Now that Spring is here and your winterization measures can be removed, it’s the time to make sure all of your Legionella-prevention items are in order. According to the CDC, Legionella grows best between 77°F and 113°F, which means summertime temperatures pose the biggest risk with respect to transmission. As a reminder, all owners of cooling towers (including evaporative coolers) must prepare a Legionella Preventive Maintenance Plan (Plan) per the New York State Department of Health (NYSDOH) Protection against Legionella regulations. These regulations ensure that all building owners and operators have a standardized plan in place to prevent bacterial spread.


This plan should contain information regarding potential sources of contamination, physical and chemical disinfection of cooling units, sampling and inspection requirements, and emergency procedures.  The Plan is to be kept onsite at all times, and is subject to NYSDOH inspection; facilities operating without a Plan are subject to punitive actions by New York State.  The good news is that there is still plenty of time to prepare your Plan if you do not currently have one!


Once the Plan is in place, the first step for owners of cooling towers is to determine a probable start-up date for their cooling system.  Cooling towers must be physically and chemically disinfected on a yearly basis prior to start-up; without this cleaning, towers are not only non-complaint with NYSDOH regulations, but also pose a much greater threat to public safety with respect to Legionella transmission.  Following this cleaning, an inspection and sampling event must be carried out no later than two weeks after system startup by a qualified environmental professional to confirm the cleaning’s effectiveness.  It is crucial not to leave this cleaning for the absolute last minute; erring on the early side allows much greater flexibility in case of an unexpectedly warm wave of weather. 


Somewhat. Although Legionnaires Disease, the disease caused by Legionella, is a bacterial infection rather than viral, it has essentially the same symptoms as we have seen so far with COVID-19. It also affects immunocompromised and elderly individuals disproportionately. Although it is not known to be communicable, the Centers for Disease Control and Prevention (CDC) reports that approximately 1 in 10 patients diagnosed with Legionnaires Disease will die from complications.

Walden has been working closely with our clients since the onset of NYS Legionella regulations in 2015 to ensure that your facilities are in compliance and safe.  Stay one step ahead of the curve – contact Walden to learn more.  Remember, there is still ample time to get your facility caught up before the 2021 cooling season!