AWWA WQTC58985

It is well accepted that laboratory experimentation on Legionella inactivation is not sufficient for predicting treatment efficacy within actual domestic water systems. In fact, several factors may compromise biocide performance within actual systems. These factors may include scale deposits, presence of biofilms and protozoans, and existence of dead legs. For the same reasons, on-site evaluation of treatment programs does not allow for direct comparison of treatment efficiency, because these factors can vary from one site to the other. These reasons led the CIRSEE to develop a domestic water supply simulation unit, allowing for comparative evaluations of treatment strategies under equivalent conditions. Studies have been performed on this pilot with different biocides. The best results in terms of Legionella control were obtained with continuous application of chlorine dioxide. Includes 2 references, figures.