Reporting Requirements for Cooling Towers

Online comments: 5

• Ron F

  I appreciate the City’s commitment to protecting public health. However, I respectfully oppose the proposed amendment to require monthly Legionella testing of cooling towers (replacing the current 90-day requirement). This amendment is unnecessary, unsupported by evidence, and will impose undue financial burdens on property owners — especially residents of cooperatives and other multi-family buildings — without a proportionate public health benefit.

  1. Current Regulatory Framework Already Includes Frequent Monitoring and Maintenance

  Under existing NYC and New York State regulations, cooling towers are already subject to comprehensive oversight:

  Quarterly (every 90 days) Legionella sampling is required while towers are in use, and all sampling must be performed by certified laboratories.

  Owners must perform weekly heterotrophic bacteria sampling and routine system monitoring (e.g., water quality measurements multiple times per week), daily biocide treatment, and at least semiannual cleaning/disinfection events.
  These multi-layered requirements already serve to identify and control conditions conducive to bacterial growth before they escalate into outbreaks.

  The regulatory approach applied in NYC is already more stringent than many other jurisdictions (which typically require Legionella culture testing only quarterly while also emphasizing maintenance and water chemistry controls).

  2. Monthly Testing is Not Proportional to the Scientific Evidence on Legionella Risk

  Legionella bacteria are naturally present in the environment, and detection in cooling tower water does not necessarily mean that disease transmission will occur. In fact, many cooling towers test positive for Legionella at times without resulting in illness.

  Additionally:

  Legionnaires’ disease outbreaks are relatively rare events given the large number of cooling towers and the existing regulatory framework in place.

  The most widely referenced industry standards (e.g., ASHRAE 188) and many state programs do not require monthly culture testing as a baseline frequency — they focus on maintenance, water quality control, and reacting to conditions that promote growth rather than a rigid monthly test schedule.

  The City Council’s rationale for the more frequent testing is linked to a recent outbreak; but that outbreak — while tragic — was linked to failures in maintenance and remediation after positive tests, not necessarily to the testing interval itself. Furthermore, existing rules already require remediation and reporting upon positive results.

  3. Significant Financial Burdens on Property Owners and Residents

  Monthly Legionella testing will impose material new costs on buildings with cooling towers. These tests must be conducted by or under supervision of qualified professionals and submitted through certified laboratories.

  For cooperative boards and other residential property owners, increased testing costs will likely translate directly into higher maintenance fees, assessments, or rents at a time when affordability in NYC is already a critical concern. Many co-ops operate on thin financial margins, and increased mandatory testing could disproportionately affect seniors, low-income residents, and others struggling with the high cost of living in the city.

  The amendment’s financial burden falls on property owners rather than on operational factors that actually contribute to Legionella risk. A more targeted approach that focuses on maintenance compliance, enforcement of existing requirements, and better support for small property owners would be more equitable and effective.

  4. Alternative Strategies Can Better Balance Public Health and Economic Impact

  Instead of strictly mandating monthly testing, the City could consider:

  Enhanced enforcement of existing maintenance and inspection requirements to ensure that quarterly tests are meaningful and that positive findings are acted on promptly.

  Targeted testing protocols for buildings with known risk factors or prior violations rather than a blanket monthly requirement for all.

  Subsidized testing programs or technical support for small residential buildings to help them comply without undue financial strain.

  This approach would preserve public health protections without imposing unnecessary costs on owners and residents.

  Comment added February 12, 2026 11:21am

• Anonymous

  We already have excessive testing requirements which puts an extreme burden on property owners and whoever they pass their expenses onto. If you are following what is in place already, there should be no issues. We keep hearing about making this city more affordable while policies like this do the complete opposite.

  Comment added February 12, 2026 3:36pm

• Mitch Kaufman

  I really wish we could all focus on the time of the year when we are most at risk. Many cooling towers run 12 months per year. Of those towers, most operate in what is known as “free cooling mode.” Condenser water temperatures are as low as 40 degrees F. This is a temperature where the legionella bacteria do not thrive. Any cells that get into the atmosphere through misting are immediately killed by the ambient temperature of the atmosphere. Let’s focus on the summer months when condenser water temperatures are higher and where bacteria thrive. It is that time when these outbreaks occur.

  Let’s also consider what overexposure to chlorine does to equipment and to the environment.

  Comment added February 14, 2026 12:15pm

• Jack Glass, CIH - ALC Environmental

  The current version of this rule requires a certified laboratory to collect the samples. This is not a viable requirement due to the fact that nearly all laboratories only provide laboratory services. Currently, sample collection is performed by a large number of environmental consultants who also provide additional services at the site, such as inspection and disinfection.

  We strongly recommend changing the wording to: Sampling shall be conducted by firms and/or individuals experienced in the collection and management of environmental samples.

  Comment added February 18, 2026 11:09am

• Abraham Cullom

  1. The proposed rule defines startup as putting one or more cooling tower systems or components into operation. Cooling tower system components are then defined broadly and include pumps, filtration devices, chemical controllers, metering pumps, and other wetted equipment. Because some of these components may operate intermittently during normal operation, the current definitions could classify routine operational adjustments as system startups. The Department may wish to clarify that “startup” refers to placing a cooling tower system, tower cell, or circulation loop into operation following shutdown, commissioning, or extended inactivity, rather than activation of individual ancillary components.

  2. The proposed rule requires manual monitoring of disinfectant residual three times per day when bacteriological indicator results exceed the specified threshold, but “manual monitoring” is not defined. As written, the requirement could be satisfied by taking multiple measurements in rapid succession following a biocide addition, which may not demonstrate sustained treatment control. In addition, three monitoring events per day may be operationally burdensome for water treaters who service sites periodically rather than maintaining continuous on-site presence. Defining manual monitoring and clarifying a procedure that captures representative system operating conditions would improve implementation. Also, the HPC retesting requirement appears to provide a minimum waiting period, but not a maximum.

  3. The proposed changes close what I felt was the most important loophole in the previous version. Namely, that summertime hyperhalogenation Legionella samples could be counted as the quarterly sample for the summer. In practice, this meant that there was less known about Legionella growth in a tower during normal operating conditions in the most critical period of the year. The monthly testing requirements, at least during the summer, ameliorate this situation. If it is the intention that Legionella tests for hyperhalogentation can still serve for the routine monitoring sample, this should be clarified. If not, the sequence and spacing of samples should be clarified.

  Comment added March 4, 2026 11:02am