An anti-microbial HDPE material that has reduced Legionella — the bacteria that causes Legionnaires’ disease — and other strains of pathogens that sometimes foul cooling towers is being put to use in plastic cooling towers from Delta Cooling Towers, Rockaway, N.J.

Following a deadly outbreak of Legionnaires' disease in New York in 2015, stakeholders in the industrial and commercial cooling water industry worked with ASHRAE to develop ANSI/ASHRAE Standard 188-2015, Legionellosis: Risk Management for Building Water Systems. While good tower and water hygiene help manage the risks of Legionella, Delta Cooling Tower opted to build equipment with inherent anti-microbial characteristics.

The anti-microbial resin is fully compounded into the base cooling tower material. The material contains additives that operate on a cellular level to continuously disrupt and prevent uncontrolled growth of microorganisms and biofilm within the cooling tower. According to Delta, it is the only company to engineer a cooling tower with both the fill and structural casing composed of anti-microbial material.

Stagnant water areas in cooling towers are prime breeding grounds for Legionella to grow. Delta’s cooling tower design includes a sloped basin or basin sweeper system to avoid this issue.