Legionella Risk Assessment in Tower Hamlets

Legionella bacteria thrive in water temperatures between 20°C and 45°C, in stagnant water, and where there is biofilm, rust, scale, or sediment providing nutrients. Systems most at risk include those with dead legs (unused pipe runs), infrequently used outlets, storage tanks without lids, and water systems where the hot water is not stored at 60°C or above. The assessment identifies these risk factors in your specific property.

There is no fixed legal frequency, but the HSE recommends reviewing the assessment at least every two years, or sooner if there is a change to the water system, the building use changes, the results of monitoring suggest problems, or a case of Legionnaires' disease is linked to the building. For higher-risk buildings such as care homes and hotels, annual reviews are standard practice.

The assessor examines all hot and cold water systems, including boilers, cylinders, storage tanks, calorifiers, showers, taps, and any associated pipework. They check water temperatures at sentinel outlets (nearest and furthest from the heat source), look for dead legs or rarely used outlets, inspect tank lids and insulation, review the system schematic, and assess whether current controls are adequate to prevent bacterial growth.

No. A risk assessment is an inspection-based evaluation of the water system's design, condition, and management, resulting in a written report with control recommendations. Legionella testing (water sampling) involves taking water samples and sending them to a UKAS-accredited laboratory to detect the actual presence and concentration of Legionella bacteria. Testing may be recommended by the risk assessment but is a separate service.

Yes. The HSE can prosecute landlords who fail to assess and control the risk of Legionella under the Health and Safety at Work etc. Act 1974. Prosecution cases have resulted in significant fines and, in cases involving death or serious illness, custodial sentences. Even where no illness occurs, failure to have a documented risk assessment is itself a breach that can lead to enforcement action.

Following the Grenfell Tower tragedy, Tower Hamlets — with its high concentration of tall residential buildings — has been a focus area for fire safety enforcement. The Building Safety Act 2022 applies to many blocks in the borough, and responsible persons face additional obligations around fire risk assessments (including Type 4 assessments for higher-risk buildings), external wall surveys, and fire door checks. The council's enforcement activity in the private rented sector is also among the highest in London. The general legal requirements for legionella risk assessment apply across England, but London Borough of Tower Hamlets may have additional conditions attached to property licences or local enforcement priorities that affect how the requirements are applied in practice.

Tower Hamlets is one of London's most densely populated boroughs, characterised by high-rise residential blocks, modern apartment towers in Canary Wharf and the Isle of Dogs, Victorian terraces in Bow and Mile End, and a large social housing stock across Bethnal Green, Stepney, and Poplar. Development has been rapid over the past two decades, with thousands of new-build flats added in tall buildings across the borough. The prevalence of high-rise living means fire safety compliance is a particular focus. Common property types that require this service include high-rise residential towers, modern Canary Wharf apartments, Victorian terraces in Bow and Mile End, social housing blocks. The specific requirements depend on the property type, tenure, and how the building is used.