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020 4532 7773The start of a new year is one of the most practical moments for anyone responsible for a commercial building to review their water safety obligations. Contracts get renewed, maintenance schedules get reset, and compliance documentation often gets its annual review. For building managers and duty holders, that makes January an ideal time to confirm that Legionella control measures are in place and that the water systems under their care meet the requirements of ACOP L8.
This guide sets out what ACOP L8 actually requires, what the common gaps look like in practice, and what building managers in London should have in place heading into 2026.
ACOP L8 is the Approved Code of Practice published by the Health and Safety Executive that sets out the practical requirements for controlling Legionella bacteria in water systems. It applies to anyone who has responsibility for a building where water is stored or distributed, including employers, landlords, building owners and facilities managers.
The code covers hot and cold water systems, cooling towers, evaporative condensers and other systems where water is heated, stored or recirculated. For most commercial buildings in London, the primary concern is the hot and cold water system, which includes storage tanks, pipework, outlets and any associated equipment.
ACOP L8 does not stand alone. It sits alongside the Health and Safety at Work Act 1974, the Control of Substances Hazardous to Health Regulations 2002, and the specific technical guidance document HSG274, which provides more detailed guidance on particular types of water system.
Under ACOP L8, the person responsible for managing Legionella risk is referred to as the duty holder. In most cases this is the employer or the person who has control of the premises. Where a building is managed by a facilities team or a managing agent, the duty holder responsibility may sit with them rather than with an individual tenant.
One of the most common misunderstandings around ACOP L8 is the assumption that responsibility automatically falls to someone else. Tenants assume the landlord handles it. Landlords assume the managing agent has it covered. Managing agents assume it is part of a wider facilities contract. In practice, the duty is attached to whoever has overall control of the water system, and that needs to be clearly identified and documented.
If you are not certain who the duty holder is for your building, clarifying that at the start of 2026 is a worthwhile first step.
The starting point for ACOP L8 compliance is a Legionella risk assessment. This is a formal evaluation of the water systems in a building to identify whether conditions exist that could allow Legionella bacteria to develop and what controls are needed to manage that risk.
A risk assessment should be carried out by a competent person and should cover the full extent of the water system, including any storage tanks, pipework, outlets, dead legs and any areas of the system that may be prone to temperature fluctuations or low use. The findings should be documented, and the documentation should be kept and updated as the system changes.
A risk assessment is not a one-off exercise. ACOP L8 requires that assessments are reviewed regularly, and specifically whenever there is reason to believe the current assessment may no longer be valid. That includes changes to the building, changes in occupancy, or any indication that the water system is not performing as expected.
Our Legionella risk assessment service covers residential and commercial properties across London, with same-day assessments available for properties where an urgent review is needed.
Once a risk assessment has been carried out, the findings feed into a water safety plan. This is the documented set of controls and procedures that the duty holder puts in place to manage Legionella risk on an ongoing basis.
A water safety plan for a typical commercial building in London would normally include the temperature monitoring regime for the hot and cold water system, the flushing schedule for infrequently used outlets, the inspection and cleaning programme for any cold water storage tanks, the procedure for managing periods of low use or vacancy, and the records of any remedial work that has been carried out.
The plan needs to be practical and proportionate to the size and complexity of the building. A small office with a simple direct water system will have a much lighter plan than a large mixed-use development with multiple storage tanks and a complex distribution network.
In practice, there are a handful of issues that come up regularly when buildings are reviewed for ACOP L8 compliance. Being aware of them makes it easier to check whether they apply to your property.
Outdated or missing risk assessments are the most common issue. Many buildings have had a risk assessment carried out at some point but have not had it reviewed since, even though the system or the occupancy has changed significantly.
Cold water storage tanks that have not been inspected or cleaned in several years are also frequently identified as a problem. Tanks with poorly fitting lids, signs of corrosion or sediment build-up, or water temperatures that are not being checked are a recurring finding.
Dead legs and redundant pipework are another common issue, particularly in older commercial properties that have been refurbished or reconfigured over the years. Sections of pipework that are no longer in use but remain connected to the live system can harbour stagnant water and should be removed or properly managed.
Finally, a lack of documented records is something that affects many buildings. Even where good practical controls are in place, the absence of records means there is no evidence that the duty of care is being met.
If any of the gaps above sound familiar, the start of the year is the right time to address them. A fresh Legionella risk assessment will give you a clear picture of where the system currently stands and what actions are needed. From there, the water safety plan can be updated and the monitoring and maintenance programme put in place.
At London Water Treatment, we work with commercial and residential clients across London to support full ACOP L8 compliance. Our services cover Legionella risk assessments, water tank cleaning and inspection, chlorination and water sampling and testing, giving building managers a single point of contact for their water hygiene requirements.
To arrange a Legionella risk assessment or to discuss your water safety obligations for 2026, contact our team today. Call us on 020 4532 7773 or visit our Legionella services page for more information on what we cover.
