The Water Safety Year: A Practical Legionella Rhythm for UK Facilities Teams

Legionella control is often described as a legal duty, but in practice it is a rhythm. The requirements under L8 and HSG274 are familiar: assess the risk, apply suitable controls, monitor performance and keep records that can withstand scrutiny. The difficulty for facilities teams is not usually knowing what to do. It is sustaining the routine across busy buildings, contractor changes, seasonal shutdowns and competing priorities. In 2026, with estates teams under continued pressure to demonstrate value, a calendar-led approach is more useful than an annual burst of activity.

The following framework is not a substitute for a site-specific risk assessment. It is a practical way to organise the year so that the right tasks happen at the right time, with fewer surprises.

January: rebuild the evidence base

Start the year by confirming that the written scheme still reflects the building. Review the risk assessment, schematics, asset register and responsible person arrangements. Check whether any works over the Christmas period changed the water system, introduced new outlets or left areas temporarily unused. Confirm that contractors remain competent and that their method statements align with the site scheme. Early flushing of little-used outlets should be scheduled before normal occupancy resumes.

February: sentinel points and temperature discipline

Use February to verify sentinel outlets and temperature monitoring routines. Confirm that cold water remains below 20C where reasonably practicable and that hot water reaches the expected temperatures at outlets and calorifier flow and return points. Thermostatic mixing valve servicing should be planned, not deferred. Where temperatures drift, record the corrective action rather than simply noting the reading.

March: cooling systems before the warm season

For sites with cooling towers or evaporative condensers, March is the point to test summer readiness. HSG274 Part 1 expectations include cleaning, biocide regime checks, drift eliminator condition, water treatment records and sampling arrangements. Confirm that online monitoring, where fitted, is calibrated and that alarm responses are understood by the team on shift. A cooling system that is stable in March is less likely to become an incident in July.

April: stagnation risk and holiday shutdowns

Easter closures and spring maintenance can create stagnant conditions in wings, annexes and remote buildings. Plan flushing and draw-off for rooms that will be empty, and document who is responsible. Where buildings are partially occupied, review whether the current regime still matches actual use. This is also a sensible month to refresh toolbox talks for cleaning and maintenance staff who may adjust outlets or isolation valves.

May: the cooling season begins

As ambient temperatures rise, weekly cooling system checks become more important. Confirm biocide dosing, bleed and make-up water controls, and visual condition of the system. Where legionella sampling is part of the scheme, ensure the sampling points, laboratory arrangements and turnaround times are still workable. Review dip slide results alongside physical inspections, not in isolation.

June to August: peak risk and visible compliance

Summer is when water safety becomes most visible. Hot weather, reduced occupancy in some buildings and increased use of showers and cooling systems can combine to raise risk. Keep temperature checks frequent enough to detect drift, inspect showerheads and outlets, and remove or flush dead legs. Records should show not only that a check was done, but what was found and what happened next. Where remedial work is outstanding, record the interim control and the target date.

September: review before autumn occupancy

September is a useful month for a mid-year audit. Review corrective actions from the summer, check that little-used areas have not quietly fallen out of the flushing programme, and confirm that any summer works did not alter the system in ways that require a risk assessment update. Thermal balancing and insulation checks can often be planned now before heating demand increases.

October: calorifiers and heating season preparation

Before the heating season takes hold, inspect calorifiers, storage vessels and associated controls. Confirm that maintenance activities do not create stagnation or bypass arrangements that undermine temperature control. Where pasteurisation or other remedial measures are required, schedule them with clear records of duration, temperatures and verification. Coordinate with mechanical maintenance so that water safety is not treated as a separate workstream.

November: winterisation and closure planning

Cold weather brings frost risk and building closures. Confirm frost protection for tanks, pipework and external outlets. For buildings that will be mothballed or used intermittently, agree a flushing and monitoring regime that is realistic. Draining down may be appropriate in some cases, but it must be planned with the risk assessment in mind. Document changes to occupancy and the controls applied.

December: audit, training and next year's plan

Close the year with a structured review. Check that the risk assessment is current, that training records are complete and that contractor performance has been reviewed. Look at the year's monitoring results for patterns rather than isolated readings. Update the written scheme and set the next year's calendar with named owners. A short lessons-learned session is often more valuable than another generic briefing.

Records that survive scrutiny

Good records are contemporaneous, legible and attributable. They should identify the asset, the check performed, the result, the person responsible and any action taken. Digital logbooks can help, but only if the workflow forces timely entry and escalation. A missing record is not a minor administrative gap; it weakens the entire compliance story.

Making the calendar work

The calendar should be integrated with planned maintenance, permit-to-work systems and building occupancy data. Assign a named owner for each month and review progress at a monthly estates meeting. Where a task cannot be completed, record the reason and the interim control. The aim is not a perfect paper trail for its own sake, but a water system that is understood, controlled and demonstrably safe throughout 2026 and beyond.