It is a standard method for disinfecting water in aqueducts. https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradiation https://en.wikipedia.org/wiki/Ult

It is a standard method for disinfecting water in aqueducts. https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradiation https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradia... > UVGI for water treatment // Using UV light for disinfection of drinking water dates back to 1910 in Marseille, France. The prototype plant was shut down after a short time due to poor reliability. In 1955, UV water treatment systems were applied in Austria and Switzerland; by 1985 about 1,500 plants were employed in Europe. In 1998 it was discovered that protozoa such as cryptosporidium and giardia were more vulnerable to UV light than previously thought; this opened the way to wide-scale use of UV water treatment in North America. By 2001, over 6,000 UV water treatment plants were operating in Europe And yes, there are also commercial products for home use.