Yes. Someone who contracted Legionnaires’ disease from a water system you control can sue you for compensation, and that civil claim is entirely separate from anything the HSE does. It runs in the civil courts, is decided on the balance of probabilities, and can succeed even if no regulator ever brings a criminal prosecution.

That last point catches duty holders out. Most of the conversation around Legionella, and most of the cost-and-law writing in this corpus, is about enforcement: improvement notices, fines, the HSE knocking. Civil liability is a different track with a different claimant, a different standard of proof, and a different person paying at the end. This explains how a Legionnaires’ disease personal injury claim actually works, for the duty holder weighing their exposure and for the guest, tenant or employee wondering whether they have a case.

This is general information, not legal advice. Whether a claim succeeds, and what it is worth, turns on the specific facts and medical evidence. If you are bringing or facing one, take it to a solicitor.

Two separate tracks: enforcement and a civil claim

When someone falls ill, two things can happen, and neither depends on the other.

The criminal track is enforcement. The HSE or local authority can prosecute the organisation, and sometimes named individuals, for failing to control the risk so far as is reasonably practicable [1]. The test is the criminal one, guilt beyond reasonable doubt, and any fine is paid to the court.

The civil track is a compensation claim. The injured person, or the dependants of someone who has died, sues you directly for damages. The test is the balance of probabilities: more likely than not. The money is paid to the claimant. We cover the enforcement side in The cost of non-compliance: legal and business impacts, and the wider fallout in The cost of an outbreak: health, legal and reputational damage. Legionella civil liability sits on this second track, and it behaves quite differently. Because the two are independent, a regulator deciding not to prosecute, or trying and failing, does nothing to close down a claim.

What a Legionnaires’ disease compensation claim has to prove

A claimant generally has to establish four things: that you owed them a duty of care, that you breached it, that the breach caused their illness, and that they suffered a loss the law compensates.

Who is owed that duty depends on the setting. An employee is owed it by their employer; a hotel guest, gym member or other visitor by the occupier of the building; a tenant by their landlord [3]. (Verify the precise basis against the Occupiers’ Liability Act 1957 and common-law negligence.) The duty is, broadly, to take reasonable care for their safety, which for water systems means doing what a competent duty holder following ACoP L8 and HSG274 would do: assess the risk, control it, monitor it, keep records [2].

Here is the part that has changed, and that even some advisers get wrong. People still talk about suing for “breach of statutory duty” over a Legionella failure, meaning a claim founded on breaking a regulation. Since section 69 of the Enterprise and Regulatory Reform Act 2013, breach of most health and safety regulations no longer gives an automatic civil right of action. So a modern Legionnaires’ disease compensation claim is run mainly in common-law negligence and occupiers’ liability, not as a freestanding breach of statutory duty.

That sounds like good news for duty holders. It is not as good as it looks, which is the bit nobody spells out.

What nobody tells you about civil Legionella claims

Four things sit beneath the surface of these claims, and they decide most of them.

The lower standard of proof is the whole game. Criminal causation, proving beyond reasonable doubt that your system and not a source streets away infected this person, is a steep climb. It is part of why Legionella deaths are so rarely prosecuted as homicide (see Corporate manslaughter and Legionella: when an outbreak becomes a case against the organisation). A civil claimant only has to show it was more likely than not. Source attribution that would collapse a criminal case can still carry a civil one, especially where environmental and genomic sampling from an outbreak investigation points at your water [4].

Your own paperwork is the case, for both sides. The risk assessment, the monitoring logs, the written scheme of control, the record of what you did when a temperature failed: all of it is disclosable, and it cuts both ways. Complete, contemporaneous records are often a duty holder’s best evidence that they took reasonable care. Their absence is close to fatal to a defence, because you cannot show you acted reasonably if you cannot show you acted at all. The same logbook that satisfies an HSE inspector is the first document a claimant’s solicitor will ask for.

Dropping “breach of statutory duty” did not make L8 stop mattering. Even though the claim now runs in negligence, a court still measures your conduct against the recognised standard, and ACoP L8 has a special legal status: a court can treat your failure to follow it as evidence that you fell below the standard of care, unless you show you did something equally effective [2]. Legionella negligence is, in practice, judged largely by whether you did what L8 expects.

Limitation is longer and more layered than “three years from when they were ill.” For personal injury the general limit is three years, but it runs from the date the claimant knew, or should reasonably have known, that their illness was significant and linked to your system, which can be well after exposure. Where someone has died, dependants get their own claim with its own timing. (Verify the limitation and dependency mechanics against the Limitation Act 1980 and the Fatal Accidents Act 1976.) For a duty holder, that means your exposure on a given failure does not necessarily expire on the neat anniversary you assumed.

Who actually pays, and what it covers

In most cases the damages are met by your public, employers’ or property-owners’ liability insurer, not out of cash flow. That is the point of the cover. The catch is that liability policies frequently require you to hold a current Legionella risk assessment and to manage the risk; a serious compliance gap can give the insurer room to dispute cover, leaving the organisation carrying the claim itself.

What a successful claimant recovers is “damages”, broadly compensation for the harm rather than a punishment. That typically spans pain and suffering, lost earnings, the cost of care and treatment, and, in fatal cases, dependency and bereavement awards. The amounts are entirely case-specific and turn on the medical evidence. This article gives no figures, and anyone quoting a number without seeing the medical reports is guessing.

FAQ

Can you sue for Legionnaires’ disease in the UK?

Yes. If you can show on the balance of probabilities that an organisation owed you a duty of care, breached it, and thereby caused your illness, you can bring a personal injury claim for damages, independently of whether the HSE prosecutes.

Can I claim even though the HSE never prosecuted?

Yes. A civil claim is decided on the lower “more likely than not” standard, so it can succeed where a criminal case was never brought or did not succeed. They are separate proceedings on separate tests.

How long do I have to make a claim?

For personal injury the general limit is three years, but it runs from the date you knew, or reasonably should have known, that your illness was significant and connected to a source, not necessarily the date of exposure. Death claims have their own timing. Get advice early, because once the clock starts it does not wait.

Is a Legionella claim “breach of statutory duty”?

Usually not in the old sense. Since 2013, breaking a health and safety regulation no longer automatically founds a civil claim, so Legionnaires’ claims now run mainly in negligence and occupiers’ liability. Failing to follow ACoP L8 remains strong evidence of negligence, however.

Who pays the compensation?

Normally your liability insurer, provided you held valid cover and met its conditions, which often include having a current risk assessment in place. A serious compliance gap can let an insurer dispute the claim, which exposes the organisation directly.

Start with your compliance file

Treat your Legionella records as legal documents, because that is what they become the day someone claims. This week, pull your current risk assessment and confirm three things: it is in date, its recommendations are tracked to completion, and your monitoring logs actually show the written scheme of control being followed. Then make sure whoever holds your liability cover has seen that file and is content with it. If instead you are the person who was made ill, keep every medical record and anything tying your illness to a specific building or stay, note when you first made that connection, and speak to a personal injury solicitor promptly. Whether the same failure also exposes a named individual is a separate question, covered in Personal liability: can individuals be prosecuted for Legionella failures?.

Sources

[1] HSE, “Legionnaires’ disease - what you must do”. https://www.hse.gov.uk/legionnaires/what-you-must-do/index.htm [2] 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 [3] HSE, “Legionella and landlords’ responsibilities”. https://www.hse.gov.uk/legionnaires/legionella-landlords-responsibilities.htm [4] UKHSA, “Investigation of Legionnaires’ disease: cases, clusters and outbreaks”. https://www.gov.uk/government/publications/investigation-of-legionnaires-disease-cases-clusters-and-outbreaks