Effectiveness of the upscaled use of a silver-ceramic (silver ionization) technology to disinfect drinking water in tanks at schools in rural India.

In many low- and middle-income countries, school children consume untreated water that has been pumped into storage tanks. The water is often of poor quality and consumption can cause gastrointestinal illnesses resulting in missed school days, growth stunting, and cognitive impairment. This study deployed a silver-ceramic technology (MadiDrop) to disinfect drinking water in school storage tanks. While silver ionization is effective at the household scale, relatively little research has been conducted on its effectiveness at the community scale. To address this gap, we assessed disinfection via MadiDrop at three schools that serve vulnerable populations in rural India. Tank inflow and treated outflow samples were tested for total coliforms (TCs) and Escherichia coli (EC). TC was significantly reduced overall and in two of three intervention tanks. Compared to the baseline, reductions in TC were significant in all three tanks and overall, while EC reductions were significant overall and in two of three tanks. TC reduction was negatively correlated with silver concentration and tank residence time, and silver concentrations were maintained below the drinking water quality guideline. While the intervention could be considered successful, several barriers and caveats are provided as are study limitations and areas for future research.