Is there a Legionella risk in your property?

Gregg Masters, Head of Client Services at 4site Consulting explains what you need to know.

Evidence suggests that Legionella, as a Health & Safety hazard within residential property, is generally considered by RMC Directors and others as a low risk, low priority issue.  In terms of Health & Safety compliance it tends to feature well down the pecking order, and can get forgotten amongst the ‘high profile’ Health & Safety issues such as Fire and Asbestos.  It would, however, be a mistake to underestimate the potential consequences of ignoring the issue.

Legionnaires disease is potentially fatal and can be contracted through inhalation of contaminated airborne water droplets that can be produced from systems where water is stored.

A source of Legionella bacteria growth can occur in any water system given the right environmental conditions.  It is reasonable to foresee a Legionella risk in your water systems if: -

  • There is stored water or the water is re-circulated as part of your system.
  • If any stored water in part of or in all of your system has a temperature of between 20-45°C.
  • There are deposits such as sediment, rust, scale, sludge or organic material within the parts of the system, for example in your Cold-Water Storage Tanks.
  • Where it may be possible for water droplets to be produced and dispersed, such as showers, fountains, taps etc. and where anyone can be exposed to the droplets.
Legionella Risk

You need to be aware that if your property has communal water systems which serve more than one property then you will need to determine if there is a risk from Legionella.  Legionella bacteria is usually found in stored water systems where water is left dormant and at a temperature that allows it to proliferate.  There is a greater risk of contracting Legionnaires’ disease when anyone is exposed to contaminated airborne water droplets.  The infirm and elderly are particularly at risk.

Although not always the case, most residential properties built in recent years, tend to have direct feed water systems, which means that there are no water tanks or stored water systems installed.  If this is the case there is no need for a Legionella risk assessment or on-going management. 

Legionella Q&A’s

Why do I need to worry? Because RMC’s and anyone who is in control of a property and who have Health & Safety responsibilities for others, have a legal duty to manage any risk of exposure to Legionella. 

Where is there a risk? Usually from a water system that serves multiple residential properties. These are properties where stored water systems are communal (serving more than one demise). Sometimes communal fountains can be a source of risk.

What do I need to do? You need to have your water system risk assessed for Legionella and, where recommended, take action to control or eliminate any risks identified. It is a requirement to identify and assess any source of Legionella risk and then to control and manage any risk identified.

When should the I have the risk assessment done? A Legionella risk assessment should be carried out as soon as possible. If there are any risks identified, then regular subsequent risk assessments and on-going monitoring and management may be required.

What is on-going monitoring and management? If the risk assessment identifies the need for on-going monitoring and management then you will need to ensure that your water system is regularly checked by a competent and qualified Legionella risk assessor.  This may entail quarterly or six-monthly inspections, water testing and temperature checks.  You will need a log book so that the results of the tests etc. can be recorded and reviewed when required. The log book should contain a simple schematic drawing of the system and your contact details.

Who should I ask to carry out the risk assessment? Employ a competent Legionella risk assessor or reputable independent company to carry out the Legionella risk assessment and provide advice and support for the on-going management of any risk identified.  Try to avoid using Water Treatment or Water Service Contractors for the risk assessment. These companies specialise in remedial works and may not provide truly independent assessments and recommendations.

Legal requirement

Carrying out a Legionella risk assessment and ensuring it is up to date is required under Health & Safety Law and is a key duty when managing the risk of exposure to Legionella bacteria.  Additional duties include the on-going management and monitoring of any risk. More information can be found on the HSE web site 

Manage your report

Last but certainly not least you should manage your risk assessment report. Many have fallen foul of the belief that just by holding a current risk assessment report somehow fulfils the inherent duties and mitigates liability. This is a dangerous misconception that has led to serious incidents and heavy fines.

All you need to do is read the document and action any points in order of their priority. A good risk assessor writes their report concisely, providing short, useful & informative action points including plenty of photographs. Managing your reports should be easy. Avoid a tick-box style risk assessment and never be afraid to ask the assessors questions: no risk assessor should ever provide advice without having the competency to fully explain their findings and recommendations to you.

Risk Assessment is only the beginning of the process and a good Risk Assessment will be your instruction manual that opens the doors to a measured decrease of your liabilities and will lead to a safer communal water system in your property.

4site Consulting Limited is an independent Health & Safety Consultancy providing a range of specialist compliance and risk management services for owners, occupiers/tenants and managers of residential blocks & commercial property.