What is water hygiene and legionella control?
Water hygiene is the management of water systems in a building to control the risk of legionella. It requires a risk assessment, a written scheme of control, and monitoring carried out and recorded.
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<a href="https://facilityoptix.co.uk/glossary/water-hygiene">What is water hygiene and legionella control?</a> — diagram by
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</figure>The controls centre on temperature and on movement. Water held at temperatures that suit bacterial growth, and water that sits still in little-used outlets, are the two conditions the whole regime is arranged against.
A risk assessment is the starting point, not the outcome. It produces a written scheme setting out what will be monitored and how often, and the monitoring records are what demonstrate the scheme is being followed.
Little-used outlets are where buildings most often fail. Flushing them is trivial work that is easy to skip and hard to evidence afterwards, which is why it is the first thing an assessor asks to see records of.
In practice
A building that was half-empty for a long period.
Occupancy returns, and outlets that have not run for months are brought back into use with no flushing regime and no reassessment.
Low occupancy changes the risk and so does the return from it, and a risk assessment written for a fully occupied building is not describing what happened in between.
The outlets that matter are the ones nobody uses, which is exactly what a quiet period creates.
What goes wrong in practice
- A risk assessment carried out once and never reviewed after changes to the building or its occupancy.
- Flushing regimes recorded on paper at the outlet and never collated, so nobody can show the pattern.
- Temperature monitoring recorded but out-of-range results never actioned.
- Responsible person appointed in name without the training the role requires.