If you have listened to or watched the local news lately, you have likely heard about the recent Legionella outbreak in late-October in Flushing, Queens, NY, which infected 14 individuals with Legionnaires’ Disease.  A total of 55 cooling towers were designated as possible bacterial transmission sources.  10 out of the 55 aforementioned cooling towers were tested for and contained Legionella bacterial DNA; cultured bacterial samples are currently being grown (results take about two weeks to process). As discussed in Walden’s previous blogs, those most susceptible to infection include young children, the elderly, current or former smokers, and persons of any age who have compromised immune systems.  In the case of the Flushing outbreak, the majority of those infected had underlying medical conditions.

Around the same time as the Flushing incident, a nursing home in the Westchester village of Croton-on-Hudson saw two residents becomes infected with Legionnaires’ Disease. Additionally, just a month previous two people were infected in a Forest Hills, Queens high-rise, where an elderly individual did not survive the infection.  It is important to note that both the Croton-on-Hudson and Forest Hills buildings do not contain any cooling towers.  Legionella bacteria can spread through the air at distances up to 2 miles from the source.  Therefore, negligence on the account of a facility owner or supervisor can have potentially deadly effects on the neighboring population.


As the weather becomes cooler, the risk of contracting Legionnaires’ decreases significantly due to less frequent operation of cooling towers and the bacteria’s inability to survive in cool temperatures.  However, there are cooling towers that operate year-round for the purpose of cooling industrial machinery.  Although less likely in cool weather, aerosolized water droplets (which potentially carry the bacteria) can find their way into building intake systems and pose a threat to public health.


Walden Environmental Engineering has a team of experienced professionals with a history of keeping our clients ­Legionella-free since the onset of NY statewide regulations in the summer of 2015.  As a reminder, all facility owners of buildings with cooling towers, evaporative coolers, whirlpools, fountains, and/or any other aerosol-generating misters must prepare a Legionella Preventive Maintenance Plan, updated continuously as time progresses, and must register their cooling units with NYSDOH.

Please call Walden at (516) 624-7200 to learn more about how to protect your facility and remain in compliance.