The Changes in the UV Disinfection OM Guidelines: New Options ProvideOperational Flexibility

摘要

The Proposed UV Disinfection Guidance Manual (UVDGM) that was released in June 2003provided the first operations and maintenance (O&M) guidelines for UV disinfection facilities ofdrinking water. When those 2003 guidelines were published, there were few operating UVfacilities to benchmark the O&M requirements and recommendations. As more UV facilitiescome on-line, more data were available to the UVDGM development team. These data andoperating experience were used to develop the final UV disinfection O&M guidelines that werepublished with the final UVDGM, and these guidelines are substantially changed from the June2003 O&M guidelines. The final O&M guidelines provide clear criteria for the calibration ofUV sensors and UVT analyzers and have recommended alternatives if a UV sensor or UVTanalyzer fail the criteria. These alternatives were developed to provide operational flexibility toallow a UV facility to keep operating for a limited time even if the UV sensor and UVT analyzerdo not meet criteria. Monitoring and recording recommendations also changed between theproposed and final UVDGM based on the final UVDGM validation protocol and UV equipmentcapabilities.This paper describes the following items:■ The key O&M tasks, including monitoring, recording, and reporting■ The methodology behind the key O&M guidelines■ New O&M options that provide flexibility in the event of UV sensor of UVTmonitor failure