The New York State Department of Health announced that final regulations protecting against Legionella in every cooling tower, and all general hospitals and residential healthcare facilities in the state have gone into effect.

The new regulations grew out of emergency regulations the Department adopted last summer when 138 residents of the South Bronx were sickened with legionellosis, and 16 people died. 

The source of the South Bronx outbreak was determined to be a cooling tower.  Cooling towers are part of a recirculated water system incorporated into a building’s cooling, industrial, refrigeration or energy production system. 

Cooling towers are a potential source of Legionella and were not regulated by the state prior to August 2015. The regulations require that cooling towers be registered, inspected and tested for Legionella.

The regulations also require all general hospitals and residential health care facilities to perform Legionella culture sampling and analysis of their drinking water systems.”

Legionella occurs naturally in the environment, usually in water.  If cooling towers are not operated and maintained properly, bacteria such as Legionella can grow in the water and be dispersed into the air.  People can get legionellosis when they breathe in mist containing the bacteria.

Under the new regulations, owners of cooling towers must:

  • Register cooling towers in a statewide electronic system.  New towers must be registered prior to initial operation and all tower registrations must be updated in the system whenever ownership changes.
  • Inspect cooling towers prior to seasonal start-up, following maintenance, and at intervals no greater than 90 days while in use.  The purpose of the inspection is to check for deficiencies or problems.
  • Have an updated maintenance program and plan by September 1, 2016 that includes a schedule for routine bacteriological culture sampling, routine Legionella culture sampling and analysis, and immediate Legionella culture sampling and analysis under specific conditions. 
  • Conduct Legionella culture sampling and analysis within two weeks after start-up for seasonal towers or within two weeks of start-up following maintenance for year-round towers and at intervals not to be greater than 90 days thereafter. Legionella culture sampling and analysis is required where NYSDOH or a local health department determines that one or more cases of legionellosis is or may be associated with a cooling tower. Bacterial culture sampling and analysis must be conducted at intervals not to exceed 30 days while the cooling tower is in use.
  • Notify the local health department within 24 hours of getting a Legionella culture sample result exceeding 1,000 colony-forming units (CFU) per milliliter (mL).
  • Use only pesticide applicators or technicians certified by the state Department of Environmental Conservation to apply biocides for disinfection.
  • Certify by November 1st each year that a cooling tower has a maintenance plan, that it has been followed and that all requirements of the regulation have been met.  


The new regulations also require hospitals and residential health care facilities to:

  • Perform or update an environmental assessment by September 1, 2016. The purpose of this assessment is to evaluate the building and the potable water systems, and identify sampling locations. 
  • Adopt and implement a sampling and management plan by December 1, 2016 for potable water systems, which  includes routineLegionella culture sampling and analysis and immediate Legionella sampling and analysis under specific conditions, including where NYSDOH determines that one or more cases of legionellosis is or may be associated with the facility.
  • Conduct Legionella culture sampling and analysis at intervals no greater than 90 days for the first year and annually thereafter. Potable water systems that serve stem cell or organ transplant patients must be sampled and analyzed at intervals not to exceed 90 days.

To view the regulations and learn about legionellosis, click here

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