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NYC cooling towers · 24 RCNY §8-05(f)

Legionella samples every 31 days

Since May 8, 2026, a cooling tower that holds water needs a Legionella culture sample at least every month, with no more than 31 days between two samples. The date of each sample goes to DOHMH through the City’s portal within 5 days, and DOHMH publishes those dates. From May 8 to September 29, 2026, nearly half of the cooling tower summonses OATH recorded were for a sample date reported late or not at all.

Check a building freeLast verified Oct 14, 2026

What it asks

What the owner has to do

  1. A sample at most every 31 daysWhile any water is in the system, circulating or not, with the system circulating for at least an hour before the sample.24 RCNY §8-05(f)(3)
  2. An ELAP-certified labThe final report includes the signed chain of custody and the lab’s ELAP number.24 RCNY §8-05(f)(3)
  3. Two days after any treatmentA sample counts only if it is taken at least two days after a biocide, a cleaning or a disinfection.Admin Code §17-194.1(e)
  4. A startup sampleBetween 3 and 14 days after a startup, including a restart after 5 or more days without circulation.24 RCNY §8-06(b)(2)
  5. The date reported in 5 daysThe qualified person enters each sample date in the City’s portal within 5 days, and the owner has to make sure it happens.Admin Code §17-194.1(f)
  6. Act on a positive resultAt 10 CFU/ml or more: disinfect within 24 hours and retest in 3 to 7 days. At 1,000 or more: full remediation within 48 hours and a notice to DOHMH within 24 hours.24 RCNY §8-05(f)(5), Table 8-1

Deadlines

The clocks

  • Next sampleNo more than 31 days after the last24 RCNY §8-05(f)(3)
  • Startup sample3 to 14 days after startup24 RCNY §8-06(b)(2)
  • Sample date to DOHMHWithin 5 days of the sampleAdmin Code §17-194.1(f)
  • Disinfection after 10 CFU/ml or moreWithin 24 hours of the resultTable 8-1
  • Notice to DOHMH at 1,000 CFU/ml or moreWithin 24 hours of the resultTable 8-1
  • Retest after a positive result3 to 7 days laterTable 8-1

Penalties

What a violation costs

First violation / repeat, per the penalty schedule, with DOHMH’s violation code where it has one. Since May 8, 2026 there is no cure period at inspection.

  • Legionella culture sample, no more than 31 days apartAdmin Code §17-194.1(e); 24 RCNY §8-05(f)(3)$2,000 / $4,000 · AH8S
  • Legionella sample 3 to 14 days after startup24 RCNY §8-06(b)(2)$1,000 / $2,000 · AH8X
  • Report the sample date to DOHMH within 5 daysAdmin Code §17-194.1(f)$1,000 / $2,000 · AHK2Filed late: $500 / $1,000 · AHK0
  • Disinfect within 24 hours of a positive Legionella result24 RCNY §8-05(f)(5), Table 8-1$2,000 / $4,000 · AH8U
  • Notify DOHMH within 24 hours of a result of 1,000 CFU/ml or more24 RCNY §8-05(f)(5), Table 8-1, level 4$2,000 / $4,000 · AH8U

FAQ

Questions owners ask

Does a drained tower need samples?

No. The clock runs while any water is in the system. A drained tower owes a shutdown report within 5 days, and a startup sample 3 to 14 days after it starts again.

Who reports the sample date?

The qualified person, through the City’s portal, within 5 days. The portal takes the date, not the result. DOHMH publishes the dates it receives, so a missing one is visible.

What if the lab result comes back after the 5 days?

The 5 days count from the sample, not from the result. Report the date first; the result starts its own clock when it arrives, often 10 to 14 days later.

Is there a grace period?

No. Since May 8, 2026 there is no cure period at inspection, and a record not shown to the inspector is presumed not to exist.

Your building

See the clock DOHMH sees

Type the address. The free check shows the last sample date DOHMH has, the days left on the 31-day clock, the inspections and any OATH summons on the lot.

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Sources · Last verified Oct 14, 2026

A plain-English summary of the rules, not legal advice. The rule text and DOHMH’s guidance decide; check them before you act.