Following a deadly outbreak of Legionnaires’ disease this summer in Harlem that resulted in seven fatalities and 90 hospitalizations, New York City lawmakers are considering new legislation aimed at increasing the frequency of cooling tower testing. These towers are known to be primary carriers of the Legionella bacteria responsible for the disease. Proposed changes would require building owners to conduct tests for Legionella every 30 days, a significant reduction from the current 90-day interval, and every 14 days during heat-related emergencies.
While this legislative effort is a step toward better public health safety, some experts contend that merely increasing testing frequency does not address critical maintenance and operational practices that are essential for effective prevention. Abraham Cullom, director of water safety and management at Pace Analytical, cautioned that a focus solely on testing could lead to loopholes. Building owners may exploit these gaps, testing cooling towers after cleaning to ensure negative results, thereby obscuring underlying problems. “You can throw as much testing at this as you want,” Cullom stated. “If you’re not doing other things that are actually controlling Legionella, the testing itself isn’t going to protect anyone.”
The proposed legislation is set to be discussed at an oversight hearing scheduled for September 29, 2023. Janet Stout, a professor at the University of Pittsburgh and an expert in waterborne diseases, emphasized that testing protocols should be revised to include testing prior to cleaning. This approach would provide a clearer picture of the effectiveness of disinfection efforts. Stout recounted instances in her lab where samples that smelled of chlorine were immediately rejected, as they indicated that the sample had been taken right after cleaning rather than reflecting ongoing conditions.
Current city regulations mandate that building owners monitor the chemical and bacteriological content of the water in their cooling towers. However, reporting for Legionella testing results is only required every 90 days. Don Weiss, a former city health official, proposed that more frequent reporting—ideally daily or weekly—would enable the city to more effectively identify potential risks. “It would probably be a bit of an expense,” Weiss noted, “but once you set the system up, it would work seamlessly.”
Cooling towers, typically located on rooftops, are integral to a building’s heating and cooling systems. They circulate water to absorb heat from the interior before returning it to the cooling tower basin, where evaporation occurs. This process can create an ideal environment for Legionella bacteria to thrive, especially in warmer water. If these bacteria become aerosolized and inhaled, they can lead to severe respiratory illness.
In response to a previous outbreak in 2015, New York City implemented regulations that mandated building owners to register their cooling towers, hire professionals for their management, and create comprehensive maintenance plans. The city health department was also granted the authority to inspect these towers to ensure compliance with testing and maintenance protocols. Nevertheless, a recent analysis by Gothamist revealed that inspections had significantly declined, with the health department on track to conduct less than half the inspections compared to 2017. Approximately 30% of the nearly 5,000 registered cooling towers had not been inspected since 2023, largely due to a shortage of inspectors.
At a press conference in late August, Health Commissioner Michelle Morse asserted that while the city had enough personnel to respond to the outbreak, there would be efforts to recruit more inspectors. Stout argued for a more robust inspection process to ensure compliance with health regulations. “Someone has to be looking over their shoulder,” she stated. “Perhaps the better answer is to better fund public health so it can do more inspections.”
The ongoing discussions surrounding cooling tower regulations highlight the complexities of public health measures in urban environments. As lawmakers consider enhancements to existing laws, the emphasis on comprehensive management and oversight will be crucial in preventing future outbreaks of Legionnaires’ disease.