What Schools Need to Have Done About Water Hygiene Before the Summer Closure
The summer break is the longest scheduled low-occupancy window in the UK school calendar, running from late July to early September for state schools and longer for independents, and at the end of it staff and pupils walk back into a building where water has been sitting in pipework at growth-range temperatures for six or seven weeks. HSG274 Part 2 covers buildings of this kind explicitly at paragraph 2.50, where the guidance on intermittent or scheduled low use sets out what a competent response looks like: a controlled flushing regime through the closure, a documented reopening process, and a risk assessment that reflects how the building actually operates rather than how it was designed.
A meaningful proportion of UK schools discover the gap between guidance and practice in late August, when routine pre-term sampling returns positive results that the operational regime should have prevented.
For bursars, school estates teams, multi-academy trust facilities directors, and the responsible person under ACoP L8, the work that needs to be done before the end of term falls into the following areas.
1. Risk assessment review against current use.
ACoP L8 requires the Legionella risk assessment to be treated as a living document, reviewed when there is reason to suspect it is no longer valid. A change in pupil numbers, a new building, a refurbished kitchen, a closed sports facility, or an extended-use letting programme over summer all count as triggers for review. An assessment dated two years ago that does not reflect any of these changes is not, on the face of it, current, and the pre-summer window is when the review needs to happen.
2. Written flushing schedule with named responsibility.
Weekly flushing of every outlet — hot and cold, including infrequently used ones — is the working minimum during the closure. Each outlet runs for two minutes, with showers handled separately because of aerosolisation risk. A shower head should either be removed and immersed in a bucket of water during the flush, or run very slowly for one minute, the operator moves away, and the flow is increased for a further minute. WCs are flushed with the lid down. The schedule needs a name against each task, a deputy named for holiday cover, and a logged record after each visit. A regime that relies on one caretaker who is on leave for three of the six weeks is not a regime.
3. Temperature monitoring at sentinel outlets continued through the closure.
The nearest and furthest hot outlets, and the nearest and furthest cold outlets, are the sentinel points under HSG274 Part 2. Weekly temperature checks at these outlets — hot reaching 50°C within one minute, cold below 20°C — provide the evidence that the system has remained in control. A break in the temperature record during the closure is what an HSE inspector will look for after an incident.
4. Cold water storage tank temperatures inspected and acted on.
Header tanks and cold water storage cisterns in roof spaces, lofts, and unventilated service areas warm in summer. HSG274 Part 2 requires cold water storage to remain below 20°C throughout, and the inside of an unventilated loft in July routinely sits above 25°C. A cistern temperature climbing into the growth range is not a monitoring observation — it is a colonisation source for the entire cold water system below.
The action is set out in HSG274 Part 2 and BS 8558:2015. Where a tank has warmed above 20°C, or where the system has been left without flushing for an extended period, the tank requires a clean and disinfection as a single operation. Chlorination follows the procedure in BS EN 806-5: drain, clean, refill with potable water, dose with sodium hypochlorite to a minimum free chlorine residual of 50 mg/l throughout the tank, hold for a minimum contact time of one hour, then flush through the entire downstream system until the chlorine residual drops to potable levels — typically below 0.5 mg/l. The disinfection certificate must record the cleaning and disinfection as a combined operation, not as separate visits.
Tank inspections that record only the water level and the lid condition are not inspections. Temperature, sediment, visible biofilm, and any signs of warmth-driven growth all form part of the record.
5. TMV servicing scheduled within the window.
HSG274 Part 2 requires thermostatic mixing valves to be inspected, tested and maintained by competent persons, with servicing in line with manufacturer's instructions — which is typically annual for TMV2-rated valves and may be more frequent for TMV3-rated installations. Mainstream UK schools and nurseries normally use TMV2 valves under the NSF (formerly BuildCert) TMV2 scheme. TMV3-rated valves are required where occupants are severely disabled and in healthcare settings, where the more rigorous service regime under HTM 04-01 applies. The summer closure is the operationally sensible window for the annual service because the building is empty, the work doesn't disrupt teaching, and the valves are returned to demonstrable compliance before reopening.
6. Pre-reopening procedure documented in advance.
Reopening is a sequence rather than an event, and the sequence needs to be written down before the closure starts. A full system flush before the first occupants arrive, temperature verification at every sentinel outlet, cold water storage tank inspection and confirmation that storage temperature is below 20°C, TMV function checks, and where the risk assessment indicates it, water sampling for Legionella with results in hand before the building is reoccupied. For higher-risk settings — schools with attached residential boarding, special schools, or on-site healthcare provision — a documented thermal or chemical disinfection of the whole system may be appropriate. The procedure that has been invented on the morning of return is operating without the audit trail an HSE inspector would expect to see.
The compliance position during the summer break carries the same dutyholder obligations as the position during term, with a materially higher risk profile attached. A school with a properly resourced flushing regime, current sentinel monitoring, cold water storage in temperature control, scheduled TMV servicing, and a planned reopening procedure has the answer in writing. A school without those things is operating outside HSG274 Part 2 guidance from the day the building empties.
The question that needs an answer before the end of term is whether the regime that is supposed to be in place is actually resourced — named people, written schedules, logged records, scheduled work — or whether the answer is "we'll sort it nearer the time."
Contact us today to ensure your school is maintained properly and professionally during the summer holiday. Call/WhatsApp us on 0800 046 1000 or email us via [email protected]