NYC health department reports modest rise in cooling-tower inspections amid new Legionnaires’ cluster on Upper East Side
City officials say inspections of cooling towers have increased slightly since 2025, but compliance remains low as a new cluster of at least 14 Legionnaires’ disease cases is investigated in Manhattan.
City inspections of cooling towers, which are intended to curb Legionella bacteria, have risen only modestly since early 2025. Data from the Department of Health and Mental Hygiene show that 1,306 of the city’s roughly 6,000 towers were inspected through late June 2026, a small increase from 1,156 inspections during the same period in 2025. The agency estimates that an additional 114 inspections were completed in June, bringing the year-to-date total to about 1,420, or 23% more than the previous year.
The limited inspection pace precedes a newly identified cluster of at least 14 Legionnaires’ disease cases in the Carnegie Hill and Yorkville neighborhoods (ZIP codes 10028, 10075 and 10128). Health officials are testing all cooling towers in the affected blocks and have deployed health commissioner Alister Martin to inform residents about the potential spread.
The cluster emerged during an extreme heat wave, with heat-index values reaching 110-115 degrees, conditions that favor bacterial growth. In the outbreak area, 48% of 179 towers have gone more than a year without an inspection, and 26% lack any record of Legionella testing for 2026, slightly above the citywide average.
Mayor Zohran Mamdani’s office did not comment on the modest inspection increase or preventive measures. The health department, which can conduct unannounced inspections, aims to inspect each tower annually, but as of April 17, more than half of the city’s towers had not been inspected in over a year.
To address staffing shortfalls, the department has doubled its “water ecologist” workforce since last year, though new hires were still in training and did not conduct inspections in May or June. The agency also introduced a new testing rule in May requiring owners to test towers every 31 days, up from the previous three-month interval. Compliance with the new mandate is unclear; one in five registered towers had not submitted a test by May 21.
Advocates emphasize the importance of inspections and owner diligence. “We’re always going to be supportive of more inspections that can prevent death,” said April McIver, executive director of The Plumbing Foundation City of New York.
Health officials advise anyone who lived in or visited the affected area since late June and develops flu-like symptoms to seek medical care. Assistance locating a provider is available through 311 or the city’s dedicated hotline.