What UV does
Ultraviolet systems expose water to germicidal UV light to inactivate bacteria and other microorganisms. They are commonly used on private wells when microbiological risk is confirmed or when an additional disinfection barrier is desired.
What UV does not do
UV does not soften water, remove iron or manganese, eliminate sulfur odor, or reduce dissolved chemicals such as PFAS. It is a disinfection stage, not a general-purpose filter.
Why pretreatment matters
Turbidity, sediment, iron and other material can shield microorganisms from UV light or foul the quartz sleeve. That is why sediment filtration and contaminant treatment are often installed upstream of the UV unit.
Where UV belongs in the treatment train
A common sequence is sediment/iron/sulfur treatment first, softening if needed, then final UV disinfection before water is distributed through the home. The exact order should follow manufacturer requirements and water chemistry.