Hello. UV disinfection is ...

Hello. UV disinfection is used quite widely in Central Asia / former Soviet Union, especially for ground water which is generally (assumed?) to be high quality. Even basic systems seem quite effective (when bulbs are new and system is switched on an maintained!)  and due to remoteness of some villages, it is preferred to transport of chlorine products. Environmental concerns also discourage low quality powder which results in a lot or residue which is sometimes just cast aside. As others have said, the biggest issue is the lack of downstream protection. For new systems or those in good condition this is perhaps less of a consideration, but mostly the systems are old (often AC pipe or similar) and storage is not well maintained or monitored. For this reason we mostly discourage UV if chlorination is an option and only advise for fairly clean (particle free) ground water.