46 HEALTH AND SANITATION
Household rainwater treatment options( Part 2)
The selection of appropriate household water treatment( HWT) systems requires prior knowledge of the quality of the water, as well as how the different options of HWT systems work and their effectiveness against different contaminants.
ThatchroofInfo
By Water Research Commission
Roofing materials play a big role in the type of rainwater treatment required.
Opposite page: A cartridge that is found in common water purifiers typically starts with a ceramic filter.
The various HWT technologies remove different types of contaminants to different levels. Thus, understanding the local water quality and contaminants will influence the selection of appropriate HWT options.
The main focus of HWT is on removing biological pathogens, because they are capable of causing diseases more rapidly than chemical contaminants. Nevertheless, a number of HWT options can also remove chemicals and improve physical qualities of drinking water.
It is worth mentioning that before addressing methods of treating water at the household level, it is important to emphasise the need to prevent and / or reduce source contamination. For domestic rainwater harvesting( RWH) systems, that amounts to preventing contamination from the catchment area and the conveying system from entering the tank.
Furthermore, health gains can only be achieved if the HWT product is adopted and its use sustained. Treatment of harvested rainwater will also depend on the intended use of such water, thus harvested rainwater for nonpotable uses such as gardening and vehicle washing will require less treatment compared to the one used for potable purposes such as drinking and dishwashing.
HWTs have proved to be effective on different types of water, including harvested rainwater. Therefore, by encouraging the use of HWT options, communities take responsibility for their own water security. Furthermore, if communities are empowered with the knowledge and tools to treat water at home, many microbial diseases will be eliminated. Low cost, safety, and efficiency in the removal of contaminants are the desirable qualities of home-based water treatment devices.
In South Africa, the most commonly used methods for treatment of household drinking water are boiling, cloth filtration, and chlorination. Each rainwater treatment system needs to be designed according to the surface from which the rain will be harvested.
August 2018 Volume 24 I Number 6 www. plumbingafrica. co. za