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Difference between NYC and NYS

Cooling Tower Requirements: What Building Owners Should Know

I. Defining “Cooling Towers”

A cooling tower is a unit that recirculates water to make the inside of a building cooler. Cooling towers are often part of a building’s heating, ventilation and air conditioning (HVAC) system.
Cooling towers may be found in or on top of large high-rise buildings. In commercial/industrial buildings, cooling towers may be part of a building’s industrial process or energy production system and may be located outside the building. Units called evaporative coolers and fluid coolers are also considered cooling towers.

Cooling towers include these features:

  • Fan on top
  • Piping entering near the top
  • Air vents on the side
  • Piping exiting the bottom

Cooling Towers

Some large cooling tower systems have more than one tower. Additionally, some cooling towers have more than one “cell” (sometimes called a “basin”). For example, an “eight-cell tower” is one cooling tower with eight cooling tower “cells.” As long as the different cells inside a cooling tower and the different towers within a system recirculate the same water, they are considered part of the same cooling tower system.

If you are unsure whether your building has a cooling tower, ask the building engineer or maintenance supervisor.

The State and City regulations overlap in many areas. The table below shows this.

Requirement New York City Local Law 77 of 2015 New York City Chapter 8 Rules New York State Emergency Regulations
Register all existing cooling towers with NYS by Sept. 16, 2015.     X
Register all existing cooling towers with NYCDOB by Sept. 17, 2015. X    
Register any new cooling tower with NYCDOB before operating it. X X  
Register any new cooling tower with NYS before operating it.     X
Securely affix an NYCDOB cooling tower registration number to each tower.   X
Number must be on outside of tower in visible location.
Test each cooling tower every 90 days. X
DOHMH specifies testing every three months. (For practical purposes, this is the same as 90 days.)
Test must be for Legionella; notify DOHMH within 24 hours if high levels found (those greater than or equal to 1,000 CFU/mL).**
Legionella testing must have been done by 9/16/15 unless done 30 days prior. Otherwise, HPC (heterotrophic plate count) dip slide or culture test allowed. When reporting test results, include any Legionella results and last HPC result.**
When replacing system parts, use corrosion-resistant, sunlight-blocking materials.   X  
Perform cleaning at least two times per year.   X  
Install and maintain drift eliminators as specified.   X  
Perform daily, automatic chemical treatment of system water and continuously recirculate water (unless otherwise justified).   X  
Perform routine manual water quality monitoring of temperature, pH, conductivity and biocide concentration unless this process is automated.   X
At least three times per week with no more than two days between monitoring.
Perform microbial monitoring.   X
Perform weekly routine monitoring. Do visual inspection of wetted surfaces, chemical treatment equipment check and completion of checklist.   X  
  X X
Also required prior to seasonal startup.
Include evaluation of proper functioning of the conductivity control.
If tower was shut down, without water treatment and/or recirculation, for ≥5 days, clean/drain and disinfect before reuse. X X
Also test for Legionella after a shutdown.
Certify annually that tower(s) was/were inspected, tested, cleaned and disinfected as required. Starts Nov. 1, 2016. X
Certify in NYCDOB online system.
Certify in NYS online system.
Keep records of activities onsite for three years. X X X
Notify NYS/NYCDOB if tower is removed/out-of-use, and confirm it was drained and sanitized. X X X
Develop and follow maintenance program and plan (MPP) in line with American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE 188-2015) Standard. X
Implement plan by March 1, 2016.
Find NYC-specific requirements in Chapter 8. Keep plan on-site; use template and guidance.
Implement plan by March 1, 2016. A Legionella culture sampling plan is required in the plan. See question 8.

*This table shows broad requirements only. More details can be found in the New York City Local Law and DOHMH rules or the State regulations, depending on the requirement. Find links to each in “Resources.” Also find links in “Resources” for registering your tower online with the City and State.

**You must notify New York City DOHMH within 24 hours if high Legionella bacteria results were found in your tower. You must notify the New York State Department of Health of any Legionella sample result and the required corrective actions. See the question and answer on this in Section III.