Three years ago, New York City and New York State enacted sweeping regulations to prevent Legionnaires’ Disease in a response to an outbreak of the bacterial pneumonia that killed at least 12 people and sickened hundreds more.

Investigators eventually traced the outbreak to a cooling tower on top of a hotel in the South Bronx. Cooling towers are big, boxy machines that help regulate air conditioning systems. They're easily confused with water towers, the cylindrical structures recognizable to most New Yorkers at street level. Cooling towers collect a sort of muck as they operate. Some of that muck can contain the bacteria that causes Legionnaires’—when that water is vaporized by the cooling tower, people at street level breathe it in and come down with the potentially deadly disease.

So, thanks to legislation passed by the city in 2015 and overlapping state regulations issued soon after, cooling towers are now subject to stringent rules. Owners of cooling towers are required to get them inspected every 90 days while in use, and get them immediately cleaned if they show a certain amount of the bacteria that causes Legionnaires'.

But data obtained by WNYC shows widespread noncompliance with the regulations.

According to state data, more than 20 percent—which is more than 1,000 towers around New York City—are not up to date with inspections required by the state. The majority that were not in compliance were last inspected in August of 2015. The second and third most common inspection dates were April of 2017 and October of 2016. The majority of noncompliant towers have not been inspected in more than a year.

 (Listen to WNYC's Sean Carlson and Lylla Younes discuss their reporting here)

Meanwhile, data provided by the city—which is kept in a separate database—shows that almost half of the cooling towers in the city are not up to date with their reporting. When asked for reports required under the 2015 law that would show compliance numbers and rates of Legionnaires' Disease in the city, the Department of Health and Mental Hygiene provided from 2016 showed that nearly half of all cooling towers registered with the city were out of compliance.

The department inspected nearly 1,000 towers on its own, and issued nearly 1,000 violations. More than 65 percent were considered “critical.” Nearly 20 percent were considered a public health hazard.

The health department has not provided an updated report showing the most recent data, even though it is required by law. When WNYC asked DOHMH for that report, they said it is almost finalized.

Meanwhile, federal data shows Legionnaires' Disease is here to stay—there was a 64 percent spike in cases in New York City alone last year. Advocates with the Alliance to Prevent Legionnaires' Disease, a nonprofit dedicated to fighting the disease worldwide, told WNYC that New York is experiencing the same increasing rates of Legionnaires' as the rest of the country, suggesting the new regulations are having little effect.