Chlorine in drinking water

Why do we have Chlorine in drinking water?

Chlorine is added to the Mains water supply by the Water Authorities to reduce or eliminate bacteria, viruses and algae that can be present and has greatly reduced the risk of water borne diseases such as cholera and typhoid. Chlorine is easy to add to water and enough of the chemical remains in the water from the treatment plants through the distribution network to the consumer's tap so that re-contamination by micro-organisms cannot occur after leaving the treatment plant.

Why remove Chlorine from drinking water?

Chlorine adversely affects the taste and smell of tap water and the release of chlorine vapour from chlorinated water is associated with respiratory problems such as asthma, bronchitis, and some allergies. A simple carbon filter fitted through the kitchen cold tap that is used for drinking and cooking, will remove up to 98% of chlorine taste and odour, also reducing the acidity of water, making food and drink more palatable and could reduce the incidence of respiratory problems.

Chlorine in the water supply may also contribute to bleaching of clothes during washing machine cycles. There are also concerns for vapour released from hot water during bathing and showering and from appliances such as dishwashers, affecting the air quality within the home. Whole-of-house filtering systems are available where a filter is not attached to a single tap but at the Point-of-Entry into the property to remove chlorine before water is distributed throughout the house. These are expensive systems as they must treat a huge volume of water, million(s) of Litres rather than the few thousand Litres of a single tap filter system.

Consumers with serious respiratory ailments could benefit from whole-of-house filter systems, removing the potential for chlorine vapours in the atmosphere. However, adequate ventilation of a property could be argued to be adequate to maintain air quality: opening windows and doors regularly to let the fresh air in is certainly a simple and cheap option. Also, if chlorine-free water is stored anywhere within the household, for example within a hot water cylinder or in toilet cisterns, the lack of chlorine could constitute a health risk over time as these are not sterile systems and there is potential for micro-organisms to contaminate the supply.

Filter systems can be adapted for removing a wide range of contaminants, including limescale, lead, heavy metals, hormone and herbicides and insecticides.