According to the World Health Organization (WHO), nearly two billion people use either unimproved drinking water sources or improved sources that are faecally contaminated. There are many factors that may prevent us from having access to safe drinking water, such as damaged piping infrastructure due to natural disasters or lack of maintenance, contamination of river water through farming activities or heavy rainfall and the inability of the centralised system to channel it to remote areas. Consequently, knowing how to treat water at home becomes a necessity.

Some advantages of at-home treatment include cost-effectiveness, lack of reliance on municipal water supply in periods of low or no access to water, and access to water during hurricane seasons, while disadvantages include lack of knowledge about proper treatment methods — which may result in further contamination of water due to misuse of methods — and inability of households to test water quality parameters to ensure they meet minimum standards. With information from the WHO suggesting that Household-level Water Treatment and Safe Storage (HWTS) can reduce episodes of diarrhoea diseases by 39 per cent, here are some examples of possible at-home water treatment methods that are used on a wider scale with more complex systems and processes.

The main treatment processes for water are sedimentation, filtration and disinfection. While a centralised water treatment company uses the best technology to ensure these steps are carried out to meet international standards, we can also use similar and less complex methods to make water potable by going through the three steps at home. To begin with, if you are harvesting water from a river or spring check your surroundings to ensure that the area surrounding the water source has limited agricultural activities; no surrounding solid waste or pit latrines.

Sedimentation

The sedimentation process is intended to remove all suspended particles settling in the water such as sand, clay, and other materials. Synthetic coagulants and flocculants are used in the process of sedimentation in the centralised processes but can be found in natural forms such as the moringa plant. While I am not aware of the exact methods, studies have shown that extracts from the moringa plant can reduce the turbidity and coliform count of water being treated. Before moving to the filtration process, you can allow your water to settle overnight in containers before filtering. A useful method is a “three pot method” whereby you allow the water to settle in a covered pot/sanitary container for at least two days, then pour into another clean container and let rest for same period. The third container can then be filtered after resting.

Filtration

Filtration is the process after sedimentation which is used to further reduce turbidity (presence of suspended particles) and remove some pathogens. Individuals attached to the central water system sometimes have filters attached to their inlet pipes to remove any pathogens or particles that may have passed through the system; however, for those who harvest water this process can be carried out after sedimentation by using makeshift filters such as clean cotton cloths which must be thick enough to retain impurities such as dirt, and insect larvae that may be present. After filtration disinfection must then take place to further treat the water for safe consumption

Disinfection

Disinfection is what most of us are used to, and involves the addition of chemicals such as chlorine (bleach solution). It can also be induced by using something as simple as ultraviolet radiation from natural sunlight. These processes will kill most disease-causing microorganisms in our drinking water. For disinfection using sunlight, we can reuse clear PET (polyethylene terephtalate) by filling and covering clean and properly sanitised bottles with water and exposing this to sunlight for six hours; which will kill viruses, bacteria and parasites. You also have the option of boiling water and then using eight drops of bleach per gallon after cooling.

Storage

After doing all this work we want to ensure that our water is safely stored, to prevent the possibility of recontamination. Clean containers with covers must always be used for storing water and these must be stored in areas which are free from waste and pest intrusion. It is advisable that you attach a piping system to your water storage containers, to avoid dipping cups and utensils into your water; as this could cause recontamination.

Treatment and storage of water for consumption are very important to public health, especially for those who practise water harvesting from springs, rivers and catchment of rain water. We need to ensure that we eliminate consumption of unsafe drinking water by taking the necessary steps to protect our households.