The legal microbiological limits for drinking water contained in Legislative Decree 31/2011 are very strict.
Methods for eliminating microorganisms from water may be chemical (chlorination) or physical (UV-C rays, heat).
In the first case, ingested water may contain harmful, chlorine-derived waste substances such as chloramines, which alter the smell and taste of the water, or other undesired by-products that are harmful to human health and to the environment such as volatile organic substances, including trihalomethanes, which are highly carcinogenic.

Heating (boiling water before use) could be helpful in preventing the above problems, but it is certainly not practical, besides creating handling problems, requiring long-term cooling.
A UV-C ray system installed close to the point of use a on water line safely removes all microorganisms, irradiating them at a dose far higher than the minimum safe dose – making it very effective – without leaving a residue. The purchase and maintenance costs of the system and its replacement parts (bulbs) are extremely low. UV-C rays also reduce the amount of chlorine and any derivatives (aqueduct) into minuscule particles that are harmless to health.

All ultraviolet disinfection products pose a UV radiation hazard. Use only as directed. Protect eyes and skin from exposure to UV light.