UV to kill germs in drinking water?

[Nicholas Landau]

Umnarj Paeratakul <umnarj at mozart.inet.co.th> writes:

>Dear good people,

>Can this be true?  I thought that UV does not penetrate
>well in water. 

UV can penetrate a thin layer of water and cause significant bacterial
mortality in the penetration layer.  However, it does not have the residual
disinfectant activity which chemicals like chlorine do.  I would not store
that water for too long.