Occurrence and Control of Legionella in Recycled Water Systems

Legionella pneumophila is on the United States Environmental Protection Agency (USEPA) Candidate Contaminant list (CCL) as an important pathogen. It is commonly encountered in recycled water and is typically associated with amoeba, notably Naegleria fowleri (also on the CCL) and Acanthamoeba sp. No legionellosis outbreak has been linked to recycled water and it is important for the industry to proactively keep things that way. A review was conducted examine the occurrence of Legionella and its protozoa symbionts in recycled water with the aim of developing a risk management strategy. The review considered the intricate ecological relationships between Legionella and protozoa, methods for detecting both symbionts, and the efficacy of various disinfectants.