A legionella risk assessment tells you where the risks are in your water system. A written scheme of control is the practical plan that follows it: what needs to be done, by whom and how often to keep those risks under control. Many buildings have the first but not the second, and that is often where control slips.
Risk assessment, written scheme, logbook: how they fit together
- Risk assessment: identifies and assesses the risks in your water system. Read what happens on a legionella risk assessment visit.
- Written scheme of control: sets out the control measures and checks that will manage those risks.
- Logbook: records that the checks were actually done. See our guide to the legionella logbook.
Think of it as: what could go wrong, what we will do about it, and proof that we did it.
What a written scheme typically includes
- A description of the water system, often with a simple schematic drawing showing tanks, heaters, main pipe runs and outlets.
- Who is responsible, including the named person managing the scheme and anyone carrying out tasks, such as staff, caretakers or contractors.
- The control measures, such as temperature control, flushing of little-used outlets and cleaning of showerheads.
- The checks and their frequency, for example temperature checks at sentinel outlets, tank inspections and descaling. These are set to suit your building.
- Target values, such as the temperatures you are aiming for, and what to do if a reading is outside them.
- Sampling arrangements, where sampling is part of your control strategy.
- What to do if something goes wrong, including a positive sample. See positive legionella sample: what to do next.
- Review arrangements, so the scheme is updated when the building, the system or the people change.
Keep it practical
A written scheme should be something your team can actually follow. Long, generic documents that sit in a drawer do not help. Plain instructions, clear responsibilities and realistic frequencies work far better.
Who should write it?
The scheme is usually prepared from the findings of the risk assessment, by someone competent in legionella control, working with the people who run the building day to day. It should reflect how your building really works.
Your legal duties
Section 19 of the Safety, Health and Welfare at Work Act 2005 requires employers to identify hazards, assess risks and put control measures in place. The HPSC National Guidelines for the Control of Legionellosis in Ireland (2009) give detailed guidance on managing water systems, and a clear written plan is a practical way of following them.
We can help
Safer Solutions provides legionella risk assessments with practical recommendations you can turn into a working plan, and legionella sampling through an independent accredited laboratory. Call 086 275 9728, email info@safersolutions.ie or get in touch. Learn more about our legionella services.