Illuminating Ultraviolet Disinfection for High-Level Reuse in Florida

Chlorine has been the mainstay of the wastewater disinfection industry for more than 100 years due to its effectiveness, low cost and availability. However, due to various problems associated with chlorine, the Hillsborough County, Florida Water Resource Services Department decided to replace the high-level reuse water chlorine gas disinfection system at the Valrico Advanced Wastewater Treatment Plant (AWTP) with an ultraviolet (UV) disinfection system. The Florida Department of Environmental Protection (FDEP) requires compliance with specific disinfection regulations to operate both a high-level reuse facility as well as a UV disinfection system. The regulations governing each are in FDEP Rule 62-600.440, “Disinfection – Design and Operational Criteria”; and a FDEP Program Guidance Memo “Permitting Ultraviolet Disinfection Systems” as well as the National Water Research Institute (NWRI) Ultraviolet Disinfection: Guidelines for Drinking Water and Water Reuse, Second Edition manual.