Legionella risk assessment for Hospitals
Updated 16 August 2026
Key points
- A legionella risk assessment is required for hospitals premises under the Health and Safety at Work Act 1974 and the Approved Code of Practice L8
- Typical cost: £800 to £3000
- Review every 6 months, or sooner if the water system, its use, or the people using it change
- A named duty holder (usually the employer, landlord, or building operator) must arrange it and act on its findings
Hospital water systems are among the most complex and highly regulated in any building type. The NHS technical standard HTM 04-01 sets out requirements that go significantly beyond ACOP L8, because hospital patients include the most immunocompromised population anywhere: transplant recipients, people on chemotherapy, premature neonates, and elderly patients with chronic respiratory disease. A single nosocomial case of Legionnaires' disease in a hospital can be fatal and will trigger a Public Health England or UKHSA investigation.
The scale of the system makes management a full-time job. A typical district general hospital has miles of pipework, multiple calorifiers, dozens of cold water storage tanks, thousands of outlets, and specialist water systems for dialysis, hydrotherapy, endoscopy, and theatres. Every one of these has its own control regime. Most hospitals run a formal Water Safety Plan with a Water Safety Group chaired by the Authorising Engineer (Water) and attended by estates, infection prevention, and clinical leads.
Cost and review frequency reflect this complexity. Annual reviews are rare because the scale of the system means elements are being reassessed on a rolling basis throughout the year.
Is it legally required?
NHS hospitals are bound by HTM 04-01: Safe water in healthcare premises as the technical standard, alongside the general duties under the Health and Safety at Work Act 1974 and ACOP L8. Private hospitals are regulated by the CQC and follow the same technical standard. The NHS England Water Safety Alert system issues specific requirements in response to identified risks.
Who is the duty holder?
The duty holder is whoever has control of the premises or the water system. For hospitals premises, this is usually the employer, owner, landlord, or managing agent. The duty cannot be contracted out: you can hire a water hygiene consultant, but the legal responsibility still sits with you.
If you are unsure who holds the duty for your premises, see: Who is responsible for a legionella risk assessment?
What the assessment should cover
ACOP L8 sets out five things a suitable and sufficient assessment must do:
- Identify and assess sources of risk across the whole water system, including stored hot and cold water, dead legs, rarely used outlets, and any equipment that generates aerosols
- Produce a written scheme for preventing or controlling the risk, with specific tasks, temperatures, and frequencies
- Implement, manage, and monitor the scheme in practice, not just on paper
- Keep records of the assessment, the scheme, monitoring results, and any remedial action taken
- Appoint a competent person (often called the "responsible person") to be accountable for the scheme
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
Specific water system risks to check
For hospitals premises, assessors typically pay close attention to:
- Hot water storage temperatures (calorifiers must reach 60°C throughout)
- Hot water distribution temperatures (50°C within one minute at outlets)
- Cold water storage tank condition, lid seal, and temperature (below 20°C)
- Dead legs, redundant pipework, and little-used outlets
- Shower heads, flexible hoses, and thermostatic mixing valves
- Any cooling tower, evaporative condenser, or spa pool (these are notifiable to the local authority under the Notification of Cooling Towers and Evaporative Condensers Regulations 1992)
How often to review
There is no fixed legal interval, but ACOP L8 requires that the assessment is reviewed regularly and whenever there is reason to believe it may no longer be valid. For most hospitals premises, that means at least every 6 months and sooner after any of the following:
- Changes to the water system (new pipework, fittings, equipment)
- Changes to the use of the building or the number of occupants
- A positive legionella test result or a case of Legionnaires' disease linked to the premises
- Prolonged periods of low occupancy or system shutdown (a risk during holidays, term breaks, or refurbishment)
- New guidance from HSE
Typical cost
A professional legionella risk assessment for hospitals premises typically costs between £800 and £3000, depending on the size of the building, the number of water outlets, and whether there are any cooling towers or evaporative condensers (these add significantly to the cost because of the statutory inspection regime).
Use our cost calculator for an estimate based on your specific water system.
Need a legionella risk assessment for your premises? We will be partnering with Legionella Control Association registered providers shortly.
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.