Legionella in cooling towers: NYC bill would make owners report far sooner
This summer, deadly Legionnaires' outbreaks hit the Upper East Side and the Bronx. Now a Council bill would make building owners report Legionella at 10 CFU/mL within 24 hours.
Building owners would have to alert the city’s health department to Legionella bacteria in their cooling towers at far lower levels than today under a bill the City Council’s health committee takes up at a hearing on Monday.
The measure follows a summer in which the Upper East Side and the Bronx each had a Legionnaires’ disease outbreak that turned deadly.
What the Legionella reporting bill changes
City rules already tie owners’ duties to how much bacteria a test finds. At 10 colony-forming units per milliliter (CFU/mL), disinfection has to begin within a day, and a new test of the water must follow three to seven days later. Notifying the health department, though, is only required once a reading hits 1,000 CFU/mL.
The bill would move that reporting trigger down to 10 CFU/mL. Once owners learn of such a result, they would have 24 hours to inform the department.
The cleanup side of the rules would stay as it is, level by level. Owners whose towers test at 1,000 CFU/mL or above would still face the stricter response already on the books, which includes a complete cleaning and disinfection of the tower within 48 hours, among other steps.
Lynn Schulman, the Council member who leads the health committee, is the lead sponsor. She said the aim is to cut the odds of outbreaks like the ones New York saw this summer and last summer, calling the bill “a tool in the toolbox.” Schulman said she expects more negotiation, and possibly changes to the bill, after the hearing.
The Council said a separate legislative package would require the Health Department to run a hotline during peak summer months. NYC Council
Monthly cooling tower testing is already the law
The proposal builds on a separate law that took effect in May. It requires owners to test cooling towers every 31 days, up from once every three months, so Legionella turns up sooner. The Health Department says its amended cooling tower rules, which took effect in May 2026, also increase fines for property owners who fail to comply. NYC Health Department
What it means for you
The Council said it would review how the Health Department communicates and notifies the public about outbreaks, and would consider further bills on public education and resident notifications. NYC Council
Quick answers
When is the hearing on the Legionella reporting bill?
The City Council's health committee holds the hearing on Monday.
What would building owners have to do under the bill?
Owners would have to notify the health department within 24 hours of learning that a cooling tower test found 10 CFU/mL of Legionella.
How often must NYC cooling towers be tested?
Since May, building owners have had to test their cooling towers every 31 days instead of every three months.
