Legionella risk assessment for Gyms and fitness centres

Updated 7 September 2026

A gym's legionella risk is concentrated almost entirely in the wet side of the building. The changing-room shower block is used by dozens or hundreds of people a day, each shower throwing a fine aerosol into a warm, humid room, which is precisely the exposure route that matters. The upside is that heavily used showers rarely stagnate; the downside is that they scale up fast, and a scaled, biofilm-coated shower head in constant use is a daily aerosol source. Descaling and disinfecting shower heads and hoses on a documented schedule is the single most visible control in a gym.

The risk assessment should map the less obvious outlets as well as the busy ones: the poolside or sauna-area showers used intermittently, the disabled-access shower that may see occasional use, the staff shower in the plant room, the jacuzzi or spa pool if one is fitted, and any steam room with a cold drench or experience shower. A spa pool changes the regime entirely, because it brings the site within HSG282 and demands daily water-quality checks, filter management and documented dosing, not just the domestic-system controls. Many gyms that install a hot tub as a membership perk underestimate how much more demanding that one asset is than the rest of the water system put together.

Where the gym is a single-let unit in a larger development, the assessment should also pin down who controls the incoming supply and any shared tank or booster set, because the landlord's common-parts system and the tenant's demise may each need their own scheme. A dry gym with no showers is a low-risk premises closer to an office, but the moment any outlet can spray, ACOP L8 applies in full and the controls need to be written down and recorded.

Is it legally required?

Gyms and fitness centres are commercial premises under the Health and Safety at Work Act 1974 and ACOP L8, with HSG274 Part 2 covering the hot and cold water system. Where a spa pool or hot tub is operated as part of the business, HSG282 applies as the controlling guidance for that system. As occupiers, gym operators also owe the section 3 duty to members and visitors, which is what brings the shower block within the duty even though its users are customers rather than staff.

Who is the duty holder?

The duty holder is whoever has control of the premises or the water system. For gyms and fitness centres 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:

1. 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
2. Produce a written scheme for preventing or controlling the risk, with specific tasks, temperatures, and frequencies
3. Implement, manage, and monitor the scheme in practice, not just on paper
4. Keep records of the assessment, the scheme, monitoring results, and any remedial action taken
5. Appoint a competent person (often called the "responsible person") to be accountable for the scheme

Specific water system risks to check

For gyms and fitness centres 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 gyms and fitness centres premises, that means at least every 12 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 gyms and fitness centres premises typically costs between £300 and £800, 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.