I bought a water company and discovered what most building owners are missing.
Legionella: What Every Building Owner Needs to Know
A plain-English guide from someone who learned it the hard way
Let me be honest with you from the start: I’m not a water-hygiene scientist. My background is in commercial property. So when I came to own a water-hygiene company, I came at it as exactly the kind of person I’m writing this for — someone who knows buildings, but who had never really had to think too much about the water running through them.
What I learned changed how I look at every building I walk into. And the biggest lesson wasn’t technical. It was this: most building owners and managers have no real idea what they’re responsible for when it comes to Legionella — and it’s almost never because they don’t care. It’s because nobody ever told them. I certainly wasn’t told.
So this is me telling you — in plain English, no jargon, no scare tactics. It’s a timely moment to do it, too: this year marks 50 years since Legionnaires’ disease was identified, and UK cases are rising rather than falling, which tells you the message still isn’t reaching the people who hold the duty. Because make no mistake — Legionella compliance is your responsibility as a building owner or manager, and it’s not something to take lightly.
Does this apply to you?
If you own or manage a building that other people use, and it has a water system — taps, showers, toilets, a hot or cold water tank — then yes, this applies to you.
That covers landlords, employers, care providers, schools, hotels, shops and offices — in fact any property that people occupy or use in a business context. You don’t have to be a water expert. But the law does expect you to make sure the risk is managed, and here’s the part that surprised me most: the responsibility sits with you, the owner or manager.
What Legionella actually is
Legionella is a bacterium that lives naturally in water. In small amounts it’s harmless. It becomes dangerous when it’s left to grow — in water that sits still and stays warm — and is then breathed in as a fine mist from a shower or tap. That can cause Legionnaires’ disease, a serious and sometimes fatal form of pneumonia.
Here’s the part that caught me out: you can’t see it, smell it or taste it. Water that looks perfectly clean can still be a risk. That’s exactly why it gets missed.
Who is at risk
This is the bit that really changed how I think about it, because it isn’t paperwork — it’s people. When a building’s water isn’t managed, the people who can be harmed are the ones who use it: tenants, residents, staff and visitors.
The most vulnerable are at the greatest risk — older people, and anyone whose health is already fragile. Which is why care homes, sheltered housing and healthcare settings carry the highest stakes of all.
What you’re responsible for: the five essentials
The law — the , and the guidance known as ACoP L8 — expects the building’s “dutyholder” to make sure the risk is assessed and controlled. In practice, that means five things every building should have:
- A Legionella risk assessment — current, and reflecting how the building is actually used.
- A named responsible person — trained and empowered to manage water safety, not just a name on a form.
- A written scheme of control — a simple, written plan of what’s done to keep water safe.
- Routine monitoring — temperature checks, flushing little-used outlets, keeping things clean, on a schedule.
- Records — evidence of what was done, when, and what it found, so you can prove it.
If you don’t recognise some of these, that isn’t a failing. It’s exactly the gap I had myself — and I’d bought the company.
A quick self-check: are you doing enough?
Ask yourself, honestly:
- Do I know whether my building has a current Legionella risk assessment? When was it last done?
- Is there a named person responsible for water safety — with the support to do it?
- Is there a written plan, and is someone actually following it?
- If an inspector, insurer or worried tenant asked me to prove my water is safe tomorrow, could I?
If the answer to any of these is “I’m not sure,” you’re in good company — I wasn’t sure either. It’s very fixable.
The “it looks fine” trap
The most common — and most dangerous — assumption in water safety is “the water looks and tastes fine, so we’re fine.”
Because the risk is invisible, a clean-looking system tells you nothing. “It’s always been fine” isn’t the reassurance it sounds like. The only thing that genuinely protects people is active, recorded management.
What I’d say to you
I came into this not knowing what I didn’t know. My hope is simply that more owners and managers get the chance to find out before something goes wrong, rather than after.
So run through the five essentials and the self-check above. And if you’d like an honest second opinion, take us up on a free, no-obligation compliance review — we’ll tell you plainly whether your water is safe and provable, or what needs doing. No sales pitch. Just an honest answer, so you can be confident you’re meeting the responsibility that rests with you as a building owner or manager.
Phil White, Director 
📞 0333 038 6286 ✉ Admin@irrigonics.co.uk 🌐 www.irrigonics.co.uk
Irrigonics is a UK water hygiene and Legionella compliance company. As always, remember: Legionella compliance is your responsibility as a building owner or manager.
You can also explore our other articles and services to better understand how to manage water safety across your sites.