New York City will launch stricter rules for cooling towers after one of the worst Legionnaires’ outbreaks in years broke out in Harlem.

The city Health Department is planning to increase its enforcement, penalties, and reporting requirements for building water systems, as these are identified as the source of numerous Legionnaires’ disease cases.

There have been three deaths and 81 infections reported in Harlem over the prior two weeks, with 24 people hospitalized.

When reached by The Post, Health Department officials asserted that the revised rules for cooling towers were in development prior to the Harlem outbreak, which they confirmed has now been controlled.

The beefed up rules are scheduled to go into effect next spring.

As detailed in a notice published in The City Record, regulators have proposed changes to existing rules “to impose penalties for failing to adhere to reporting inspections that include testing for Legionella” and to “establish penalties for previously added requirements” to the city administrative code.

The revisions will also add a new laboratory certification requirement for Legionella. Any such sampling must be conducted by a laboratory certified by the New York State Environmental Laboratory Accreditation Program.

The goal is to “improve enforcement,” the Health Department’s Bureau of Environmental Sciences and Engineering said.

Jory Lange, one lawyer who specializes in Legionnaires’ cases, said New York City already has the toughest rules for cleaning towers in the country “but the building owners are not following them.”

Lange said the current level of fines are not stiff enough to force compliance in buildings worth tens of millions of dollars.

He said it is troubling that 11 of the 43 towers inspected in Harlem — about 25% — tested positive for Legionella.

Also, inspections for Legionella bacteria in the city’s cooling towers plummeted in the months leading up to an outbreak in Harlem, according to a review of records by Gothamist.

The department inspected 5,200 cooling towers and issued over 48,000 violations to building owners in 2017 after a new law went into effect following a deadly Legionnaires’ outbreak in The Bronx.

This year, the city projected completing fewer than half that number of inspections, a record low when excluding the 2020 and 2021 COVID-19 pandemic years, the Gothamist review found.

People can catch Legionnaires’ disease from bacterial droplets that come from water systems like cooling towers.

It can take between 12 and14 days from exposure to the droplets to start feeling sick, according to city Acting Health Commissioner Dr. Michelle Morse.

The current rules for owners of buildings with cooling towers lay out a range of penalties covering 31 different categories.

The maximum fine of $1,000 for a first offense and $2,000 for each additional offense include: failing to take immediate action for positive legionella results; failing to take samples for reporting them to the department;, not properly using recycle or rainwater; failure to minimize the release of water droplets that carry Legionella or having no maintenance program.

Owners also currently face initial $500 fines for failing to routinely monitor and conduct inspections for Legionnaires’ disease or cleaning the tanks, or failing to increase chlorine or other disinfectants during the summer months of July and August when Legionella is more of a threat.

The city declined to provide any more details at this point about the beefed-up enforcement.