Swimming Pool Risk Assessment: A UK Guide for Service Engineers

If you service commercial or shared-use pools — leisure centres, hotels, holiday parks, schools, swim schools — a written risk assessment is not an optional extra. It is the document an HSE inspector, an insurer, or a coroner will ask for first when something goes wrong. As the service engineer, you are often the person whose records and on-site judgement feed directly into that assessment.

This guide explains what a swimming pool risk assessment is, who is legally responsible for it, what UK guidance expects it to cover, and how your service records support it.

Is a Swimming Pool Risk Assessment a Legal Requirement?

There is no single "swimming pool licence" or "pool operator licence" in Great Britain — no statutory scheme you register for to run a pool. What does apply is general health and safety law, and that law requires a risk assessment.

The duty comes from two main places:

• The Health and Safety at Work etc. Act 1974 (HSWA) places a general duty on employers and those in control of premises to protect the health and safety of employees and anyone else affected by their work — which includes pool users.
• The Management of Health and Safety at Work Regulations 1999 require a "suitable and sufficient" assessment of the risks. Where an employer has five or more employees, the significant findings must be recorded.

For the water-quality and chemical side, the Control of Substances Hazardous to Health Regulations 2002 (COSHH) add a specific duty to assess and control the risk from hazardous substances — both the pool chemicals you handle and biological agents such as Legionella.

So while no one issues you a pool licence, the risk assessment itself is a legal obligation that flows from these duties. Skipping it is not a paperwork shortcut — it is a breach of health and safety law.

What HSG179 and PWTAG Expect

The two reference documents you will be measured against are both non-statutory but treated as the benchmark of good practice:

• HSE HSG179 — Health and safety in swimming pools (4th edition, 2018; last updated February 2024). This is HSE's main guidance for everyone involved in operating and managing swimming pools. It sets out the measures to take to reduce risks and comply with the law, and it is the document inspectors expect a pool operator to have worked from.
• PWTAG (Pool Water Treatment Advisory Group) publishes the Code of Practice and technical notes covering water treatment, testing, and plant operation. PWTAG guidance is not law, but it is the recognised industry standard for the water-quality elements of the assessment.

Following these does not, on its own, discharge the legal duty — but a risk assessment that ignores them is hard to defend. They give you the structure and the parameters to assess against.

Who Is Responsible — Operator or Engineer?

The legal duty holder is the pool operator — the employer or the person in control of the premises. That is your client, not you.

But the line blurs in practice. You are usually the person with the technical competence on water chemistry, plant operation, and microbiological risk. A well-run arrangement makes that explicit:

• The operator owns the risk assessment, the pool safety operating procedures, and the overall management of the site.
• The service engineer provides competent advice, carries out testing and dosing, maintains the plant, and produces the records that evidence the controls are working.

If you are servicing a site without a documented risk assessment in place, flag it in writing. Your service records are part of the operator's compliance evidence — but they do not replace the operator's own assessment.

Hazards a Pool Risk Assessment Should Cover

A pool risk assessment is broader than water chemistry. The main hazard categories an HSG179-aligned assessment covers include:

Water quality and microbiological risk

• Disinfection failure (free chlorine outside the PWTAG operating range)
• Cryptosporidium, E. coli, and other waterborne pathogens
• Legionella in associated systems (showers, spa pools, balance tanks) — see the spa-pool section below

Chemical handling (COSHH)

• Storage, dosing, and handling of chlorine-based products, acids, and alkalis
• Risk of mixing incompatible chemicals (the classic acid-plus-hypochlorite chlorine-gas hazard)
• Personal protective equipment and spill procedures

Plant and equipment

• Filtration and circulation failure
• Automated dosing system malfunction
• Electrical safety in a wet environment

User safety

• Drowning and the level of supervision required
• Slips, trips, and pool-surround surfaces
• Water depth, signage, and access for the pool's user group

Records and competence

• Whether the people operating the plant hold a relevant pool plant operator qualification
• Whether testing and treatment records are kept and reviewed

Spa Pools and Hot Tubs: A Separate Assessment

If the site includes a spa pool or commercial hot tub, it needs its own Legionella risk assessment. Spa pools generate aerosols at temperatures within the Legionella growth range (20–45°C), which makes them a higher-risk system.

The duty to assess and control Legionella sits under HSWA and COSHH, with the Approved Code of Practice L8 and the technical guidance HSG274 setting out how. For spa pools specifically, HSE's HSG282 — Control of legionella and other infectious agents in spa-pool systems is the document to work to. It applies to commercial and business-use hot tubs, including those in holiday-park rental units and hotel bedrooms.

We cover this in detail in our hot tub water chemistry guide.

How Your Service Records Support the Assessment

A risk assessment is only credible if the controls it relies on are demonstrably working. That is where your records come in. The assessment says "free chlorine is maintained within the PWTAG operating range"; your testing log is the evidence that it actually was, visit after visit.

Records that strengthen a pool risk assessment include:

• Dated water chemistry readings (free and combined chlorine, pH, and the other PWTAG parameters)
• Actions taken when a reading was out of range
• Microbiological sampling results for spa pools
• Plant checks and any remedial work

Paper round sheets and notebooks make this fragile — readings get lost, handwriting is illegible, and reconstructing a history for an inspection is painful. A structured digital log keeps the trail intact. Our free PWTAG water testing log template gives you a compliance-grade format to start from.

Practical Steps

1. Confirm the operator has a written risk assessment. If not, advise them — in writing — that one is legally required.
2. Scope it to the site. A school pool, a hotel spa, and a holiday-park splash pool have different hazard profiles.
3. Cover all five hazard categories above, not just water chemistry.
4. Assess spa pools separately for Legionella under HSG282.
5. Keep records that evidence the controls. Your testing and treatment logs are the operator's proof the assessment is being acted on.
6. Review it. A risk assessment is not a one-off — review after any incident, plant change, or change in how the pool is used.

PoolRound is being built to keep your water chemistry readings, dosing actions, and service reports in one place — so the records that back up a client's risk assessment are always to hand. If that would help your round, join the waitlist.

Sources

• HSE HSG179: Health and safety in swimming pools (4th edition, 2018) — main HSE guidance for pool operators
• Health and Safety at Work etc. Act 1974 — general duty of care
• Control of Substances Hazardous to Health Regulations 2002 — chemical and biological agent risk
• HSE L8: Legionnaires' disease — Approved Code of Practice
• HSE: Spa-pool systems — HSG282
• PWTAG Code of Practice — UK industry water-treatment standards