Sophia Motteu, graduate chemical engineer and the latest addition to our growing team, has demonstrated a proof-of-concept electrolytic chlorinator in our Oxford lab. The chlorinator, which could enable water to be automatically treated to within WHO guidelines at the tap, could eliminate dependence on free-chlorine reagents and skilled operators on-site. It could be cheaply produced, and widely deployed at water collection points. Leveraging recent trends in power electronics and benefiting from cheap and widely available PV, the solution could cost-effectively treat viruses as well as bacteria, and provide residual protection against contamination beyond the point of collection.