Cold water tank clean and disinfection
A clean and chlorine disinfection of any stored cold water tank, carried out as part of the control scheme set out in your legionella risk assessment.
A clean and chlorine disinfection of any stored cold water tank, carried out as part of the control scheme set out in your legionella risk assessment.
Stored water that sits stagnant or picks up sediment is exactly the environment legionella bacteria need to multiply. A dirty tank undermines every other part of your water hygiene routine.
WHEN
Every 12 months, or as your risk assessment's control scheme specifies.
COST
£150–£400 per tank depending on size and access
indicative, checked 2026-08
WHO DOES IT
A qualified contractor
R10
LEGAL BASIS
Health and Safety at Work etc. Act 1974; Control of Substances Hazardous to Health Regulations 2002; HSE Approved Code of Practice L8.
Find a water tank cleaning specialist
Ask for a clean carried out to BS 8558, with a disinfection certificate afterwards.
Who this is for
Any venue with a stored cold water tank (as opposed to mains-fed only).
What you’ll hold
- Tank clean and disinfection certificate
Watch out for
- Only cleaning the tank when it looks dirty rather than on the schedule your risk assessment sets.
- No disinfection certificate kept — inspectors and insurers want evidence, not just a memory of it being done.
- Forgetting a tank exists because it is out of sight (loft, plant room) and nobody has looked at it in years.
Sources
- HSE — Legionnaires' disease and legionella checked 2026-09-02
See also
- Legionella risk assessment and control scheme— this becomes part of getting open →
- Legionella risk assessment review
This is item 53 of 60 in the free UK Compliance Calendar. See the whole list →