Water Hygiene Records: L8 ACoP Compliance for UK Businesses (2026)
What water hygiene records L8 ACoP requires from UK businesses — the written control scheme, monitoring logs, tank cleaning, the responsible person, and retention rules.
Quick answer: The HSE's L8 Approved Code of Practice requires UK businesses to control legionella risk and keep supporting records. For higher-risk systems this means: a written legionella risk assessment, a written control scheme, ongoing monitoring logs (temperatures, flushing), tank inspection and cleaning records, TMV servicing records, and a named, competent responsible person. Monitoring records should be kept at least 5 years. L8 compliance is enforced by the HSE — breaches risk unlimited fines and prosecution.
What L8 ACoP is
L8 is the HSE's Approved Code of Practice and guidance document: "Legionnaires' disease: The control of legionella bacteria in water systems". It has special legal status — following it is generally accepted as compliance; departing from it means you must show you've achieved equivalent control. Supporting technical detail is in HSG274 (parts 1-3, covering cooling towers, hot and cold water systems, and other risk systems).
The records L8 requires
| Record | Purpose | Retention |
|---|---|---|
| Legionella risk assessment | Identifies the risks | Life of system + reasonable period |
| Written control scheme | How risks are managed day-to-day | Life of system |
| Temperature monitoring log | Evidence of temperature control | 5 years |
| Flushing records | Little-used outlets managed | 5 years |
| Tank inspection/cleaning | Storage kept clean | 5 years |
| TMV servicing | Mixing valves maintained | 5 years |
| Responsible person + training | Competence evidence | Current |
| Remedial actions | Out-of-range responses | 5 years |
The written control scheme
For higher-risk systems, the control scheme is the operational heart of compliance. It specifies:
- A schematic diagram of the water system
- The specific control measures (temperature regimes, flushing)
- Monitoring tasks and frequencies
- Action levels and what to do when exceeded
- Who is responsible for each task
- Record-keeping requirements
The responsible person
L8 requires a named, competent "responsible person" with authority and training to manage legionella control. Key points:
- Must be competent — appropriate training and knowledge
- Has sufficient authority and resources
- For larger organisations, often a facilities or H&S manager
- The duty can be delegated to a water hygiene contractor, but legal accountability remains with the employer/duty holder
- A deputy should cover absences
Higher-risk systems needing full L8 compliance
- Cooling towers and evaporative condensers (also notifiable to the local authority)
- Hot and cold water systems in larger buildings
- Spa pools and hot tubs
- Care homes and healthcare premises (vulnerable occupants)
- Systems with stored hot water and multiple outlets
- Anywhere water is aerosolised
What an HSE inspection checks
- Is there a current legionella risk assessment?
- Is there a written control scheme (for higher-risk systems)?
- Are monitoring records up to date and complete?
- Is there a named, competent responsible person?
- Are tanks, TMVs, and outlets being maintained?
- Have out-of-range readings been acted on and recorded?
Common L8 compliance failures
- Risk assessment exists but no written control scheme for a complex system
- Monitoring logs with gaps or no corrective actions recorded
- No named responsible person, or one without training
- Cooling tower not notified to the local authority
- Tank cleaning and TMV servicing not documented
- Records discarded before the 5-year retention
FAQs
Does every business need a written control scheme?
Higher-risk systems do. Simple low-risk systems may need only the risk assessment and basic monitoring. The risk assessment determines what's required.
Are cooling towers treated differently?
Yes — cooling towers and evaporative condensers must also be notified to the local authority under the Notification of Cooling Towers and Evaporative Condensers Regulations 1992, and require the most rigorous control.
Can I outsource water hygiene to a contractor?
Yes — many businesses use specialist water hygiene contractors. But legal accountability stays with the duty holder; you must still oversee the contractor and keep the records.
How does L8 relate to COSHH?
Legionella bacteria are a hazardous substance under COSHH. L8 ACoP is the specific guidance for controlling that particular hazard. Both apply.
Related guides
- Legionella risk assessment: landlord & business guide
- Legionella temperature monitoring log
- Water hygiene records: L8 ACoP compliance
Last reviewed 2026-06-08 by Jamie Dawson, Editor.
