What is My UV System Telling Me? A Comprehensive Evaluation and Lessons Learned on Startup, Training, and Performance of UV Systems in the Carolinas

Ultraviolet (UV) disinfection is vastly being selected as the preferred disinfection method at many wastewater treatment plants (WWTPs) due to overall present worth costs as well as numerous non-cost benefits including the elimination of toxicity issues related to chlorination and dechlorination by-products and the higher level of safety that UV disinfection provides to plant employees and the surrounding public. Although the design of a UV system can be a fairly straightforward process, the real work and energy needed to successfully implement a UV system is during the startup, training, and performance testing of these systems.CDM recently completed the construction, startup, training, and performance testing of the Irwin Creek and Sugar Creek WWTPs owned and operated by Charlotte-Mecklenburg Utilities (CMU) in April 2005. In August 2005 CDM completed the construction, startup, training, and performance testing of Gilder Creek WWTP located in Greenville, South Carolina. The Gilder Creek WWTP is owned and operated by Western Carolina Regional Sewer Authority (WCRSA). During the construction and startup phases of each plant, they experienced similar issues and concerns including, including proper training of operations and maintenance staff, evaluation of how well the UV system was performing, and understanding the control philosophy of the UV system.This paper will discuss training expectations and evaluation of UV performance. This paper also focuses on several key areas of note during implementation of any UV system, including several “Lessons Learned” based on reoccurring problems encountered at all three plants. The following keys points will be discussed:How to select the criteria by which a UV system will be evaluatedHow to implement a successful startup and performance testing planEvaluation of the UV system performance after installationRecommendations on how much and what topics should be included in operator trainingIt is hoped that through this paper the owner and engineer will be better equipped to facilitate a smoother transition from a chlorine disinfection system to a UV disinfection system.