Taste and odour
Because our drinking water comes from a variety of sources, each of these has its own distinct taste due to its chemical composition (the natural minerals it contains). Find out what you can do to limit these taste and odours.
The temperature of water also influences the perception of taste and odour.
Some people are more sensitive to taste and odour and can detect tastes in water that most people do not notice.
Many tastes and odours in water are related to plumbing or appliances within a property.
TOP TIP: Installing fittings that have been tested and approved as meeting Regulation 4 of the Water Fittings Regulations will reduce the likelihood of experiencing taste and odour problems. A directory of approved fittings can be found on the WRAS website
You can also reduce tastes and odours in water by:
- not reboiling water that has been allowed to stand and cool in the kettle. ‘Off flavours’ are more pronounced when reboiled water is use
- only using freshly drawn water for drinking or cooking, taking it from the cold water tap supplied directly off the water mains. This is nearly always the cold tap in your kitchen
- flushing the tap before taking water for drinking if no water has been used in your home for several hours. This ensures that you do not drink water which may have lost its freshness while standing in the domestic pipework. Ideally use the water you run off for other purposes, eg, watering plants.
Hard water and taste
Different tastes are often caused by differences in the hardness of water. Most of the water in our region is naturally hard as it comes from groundwater sources.
Water that has been held in chalk or limestone will tend to be harder and is mainly found in the south and east of the region. This water has percolated underground through layers of limestone, chalk or rock - it means hard water has high mineral content with lots of calcium and magnesium.
Water from moorlands tends to be softer and is mainly found in the west of the region.
Find out more on hard water.
Metallic or bitter tastes
TOP TIP: To avoid metallic, bitter or sharp tastes in your drinking water, never use water from the hot water system for drinking and cooking.
Metallic, bitter or sharp tastes may be the result of metal dissolving from copper, iron or galvanised pipes in the plumbing system.
This may arise after the installation of new metal pipes but the taste will reduce over time as the pipework becomes conditioned with a protective layer of limescale or metal oxide which prevents the metal from dissolving.
In the meantime, metallic or bitter tastes can be reduced by running the tap to flush out the water that has been sitting in the pipes before drinking.
Earthy or musty tastes and odours
TOP TIP: Before using water for drinking and cooking, run your tap for a short while to flush out any water standing in the pipes. The run off water can be used on your houseplants.
Because the water may not have moved in the pipework for a prolonged period it can develop a musty taste and smell if it is left to stagnate.
Musty odours can also develop when cold water pipes are warmed by being too close to hot water pipes. To avoid this, ensure that both hot and cold water pipes in your property are separated and insulated and that you only drink water direct from the mains supply.
Unapproved plumbing materials and fittings can also cause musty odours.
While we optimise treatment processes to prevent unusual tastes and odours in drinking water, naturally occurring organic compounds can be present in our surface water sources at certain times of year.
Hot weather and the growth of certain bacteria can give rise to geosmin which has a characteristic earthy or musty taste. Some people can detect at geosmin extremely low (parts per billion) concentration.
The majority of Wessex Water’s customers receive drinking water from our groundwater sources.
TCP or medicinal tastes or smells
Medicinal or TCP type tastes are usually traced to unsuitable or degraded tap washers, rubber tap extensions and other fittings, such as sealing rings in electric kettles.
If these contain even very low concentrations of phenolic chemicals, traces can dissolve in water and react with the chlorine forming chlorophenols, including TCP.
Although these are not considered harmful, they can cause noticeable tastes and odours at extremely low levels.
A frequent cause of TCP taints in the water supply is the flexible cold water feed pipes on washing machines or dishwashers. To identify whether an appliance connection is causing the taste issue, turn off the water supply to the appliance using the service valve at the point where the hose connects to the mains supply.
If the TCP taste disappears after running the tap for a short while when this valve is closed, this suggests that the flexible hose is the source of the problem.
The best solution is to have a one-way check valve fitted to the connector just before the flexible pipe to prevent backflow. Check valves are simple to install and can be purchased from most plumbing merchants and DIY stores.
Another cause of TCP taints in the water supply is the dissolving of materials from within your kettle, particularly when new. Always follow manufacturer's instructions when using a new kettle for the first time.
If a TCP taste is only present in hot drinks, boil some water in a clean saucepan. If the taste is no longer apparent, it suggests that something in the kettle is responsible.
For more information see plumbing tips
TOP TIP: Chilling tap water in the fridge will reduce the chlorine taste and smell.
Without chlorine, the water is at risk of bacterial contamination so it should be kept covered in the fridge for no more than 24 hours after being drawn from the tap.
Chlorine is added to water to disinfect it and make it safe to drink. It is a legal requirement to disinfect water. We use a dose of chlorine during the treatment process to disinfect water.
At times of high demand, normally first thing in the morning and late afternoon, more people use water meaning the water travels to you more quickly and may contain slightly more chlorine than at other times. This is because the concentration of chlorine in the water pipes reduces with time.
The residual level of chlorine in the water supply may vary according to:
- the time of day - it may seem higher in the mornings and at dinner time due to increased water usage
- the proximity of your home to a water treatment works - the nearer your home, the higher the level as the water has travelled least distance
- the water treatment works supplying your home - if it changes you may notice a change in taste.
If you dislike the chlorine taste to your water, it can be removed using a water filter. Please follow the manufacturer's instructions with regard to cleaning, maintaining and replacing the filter at specified intervals.
Plastic tastes are often caused by the use of unsuitable plumbing materials; only materials approved for use in contact with drinking water should be used.
Salty tastes can be caused by incorrectly installed ion water exchange water softeners. This may result in a backflow which can allow salty water from the softener to syphon back into the drinking water system.
To avoid this, always follow the requirements of the Water Supply (Water Fittings) Regulations 1999 and the British Water code of practice on installing water softeners.
We recommend you use WaterSafe approved plumbers to carry out plumbing work and do not drink softened water.
One tap in your home - ideally the kitchen cold water tap - should be reserved for drinking water and remain unsoftened.
If a property has not been occupied for a while it is possible that an eggy or sulphur tastes or odours might be noted.
These are usually a result of the odour from the waste trap of the sink affecting your perception of the water - the water itself will not be affected.
You can check this by filling a clean glass with water from the tap and taking it away from the sink into another room before tasting it again.
If the water tastes and smells fresher away from the sink, it suggests the waste trap is the cause of the odour.
Over time, organic matter (such as food waste and soap) can accumulate on the walls of the drain and bacteria can grow on these organic deposits.
As the bacteria grow and multiply, they can produce gases that may smell like eggs or wastewater. To get rid of this smell, clean and disinfect the drainpipe below the sink.
Petrol, diesel or solvent tastes or smells
Petrol, diesel or solvent tastes and smells can be associated with spills of chemicals or fuels such as heating oils, petrol or diesel on the ground near water pipes. These contain chemicals that can soak rapidly through a driveway or soil and permeate plastic water pipes to cause an unpleasant taste or smell.
If you become aware of a spill or notice an oily taste or smell to your water, contact us immediately.
Bits in water
Bits in water are usually caused by:
- limescale which can become discoloured by traces of metal from pipework. These bits are usually white, but can sometimes appear green/blue due to copper or brown/black as result of iron pipework. Sometimes scale particles from the bottom and side of kettles can be poured accidentally into drinks. Films of fine particles can also float on the surface of hot drinks. Fully emptying and rinsing your kettle before boiling can help to reduce this
- water filters or water softeners can cause bits in water - please refer to the manufacturer with any queries
- limescale or particles of corroded iron pipes dislodged from the pipes can appear as gritty or sandy bits in water
- microbial growth unrelated to the water itself can cause slimy bits. The best way to avoid this is to keep taps and surfaces clean.