Legionnaires’ disease is caused by the waterborne legionella bacteria, named after the 1976 outbreak involving a Philadelphia convention of the American Legion. During the event, many veterans and some attendees developed a severe, previously unrecognized form of pneumonia that became known as Legionnaires’ disease. The Centers for Disease Control and Prevention estimates approximately 8,000 cases of Legionnaires’ disease annually. Peer-reviewed literature suggests that building drinking water systems are the primary pathways for exposure to Legionella bacteria which originates in fresh and municipal water systems.