Hidden systems,
same discipline.
Legionella is a waterborne organism with an airborne route into the body: the fine spray from showers, taps and evaporative plant. Gemini AMPM manages building water systems with the same planned, evidenced discipline we bring to ventilation: risk assessment to ACoP L8, monitoring, cleaning and independently analysed sampling, recorded so the duty is provable.
Someone holds the duty.
Usually you.
Under the Health and Safety at Work etc. Act 1974 and the COSHH Regulations, whoever controls a building holds a legal duty to assess and manage the risk from legionella. The HSE’s Approved Code of Practice L8 and its technical guidance HSG274 describe what discharging that duty looks like: a current risk assessment, a written scheme of control, routine monitoring, and records proving all of it actually happened. When an environmental health officer or an insurer asks about your water systems, the answer is your paperwork.
The risk itself lives in the quiet parts of the system: storage tanks running warm, calorifiers stratifying, dead legs nobody flushes, outlets nobody uses. Water sitting between 20 and 45 degrees is an incubator, and the exposure happens wherever that water becomes breathable spray. It is a building-services risk with a respiratory outcome, which is why it belongs in the same conversation as the air.
Scoped, delivered,
evidenced.
- Legionella risk assessments: hot and cold water systems assessed to ACoP L8 and HSG274 by our own engineers.
- Monitoring & flushing: sentinel outlet temperatures checked, little-used outlets flushed, results logged.
- Tank & calorifier care: inspected and photographed, cleaned and disinfected when condition requires it.
- TMV servicing: thermostatic mixing valves serviced so scald protection and temperature control both hold.
- Sampling to BS 7592: taken by our engineers, analysed by an independent UKAS-accredited laboratory.
- Written scheme & logbook: every task recorded in a form your auditor, insurer and EHO can rely on.
Assessed, monitored,
independently analysed.
Our engineers carry out the assessment, the monitoring and the remedial work; the laboratory does not work for us. Samples are taken to BS 7592 and analysed by an independent UKAS-accredited laboratory, so the result in your logbook is verified by someone with no stake in it. Tanks and calorifiers are inspected and photographed, and cleaned on condition rather than on ceremony; disinfection and chlorination follow alterations, tank works or periods out of use, so the system returns to service in a defensible state.
The practical win is consolidation. The estate that trusts us with its ductwork, air handling units and fire dampers can put the wet systems on the same planned schedule: one contractor, one standard of evidence, and no gap between two suppliers each assuming the other has it covered.
Common questions on
water hygiene & legionella control.
Who is responsible for legionella control in a commercial building?
The duty holder: the employer, landlord or whoever controls the premises, which in practice usually lands on the facilities manager. The duty holder does not have to do the work personally, but they must ensure a competent party assesses the risk, runs the control scheme and keeps the records. That is the role we take on, and we report in a form that shows the duty being discharged.
Is legionella management actually a legal requirement?
Yes. The Health and Safety at Work etc. Act 1974 and the COSHH Regulations place the duty, and ACoP L8 describes the regime a duty holder is expected to run. An ACoP has special legal status: failing to follow it is evidence of non-compliance unless you can show you complied in some equally effective way. A current risk assessment, a written scheme and dated records are the minimum defensible position.
How often should water tanks be inspected and cleaned?
Annual inspection is the common baseline for cold water storage tanks, with cleaning and disinfection when the inspection finds sediment, scale, corrosion, staining or anything else that compromises the water. Cleaning frequency honestly depends on condition, which is why we photograph and report every inspection rather than cleaning to an arbitrary calendar.
What records do we get?
Risk assessments, inspection reports with photographs, temperature and flushing logs, sampling certificates from the UKAS-accredited laboratory, and cleaning and disinfection certificates, all filed so your logbook shows a continuous, dated trail of control. If you have inherited a building with no water hygiene history, we establish the baseline and build the file from there.
Can water hygiene run under our ventilation contract?
That is how it works best. One planned schedule covering ductwork, kitchen extract, dampers, AHUs and the water systems means one point of contact, one reporting standard and no assumptions about what the other contractor covered. The disciplines are close cousins: both are hidden systems where the evidence matters as much as the work.
Tell us about
the building.
A named engineer comes back within 24 hours, not a call centre. Site surveys are free for commercial premises, no obligation.
Talk to us about
water hygiene & legionella control.
A named engineer, not a call centre, comes back within 24 hours. Tell us the building and what you’re dealing with, and we’ll scope it properly.