Florida's First Permitting Experience with the New NWRI/AWWARF UV Disinfection Guidelines

Abstract

The Florida Department of Environmental Protection (FDEP) recently adopted the Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse , published in December 2000 by the National Water Research Institute / American Water Works Association Research Foundation (NWRI/AWWARF). These guidelines now serve as the design basis for new stand-alone, high-level UV disinfection systems at wastewater treatment facilities in Florida. The NWRI/AWWARF guidelines establish minimum design requirements for UV disinfection of filtered reclaimed water. An integral part of the guidelines is performance-based testing in which the dose delivery capability of the UV reactor is experimentally validated. The City of Auburndale's Raymond Allred Wastewater Treatment Plant (WWTP) recently became the first facility in Florida permitted under the new guidelines. Several issues related to UV dosage, reactor and reliability design, monitoring requirements, and manufacturers' validation studies came to light as a result of the FDEP permitting process. Unlike California, the FDEP does not conditionally accept specific models of UV systems. Rather, Florida approves a system on an individual basis and requires the engineer of record to provide assurance that the system design and validation comply with the NWRI/AWWARF guidelines. Key aspects of the NWRI/AWWARF guidelines and validation requirements will be presented using Auburndale's permitting experience as a case study.