Risk Assessment and Legionella Control Legislation

Housing Associations and Private Letting Agencies have a responsibility to their tenants to prevent legionella bacteria in their water systems. The Approved Code of Practice “Legionnaires’ disease -The control of legionella bacteria in water” (ACoP L8) outlines how to control legionella bacteria in water systems. This is a free download which has been published by HSE HSG 274 Part 2

However, in some cases, legionella bacteria is not considered a  serious problem and this has lead to legionella risk assessment and monitoring has been overlooked.

Legionella control should be treated as seriously as annual gas checks as they are both a legal requirement.

At the recent Heating and Ventilation Conference the HSE specifically said they were targeting Landlords of Housing Associations and Private Letting Agencies to ensure that their duties under ACoP L8 was being addressed.

Landlords need to carry out legionella risk assessments on properties. These risk assessments must provide details of monitoring, remedial and disinfection work required. The tenants should also be supplied with specific instructions for legionella control.

Legionella Risk Assessment

The Duty Holder must ensure that a suitable and sufficient legionella risk assessment is carried out. They must also ensure the competency of the person who carries out this task. The responsible person can help him to carry out this task.

The HSE advise that findings do not need to be recorded if there are less than five people living at the property but it may be advisable for your own records.

Housing associations who hold a large housing stock can have a rolling programme of work to carry out assessments. This could be, for example 10% of the houses each year on a ten year programme. A number of housing associations carry out the legionella check at the same time as the annual gas check.

Legionella Remedial Work

The legionella risk assessment can find that you have a low risk system, for example, a direct mains system with a combi boiler. There is  minimum maintenance associated with this type of  system. However, if the system changes the legionella risk assessment should be reviewed.

However, there maybe an old cold water tank in place and this ideally should be removed. Alternatively, the tank must be upgraded to meet the current water regulations. It should also be cleaned and disinfected at this time.

There may also be deadlegs in properties such as old supplies to washing machines, and redundant outside taps that should be removed to prevent water stagnation.

Legionella Monitoring

It is advisable for your tenant to carry out the following monitoring

1) Clean and disinfect the shower on a quarterly basis. This can be done using an Huwa-San TR3 (soft water) or SAFESOL descale and disinfect  DD1(hard water) spray.

2) Flush through outlets, without creating aerosols, if their property has been vacant for over a week for example  if they have been on holiday or in hospital.

3) Ensure that their water heater temperature is maintained. If there is an immersion heater in place the thermostat should be set at 60°C and the tenant should not alter this. The tenant should also inform the landlord if they notice changes to their hot water temperatures.

Vacant Properties

There must be a suitable weekly flushing regime in place for all vacant properties. Alternatively dose the system with Huwa-San as this will keep the water sweet for 6 weeks.


 As part of the risk assessment it should be ensured that the water storage tanks and water systems are clean and free from bacteria. A simple and cost effective way to disinfect cold water storage tanks is using Huwa-San TR3.

As the disinfection process using Huwa-San is extremely simple. Housing Associations or private landlords can use their direct labour force, with appropriate training, to carryout disinfections. This will reduce costs and the use of external labour.

These disinfections can be carried out quickly with minimum disruption to tenants who can still use the water during and after the disinfection. It would also be possible to carry out disinfections when carrying out a legionella risk assessment.

SAFESOL can provide training courses in legionella control and tank disinfection using Huwa-San. We can also advise on appropriate monitoring regimes to help keep your tenants safe. Please do not hesitate to get in touch if you require more information and advice. Either contact us through our contact page or phone on 0191 447 8008 or email on info@safesol.co.uk. We would love to speak to you.