Four approaches for dose monitoring with ultraviolet (UV) disinfection systems are described. The first
approach uses alarm setpoint values of flow, UVT, and relative lamp output. The second
approach uses alarm setpoints of flow and UV intensity. The third uses empirical equations,
calibrated using validation data, that given RED as a function of flow, UVT, lamp status, and
relative lamp output. The forth uses empirical equations, calibrated using validation data
obtained at a default UVT, that given RED as a function of measured flow and UVT. Test
conditions needed to validate each approach is given with examples. Application of the
validation data for sizing the UV system and operation at the water treatment plant (WTP) is
described including the approaches for operation outside the validated range. QA/QC during
validation and operation at the WTP is described to ensure validation and dose monitoring is
meaningful. A two-step process is described for approving the validation report and the
application of that report with a given UV installation. Includes 7 references, tables, figures.