On the issue of water ...

On the issue of water sanitation in Nepal, apart from the use of ozone and UV disinfection which could be expensive, Charcoal-Sand filtration and Boiling may be useful especially in the rural communities. Activated charcoal will remove toxic organic compounds that could have contaminated the surface water and remove bacteria to some extent but boiling after filtration will completely remove bacteria for surface water to fit for drinking and other domestic purposes.