Local Law · Systems
Local Law 77: cooling tower registration & Legionella
Cooling towers and evaporative units must be registered with the City and tested for Legionella on a strict schedule — a public-health rule with real penalties.
What Local Law 77 requires
Owners of cooling towers and evaporative condenser units must register each unit with the City within 30 days of installation, maintain a management plan, test for Legionella quarterly, and certify annually that the tower was inspected, tested, and cleaned per the plan. The rules exist because cooling towers can aerosolize Legionella bacteria and cause outbreaks.
How to comply
- Register each cooling tower / evaporative unit with the City.
- Maintain a written maintenance and Legionella management plan.
- Test for Legionella quarterly and act on results.
- File the annual certification.
Common mistakes
- Failing to register a newly installed unit within 30 days.
- Skipping a quarterly test cycle.
Reviewed against current NYC agency guidance by the NYC Building Compliance editorial team. Found something out of date? Tell us. Informational only — not legal or engineering advice.
Frequently asked questions
Which buildings must comply with Local Law 77?
Any building with a cooling tower or evaporative condenser unit — common on larger commercial and high-rise residential buildings.
How often is Legionella testing required?
Quarterly, along with an annual certification and an ongoing maintenance plan.
What’s the penalty for cooling tower non-compliance?
Penalties commonly range from $500 to over $2,000, and public-health enforcement can be aggressive.
Need help handling this?
Tell us about your building and we’ll connect you with a cooling-tower / Legionella specialist who works on NYC compliance — no cost to ask.
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