Chlorine
A small amount of chlorine is added to water during the final stages of treatment, to ensure the tap water is free from bacteria.
Chlorine in your water
Do you add chlorine to drinking water?
Yes. We add a small amount of chlorine during the final stages of treatment to ensure the tap water is free from harmful bacteria. It is a legal requirement to disinfect water and have a small amount of chlorine in the water when it reaches your home. We do not add chloramine to the water we supply.
How much is added?
The amount of chlorine added to the water is typically between 0.5 and 1.0 mg/l (parts per million). The levels are monitored continuously by online instruments to ensure the correct amount is added, with our treatment works operatives also checking the levels daily.
Once the water leaves the treatment works, the chlorine starts to dissipate, which means the amount left in the water when it reaches your home will be lower, typically between 0.1 and 0.8 mg/l. For comparison, the typical level of chlorine in your local swimming pool is normally between 1.5 and 5.0 mg/l.
The amount of chlorine in your tap water will be dependent on:
- The distance your home is from the water treatment works. As chlorine dissipates over time, the further you are from the treatment works, the lower the level will be.
- The time of year. Cold water retains chlorine for longer meaning that during the winter months the level will be slightly higher than in the summer months.
- The time of day. First thing in the morning and early evening are when people use the most water, which means the water is travelling more quickly through our network so there is less time for the chlorine to dissipate.
- If there has been a burst main, or the fire service are drawing water, or we are flushing the local water mains the water may also reach you more quickly.
Answers to your questions about chlorine
Simple ways to reduce the amount of chlorine
Store water in a covered jug in the fridge for a few hours before using it. It is important not to keep this water for more than 24 hours. Removing the chlorine will mean the water is no longer protected against bacterial growth.
Boiling reduces chlorine
Boiling the water can also reduce the amount of chlorine.
Tap water still tastes like chlorine
The smell of chlorine in hot water
The smell of chlorine can be more noticeable in hot water, particularly if the water is heated using a combi-boiler or electric shower. Unlike a traditional hot water system, which heats the water in a hot water cylinder, combi-boilers and electric showers heat the water directly. Hot water is not able to hold as much chlorine which means the first opportunity the chlorine must escape the water is when the water flows from the hot water tap or shower head, causing a noticeable smell.
Simple ways to reduce the amount of chlorine
Store water in a covered jug in the fridge for a few hours before using it. It is important not to keep this water for more than 24 hours. Removing the chlorine will mean the water is no longer protected against bacterial growth.
Boiling reduces chlorine
Boiling the water can also reduce the amount of chlorine.
Tap water still tastes like chlorine
The smell of chlorine in hot water
The smell of chlorine can be more noticeable in hot water, particularly if the water is heated using a combi-boiler or electric shower. Unlike a traditional hot water system, which heats the water in a hot water cylinder, combi-boilers and electric showers heat the water directly. Hot water is not able to hold as much chlorine which means the first opportunity the chlorine must escape the water is when the water flows from the hot water tap or shower head, causing a noticeable smell.
Simple ways to reduce the amount of chlorine
Store water in a covered jug in the fridge for a few hours before using it. It is important not to keep this water for more than 24 hours. Removing the chlorine will mean the water is no longer protected against bacterial growth.
Boiling reduces chlorine
Boiling the water can also reduce the amount of chlorine.
Tap water still tastes like chlorine
The smell of chlorine in hot water
The smell of chlorine can be more noticeable in hot water, particularly if the water is heated using a combi-boiler or electric shower. Unlike a traditional hot water system, which heats the water in a hot water cylinder, combi-boilers and electric showers heat the water directly. Hot water is not able to hold as much chlorine which means the first opportunity the chlorine must escape the water is when the water flows from the hot water tap or shower head, causing a noticeable smell.