Easy access to a safe water supply is not always possible in some communities. However there are some practical ways to improve the quality of household stored water and hence reduce risks of diarrhoeal disease
Even if water looks clean, it might not be safe to use. Untreated water can contain millions of germs, including those that cause gastrointestinal infections such as cryptosporidiosis, cholera, typhoid, dysentery and hepatitis A. It can also contain germs that cause skin and eye infections. Many of these germs are excreted in animal and human faeces and they can get into the water if the supply is not protected from contamination. Many homes around the world do not have a piped water supply and even in homes that do have piped water, problems with water safety can arise from time to time (e.g. when sewage enters a fractured pipe). Drinking this unsafe water or using it to prepare food (e.g. for washing fruit or vegetables that you will eat raw) can lead to illness.
Using unsafe water can put everyone, but particularly the very young, the elderly and the sick at risk. Once someone becomes infected, many of these water-borne diseases can spread from person to person through direct or indirect contact with their faeces, for example, when someone forgets to wash their hands before preparing a meal for you.
If you do not have access to a piped supply of safe water, you will need to treat your water before you use it for drinking or food preparation to ensure that it is safe. If the water is very dirty, it may also be necessary to pre-treat it by filtering it or decanting it to remove any visible debris. The water then needs to be purified, for example by:
Boiling your water or exposing it to ultraviolet radiation are effective ways of destroying the germs in water. However, these methods can be impractical and do not provide any long-lasting protection. There is a high risk of re-contaminating the water with germs. For example, when you transfer the water to a contaminated container, or dip an unwashed ladle or your hands in the water.
Chlorination is usually the disinfection method of choice because it is efficient and easy. Provided you add the right amount of chlorine for the right amount of time, chlorine can effectively reduce the risk of water-borne infections. At doses of just a few milligrams per litre of water, chlorine can destroy more than 99.9% of water-borne germs. And, since some residual chlorine persists in the treated water, chlorination also helps to keep the treated water safe during storage and use.
Water purification tablets provide a simple and effective method of chlorinating your water and making it safe for drinking and food preparation. You just need to add the correct number of tablets to your water and leave them to work for the recommended amount of time. The chlorine will keep your water free from germs and help protect you and your family from water-borne disease.
Most water purification tablets effectively disinfect water without changing the colour of your water, leaving any objectionable taste or removing any of your water’s natural minerals. By providing residual activity that protects your water from re-contamination, they also helps keep water clean for longer.
Household water treatment and safe storage interventions can lead to dramatic improvements in your drinking water quality and reductions in diarrhoeal disease. It is preferable to store treated water in plastic, ceramic, or metal containers with the following characteristics, to reduce recontamination: