19-06: Impact of Legionella Regulations on Water Treatment Programs and Control

Implementations of local Legionella regulations bring attention to cooling towers and their perceived Legionella risk. Following the enactment of a local regulation in the Province of Quebec in Canada, an observational prospective survey was undertaken by a leading water treatment firm. A review of a large dataset of Legionella culture results from more than 300 cooling towers with their associated water treatment program control over three years allows to draw important conclusions on the impact of Legionella regulations on water treatment program controls. This paper reviews specifically how the regulation affected the client engagement in their water treatment programs and their associated biocide feed control mechanisms. This led to a significant improvement in overall Legionella results. Conclusions are drawn on the impact of such regulations on the water treatment program, control and the industry.