In such remote places, there are regular outbreaks of serious waterborne diseases like cholera and dysentary, hepatitis A is widespread, and amoebas, giardia, schistosoma, various parasitic worms, etc. are endemic.

The hard part is setting up the social/institutional structures to maintain the equipment. The technological problems per se are relatively straightforward at this point.

Rural peasants typically don’t have the technical knowledge, connections, or capital to set up their own water treatment facilities, and often communities are too remote and sparsely populated to be worth piping fresh water in from a long distance.

I particularly appreciated how the MIT engineers trained local residents to operate and maintain the system, and they set up enough payment structure for the plant to pay for its ongoing costs. If that can be sustained indefinitely without too much need for additional external help, then the project should hopefully keep people healthy for decades, on only a small up-front investment.