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Adopted Rules: Closed to Comments

Adopted Rules Content: 

Statement of Basis and Purpose

Statutory Authority

This amendment is made pursuant to sections 556 and 1043 of the Charter and section 17-194.1 of the New York City Administrative Code (Administrative Code). Section 556 of the Charter authorizes the Department to regulate all matters pertaining to the health of the City. Charter section 1043 grants the Department rulemaking authority. Section 17-194.1 of the Administrative Code requires owners of buildings with cooling towers to maintain, clean and disinfect such cooling towers and authorizes the Department to adopt rules to implement these requirements.

Chapter 8 of Title 24 of the RCNY (Chapter 8) contains the Department’s rules for the operation and maintenance of cooling towers in the City. A cooling tower is a device that extracts heat to the atmosphere through the cooling of a water stream to a lower temperature. The term “cooling tower” includes any evaporative cooling equipment with recirculating water, including direct (open circuit) and indirect (closed circuit) cooling towers, evaporative condensers, or evaporative spray fluid coolers capable of aerosolizing water. Common applications of cooling towers are for air conditioning, refrigeration, industrial/manufacturing processing or electric power generation. This includes mobile or portable cooling towers. A cooling tower may comprise one or more cooling tower cells.

Because water within a cooling tower uses heat exchange, it can provide an ideal environment for Legionella bacteria to grow, particularly if the cooling tower is not properly disinfected and maintained. Exposure to the Legionella bacteria (Legionella pneumophila) can cause Legionellosis disease. Cases of Legionellosis must be reported to the Department in accordance with section 11.03 of the Health Code and section 2.1 of the New York State Sanitary Code (found in title 10 of the New York Codes, Rules and Regulations). The more serious form of Legionellosis is a pneumonia known as Legionnaires’ disease; a less serious form of Legionellosis is known as Pontiac fever, which is a flu-like illness. Legionnaires’ disease is known to have a case fatality rate of 5-30%. The US Centers for Disease Control and Prevention estimates that there are between 8,000 and 18,000 cases of Legionnaires’ disease in the United States annually and that more than 10% of cases are fatal.1

Section 8-04 of Chapter 8 provides requirements for cooling tower process control measures. The Department is requiring a summertime hyperhalogenation, a one-time per year dosing of higher-than- normal levels of chlorine or bromine based biocide, to each cooling tower system between July and August 31. Periodic hyperhalogenation is an effective method of limiting Legionella in recirculating water by preventing the risk of biofilm growth, which can be a host for Legionella survival and replication. Periodic hyperhalogenation performed routinely, while ensuring water flow throughout the cooling tower system and all its components, may reduce the need for more intensive cleaning and disinfection procedures in the future. The Department’s Legionella sampling results indicate that concentrations of the bacteria are highest during the summertime months. Surveillance data also indicates more cases of Legionnaires’ disease during the summertime.


Accordingly, Section 8-04 is amended by establishing a new subdivision (f) requiring a summertime hyperhalogenation to be conducted for each cooling tower system at least once each year between July 1 and August 31. Summertime hyperhalogenation is expected to occur this summer, 2020, but an owner is not required to update their cooling tower maintenance plans until the 2021 cooling season. Finally, the penalty schedule in §8-09 of Chapter 8 is amended to include monetary penalties associated with the violation of this requirement.



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Effective Date: 
Tue, 07/07/2020

Proposed Rules: Closed to Comments (View Public Comments Received:28)

Comment By: 
Monday, January 4, 2016
Proposed Rules Content: 

Statement of Basis and Purpose



Legionellosis is an illness that must be reported to the Department in accordance with New York City Health Code §11.03 and State Sanitary Code (SSC) §2.1 (found in title 10 of NYCRR). The more serious form of legionellosis is a pneumonia known as Legionnaires’ disease (LD); a less serious form, Pontiac fever, is a flu-like illness.  LD has case fatality rate of 5-30%.  The US Centers for Disease Control and Prevention (CDC) estimates that there were between 8,000 and 18,000 cases of LD in the United States annually, and that more than 10% of cases are fatal.[1]


People are exposed to Legionella through the inhalation or aspiration of aerosolized water (droplets or mist) that contain the bacteria.  Person-to-person transmission of Legionella has not been demonstrated. Susceptible people at higher risk for LD include the elderly, people who are immune compromised or have other medical conditions, and heavy smokers.  In New York City, there were 301 cases of LD in 2013 and 225 cases in 2014.  Between 2000 and 2014 there were, on average, 165 confirmed cases a year with the number of annual cases ranging from 44 to 301.  This year, there have been 374 confirmed cases of LD as of October 7, 2015.  In July and August, the Department investigated an unusually large cluster of 133 cases of LD that occurred in the Bronx and resulted in 16 deaths.[2] The Department determined that this outbreak was associated with aerosolized Legionella bacteria emanating from one or more building cooling towers to which susceptible persons were exposed.  Responding to the outbreak, the City Council and Mayor enacted Local Law 77 of 2015.  At the same time, the State Public Health and Health Planning Council (PHHPC) adopted a new Part 4 of the State Sanitary Code (“SSC”), found in 10 NYCRR Chapter 1, on an emergency basis, citing other instances of LD outbreaks and fatalities occurring in other parts of the State that are believed to be associated with cooling towers.[3]


Both Local Law 77 and the SSC §4.2(c) define a cooling tower as “a cooling tower, evaporative condenser or fluid cooler that is part of a recirculated water system incorporated into a building’s cooling, industrial process, refrigeration or energy production system.”  As the PHHPC’s Emergency Justification for Part 4 of the State Sanitary Code states:


Because water is part of the process of removing heat from a building, cooling towers require treatment with biocides – chemicals that kill or inhibit bacteria (including Legionella)—as means of controlling bacterial overgrowth. Overgrowth may result in the normal mists ejected from the tower having droplets containing Legionella.


Local Law 77 added a new Article 317 to Title 28 of the Administrative Code that required owners of cooling towers to register them with the Department of Buildings (“DOB”) by September 17, 2015. Towers must be inspected, tested, cleaned and disinfected in accordance with new Administrative Code §17-194.1 and rules adopted by the Department.  Owners and operators of cooling towers must annually certify to DOB that their cooling towers have been inspected, tested, cleaned and disinfected and that a management and maintenance program has been developed and implemented in accordance with Administrative Code §17-194.1.  Statewide, including in New York City, owners of all cooling towers must also comply with SSC Part 4, which includes registration with and reporting requirements to the State Department of Health. 


This proposed new Chapter sets forth specific requirements for the operation and maintenance of cooling towers in New York City comply with and further those contained in Part 4 of the SSC.  The Chapter’s provisions that are equivalent to the SSC are noted below. This Chapter is organized in a differently than the SSC requirements; more terms are defined in this Chapter and more detailed instructions for management and maintenance are provided than those contained in SSC Part 4 to facilitate compliance with both the City and State rules and requirements. 


Proposed Changes

The Department is proposing to add a new Chapter 8 to Title 24 of the Rules of the City of New York to include:

            §8-01   Scope and applicability: applicable to all owners and operators of buildings and other premises that are equipped with cooling towers.

            §8-02   Definitions: to facilitate compliance with and enforcement of these rules, more terms are defined in this Chapter than in the corresponding sections of either Administrative Code or SSC Part 4.

            §8-03   Maintenance program and plan: the requirements of this section exceed those of SSC Part 4, including specific routine maintenance tasks; identification of persons responsible for various functions; identifying system components; and establishing a system risk management assessment to identify areas that may create problems and lead to proliferation of Legionella bacteria.

            §8-04   Process control measures: this section establishes requirements for routine monitoring, to be conducted at least weekly by a “responsible person” under the supervision – remote or on-site -- of the “qualified person” identified in SSC Part 4, and for compliance inspections, to be conducted at least every 90 days, by the qualified person. It specifies standards for maintenance, cleaning, and parts replacement; and requires installation of high efficiency drift eliminators in all new and retrofitted cooling tower systems and in existing ones, where practicable.

            §8-05   Water treatment: this section specifies requirements for automatic treatments, use of chemicals and biocides, and monitoring water quality characteristics/parameters, and establishes a schedule for sampling for Legionella and other bacteria including requiring additional sampling when certain events occur.  This section also mandates the use of certain qualified laboratories for analysis and requires reporting levels of Legionella at a certain magnitude to the Department within 24 hours of obtaining test results; and specifies corrective actions for various levels of bacteria. Although the 2014 New York City Plumbing Code Appendix C authorizes use of rainwater or recycled water as makeup water for cooling towers, it does not require disinfection for Legionella bacteria before use. These rules prohibit such use unless owners use additional control measures approved by the Department that protect against cooling tower system contamination since the Department believes that this water may not meet public health standards and may tend to support microbial growth.

            §8-06 System shutdown and start-up; commissioning new cooling towers: this section sets forth requirements for pre-seasonal cleaning and disinfection and for new cooling towers being placed into use.

            §8-07 Records: this requires the maintenance of records of all activities and that such records be made available for immediate inspection by the Department at the premises where the cooling tower is installed.

            §8-08 Modification: authorizes the Commissioner to modify the application of a provision of these rules where compliance imposes an undue hardship and would not otherwise be required by law, provided that the modification does not compromise public health concerns.

            §8-09 Penalties: establishes a schedule of penalties for initial and subsequent violations within the limits set forth in Administrative Code §17-194.1.    


Statutory Authority

This amendment to Title 24 of the Rules of the City of New York (“RCNY”) is promulgated pursuant to Local Law 77 of 2015, and sections 556 and 1043 of the New York City Charter (“the Charter”).  Section 556 of the Charter broadly authorizes the Department of Health and Mental Hygiene (“the Department”) to regulate all matters pertaining to the health of the City.  Section 1043 grants the Department rule-making authority.  Local Law 77 of 2015, enacted August 18, 2015, added a new §17-194.1 to the New York City Administrative Code (“Administrative Code”) requiring owners of buildings to clean and disinfect cooling towers and authorizing the Department to adopt rules to implement these requirements. Many of Local Law 77’s substantive provisions for inspection and disinfection become effective upon the promulgation of these Department rules. 




[3] The State’s emergency rules originally were scheduled to expire November 18, 2015 but have been reissued, and permanent rules are expected.




Proposed resolution to add new Chapter 8 (Cooling Towers) to Title 24 of the Rules of the City of New York to establish rules for maintenance of cooling towers to minimize potential contamination by Legionella bacteria to prevent outbreaks of Legionnaires’ disease, a type of pneumonia with a high case fatality rate.

New York City Department of Health and Mental Hygiene, Gotham Center
42-09 28th Street 14th Floor, Room 14-43
Queens, NY 11101-4132

Svetlana Burdeynik at (347) 396-6078 or

Download Copy of Proposed Rule (.pdf):