Can You Prevent Legionella? Here’s What You Need to Know

Legionella is the word no property owner, landlord or facilities manager wants to hear – and for good reason. Left unchecked, this bacteria can pose a serious risk to health, leading to Legionnaires’ disease, a potentially fatal form of pneumonia.

But here’s the good news: with the right approach, you can prevent Legionella from taking hold in your water system.

In this blog, we’ll explain how Legionella spreads, who’s responsible for managing the risk, and what practical steps you can take to stay compliant and protect people using your property.

What Is Legionella and Why Is It Dangerous?

Legionella is a type of bacteria that occurs naturally in freshwater environments like lakes and streams. But in man-made systems – like plumbing, cooling towers, water tanks, and hot tubs – it can quickly multiply to dangerous levels.

If water droplets containing Legionella are inhaled (from a shower, tap, spray or humidifier, for example), it can cause Legionnaires’ disease – a severe form of pneumonia that can be life-threatening, particularly for older people, those with lung conditions, or anyone with a weakened immune system.

That’s why preventing Legionella is such a critical part of water hygiene management.

Can Legionella Be Completely Prevented?

In short – yes, Legionella growth can be prevented, but it takes proactive water hygiene management.

Legionella thrives in certain conditions – and if you control those conditions, you control the risk.

Here’s what Legionella needs to grow:

• Water temperatures between 20°C and 45°C
• Stagnant or slow-moving water
• Nutrients (like scale, rust or biofilm)
• A host system (taps, tanks, showers, cooling systems)

So the goal of Legionella prevention is to keep water moving, manage temperatures, and remove opportunities for bacteria to grow.

Who’s Responsible for Legionella Prevention?

If you’re a landlord, employer, facilities manager, or business owner, you have a legal duty under the Health and Safety at Work Act 1974 and COSHH Regulations to assess and manage the risk of Legionella.

This includes:

• Carrying out a Legionella risk assessment
• Implementing a written scheme of control
• Ensuring water systems are regularly maintained
• Keeping records of monitoring and actions taken

You don’t have to do it all yourself – but you do need to ensure competent people (like H2O Comply) are helping you manage the risk.

6 Practical Ways to Prevent Legionella

1. Get a Legionella Risk Assessment

This is always step one. A risk assessment identifies where and how Legionella could grow in your system and provides a roadmap for reducing the risk. If you’ve never had one – or it’s been more than two years – now’s the time.

2. Control Your Water Temperatures

Legionella grows best between 20°C and 45°C. So:

• Store hot water above 60°C
• Distribute hot water at 50°C or higher
• Keep cold water below 20°C

This temperature control is your first line of defence. Our team can check and adjust your systems to keep things within safe ranges.

3. Keep Water Moving

Stagnant water is a breeding ground for bacteria. Prevent this by:

• Flushing unused outlets regularly
• Removing dead legs (see our other blog on that!)
• Ensuring regular use of taps and showers

If you have outlets that are rarely used, put a flushing regime in place.

4. Clean and Disinfect Tanks and Systems

Over time, scale, sediment and biofilm can build up – providing nutrients for Legionella. Regular water tank cleaning and system disinfection is key.

We offer tank chlorination and chemical cleaning services that help break the bacterial cycle and keep your system hygienic.

5. Monitor and Record

Legionella control isn’t a one-off job – it’s an ongoing responsibility. Make sure:

• Temperatures are regularly recorded
• Systems are inspected as scheduled
• Actions are documented and followed up

Our clients benefit from clear, easy-to-understand monitoring records that help them stay compliant.

6. Work With a Water Hygiene Expert

Legionella prevention isn’t always straightforward – especially in complex systems. At H2O Comply, we take the stress out of compliance by managing the process for you, from assessment through to regular maintenance and reporting.

What Happens If You Don’t Prevent Legionella?

Aside from the health risk to tenants, staff or customers, failure to manage Legionella can lead to:

• Legal action or fines
• Damage to your business or property reputation
• Closure notices from Environmental Health
• Increased insurance premiums

Prevention isn’t just best practice – it’s a legal requirement.

Why Choose H2O Comply?

We’re trusted by businesses, landlords, schools and care homes across Kent and the South East to handle all aspects of Legionella prevention and water hygiene compliance.

Whether you need a risk assessment, remedial plumbing, monitoring support, or system disinfection, our experienced team is ready to help.

We don’t just tick boxes – we make water safety easy to understand and manage.

Ready to Prevent Legionella in Your Property?

If you’re unsure about the condition of your water system, haven’t had a risk assessment in a while, or want help staying compliant – get in touch with H2O Comply today.

Message us to arrange your free initial consultation