Household water treatment and safe storage – effectiveness and economics
Abstract. Household Water Treatment and safe Storage (HWTS) systems aim to provide safe drinking water in an affordable manner to users where safe piped water supply is either not feasible or not reliable. In this study the effectiveness, economic parameters and costs of three selected HWTS systems were identified. The selected systems are SODIS, ceramic filter and biosand filter. These options were selected based on their accessibility, affordability and available scientific data. Data was obtained through peer-reviewed literature, reports, web-pages and informal sources. The findings show a wide dispersion for log removal of effectiveness of the HWTS systems. For bacteria (E. coli), log removals of 1–9 (SODIS), 0.5–7.2 (ceramic) and 0–3 (biosand) were reported. In the case of viruses (mostly echovirus and bacteriophages), log removals of 0–4.3 (SODIS), 0.09–2.4 (ceramic) and 0–7 (biosand) were found. The dispersions of log removals for both bacteria and viruses range from non-protective to highly protective according to WHO performance targets. The reported costs of HWTS systems show a wide range as well. The price per cubic meter water is found to be EUR 0–8 (SODIS), EUR 0.37–6.4 (ceramic) and EUR 0.08–12.3 (biosand). The retail prices found are: negligible (SODIS), USD 1.9–30 (ceramic) and USD 7–100 (biosand). No relationship was observed between removal efficiency and economics of the three systems.