If your building runs a cooling tower or an evaporative condenser, the local council is supposed to know it exists — by address, by how many devices there are, and by who is responsible for them — long before anything goes wrong. That is the entire purpose of the notification duty. When public health teams trace the source of a Legionnaires’ cluster, the register of notified devices is one of the first lists they pull [1]. A tower nobody told the authority about is a tower that gets found the hard way.

The good news is that notifying is quick, free, and one of the very few Legionella duties you can fully discharge in an afternoon. The trap is that it is easy to assume it was already done — by the developer, the installer or a contractor — when in fact nobody did. This walks through how to confirm it, do it, and keep proof.

What “notifiable” actually means

The duty applies to “notifiable devices”: broadly, wet cooling towers and evaporative condensers that expose recirculating water to a moving air stream and so can throw out fine spray, or drift. HSE groups these among the systems most likely to create Legionella risk precisely because that drift can carry contaminated droplets well beyond the plant deck [3]. Their risk profile is different enough from ordinary hot and cold water that HSG274 treats evaporative cooling systems as a separate regime with their own control and monitoring expectations [2].

The legal mechanism is the Notification of Cooling Towers and Evaporative Condensers Regulations 1992, which sit alongside your duties under the Health and Safety at Work Act. The local authority holds the register; you put your devices on it. The exact definition of a notifiable device, and any exemptions for closed or genuinely dry systems, is worth confirming against current HSE guidance — the boundaries are not always obvious from the nameplate.

How to notify, step by step

The sequence below takes you from “we think we have a tower” to “the council has it on the register and we can prove we told them.”

  1. Confirm the device is genuinely notifiable. Walk the roof and plant areas and identify every wet cooling tower and evaporative condenser, open or closed circuit. Why: the duty bites where water meets air and creates drift [3]. Done when: you have a short list of each device with its location, type and whether it is in use. Where it goes wrong: writing off a unit as a “dry cooler” without checking whether it has an adiabatic or spray-assist mode that wets the air in hot weather — that hybrid behaviour can pull it back into scope, so verify rather than assume.

  2. Find the right local authority. Notification goes to the council for the area where the device physically sits — usually its environmental health team — not to HSE. Why: the council, not the national regulator, maintains the register for its patch [1]. Done when: you have the correct department and its notification route confirmed. Where it goes wrong: notifying the council where your head office is registered instead of where the tower actually stands, or sending it to HSE and assuming that counts.

  3. Notify in writing with the required detail. Provide the premises address, the number and location of devices, and a named responsible person with contact details, via the council’s form, email or letter. Why: a written submission creates the dated record the register entry depends on. Done when: the notification is sent and you have kept a copy. Where it goes wrong: a phone call with no paper trail. Confirm the precise fields each authority wants, as the required information is set out in the regulations and some councils ask for it on their own form.

  4. File the confirmation as compliance evidence. Store the notification and any acknowledgement in the Legionella logbook or risk file, cross-referenced from your written scheme. Why: this is part of demonstrating you have met your duties, not a loose email. Done when: the responsible person can produce a dated copy on request. Where it goes wrong: the notification is made but the only proof leaves with the staff member who sent it.

  5. Keep the entry current. Re-notify when a device is installed, when control of the premises passes to a new operator or owner, and — the one most people forget — when a device is permanently taken out of use, so it can be removed from the register. Why: the register only helps investigators if it reflects the real world. Done when: notification triggers are written into your change and decommissioning procedures. Where it goes wrong: a tower is scrapped but lingers on the register for years, or a building changes hands and nobody updates whose name the device sits under.

  6. Verify it landed. Where the authority acknowledges, keep that confirmation; if you hear nothing, follow up and ask them to confirm the device is recorded. Done when: you have a written acknowledgement or register reference on file. Where it goes wrong: treating “I sent it” as the finish line instead of “they have it.”

Notification puts you on the map — it does not control the risk

Being on the register tells the council your tower exists. It does nothing, by itself, to stop the tower growing and dispersing Legionella. That control work is separate and ongoing: a site-specific risk assessment, a written control scheme, water treatment, cleanliness, drift management, inspection and a documented restart procedure after any shutdown [4][2]. Passing one duty says nothing about the other. For the control side, see Cooling towers and evaporative condensers — high-risk systems and Risk assessing cooling towers for Legionella.

Notification and RIDDOR are not the same thing

This catches people out often enough to be worth stating plainly. Notification is proactive and one-off: you register the device with the local authority before there is any problem [1]. RIDDOR is reactive: where someone is reasonably believed to have contracted Legionnaires’ disease from your work activity, that is a separate report to the enforcing authority under different rules [5]. Doing one does not satisfy the other, and the moment you might be reaching for RIDDOR is exactly the wrong moment to discover your tower was never on the register. Reporting Legionnaires’ disease covers the reactive side.

Before you take this as settled

Treat the steps above as orientation, not a substitute for the regulations or a competent adviser. The information a notification must contain, and how a particular council wants to receive it, vary enough to confirm directly with the authority before you rely on them. And where a hybrid or adiabatic unit’s scope is genuinely unclear, that is a question for your risk assessor, not a coin toss.

Common questions

Do I notify the council or HSE about a cooling tower?

The local authority where the device is located, usually its environmental health team, because the council holds the register for its area [1]. HSE is the wrong recipient for the notification itself, even though HSE guidance describes the duty.

Is an adiabatic or “dry” air cooler notifiable?

It depends on whether it wets the air. A unit that only ever cools dry generally sits outside the duty, but many adiabatic and hybrid coolers spray or wet the air stream in hot conditions, which can bring them into scope. Check the actual operating modes and confirm the boundary with HSE guidance or the council rather than going by the label.

We’ve just bought a building with a cooling tower — do we need to re-notify?

If you are now the person in control of the premises, make sure the register entry is accurate under your organisation and your responsible person, and notify the authority if it is not. Do not assume the previous owner’s notification automatically carries across or still reflects who is now accountable.

Do this before the week is out

Walk the roof and plant deck, list every wet cooling tower and evaporative condenser, and email your local authority’s environmental health team to ask whether each one is already on their register under your organisation’s name. If it is not, that email — with the address, device count and responsible person — becomes your notification. Save the reply in the logbook, and you have closed a duty that most buildings quietly leave half-open.

Sources

[1] HSE, “Other duties: RIDDOR and notification of cooling towers or evaporative condensers”. https://www.hse.gov.uk/legionnaires/what-you-must-do/duties.htm [2] HSE, “Legionnaires’ disease: Technical guidance (HSG274)”. https://www.hse.gov.uk/pubns/books/hsg274.htm [3] HSE, “Systems most likely to create legionella risk”. https://www.hse.gov.uk/legionnaires/risk-systems.htm [4] HSE, “Legionnaires’ disease. The control of legionella bacteria in water systems - Approved Code of Practice and guidance (L8)”. https://www.hse.gov.uk/pubns/books/l8.htm [5] HSE, “RIDDOR - Reporting of Injuries, Diseases and Dangerous Occurrences Regulations”. https://www.hse.gov.uk/riddor/