Book 30, Question 106
How does ultraviolet light kill germs in water?
Ultraviolet, or UV, light is invisible light from special lamps.
When water flows past the lamp, the UV light damages the genetic material of germs so they can't multiply. It adds no chemicals or taste. Many treatment plants and some home systems use it. UV light can hurt eyes and skin, so the lamps are enclosed and no one should look at them.