Two building managers went to prison last year. Not for negligence. Not for an accident. For deliberately falsifying water temperature records on their legionella management logs. Let that sit with you for a moment. Prison. For paperwork fraud on a water system.
HSE legionella prosecutions were up 40% in 2025. The regulator isn't targeting the buildings with outbreaks — it's targeting the buildings where the documentation doesn't match reality. Because that's where the next outbreak comes from.
Why the HSE Escalated
The COVID pandemic accelerated legionella risk across the UK's commercial building stock. Buildings that sat empty or partially occupied for months had stagnant water systems — perfect breeding conditions. When buildings reopened, many didn't recommission their water systems properly. The HSE's data showed a correlation between buildings that cut corners on water hygiene during COVID and subsequent legionella detections.
What Gets You Prosecuted
The prosecution threshold is lower than most people think. You don't need an outbreak. You need evidence of systemic failure:
- Temperature logs that don't match automated BMS readings (the falsification that sent two managers to prison)
- Missed monthly temperature checks with no documented reason
- Dead legs in the water system that aren't on the risk assessment
- No evidence of L8 training for the responsible person
- A risk assessment that's older than 2 years or doesn't reflect building changes
The Minimum Viable Compliance Programme
Legionella compliance isn't complex. It's consistent. Monthly temperature checks at sentinel points. Quarterly tank inspections. Annual risk assessment reviews. Biennial full risk assessments. Records kept digitally with timestamps that can't be retrospectively altered. That last point is what caught the two managers — they were backdating paper records.
Frequently Asked Questions
How often should legionella risk assessments be reviewed?
Full reassessment every 2 years minimum, with annual reviews of the existing assessment. Any significant change to the water system (new outlets, changed supply, building modifications) triggers an immediate review.
Can automated monitoring replace manual temperature checks?
Automated monitoring complements but doesn't replace manual checks. The HSE expects both — automated systems for continuous monitoring and manual checks to verify the automated readings are accurate.
Until next time — keep the evidence closer than the deadline.
Walk into your next senior management meeting with the answers
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About HermanWa
HermanWa is a building compliance and operations platform for property and facilities teams in the United Kingdom and Singapore, with portfolios across the Gulf. It keeps one auditable file per building — statutory deadlines, inspection evidence, contractor work, energy and carbon — and its AI assistant, Herman, answers questions about your buildings in plain English. HermanWa tracks obligations including fire risk assessments and fire door checks, Building Safety Act duties, Legionella (ACOP L8), EICR, gas safety and EPC in the UK, and SCDF fire certificates, Periodic Facade and Structural Inspections, lift permits and Green Mark in Singapore. Directors can check their exposure with the free Director's Risk Check.