of iron and/or manganese deposits within your home’s plumbing or the wider mains water network. Low concentrations of iron and manganese in the water can accumulate in water pipes over extended periods of time and when disturbed it can cause an orange, brown or yellow colour when you run your taps.


Why does this happen??

Iron and manganese deposits can be disturbed by sudden changes in flow for example when:

  • there has been a burst water main
  • a large surge in water usage
  • the fire brigade is using or testing fire hydrants.

You can check Service Announcements to see if there are any known issues nearby which may be causing the discolouration.

Private internal plumbing and service pipes made of iron, including galvanised pipes, can also lead to the accumulation of iron sediments over time which can cause brown/orange discoloured water within your property.


What should I do?

If you experience orange, brown or yellow water, run your cold kitchen tap for 10 minutes to see if this clears the discoloured water.

If it doesn’t run clear, repeat the process checking the supply every ten minutes. If the discolouration doesn’t clear within an hour, please call us.

White or cloudy water

White or cloudy water

Why is my water white, cloudy or milky?

Your water may appear white, cloudy or milky if air has become trapped in the water pipes. This can occur following a repair to a burst water main. This usually clears within 24 to 48 hours. Find out if we are currently carrying out any work through our Service Announcements.

If this issue is only seen in your property and not your neighbours, then the cause may be your cold pipe running too close to your hot pipe or internal issues with the pipework in your property, such as a leaking tap.

The air bubbles are harmless and it’s perfectly safe to drink.


Why has this happened?

The air dissolves in the water when it’s under pressure but, once you turn your tap on and the pressure is released, thousands of tiny air bubbles are formed. This gives the water its white or cloudy appearance. We call this aeration. This can be checked by pouring a glass of water and seeing whether the water clears from the bottom up in a few minutes as the air bubbles rise and escape the glass.

Common causes of aeration in cold water are repair work following a burst water main, seasonal changes in water temperature or water supply valves being replaced. Aeration can also occur in your hot water system where the boiler heats the water very quickly. If it’s only your hot water that appears aerated, the aeration is not caused by your water supply but by your boiler or domestic plumbing.

You may notice a white powdery build-up within your kettle or on glass wear that has been left to dry following washing up. This is caused by the hard water that is found across our supply area and is the residual naturally occurring minerals that remain after heating the water or when the water evaporates away. Please refer to the water hardness section of our website for more details.


What should I do?

You don’t usually need to do anything – the cloudiness will disappear in time as the air is released.

Bits in water

Why does my water have bits in it?

Soft bits in water are usually caused by biological growths which grow on damp surfaces such as end of taps and on showerheads.


What should I do?

Regularly clean tap spouts and showerheads with a household disinfectant to prevent the growth of slimes.

Airing your kitchen and bathroom regularly can also help to limit bacteria and mould.

Here are a few ways to keep your kitchen and bathroom aired:

  • After you’ve cooked or showered, open the window slightly
  • If you have double-glazed windows, keep the trickle vents open (these are normally narrow flaps at the top of the windows)
  • Improve room ventilation with installing extractor fans or use a dehumidifier
  • Avoid using aerosols, as they often contain ingredients that bacteria and moulds can feed on.


Water Filter Jugs

If you notice bits in your water filter jug, it is likely due to the filter media in the cartridge. Our top tips for looking after your filter jugs:

  • Regularly replace water filter cartridges and store them away from direct sunlight, preferably in the refrigerator. 
  • Always store your filter jug in the refrigerator and change the water every 24 hours; this will help maintain clean and healthy water.

Note: At times, the inside of your filter jug may develop a green tint, which is more likely if it is exposed to sunlight.

Blue or green water

Why is my water blue or green?

Blue or green water is sometimes caused by the formation of copper salts which dissolve in water when it passes through copper pipes, giving a blue or turquoise appearance. It commonly shows as a stain on fixtures and fittings, especially those made of enamel. The source of the blue water is normally through the use of copper pipes in domestic plumbing.

Another potential cause of blue water relates to the use of blue coloured disinfectant tablets in toilet cisterns. If the toilet does not have the correct plumbing it is possible for blue water to syphon out of the cistern into the domestic plumbing.


What should I do?

To confirm the issue is related to domestic plumbing, run the cold tap that is fed directly off the mains supply (this is usually the cold water tap in the kitchen), the water should clear with flushing. If the water clears with flushing this indicated the source of the discolouration is the plumbing system. Check the condition of your domestic plumbing. If it is old and starting to deteriorate, this will increase the chance of getting blue water. If you have had some recent plumbing work done, check that the plumber has not used a different metal pipe connected to the copper pipe work. This can cause a galvanic action leading to copper being dissolved. Check your water pipes are correctly earthed. Poor earthing can lead to electrolysis and copper becoming dissolved. If your boiler or hot water system has a sacrificial anode, check this has not fully corroded. It may need replacing. This will likely need the services of a plumber.

If the blue water is coming from your toilet cistern it will need repairing by a qualified plumber.

If the blue green colouration does not clear with flushing, you can check Service Announcements to see if there are any known issues nearby which may be causing the discolouration or alternatively please call us and we can investigate the issue.


**For customers supplied from our Knapp Mill water treatment works (this includes Christchurch, New Milton, Lymington, New Forest and Beaulieu)**

Customers supplied from our Knapp Mill water treatment works; Christchurch may notice periodic slight changes in the colour of the water supply during the autumn/winter period following heavy rainfall. Typically, this colour change is identified in bathtubs or sinks (when the water is deep against a white background) and described as being clear of particles but with a slight green/yellow colouration. This colouration does not clear with flushing.


What is the cause?

This change in colour is caused by seasonal changes in the natural colour of the river Avon which supplies Knapp Mill water treatment works. The source of the colouration is the New Forest which naturally releases coloured water following heavy rainfall each autumn/winter.

The water treatment process at Knapp Mill removes the vast majority of colour from the raw water but during these specific periods, the colour in the river is at a level which cannot be completely removed. Some customers in these areas notice a slight green/yellow colouration see in bath tubs and sinks.  

The increase in colour in the river and treated water during these periods is closely monitored and is fine to continue to use as normal.


Might this happen this winter?

While we are making every effort to improve the situation, there is a possibility that some customers may notice a slight change in the colour of their water during the wetter winter months. We are sorry for any inconvenience this may cause, but please be assured that the water is completely fine to drink and use as normal.


How long might this seasonal change last?

Customers may only notice the colour for a few days, but it could take a couple of weeks to clear fully. It may happen more than once this winter but we are doing everything we can to minimise the impact.


What areas are affected?

Customers supplied by our Knapp Mill water treatment works. This includes Christchurch, New Milton, Lymington, New Forest, Ringwood, and Beaulieu.


Is this water safe to use?

Please be assured that the water is completely fine to drink and use as normal. Our water quality monitoring teams ensure everyone’s water supply meets the necessary standards.


What are we doing about the colour?

Please be assured that during these periods we continue to actively manage the treatment processes to specifically target and enhance colour removal in real time as the colour of the river fluctuates. We are:

  • undertaking continual monitoring of colour through the treatment processes
  • recirculating treated water back through the treatment process to allow for greater colour removal
  • managing our filter assets to promote increased colour removal

Long-term solution

Construction is already underway at our Alderney site, where we are installing advanced treatment technologies and planning is progressing at our Knapp Mill site. These improvements are part of our ambitious plan to build state-of-the-art facilities at both our water treatment sites in Bournemouth and Christchurch (Knapp Mill). We are investing £113 million at our Alderney site and £85 million at Knapp Mill over the next few years and aim to complete them by 2026.

The delivery of the upgraded Knapp Mill water treatment works will: 

  • improve the region’s drinking water quality
  • improve the security and resilience of the region’s water supply against extreme conditions
  • use the latest technology in addition to our water treatment process which will be energy efficient and contribute to the reduction of carbon emissions
  • ensure the environmental impacts of the work has been assessed and improve the site’s ability to attract wildlife by 10% without impacting the natural habitat of the River Avon.

To find out more about our Knapp Mill treatment works upgrade, please click here.


What can I do?

Please accept our apologies for any inconvenience caused and be assured it is fine to continue to use the water as you normally would. The colour will return to normal as the impact of the enhanced treatment processes take affect and the concentrations of colour within the river return to normal levels.  You may notice the colour for several days but if you have any concerns, please contact us and we can further discuss the issue.

Black or dark brown water

Why has this happened?

Black or dark brown coloured water is associated with manganese. Very low levels of manganese can accumulate over time in the water mains. This can become disturbed if there is a large change in flow, for example following a burst main, resulting in temporary discolouration.


What should I do?

Run a cold water tap that is fed directly off the mains (this is usually the cold water tap in the kitchen) to clear out any of the discoloured water which is held in your pipework. Check the supply every ten minutes and if it doesn’t clear within an hour, please call us.

Discolouration is normally short lived following a burst or repairs to our network and should clear after running your cold kitchen tap for an hour. Sometimes it may persist due to the size of the burst or time taken to make the repair but it shouldn’t last beyond 24 hours. We will normally flush the pipes after a repair to clear the sediment and get your water running clear again.

If you’re on a meter and have had to run your tap to clear the discolouration for more than an hour, fill in this form and we’ll credit your account to cover the cost of the water.


Play your part, be water smart

Don’t waste the water you run from your tap, collect and use it in your garden, or to wash your car. Save water, help the environment and save money off your bills too! Every litre saved is a litre left in the environment. The less water we use, the more we can keep our rivers and streams flowing and nature thriving.