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Cooling towers: where they are regulated, and what each law requires
There is no federal cooling tower rule. Four jurisdictions have written one into law, and one of them, New Jersey, has a deadline on December 12, 2026 that reaches every hotel with central hot water serving 25 or more units and every building with a cooling tower, spa or pool. Everywhere else the obligation is ASHRAE 188 by way of the general duty clause, your insurer and the health department that shows up after a case.
The federal picture
| Body | What it says |
|---|---|
| OSHA | "There currently is no specific OSHA standard for Legionellosis." Enforcement is under the General Duty Clause, Section 5(a)(1), together with the PPE, respirator and Hazard Communication standards where staff handle treatment chemicals. |
| CDC | The Water Management Program Toolkit (last updated March 15, 2024) is guidance, built on ASHRAE 188. It is what health departments ask to see after a case. |
| ASHRAE | Standard 188-2021 (Legionellosis: risk management for building water systems) with Guideline 12-2023. Every law below points at it. |
| CMS (healthcare only) | QSO-17-30: hospitals, critical access hospitals and nursing facilities must have a water management program. Not applicable to hotels or condominiums. |
New Jersey: the law with a date
P.L.2024, c.66, "An Act concerning Legionnaires' disease," approved September 12, 2024, N.J.S.A. 26:1A-139 to 142. Effective immediately; the program deadlines run from that date.
| Who it covers | What it requires |
|---|---|
| Any building with an "open-circuit or closed-circuit cooling tower or evaporative condenser," a whirlpool, spa, pool, ornamental fountain, mister or humidifier | A written water management program following ASHRAE Standard 188-2018 or later, developed within 24 months (by September 12, 2026) and implemented within 27 months (by December 12, 2026); a written public notice posted on the premises that the program is in place; the program and records kept on site at least five years and produced to the Department of Health on request. Periodic Legionella sampling is mandatory only for hospitals and nursing facilities linked to an outbreak or on CDC recommendation; other buildings may include it. Civil penalties up to $2,000 for a first violation, $5,000 after, $10,000 where a violation causes serious injury or death. |
| Hotels and motels: a central potable water heater shared by 25 or more transient units | |
| Residential buildings of six or more floors with a central potable water-heater system | |
| Senior, disabled or subsidized housing of 25 or more units on a central water heater; correctional facilities; hospitals and nursing-type facilities | |
| Any building the Department of Health or a local health officer links to an outbreak |
Residential properties with four or fewer units are exempt. The law does not register cooling towers; it requires the program. As of this reading no implementing rule from the New Jersey Department of Health has been adopted; the statute stands on its own.
New York State: every cooling tower, since 2016
10 NYCRR Subpart 4-1, effective July 6, 2016, applies to every cooling tower in the state regardless of building type.
| Requirement | Interval |
|---|---|
| Electronic registration with the Department of Health (§4-1.3) | Before operation; kept current |
| Maintenance program and plan per ASHRAE 188 (§4-1.4) | Written, on site |
| Bacteriological (HPC) sampling while in use | At least every 30 days |
| Legionella culture | Within 14 days of seasonal start-up, then at least every 90 days while in use; results above 1,000 CFU/mL reported to the local health department within 24 hours |
| Inspection by a professional engineer, certified industrial hygienist, certified water technologist or qualified consultant | Before seasonal start-up and at least every 90 days |
| Annual certification that the program was carried out (§4-1.8) | By November 1; records kept three years |
New York City: the strictest schedule in the country
Local Law 77 of 2015 (Administrative Code §17-194.1 and §28-317), Health Code Chapter 8 as amended effective May 8, 2026 under Local Law 159 of 2025, and the state law of August 5, 2026 (S.8472-A) that amends the city's code.
| Requirement | Interval or deadline |
|---|---|
| Legionella culture by an ELAP-certified laboratory | At least monthly, no more than 31 days apart while operating (was 90 days before May 8, 2026); each sample date reported in the city portal within 5 days |
| Bacteriological indicator test | Weekly |
| Compliance inspection by a qualified person | At least every 90 days |
| Hyperhalogenation | Once between July 1 and August 31 each year, Legionella sample 3 to 31 days after, declaration filed within 30 days |
| Cleaning and disinfection | Within 15 days before seasonal operation; start-up sample within 3 to 14 days; maintenance deficiencies corrected within 48 hours and serious-threat results within 24 hours with notice to the department (state law, 2026) |
| Certification that inspection, testing, cleaning and disinfection were done | Twice a year, in January and July (state law, 2026; previously once by November 1); the department sends a reminder 30 days ahead |
| Records | Ten years (state law, 2026; previously three) |
| Penalties | Up to $2,500 first violation, $7,000 after, $12,500 where a fatality or serious injury results (state law, 2026); Health Code penalties such as $1,000 and $2,000 for improper treatment and $500 and $1,000 for a late sample-date report |
| Building filings | Since October 26, 2026, DOB NOW mechanical filings needing a Certificate of Compliance include the tower's registration number, installation date and commissioning date |
Why the city moved: the summer 2026 Upper East Side cluster reached 94 cases and 11 deaths; 83 of more than 180 towers tested came back positive and were ordered cleaned. Monthly-testing compliance citywide was 77% before the cluster. The detail is on the Legionella page.
Garland, Texas: the oldest local rule
City Code §32.04(D)(6), restated in Ordinance No. 6671 of January 21, 2014: every owner of a multifamily dwelling or lodging establishment with an HVAC cooling tower has it tested for Legionella pneumophila once a year by a City-approved third party at the owner's expense, with the laboratory report to the City within 10 days of a negative result and 48 hours of a positive one. No registration, no action level and no cleaning schedule are written into the section; a violation is a misdemeanor.
Where there is no law, and bills that did not pass
| Place | Status, as read |
|---|---|
| Florida | No statute. SB 1654 / HB 1377 (2026) would have required registration, 30-day Legionella sampling and a November 1 certification; it died in the Senate Health Policy Committee on March 13, 2026. Expect it to be filed again. |
| Nevada and Clark County | No statute; AB 263 (2023, healthcare programs) died June 6, 2023. The Southern Nevada Health District's 2026 public accommodation regulations contain no Legionella or cooling tower requirement. |
| Pennsylvania and Allegheny County | No statute; HB 2085 (introduced December 9, 2025) pending. The county health department's 2016 survey said it was "not recommending cooling tower regulation at this time." |
| Maryland | HB 204 (2026) heard in committee; no passage found. |
| California | No statewide building rule; SB 1144 (2022) was vetoed. |
| Virginia | Public school buildings only: Va. Code §22.1-138(C), water management program validated at least annually (effective July 1, 2021). |
| Illinois, Michigan | Healthcare facilities only (210 ILCS 85/6.29; Mich. Admin. Code R 325.45303). |
| Chicago, Los Angeles, Las Vegas, Houston, Philadelphia, Boston, Washington, D.C. | No cooling tower registration or building water management ordinance found. |
What this means for a hotel or a condominium
| If your building is in | Do this |
|---|---|
| New Jersey | If you have a cooling tower, a spa or pool, six or more floors on central hot water, or 25 or more hotel units on a central water heater: the written program was due September 12, 2026 and must be running by December 12, 2026. Post the notice. Keep the program on site for five years. |
| New York City | Monthly Legionella tests 31 days apart at most, weekly dip slides, the July–August hyperhalogenation, and now two certifications a year with ten-year records. Have the water-treatment contractor's calendar in your own calendar. |
| New York State outside the city | Registered, 90-day cultures and inspections, 30-day HPC, November 1 certification. |
| Garland, Texas | One Legionella test a year by an approved third party; report within 10 days, or 48 hours if positive. |
| Everywhere else | No registration or test is required by law today. A written ASHRAE 188 program is what OSHA's general duty clause, your insurer and the health department will measure you against after a case, and Florida's bill will be back. |
Confirm applicability and dates with the state or city health department and a qualified water-treatment professional; this page restates the laws as read on the date above.
What is not on this page, and why
Healthcare-facility rules (CMS, VA Directive 1061, state hospital rules) are named but not detailed; they do not reach hotels or condominiums. Local health department guidance documents that are not law are left off. The VA directive, the 2018 revised CMS memo and Michigan's rule text were not opened directly and are stated from their agencies' summaries. Chapter numbers for the 2026 New York law were not yet published when this page was read.
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