Cooling Towers

There are now 71 documented cases of Legionnaires’ disease in the Bronx. Four of the people stricken with the illness have died from the disease, which can spread when people breathe in water droplets from rooftop cooling towers, fountains or even showers connected to water systems where legionella bacteria thrive. Five cooling towers in the South Bronx have tested positive for legionella — including towers at the Opera House Hotel and the Lincoln Medical and Mental Health Center — but health investigators have not determined which is responsible for the outbreak.

Officials are confident that the disease spread from one or more of the five cooling towers, not from another water source, because interviews with the patients have shown that the only thing those who fell sick had in common was living and working in the same few South Bronx neighborhoods.

The other towers that tested positive are on a Verizon office building, Streamline Plastics Company and the Concourse Plaza, a mall near Yankee Stadium. All five have been flushed with bleach, followed by fresh water.

Legionella has an affinity for water systems that are particularly old, corroded and not well maintained. Cooling towers are particularly attractive because the water is warm water year-round however the disease spreads through the other water systems that supply water for drinking, cooking and bathing.

Your office building perhaps?

New industry guidance on legionellosis is now available from ASHRAE. The document establishes minimum legionellosis risk management requirements for building water systems.