Choose UV when source water is clear enough for effective irradiation and you want chemical-free point-of-entry disinfection. Choose chlorination when residual protection, storage tanks or broader oxidizing treatment is part of the design.
UV strengths
UV does not add disinfectant chemicals or change taste. CDC describes UV as a home-treatment method for reducing parasites, bacteria and viruses when properly prefiltered.
Chlorination strengths
Chlorine provides a residual that can continue suppressing microbes downstream, unlike UV, which does not leave residual protection after the chamber.
When chlorine solves more than disinfection
Chemical oxidation can also be part of treatment for iron, manganese or sulfur in some systems, making chlorination a broader process than UV alone.
When UV is simpler
For a private well with good pretreatment and a straightforward microbiological risk, UV can avoid storage tanks, chemical feed and ongoing disinfectant handling.