Chlorine

In the UK, all public water supplies must be disinfected by law to destroy any bacteria which may be harmful to your health. Predominantly, chlorine is used to ensure your water is safe to drink and meets our quality standards. We add chlorine at the final stage of water treatment in order to kill any harmful germs that may be present, and concentrations are monitored closely, 24 hours a day.

Although the level of chlorine left in our water is not harmful to health, some people are more sensitive to the taste and smell of chlorine than others.  We try and keep chlorine levels as low as possible whilst maintaining a safe level for consumption. Chlorine concentrations at your tap can vary throughout the day and through the seasons, and may be higher if you live close to one of our treatment works.

Chlorine tastes and smells are often the result of our regulated disinfection process and your individual sensitivity to this, but there are a few other things within your home that may cause chlorine-like tastes or smells:

• Sometimes chlorine reacts with materials used for tap washers, anti-splash devices and seals in kettles, causing an unpleasant ‘chemical’ taste. For more information please see our page on Chemical tastes and smells. 
  
  
• 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 and washing machines) plumbed in before taps used for drinking water. One way to resolve this problem is to use a one-way check valve between these and your tap.

The levels of chlorine needed to disinfect drinking water are not harmful, but some people are more sensitive to the taste and smell of chlorine than others. Below are some ways you can reduce tastes and smells associated with chlorine:

• Fill a jug or glass container, cover it and allow the water to stand in the fridge until needed. If you don’t use it within 24 hours, you should discard it – 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. 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 and use it to water your plants.
  
  
• 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.  You will need a filter containing activated carbon, which absorbs chlorine and other substances that can influence the taste of the water.
  
  
• If not properly maintained, such devices may cause problems with water quality. Any device which is ‘plumbed-in’ must comply with the Water Supply (Water Fittings) Regulations 1999. Further information and advice about water filters can be found from the Water Regulations Advisory Scheme.