Another alternative is water filters. This is used in Brazil by Neymar-backed Waves For Water (90k filters) and Project AmaZon (10k filters). The latter filte

Another alternative is water filters. This is used in Brazil by Neymar-backed Waves For Water (90k filters) and Project AmaZon (10k filters). The latter filter design uses cheap sedimentary layers inside a framed structure. Pour the turbid water on top, and clear water comes out the bottom.