Along with a brief history of Legionnairesƒ disease, this paper presents a detailed review of several outbreaks in the United States since 1995 relative to cooling tower systems. Discussion of these systems, water treatment programs before the outbreaks, important system design and operation considerations, investigative finds, and corrective actions after the outbreaks are given in detail. What happened can be a lesson on what should be done. Specific guidelines, incorporating current knowledge and practices in cooling tower water treatment, LB testing, system operation, and verification of treatment application, are provided.

Units: Dual