General Legionella FAQ 

  • What measures can our business take to reduce the risk of Légionnaires’ disease?

The first step would be to undertake a Legionella Risk Assessment. The Risk Assessment will provide a basis for how the risk from legionella is to be managed and provide suggested remedial actions for areas of concern

  • Is Legionnaires disease dangerous?

The short answer is Yes. Legionnaires disease is a potentially fatal form of pneumonia, caused by the legionella bacterium. Where the conditions are right, they will multiply into harmful numbers which can then cause infection

  • Where does Legionnaires disease come from?

Legionella bacteria can be found in natural water such as rivers, lakes and streams. Small numbers of these bacteria are present in mains water (even after treatment by the water authority), and these can enter man-made water systems. Given the right conditions, legionella bacteria will multiply and pose health risks to end users

  • What formal accreditations Do you hold? (Are you members of LCA?)

Envrioliance are members of the Legionella Control Association (LCA), the UK industry body which provides certification for companies involved with legionella management. The LCA issues certification to those companies that can demonstrate they are able to undertake legionella management within water systems over a wide range of disciplines, in accordance with the LCA Code of Conduct and Service Provider Commitments

  • Do I need a legionella risk assessment?

A legionella risk assessment is a statutory obligation placed upon business owners and those who own or run premises, under the requirements of the Health and Safety at Work Act 1974. You have a legal duty of care to minimize the risk posed by legionella to employees and members of the public

  • What is a Water Systems Logbook?

A Water Systems Log Book provides the framework for how legionella is to be managed in domestic water systems on a day-by-day basis. The logbook details the required inspections/testing as recommended within the ACoP L8, HSG 274 and other applicable guidance. The log book allows the user to record the monitoring activities undertaken and highlight areas of concern where remedial actions may be required

  • When and how often do I need a risk assessment?

The ACoP L8 states that a risk assessment needs to be reviewed regularly and whenever there is a reason to suspect it is no longer valid. Potential reasons for a Risk Assessment no longer being valid are:

    • A significant change to the water systems – for instance the installation of a new hot water systems, cold water storage tanks or the fitting of new water services which may increase the potential for legionella infections (eg new shower installations)
    • A change to the building use and/or occupant susceptibility (older people are significantly more susceptible than the young)
    • The primary method for legionella control has changed (for instance in systems where temperature was the primary control, and has now been replaced by a chemical control method)
  • How long will the legionella risk assessment take?

This largely depends on the size of the building or buildings and the complexity of the systems. Enviroliance will provide estimated times for the completion of the on-site works taking this into account.

Following the onsite survey, Enviroliance will produce a formal written assessment detailing all findings and recommendations.

  • What are the main legionella regulations In The UK?

The Health and Safety at Work Act 1974 and COSHH regulations are the main drivers for legionella regulations in the UK. The Approved Code of Practice L8 and HSG 274 Parts 1, 2 & 3 provide guidance on how water systems should be managed in order to minimize the risk posed by legionella

  • How do I ensure my business is Legionella Compliant?

You should ensure that you have a robust legionella control programme in place. This includes and up-to-date risk assessment, log book for monitoring and maintenance purposes and a Written Scheme which defines how you will manage the risk from legionella.

  • Do You offer Legionella awareness training?

Yes, Enviroliance offers half and full day legionella awareness courses, designed to give those who are involved with the day-to-day management of legionella within buildings, the knowledge they require to undertake their duties to the required standards

  • What Does Legionella Need to thrive?

Legionella bacteria will multiply wherever the conditions are right. Legionella grows best at 37˚C, whilst the growth range is between 20˚C and 45˚C. Water temperatures below 20˚C, and between 46˚C and 50˚C, can survive but does not multiply. Temperatures above 50C begin to kill legionella.

Legionella also needs a nutrient source. Silts, sludges, organic material and rust can all provide a suitable food source for legionella

Biofilms in water systems provide an ideal growth medium for legionella, as well as protecting the bacteria from normal water flow and disinfectant chemicals

Stagnation in water systems should be avoided, as this is where temperature and biocidal controls are likely to be least effective, as well as promoting biofilm formation

  • How often do Cold Water Storage Water Tanks Need Cleaned and disinfected?

Your current Legionella Risk Assessment will identify the recommended frequency of Cleaning and disinfecting your cold water storage tank. This will depend on the level and type of contamination and risk profile of the building’s users


Water Sampling / Assessment FAQ

  • Do I need to carry out Legionella Testing?

You should carry out legionella sampling wherever there is cause to suspect legionella bacteria may be present. These include water systems where the primary method of control has failed (e.g. temperature control), systems which remain unused for extended periods and wherever a case of legionnaires disease has been detected or suspected

Legionella sampling should form part of the control regime in certain “high-risk” environments, such as healthcare premises (Hospitals, Care Homes)

In addition, legionella sampling provides added reassurance that the legionella control regime in place is effective at controlling the risk

  • What types of water systems do you sample?

We sample Hot and Cold water systems within all types of buildings including retail units, Hospitals and Schools. We are interested in identifying any bacteria within the water samples that are collected including Legionella, E.coli and other indicator organisms that can be harmful to the building population.

We also sample closed systems such as heating and chilled systems. In these samples we analyse for levels of inhibitors, biocide, bacteria and other contaminants that can cause damage over time to the systems assets due to corrosion.

  • Why should you carry out routine water sampling?

Routine legionella water sampling is recommended as a measure of the efficacy of the legionella control regime. In addition, monitoring for other potentially harmful bacteria may be appropriate dependant upon the situation. Enviroliance can provide guidance with respect to legionella/bacteriological sampling which would best suit your particular scenario

Please get in touch today if you have any queries or questions relating to services.