Taste and Odour in Drinking Water

Most drinking water does not have a noticeable taste or odour, however there may be some situations where this is not the case. If you suddenly notice a particularly bad or strong smell or taste which makes the water unpalatable, you should contact your water company.

What are some of the possible tastes and smells?

Water may pick up traces of substances from your plumbing and water fittings or appliances and this situation is the most common cause of unusual or strange tastes.

For example:


The most common method of disinfecting drinking water is to use chlorine. Normal levels should be kept low enough to not be noticeable, however you may sometimes notice a slight taste or smell of chlorine, follow the advice given in our chlorine leaflet.

Metallic or bitter

Water in contact with copper, iron or galvanised pipes, tanks or fittings for long periods may pick up a metallic or bitter flavour. This can be more noticeable when the water has been warmed. Flushing of the tap before use will draw fresh water through the pipes and fittings and remove the taste.

Plastic or rubbery

Unapproved fittings and plumbing materials can leach out compounds which cause undesirable tastes. Only approved fittings should be used and installed by WaterSafe approved plumbers. More information can be found in our advice leaflet.

TCP or medicinal

Chemical reactions can occur between chlorine and chemicals in kettles, rubber or plastic components within your domestic plumbing system, which lead to antiseptic and medicinal tastes. The taste and smell may be stronger if the water has been boiled or left to stand in a glass. This taste is not harmful at the levels usually seen in tap water but can be very unpleasant. More advice on this can be found in our advice leaflet.

Salty or chemical

Incorrectly installed softeners, treatment devices and filters or those which are not functioning correctly may result in backflow of water with added salt in it. Further information on filters and softeners can be found in our advice leaflet.

Petrol or fuel

This is most frequently a result of where a fuel has been spilled or leaked into the ground or soil around plastic water pipes. You should contact your water company and local authority immediately if you suspect a spill or leak of fuel has occurred. Further advice on this can be found in our advice leaflet.

Woody or pencil

Across the country many black plastic pipes installed in the 1960’s and 1970’s were made of alkathene. When water is in contact with these pipes for an extended period of time it can pick up a taste which is similar to that of a wooden pencil. Flushing your taps will bring through fresh water to remove the taste.

Rotten, stagnant, sewage

If you fill a glass with water and take it into another room and the stagnant or rotten smell is no longer present then the issue is likely to be with the sink or the drains, which should be cleaned or unblocked. If the smell is still present away from the sink this could indicate an issue with your plumbing, and you should contact your water company immediately.

Musty or earthy

Where water has been left to stand for a long time or has been warmed in little used sections of plumbing. The taste is caused by harmless naturally occurring bacteria or fungi which can grow, especially on rubber fittings. Running your taps for a few minutes should remove any stale water.

Do seasonal changes affect my water?

About half of our drinking water comes from rivers and reservoirs. In summer these waters sometimes develop a musty or earthy smell or taste due to natural processes in the environment. Water companies are required to treat these tastes but occasionally, especially during exceptionally hot weather, the treatment is not optimal. A common cause is the growth of algae in reservoirs. For more information about algae in water see our advice leaflet.

How can I find out if it is my plumbing?

Your water company will be able to help you find out if there is anything wrong with your household plumbing. They can carry out an inspection and take some tests. Alternatively, you could get advice from an WaterSafe approved plumber.

What if my water supply changes or if I move to a new house?

The natural properties of drinking water can vary from area to area due, in part, to the local geology. Water picks up minerals from rocks as it flows across and through the ground. For example, hard water from a chalky area will have a very different taste from soft water from a reservoir in the hills. More information available on water hardness can be found here.

In order to ensure an adequate supply of water at all times, water companies may use different sources at different times of the year, or they may supplement one source with another during the summer period. Some people are able to detect these changes. Occasionally a water company will develop an entirely new water source or install a new process of water treatment. Usually there will be publicity when a major change is made, and this will explain what the water company is doing and why.

In all these circumstances the slight change in water quality is no cause for concern regarding the safety of your drinking water supply. Your water supply is regularly tested to ensure it meets the drinking water standards.

What should I do if I notice any changes?

If you experience any changes to the taste or smell of your drinking water, firstly check other taps within your house to find out if it affects more than one tap. The next step should be to check with your neighbours to see if the problem is only confined to the plumbing inside your home. If the problem persists, or you have concerns, contact your water company. They can provide further information and carry out investigations if necessary. The following information may be useful to the water company when responding to your report.

  • Description of the taste, odour, or both.
  • Whether it affects other taps in your house or any neighbouring properties.
  • When you first noticed a change to the taste or odour.

Remember that you should only be using cold water from the kitchen for drinking and cooking. Water from the hot tap is not recommended for drinking as it can contain elevated levels of metals, such as copper, which makes the water taste astringent. Cold water in bathrooms and washrooms is not recommended for drinking as it may be from a tank that is not suitable for drinking water purposes. You can find advice on what to do if your drinking water comes from a tank in our advice leaflet here.

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