Taste and Odour

Unusual drinking water tastes and odours can pose a significant concern for homeowners and businesses, but there are a number of ways to remedy these problems. Chlorine, antiseptic or TCP, earthy and musty, stagnant or sewage, and metallic or bitter tastes and smells are all common complains that can be resolved by following some simple guidelines or enlisting the support of a WaterSafe approved plumber. In these films, we feature advice from water quality experts, plumbers and the Drinking Water Inspectorate on the causes of taste and smells in tap water -- and how to avoid them.

If your tap water has an unusual taste or smell, there are a few things you should know. We've put together an informative video with some advice, and you can read our tips for specific problems in the questions below.

Chlorine in drinking water is not harmful, but some people are more sensitive to the taste and smell of chlorine than others. Chlorine is essential to protect public health and so it is added to drinking water as the final stage of treatment to kill any harmful germs that may be present. The concentration of chlorine in drinking water is monitored closely 24 hours a day.

Water suppliers try and keep chlorine levels as low as possible, while at the same time ensuring supplies are kept safe. Chlorine concentrations can vary throughout the day and through seasons, and may be higher if you live close to a water treatment works.

The taste of chlorine can be reduced by filling a jug or glass container, covering it and allowing the water to stand in the fridge until it is needed. If you don’t use it within 24 hours, you should discard it. If you do need to discard it then why not use it to water your plants rather than pouring it down the sink?

If you're really sensitive to the smell and can still detect it after storing it in the fridge, try boiling the water for about five minutes. This removes most of the chlorine. After the water cools, store it in a closed container in the fridge. Again, if you haven’t used it all within 24 hours please discard it.

You might also consider using a home treatment device like a water filter, generally these are not necessary but some customers like to use them. There are several types of water filters on the market ranging from jug type filters to permanently fitted devices. You will need a filter containing activated carbon, which absorbs chlorine and other substances which can influence the taste of the water.

Any device which is ‘plumbed-in’ must comply with the Water Fittings Regulations and Byelaws. If not properly maintained, these devices may cause problems with water quality.  Click here for further information and advice about the Water Fittings Regulations and Byelaws.

Sometimes chlorine reacts with materials used for tap washers, anti-splash devices and seals in kettles and this can cause an unpleasant ‘chemical’ taste.

A chlorinous or metallic taste in hot drinks, especially tea, will not be due to the presence of chlorine. Instead it is most likely to be associated with plumbing materials, such as rubber washers, or if you have appliances (such as vending machines, dishwashers or washing machines) plumbed in close to taps used for drinking water.

To solve this, either change the hoses for ones approved by  WRAS (Water Regulations Advisory Scheme), for example a food-quality hose, or change the isolating valve for one fitted with a check valve - also known as a one-way or non-return valve.

Water that passes through peaty land can have an earthy or musty taste and/or odour. The water treatment works in such areas are designed to remove the organic material that causes these tastes.

Several types of bacteria and algae that are normally present in lakes, reservoirs and rivers can naturally produce substances which are not harmful to health, but which can give a musty or earthy taste or odour to water. Some of these organisms can also grow on washers and the inside of taps in homes, which can lead to musty or earthy tastes or odours.

If you notice a smell or taste like this for the first time, try using a mild household disinfectant to wash outside and inside your drinking water tap. Don’t forget to let it run a little before you use it again to rinse out the disinfectant.

If you've tried this but are still concerned, or you'd like more advice you should contact your water supplier.

Some plumbing materials that come into contact with the water supply in homes, offices and factories can give water unpleasant tastes and odours. 

When water stays in contact with plastic or rubber pipes or fittings, small amounts of substances may dissolve into the water. Traces of chemicals routinely used in the manufacture of flexible plastic hoses, usually ones which supply cold water to dishwashers or washing machines, can interact with chlorine to create an antiseptic or TCP-type taste. When the drinking water tap is turned on a small amount of the water lying in these hoses can be drawn back into the cold supply. This problem usually occurs when the hose is connected directly to the rising main.

To check whether these hoses are causing the taste, close the isolating valve for 24 hours and then check the taste again.

You could also change the hoses for those approved by  WRAS (Water Regulations Advisory Scheme), for example a food-quality hose, or change the isolating valve for one fitted with a check valve.

This type of taste can also be caused by a having a garden hose permanently connected to an outside tap.

You should remove hoses from the tap when they are not in use and install a double check valve between the tap and the hose. A qualified plumber will be able to offer advice on how to do this.

As with all fixtures and fittings, plumbing materials deteriorate over time. Very old washers can begin to disintegrate or become damaged, for example by a worn tap seating, and this can change the taste of your water. The most commonly affected areas are the kitchen tap and the stop tap.

Try replacing old and worn out washers and or tap seats - this will help improve the taste.

Drinking water with this taste, although unpleasant, is not harmful in itself.

If you've tried this but are still concerned, or you'd like more advice you should contact your water supplier.

Sometimes taste problems can arise after water has been boiled. As a general rule, if your drinking water is satisfactory prior to boiling and you then notice a taste after boiling the cause of the problem is usually the kettle. 

Boiling water in a saucepan on your hob or stove will help determine if your kettle is the cause of the unusual taste.

If you have a new kettle, allow a layer of limescale to build up inside it by boiling and then discarding the water a few times. Only boil the required amount of water each time. Do not re-boil water, rather discard it, rinse the kettle and fill with fresh water. Also try to avoid frequent de-scaling of the kettle.

If you've tried this but are still concerned, or you'd like more advice you should contact your water supplier.

Higher levels of metals can be introduced into water through your internal pipework and can cause a metallic or bitter taste. 

This is most apparent after water has been standing in pipework for a period of time, such as overnight. You may also notice it in places where there are long runs of pipework or in places where water becomes warm as it passes to a drinking water point.

Try running water through the tap to clear any which has been allowed to stand. If you collect this in a bowl it can be used for watering plants rather than being wasted.

If you have new pipework the taste should improve with time as a thin protective layer of limescale will form on the inside of the pipework. Where water heats up during transit you should check the route of the pipework and the proximity of cold and hot water pipes. Affected pipework should be lagged or re-routed as necessary.

Occasionally glasses or cups that have been through a dishwasher may retain traces of detergents.

As a test, try rinsing the glass or cup with tap water and see whether the taste is still there. If so, adjust the settings on your dishwasher and use no more than the recommended amount of detergent and rinse aid.

If you've tried this but are still concerned, or you'd like more advice you should contact your water supplier.

If there is a petrol or diesel taste and/or odour to the water from your kitchen tap please contact your water supplier straight away. Please do not drink the water or use it for cooking until you have sought advice.

Please check if you have had any work done at the property (for example on the heating system), if you have any oil fired heating/storage tanks on the premises or if you have recently had any oil leaks, i.e. a car or motorbike leaking oil. This is the most common cause for this type of issue.

Sometimes a sewage or stagnant-type odour can come from a sink/plug hole. This usually means there has been a blockage or build up of waste materials, which makes the drinking water appear to smell. 

Filling a glass with water and smelling it in a different room, away from the kitchen sink, will help you work out whether the odour is genuinely from the water or not. If you think it is the water please contact your water supplier immediately.

If the odour disappears when you're away from the sink you should try cleaning your sink/plug hole with a normal domestic cleaner. However, if there has been recent work on your service pipe, or you have had a new connection to your property, it could indicate a problem with this work and you should contact your water supplier immediately.

This helpful video from Wessex Water offers advice for improving a variety of water taste and odour issues.