In a UV disinfectant system, water passes beside a lamp which exposes it to ultra violet light. This light - which is the same type that causes sunburn - damages the DNA of bacteria, rendering them sterile and therefore incapable of causing disease. Ultra violet disinfectant systems provide on-going protection against bacteria.
One of the key considerations in the installation of a UV system is the dose that the bacteria receive. The NSF has established that a minimum dose of 40 mJ/cm