NYCDOH Legionella Rules Update 2026
Last week, the New York City Department of Health & Mental Hygiene released proposed updates to cooling tower regulations under Chapter 8 of Title 24, effective May 9, 2026, pursuant to Local Law 159-2025.
The most notable change, following last summer’s outbreak, is mandatory monthly Legionella culture testing. Additional proposed requirements include:
- Annual certification of the Cooling Tower Management & Maintenance Plan (MMP) by a qualified person
- Municipal water required for tower fill during start-up/commissioning
- DOH approval required for use of non-potable makeup water
- Documented valve schedules for all operating configurations
- Risk procedures for components idle more than three (3) days
- Increased disinfectant testing when bacteria indicators exceed limits
- “In operation” is broader than “running”; once the system contains water, it is treated as in operation.
- Mandatory reporting of seasonal start-up and shutdown dates
- Full record availability at inspection and complete system drainage during shutdown
- Doubled fines and new violation categories
All existing Cooling Tower Management & Maintenance Plans (MPP) will require updates.
Now is the time to engage a qualified expert to ensure compliance, water safety, and operational readiness. We will be assisting our clients with these updates and are available to help others prepare as well.