AWWA WQTC63972

This slide presentation outlines information on operational issues associated with ultraviolet (UV) disinfection. Issues outlined under project background include: estuarine water systems in the U.S.; promulgation of the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR); and, UV disinfection implementation issues with UV transmittance, lamp sleeve fouling, sensor reliability, and power quality. The UV demo site was the CCWD Bollman Water Treatment Plant in Concord, California, and conclusions are presented for each of the implementation issues. Recommendations included: monitoring of UVT254 with a laboratory spectrophotometer: continued monitoring UVT to get a better dataset for sizing UV systems; comparison of reference sensor and duty sensor UV intensity measurements; water quality monitoring of pH, alkalinity, hardness, metals (including Fe and Al at low detection limits) and major ions; monitoring of UV intensity to capture variation in system and allow cause and effect relationships between other parameters to be developed; maintenance activities including lamp sleeve cleaning, sensor port window cleaning, and lamp replacement; and, develop better approaches for decoupling the impacts of factors impacting UV intensity. Includes figures.