Legionella control in public sector buildings

In this article, the Legionella Control Association (LCA) explains why effective water management is essential and outlines the legal responsibilities of those managing buildings

In summer 2023, the Bibby Stockholm Barge hit the headlines for all the wrong reasons when traces of Legionella bacteria were found in the on-board water system. This was an embarrassment for the government at the time, but not entirely unexpected by “those in the know” given the size of the vessel and the low levels of occupancy (and hence, water use). Though no one contracted Legionnaires’ disease, the publicity was very damaging as these type of situations often are, but they can also sometimes result in prosecutions such as during 2024 when UK Health and Safety Executive (HSE) took two separate actions, one against Vincent Naughton Court sheltered housing accommodation in Birkenhead following discovery of the bacteria in their water and their failure to manage the risks of exposure, as well as a second against Amey Community Ltd who were the facility management company involved at HMP Lincoln when one of their inmates died from Legionnaires’ disease.

Background 

Legionnaires’ disease is a potentially fatal form of pneumonia, first identified in summer 1976 following an outbreak of an unknown infection at a convention of the American Legionnaires in Philadelphia. The causative bacteria was identified early the following year and since then, more than 60 species of the bacteria have been identified. These bacteria are widespread in nature so are often able to enter water systems at low levels (>10 per cent of water samples tested return a positive result for legionella bacteria), and presence of any of them in a water system could be indicative of a situation where there is a risk that it is not being adequately controlled. Exposure to this risk occurs when the water system is then able to create small droplets that could be inhaled by susceptible individuals. Correct management of these situations is therefore essential and there are legal implications if employers or businesses fail to manage these risks.

Applicable legislation

In most situations, there is an obligation on the employer to keep people safe and this stems from the Health & Safety at Work etc. Act (1974). This is further reinforced by supporting regulations that identify specific risks, and in this instance, as legionella is considered a hazardous substance, it falls under the Control of Substances Hazardous to Health (COSHH) Regulations (2002). Among other things, COSHH requires the employer to: understand the risk of exposure to any hazardous substance (including legionella); where a risk is identified, consider elimination, but if this is not possible, ensure suitable controls are put in place; and ensure that the identified controls are implemented and checked to ensure they are working correctly.

As legislation is sometimes considered “complicated”, UK HSE produce an “Approved Code of Practice” for legionella management (known as ACoP L8) that identifies what legislation applies and how to comply. The ACoP is further supported by a series of system specific technical guidance documents providing practical advice for systems known to be a likely legionella risk. These are known as the HSG274 parts 1-3 and they cover evaporative cooling systems (part 1), hot and cold water systems (part 2) as well as many other types of industrial water systems (part 3).

ACoP L8 specifies the “high level” legal requirements of: identification of risk; creation of a suitable prevention or control scheme; implementation of the scheme including checks to manage effectiveness; and an appropriate management structure to ensure all tasks occur including a person in overall control of the scheme and an effective record keeping system to enable easy understanding of risk management.

In addition, within the ACoP, paragraph 59 identifies factors that can lead to bacterial growth, which in turn can provide a structure for control strategies by avoiding these situations. To paraphrase the ACoP, attention should be given to: avoiding water temperatures between 20 °C and 45 °C as this is where legionellae are most likely to grow; avoiding water stagnation as this provides time (and location) for the bacteria to grow; avoiding the use of materials of construction that can act as a nutrient or environment where the bacteria could grow; and minimising (or containing) droplet creation (where possible) to avoid exposure. There should also be actions aimed at keeping water systems clean as any build ups can provide ideal nutrients and environment for growth; using an appropriate water treatment technique where necessary (chemical dosing, temperature maintenance, filtration etc) to actively reduce bacterial populations; and having action plans for if problems are identified.

The intention of the ACoP isn’t that all of the above can be applied in all situations, but rather to identify controls that can reduce risk but if there are aspects that cannot be met, this might elevate the risk and greater attention should be given to alternative efforts.

Risk to public buildings

The past 10 years have seen a seismic shift in how buildings and workplaces operate. Working from home, fewer staff, water-saving efforts etc. have all meant that systems that were perhaps installed when the building was built, may now not be aligned with current building use and risk management. If we compare the effect of all the above influences on water use today, we might find that we now have oversized tanks, pipework with no flow, temperatures that are no longer achieved, taps or showers that no longer used etc. Even if we have removed items that are no longer in use, have we left redundant pipework behind walls or under floors? This then leads to the question of whether our strategies of control have changed to reflect the way our building and water use has changed? 

The first step will always be to identify that there are systems that might present a risk (and almost all buildings will have them…) as this will trigger the need to manage this and follow the steps laid out in the ACoP (assess, control, manage etc). 

Legionella Control Association (LCA)

You don’t have to tackle this alone, however. There are many organisations out there that can assist with this and an excellent first point of call would be to refer to the Legionella Control Association (LCA) which has ~400 members who are legionella control specialists and have committed to comply with and be audited against the LCA Code of Conduct. This Code is highlighted in Paragraph 83 of ACoP and explains what standards a service user should expect. The Code itself has 28 requirements that must be followed in all cases, plus specific Service Delivery Standards for the eight key Legionella control service areas. 

The need for consistent management procedures is emphasised and all audits focus on evidence that this is in place in all provided services. Where we find a member’s performance lacking, either at audit or as part of a complaint to us, they can face sanctions or even removal from the association unless improvements are made. 

Summary

Legionnaires’ disease is potentially fatal but is preventable with the correct, often simple measures.  Employers and those in control of premises have a legal duty to ensure risks are identified and controlled. It is not necessary for there to be a death or case of disease for a successful prosecution and these can result in hefty fines and custodial sentences. If your water system exposes individuals to risk of harm, you are committing an offence.

www.legionellacontrol.org.uk