Water is a vital resource. Life on earth, as we know it, is impossible without access to safe drinking water. Concerns over declining quality and consistency of municipal drinking water supplied to consumers have been increasing over a long time.
In South Africa, widespread problems with the availability and quality of drinking water across urban areas have been well documented and have often given rise to protests.
For example, there have been service delivery protests in the eThekwini municipality, an important port city, amid power and water outages as well as in Johannesburg, the country’s economic centre.
There are many types of contaminants that can threaten the safety and quality of drinking water. The major water pollutants are disease-causing organisms (pathogens) and toxic chemicals.
Drinking water means more than the relatively small amount used for direct drinking. Water used for brushing teeth, washing food, washing hands (particularly when handling babies or young children) and washing tableware used while eating should receive priority when clean, safe water is scarce.
As a researcher working for decades on water issues, health and water quality, I can offer some suggestions about how people can purify their water and deal with water interruptions.
It’s not possible for the general public to purify all the water supplied to them every day using home-based methods. It is simply too expensive and laborious. So, the advice below concentrates on the situations when disasters or emergencies force residents to temporarily purify drinking water for themselves and their families.
Making water safe to drink
A simple filter: If the only available water has not been purified by any official system, pour the water through a sieve lined with one or more layers of paper towel or a dishcloth. When the “filter” becomes clogged, replace it with a clean layer. Do not reuse the soiled dishcloth without thoroughly washing it in hot water and soap and drying it in the sunlight.
Boiling: Bring the filtered water to a rolling boil for at least 3 minutes. Boiling the filtered water will get rid of the disease-causing organisms. It won’t remove any harmful chemicals that may be present, but may reduce the concentration of some of them.
Bleach Add a teaspoon of unscented household bleach (5 millilitres of a 3.5% sodium hypochlorite solution) to 25 litres of water for the treatment of drinking water. Mix well, cover the container and let the water stand for at least two hours before using it.
This should disinfect most of the disease-causing organisms and make the water much safer to use. Important: do not use any cleaning solution containing bleach that also includes other soaps or cleaning compounds. Use only unscented chlorinated household bleach.
Solar disinfection of water: Nicknamed SODIS, it can be used to disinfect water by killing disease-causing organisms using sunlight. Fill glass (preferable) or plastic bottles with contaminated water and place them in direct sunlight for at least six hours on a sunny day or up to two days if the weather is overcast. The heat and the ultraviolet radiation from the sun disinfect the water by killing most of the disease-causing organisms.
Water quality is not the only aspect of water provision that affects the health and safety of citizens. Water availability is crucial for hygiene and safe living standards.