New York City has more than doubled the number of cooling tower inspectors on its payroll since last summer’s deadly outbreak of Legionnaires’ disease in Central Harlem, according to new staffing levels announced by the Department of Health and Mental Hygiene.
Rooftop cooling towers function as part of a structure’s air conditioning system, but can spread deadly Legionella bacteria if they are not maintained properly. In August last year, health officials traced the source of the outbreak to two cooling towers, one on Harlem Hospital and another on a city-run health lab on the same block.
The health department will also begin enforcing more frequent testing of cooling towers for Legionella bacteria. A law passed by the City Council in October requires building owners to now test the water in their systems every 31 days, up from once every three months under previous requirements.
“As the summer approaches, we are working collaboratively to ensure that the city is utilizing every tool in the toolbox to monitor for this bacteria and help keep our residents safe,” Yume Kitasei, the commissioner for the Department of Citywide Administrative Services, said in a joint statement with the health department.
This new regulation, which took effect Friday, comes nine months after the Central Harlem outbreak sickened 118, hospitalized 92 and killed seven people.
City Councilmember Lynn Schulman, who chairs the health committee, said the Council will closely monitor whether the health department enforces the new law and pre-existing regulations around cooling towers.
“Legionnaire's disease is not a one-size-fits all problem,” she said. “Even with the stringent regulations that the NYC Council has passed over the years, there is no guarantee that an outbreak won't occur.”
A Gothamist analysis of city data last year found that the health department inspected a nearly record-low number of cooling towers in the lead-up to last summer’s outbreak.
At the time, a spokesperson for the agency attributed the drop in inspections to short staffing resulting from budget cuts. The total number of inspectors stood at just 24, down from 37 in 2022.
The health department hired six new cooling tower inspectors in the immediate aftermath of last year’s outbreak. It announced on Friday that the team has expanded to 54.
The city’s preliminary budget for 2027 allocates $13 million in additional funding for the additional staff. The health department said the money would also go to establishing a community outreach team in the event of another outbreak.
As the outbreak spread through Central Harlem last year, the health department said it collected eight samples of the bacteria from infected patients. Those matched the genetic material taken from two cooling towers located atop city-owned buildings.
The first was a construction site for a public health lab. The site was being managed by the construction company Skanska. Health officials said in August that the company had failed to register the tower with the city and conduct any required testing and monitoring of the cooling tower.
The second was located atop Harlem Hospital. A Gothamist investigation found that hospital staff failed to conduct weekly rapid testing required by its cooling tower management plan in the months leading up to the outbreak.
Cooling towers can be breeding grounds for dangerous Legionella bacteria.
Water is often circulated through pipes in larger buildings to absorb heat. That warmed water is then pumped into cooling tower basins on the roof, where it is evaporated by big fans.
But if the water is not regularly tested and disinfected, Legionella can not only thrive, it can be blown out in vapor and inhaled by passersby. The bacteria can cause a type of pneumonia. Older adults and immunocompromised individuals are especially susceptible. But even healthy people can suffer long-lasting effects from the disease.
April McIver, the executive director of the Plumbing Foundation, an advocacy group for water and gas professionals, said that while more testing is needed to prevent deadly outbreaks, the city should also broaden its efforts beyond cooling towers.
In January, the health department advised residents in a Harlem housing complex to use buckets and hoses to bathe after two residents contracted Legionnaires from the buildings’ internal water system.
McIver said plumbing systems must also be more strictly regulated.
“Any expert will say that this is the only way to better protect New Yorkers, and until that happens, we can expect to see another tragedy related to this dangerous disease,” she said.