Legionella Control & HSE L8 — Water System Cleaning and Pressure Washing | V-TUF
Legionella Control and HSE L8 — Water System Cleaning and Pressure Washing Compliance
Legionella bacteria thrive in water systems where temperature, stagnation and scale create the right conditions for growth. The Health and Safety Executive's Approved Code of Practice L8 — Legionnaires' Disease: The Control of Legionella Bacteria in Water Systems — places a legal duty on dutyholders to identify and manage Legionella risk in any water system under their control. This includes cooling towers, evaporative condensers, hot and cold water systems, spa pools, and vehicle wash systems.
Pressure washing and high-pressure water jetting are used in Legionella control programmes for cleaning water storage tanks, cooling tower fill, distribution pipework and associated plant. The cleaning equipment used must not introduce additional contamination risk — and the operative must be protected from aerosol exposure during the cleaning operation.
HSE L8 — the legal framework
The Health and Safety at Work Act 1974 and the Control of Substances Hazardous to Health Regulations 2002 (COSHH) both apply to Legionella risk. HSE L8 (the Approved Code of Practice) and HSG274 (the associated technical guidance) set out what dutyholders must do:
- Identify and assess sources of Legionella risk — a written risk assessment
- Implement a written scheme to prevent or control the risk
- Implement, manage and monitor the precautions
- Keep records of the precautions taken
- Appoint a person to be responsible for carrying out the precautions — the Responsible Person
Failure to comply with L8 is a criminal offence. The HSE can prosecute under HSWA 1974 and COSHH 2002. A Legionella outbreak traced to inadequate control in a premises under your control can result in unlimited fines and imprisonment.
Pressure washing in Legionella control programmes
High-pressure water jetting and pressure washing are used for:
- Cooling tower cleaning — removal of scale, biofilm and accumulated debris from cooling tower fill, basins, drift eliminators and distribution systems. Typically requires disinfection before and after cleaning.
- Water storage tank cleaning — cold water storage tanks (calorifiers, break tanks, header tanks) must be periodically inspected and cleaned. Pressure washing removes sediment, biofilm and scale from tank walls and floors.
- Spa pools and water features — high-pressure cleaning of pool shells, pipe systems and filtration equipment as part of the remediation process following a Legionella incident or routine maintenance programme.
- Vehicle wash systems — recirculating vehicle wash water is a recognised Legionella risk. Periodic high-pressure cleaning and disinfection of recirculation tanks and pipework is required.
Operative protection during water system cleaning
High-pressure cleaning of Legionella-contaminated water systems generates aerosols — fine water droplets that can remain airborne and be inhaled. Operative protection requires both RPE (Respiratory Protective Equipment) and appropriate equipment selection:
- Use hot water pressure washing where possible — water above 60°C kills Legionella on contact
- Minimise aerosol generation — lower pressure, appropriate nozzle selection, wet rather than fan jet where possible
- Contain the work area — prevent aerosol migration to occupied areas
- RPE — appropriate for biological aerosol exposure
- Disinfect equipment after use — pressure washer, hoses, guns and lances used in contaminated systems must be disinfected before being used elsewhere
Equipment for Legionella control cleaning
Hot water pressure washers are the preferred specification for Legionella control cleaning — water above 60°C is lethal to Legionella. The V-TUF RAPID VSC and RAPIDMSH hot water ranges provide the water temperature and pressure needed for effective cooling tower and water system cleaning.
Telephone: 01522 787978 for Legionella cleaning equipment specification. Contact the V-TUF trade team →