ABSTRACT
“The water coming from the tap is very clean since the construction of the treatment plant and children have less diarrhoea.” This kind of statement can be heard in many of the communities where multi-stage filtration (MSF) water treatment systems have been installed. MSF is a combination of coarse gravel prefiltration and slow sand filtration (SSF). This combination allows the treatment of water with considerable levels of contamination well above the levels that can be treated by SSF alone. MSF technology can be preceded by other treatment processes such as simple sedimentation, sand traps and screens. Wherever possible, terminal disinfection needs to be included as a safety barrier after the MSF. SSF is the heart of MSF technology and has been recognized as a simple, reliable and efficient treatment technology and the most effective one as a single unit treatment process.
