UV disinfection: US wastewater treatment plants
417 plants in 17 states · 441 MGD reported by 399 plants · 89 planning upgrades
Klarifi identifies 417 publicly owned wastewater treatment plants with uv disinfection in the United States (441 MGD reported by 399 plants). The largest is Metropolitan St. Louis Sewer District Lemay WWTP in St. Louis, MO at 79.3 MGD. Each state below links to its own list with every plant.
Ultraviolet disinfection destroys pathogens in the final effluent without chemicals or a chlorine residual. It has replaced chlorine at many plants since the 2000s and needs lamp, ballast and sleeve replacement on a fixed cycle, which keeps these plants in the market for UV suppliers.
UV disinfection by state
297 plants
21 plants
18 plants
17 plants
15 plants
11 plants
8 plants
7 plants
7 plants
6 plants
2 plants
2 plants
2 plants
1 plants
1 plants
1 plants
1 plants
The largest plants with UV disinfection in the US
Other treatment technologies
UV disinfection: questions
Sources and methodology
Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.
Data refreshed September 11, 2026.