Five Hidden Risks in “Compliant” Water Systems: Are You Really Covered for Legionella?

When it comes to Legionella control, appearances can be deceiving. A building might tick all the boxes on paper- routine testing, logs, compliance certificates, but still be vulnerable to serious risks. At SMS Environmental, we regularly encounter issues lurking in systems that seem well-maintained. Here are five of the most common gaps we find, even in buildings that look compliant:

1. Dead Legs and Infrequently Used Outlets

Water that stagnates in rarely used pipes or fixtures creates ideal conditions for Legionella growth. These “dead legs” often go unnoticed in audits, especially in complex systems or low-occupancy areas like spare meeting rooms, infrequently used showers, or annex buildings.

2. Inconsistent Temperature Monitoring

Legionella thrives in water temperatures between 20°C and 45°C. Systems may have monitoring protocols in place, but if the data isn’t consistent, or if key points are being missed, those protocols provide a false sense of security. Spot checks alone aren’t enough.

3. Inadequate Record Keeping

Documentation is often the first thing reviewed during an investigation. We frequently find records that are incomplete, outdated, or difficult to verify. Accurate logs aren’t just for compliance- they’re your safety net when something goes wrong.

4. Poorly Trained Personnel

Even the most robust system can falter if the people managing it don’t fully understand the risks or procedures. Legionella control is a technical and legal responsibility, and every person involved- from facilities staff to contractors- needs appropriate training.

5. The Assumption That “It’s Someone Else’s Job”

Perhaps the most dangerous issue of all: diffusion of responsibility. Water safety often spans departments, facilities, compliance, external contractors- and unless roles are clearly defined, tasks fall through the cracks.

Is Your Building Safe?

If you're unsure whether your current controls cover these hidden vulnerabilities, we can help. Our Legionella risk assessments don’t just check for compliance, they identify real-world risks before they become real-world problems.

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