Cooling Towers - New Chapter 8 in Title 24 of the Rules of the City of New York to establish rules for maintenance of cooling towers

Adopted Rules: Closed to Comments

Effective Date: 
Monday, May 9, 2016
Download Copy of Adopted Rule (.pdf): 


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 a case fatality rate of 5-30%.  The US Centers for Disease Control and Prevention (CDC) estimates that there are 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 bacteria 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.  Preliminary data indicate there were 438 confirmed cases of LD diagnosed in New York City residents in 2015.  In July and August 2015, 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 SSC 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, effective March 2, 2016, states: 

Because water is part of the process of removing heat from a building, these devices require 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 maintenance program and plan 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 to the State Department of Health. 

This new Chapter of the Department’s Rules sets forth specific requirements for the operation and maintenance of cooling towers in New York City that comply with and further those in Part 4 of the SSC.  The Chapter’s provisions that are equivalent to the SSC are noted below. This Chapter is organized somewhat differently than SSC Part 4; 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. 

Chapter 8 contents and further changes

The new Chapter 8 includes the provisions outlined below.  The description also notes changes made to the original published proposal in response to comments received.

   §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 the Administrative Code or SSC Part 4. Since the proposed rule was published for public comment, a definition has been added for “biocidal indicator,” and the definition of “water quality parameters” has been amended to delete “total dissolved solids (TDS)” and “oxidation reduction potential (ORP)” as parameters and add “biocidal indicator” as an additional parameter.  The term “responsible person” has also been redefined as someone who is working under the guidance of a “qualified person.” This change was made to clarify that the “qualified person” is not required to be the direct supervisor of the “responsible person.”

     §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.  In response to comments that the records of cooling tower operations and the maintenance program and plan may not be kept at the cooling tower itself, the Department has modified this requirement to allow the plan to be kept in an adjacent location on the same campus, complex or lot where the cooling tower is located. Section 8-07(a) has also been amended to be consistent with this change.

   §8-04   Process control measures: this section establishes requirements for routine monitoring, to be conducted at least weekly by the “responsible person,” and for compliance inspections to be conducted at least every 90 days by a 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. In response to comments received since the proposed rule was published, subdivision (a)(3) has been changed to require observations of wetted surfaces only if this can be done without shutting down the cooling tower system.  Subdivision (c)(2) has been amended to require that alterations to equipment be made in compliance with the current City Construction Codes and that cleaning protocols and safety equipment be included in the management program and plan. 

     §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. In response to comments received since the proposed rule was published, provisions in subdivision (c) on biocide applications and recordkeeping have been clarified, and a new requirement added that any water treatment system that does not use any oxidizing biocide must be approved by the Department. Subdivision (d) has been amended to restrict (as opposed to completely prohibit) the use of non-chemical water treatment to systems where effective chemical treatment is also in place to control Legionella. In subdivision (f), provisions have been added to clarify that continuous automated monitoring is allowed in lieu of manual monitoring.  The initially published Table 1 of corrective actions has been split into two tables: Table 8-1 indicates required actions when water samples are culture positive for Legionella and Table 8-2 indicates the required actions for heterotrophic and dip slide results for uncultured bacteria.         

     §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. In response to comments received since the proposed rule was published, subdivision (c) has been amended to require pre-startup inspection and Legionella sampling.           

    §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.