🚰 The Hidden Impact of Hybrid Working on Water Quality: Why Legionella Risk is a Growing Concern for UK Workplaces

In the wake of the pandemic, hybrid working has become a long-term reality across the UK. Businesses have adapted — with staff splitting their time between home and office, and buildings operating under partial or fluctuating occupancy.

While this shift brings productivity gains and greater flexibility, it also creates unexpected safety challenges. One of the most overlooked — but potentially deadly — is the risk of Legionella proliferation in building water systems due to reduced usage and stagnation.

If you are a business owner, facilities manager, or dutyholder, this blog post is essential reading. It outlines:

What Legionella is and how it develops

The legal responsibilities you must meet

How hybrid working conditions exacerbate the risk

What practical steps can be taken to manage and reduce exposure

How SJH Safety Solutions can support you in achieving compliance and peace of mind

What Is Legionella?

Legionella bacteria are naturally found in water systems. When conditions are right — particularly in stagnant, warm water — the bacteria can grow and spread, posing a risk of Legionnaires’ disease.

This is a severe form of pneumonia contracted by inhaling airborne water droplets containing Legionella. It is not transmitted from person to person and often originates from water systems within buildings — especially those left unused or poorly maintained.

Key Facts:

Temperature range for growth: 20°C–45°C

Infection risk: Inhalation of aerosolised contaminated water

Symptoms: Fever, cough, muscle aches, shortness of breath

High-risk groups: Elderly, immunocompromised, smokers

Mortality rate: 10–15% in diagnosed cases

How Hybrid Working Increases Legionella Risk

The Issue: Stagnation

In traditionally occupied buildings, water flows regularly through all outlets — keeping temperatures stable and systems flushed. However, in hybrid or underused premises, water can stagnate in pipework, creating ideal conditions for Legionella growth.

Even if a building is “technically open,” reduced staff presence can mean entire wings, floors, or facilities (e.g., showers, kitchenettes, meeting rooms) go unused for days or weeks. As water sits in pipes without circulation, biofilms can form — providing protection and nutrients for bacteria.

At-Risk Premises:

Offices with hybrid or rotational staffing

Multi-tenant properties with partial occupancy

Hotels, gyms, and retail units with seasonal demand

Educational facilities during holidays

Warehouses and distribution centres with unused amenities

The Legal Landscape: Your Responsibilities as a Business Owner

Managing Legionella isn’t just best practice — it’s a legal requirement in the UK.

Your key obligations are defined under:

🧾 1. Health and Safety at Work etc. Act 1974

Employers and those in control of premises must ensure the health, safety, and welfare of employees and others who may be affected.

⚖️ 2. The Control of Substances Hazardous to Health Regulations 2002 (COSHH)

Legionella is classified as a hazardous biological agent. COSHH requires you to:

Assess the risk of exposure

Implement control measures

Maintain adequate records

Review controls periodically

📘 3. ACoP L8: The Control of Legionella Bacteria in Water Systems

This Approved Code of Practice (published by the HSE) sets out practical guidance on compliance with COSHH. While not legally binding, failure to follow it may be used as evidence of non-compliance in a court of law.

📚 4. HSG274 Part 2: Technical Guidance for Hot and Cold Water Systems

This document supports ACoP L8 with specific recommendations on the design, operation, and maintenance of water systems.

In short:

If your water systems are underused due to hybrid working, you are legally required to assess and manage the risk.

Consequences of Non-Compliance

Ignoring water safety risks can have severe outcomes:

Financial Penalties & Enforcement:

HSE prosecutes where risks are not managed

Fines can range from thousands to millions depending on severity

Enforcement notices may lead to temporary closure

Health Outcomes:

Legionnaires’ disease can result in hospitalisation or death

You may face civil liability for harm caused

Reputation Damage:

A single case linked to your site may draw media attention

Loss of trust among staff, clients, and the public

Damage to brand image, especially in healthcare, hospitality, or education sectors

How to Identify and Control Legionella Risks

Step 1: Conduct or Review a Legionella Risk Assessment

This must be completed by a competent person and should consider:

Type and design of the water system

Building usage patterns

High-risk areas and outlets

Existing control measures

The assessment should be updated if any significant change occurs — such as hybrid working reducing outlet usage.

Step 2: Implement a Water Safety Plan

This document sets out:

Specific control measures

Monitoring schedules

Responsibilities

Emergency procedures

Ensure the plan reflects the actual pattern of use in the building.

Practical Control Measures: What You Can Do Now

Here are proven methods for keeping Legionella at bay in hybrid-occupied premises:

🔄 Flushing Infrequently Used Outlets

Flush all taps, showers, toilets, and dead-ends at least weekly

Let water run for several minutes to replace stagnant water

Record each flushing activity in a logbook

🌡️ Temperature Control

Cold water: stored and distributed below 20°C

Hot water: stored at 60°C and distributed at 50°C minimum at outlets

Monitor and log temperatures at key points weekly

🧼 Clean and Descale

Remove and clean showerheads, hoses, and spray taps every 3 months

Consider replacing heavily scaled or contaminated fixtures

🧪 Microbiological Testing

Not always legally required but recommended in higher-risk premises

Sampling should be done by a specialist and analysed at a UKAS-accredited lab

🔧 System Design Improvements

Identify and remove dead legs or blind ends in pipework

Use automatic flushing devices in hard-to-reach areas

Reroute plumbing to reduce stagnation in low-use areas

Documentation and Record-Keeping

HSE expects all organisations to maintain clear records of:

Risk assessments

Monitoring results

Flushing schedules

Remedial works

Training provided

These must be:

Kept for at least 5 years

Accessible in case of audit or investigation

Good records not only demonstrate compliance — they provide evidence that you're proactively managing health risks.

Common Mistakes to Avoid

🚫 Assuming that “low occupancy = low risk”

🚫 Using old risk assessments that don’t reflect hybrid usage

🚫 Relying solely on temperature checks without flushing

🚫 Failing to clean or inspect outlets not used weekly

🚫 Not providing training to those with responsibility

The SJH Safety Solutions Approach

At SJH Safety Solutions, we specialise in working with businesses across sectors — from offices to industrial, education to healthcare — to help them identify, manage, and eliminate Legionella risk.

Our services include:

✅ Legionella Risk Assessments (including hybrid building usage)

✅ Water Safety Plan development and review

✅ Legionella control system implementation

✅ Temperature monitoring and flushing support

✅ Staff and dutyholder training

✅ Independent sampling and analysis coordination

We’re fully versed in ACoP L8 and HSG274, and can help you stay compliant, confident, and in control — without unnecessary complexity or cost.

Final Thoughts: Don’t Let a Flexible Workplace Create a Fixed Risk

The modern workplace may be flexible, but your approach to health and safety must remain rigorous. Hybrid working has altered how buildings are used — and that means your water safety practices need to change too.

🛑 Don’t wait for a Legionella incident to prompt action.

🔍 Review your controls now and ensure your building is safe for all who use it.

📞 Need help navigating your water safety obligations?

SJH Safety Solutions is ready to support your business. Contact us today to book a consultation or learn more about our Legionella management services.