Legionella Risk Assessment

The HSE guidance document Legionnaires’ disease: The control of legionella in hot and cold water systems (HSG 274) states that

“all water systems require a legionella risk assessment but not all systems require elaborate control measures” (s.2.140)

…if a water system design does not present a high risk of legionella growth, the risk assessment report confirms this and can be used to demonstrate this, but it also gives guidance on how the risk of legionella can be controlled. Even where a system design is low risk, incorrect temperatures, low-usage, lack of maintenance and many other factors can raise the risk of legionella growth and exposure.

HSG 274 continues, “it is a legal duty to carry out an assessment to identify and assess whether there is a risk posed by exposure to legionella from the hot and cold water system or any work associated with it”. This guidance is enforceable under the Health & Safety at Work Act 1974 and COSHH Regulations 2002 (Control of Substances Hazardous to Health).

The legionella bacteria can survive and grow in any type of water system. Even the most simple water system, treated in a certain way, is capable of encouraging it’s growth.

The Approved Code of Practice: Legionnaires’ Disease: The Control of Legionella Bacteria in Water Systems L8, Fourth Edition (also known as ‘ACoP L8’) outlines the duties placed upon those in control of buildings in relation to management and control of legionella risks in their water systems. Duty holders are identified as residential and commercial landlords and those under the Health & Safety at Work Regulations who are responsible for the water systems within their premises.

The legionella risk assessment is one of the main criteria of each duty holder and ACoP L8 states that “the dutyholder must ensure that the person who carries out the risk assessment and provides advice on prevention and control of exposure must be competent to do so” (Section 28). It continues by advising “Inadequate management, lack of training and poor communication are all contributory factors in outbreaks of legionnaires’ disease. It is therefore important that the people involved in assessing risk and applying precautions are competent, trained and aware of their responsibilities.” (Section 50).

Legionnaires’ disease is contracted by inhaling water droplets which contain the legionella bacteria. It affects patients in different ways but can potentially be life-threatening and is a risk which can be avoided, or at least reduced significantly, in most situations. The legionella risk assessment helps duty holders to ensure they are compliant with the law and, more importantly, that users of the building are safer.

We try to calculate the approximate time the survey will take, and then factor in the writing up time and travel and, as we are a small family company, we do not add any more money than that. Midlands Legionella Control offer the lowest prices for all legionella risk assessments – and we guarantee to beat any written quotation from a recognised competitor.

We are based in Willenhall and work both locally and nationally. We carry out many legionella risk assessments in the Midlands, although we also offer our services nationally to all of the mainland UK and also have regular work in Devon, London, Dorset, Norfolk, Flintshire and Lancashire, giving us truly national capabilities.

The legionella risk assessment outlines 2 main areas:

Short-term remedial actions (ie, parts of the plumbing that would benefit from being replaced, removed or fixed). These actions will be prioritised in terms of risk factor and a timeframe will be set in place for them to be carried out;
An ongoing control regime (ie different tasks – to be performed at different times of the month or year to help reduce the risk of legionella growth within the water system and exposure to the bacteria for building users).

You will need to ensure your management regime and lines of communication are confirmed in accordance with the legionella risk assessment and then, if deemed necessary by the report, a written scheme of compliance should be compiled in accordance with HSG274.

Are residential landlords required to have legionella risk assessments?

Residential landlords are required to have in place a legionella risk assessment carried out by a competent person for each of their rental properties. The risk assessment report will advise on the risks (if any) presented by the design of the dwelling’s water system and explains what can be done by the tenant on a regular basis to limit any risks. It is important to make the ongoing recommendations available to the tenant in order for the risk assessment to be effective.

Legionella is a bacterium which exists and grows in any type of water – from lakes and rivers to domestic water systems. Legionella can cause susceptible people to contract Legionnaires’ Disease when they inhale water spores carrying the bacteria. In the correct conditions, legionella can proliferate at a rapid rate

The bacteria can be present at very low levels even in mains cold water but it is conditions which can allow it to survive or even thrive and grow (‘proliferate’) which must be avoided. Conditions such as stagnated water (water which doesn’t move), temperatures between 20°C-50°C and water which has sediment or other contamination can all aid the proliferation of legionella. Lack of use, inadequate temperatures in any part of the system (including the pipework) and contaminants can all contribute. Building users who are susceptible in any way to the bacteria can contract Legionnaires’ Disease by inhaling water spores carrying the bacteria – often by showers, spray heads, hoses, or air conditioning.

The legionella risk assessor will then begin to survey the outlets, pipework, boilers/water heater, pipework and showers. A detailed asset register will be compiled and the pipework will be traced. All areas and parts of the plumbing system which are deemed to be susceptible to the risk of legionella growth will be inspected and recommendations intended to reduce these risks will be made where appropriate. The legionella risk assessor will take close-up photographs of certain parts of the plumbing system, as required by ACoP L8, in order to help to more effectively demonstrate the risk areas.

Based upon the findings of the survey, the risks will be calculated and prioritised. A regime of control measures will be drawn up, which will include various procedures to be carried out at certain times of the week/month/year in order to control any legionella risks present. Where the property is a residential letting, there will be advice included to the landlord as to what they can do to the water system (design-wise) to reduce any legionella growth risks, as well as advice specific to that property intended to be given to the tenant to help them to reduce the risk of legionella growth on a day-today basis.