What is a water hygiene risk assessment?

As a business owner or landlord, it’s your legal responsibility to ensure the health and safety of all people on your premises, including visitors, residents, customers and staff. Risk assessments and maintenance will need to be undertaken for various parts of the building and your equipment, such as your on-site water facilities.

A water hygiene risk assessment involves the evaluation of your business’s water systems and recommendations to minimise health and safety risks associated with water hygiene. Businesses should also have a water safety plan that’s regularly reviewed and updated as part of these assessments. This plan should include the steps you’re taking to manage water risks identified in risk assessments.

Water hygiene risk assessments are a legal obligation, so it’s important that you fully understand what you need to do as a business owner or landlord. In this article, we’ll discuss your responsibilities, what a Legionella risk assessment is and what it involves, how frequently these assessments should be carried out, and who should be performing them.

Water hygiene risk assessments: your responsibilities

Although the Health and Safety Executive (HSE) doesn’t specify how often you’re legally required to undertake a water hygiene risk assessment, it’s generally recommended that you assess your water hygiene risk at least every two years to ensure that your water safety plan is still up-to-date. If you’ve recently changed any of your water systems, a new risk assessment should be carried out to assess the new risks associated with these systems.

Why do a water hygiene risk assessment?

Water hygiene risk assessments are needed due to potential microbial, physical and chemical hazards in water systems. Therefore, any building where people come into contact with water on the premises must be subject to water hygiene risk assessments to evaluate the risk of harm to the public.

Waterborne pathogens like Legionella, P. aeruginosa and E. coli are of particular concern, especially in healthcare settings where people are more vulnerable to these pathogens due to old age or illness. The high risk of Legionella pathogens in many water systems means that Legionella risk assessments are a major part of water hygiene risk assessments.

What is a Legionella risk assessment?

Legionella is a genus of pathogenic bacteria that can cause Legionnaires’ disease, which is a serious type of pneumonia. Legionnaires’ disease can be fatal and is particularly dangerous for older people, smokers, heavy drinkers and people with pre-existing medical conditions or illnesses.

Legionnaires’ disease is usually contracted by inhaling droplets of water that contain Legionella bacteria. This means that any water system that produces water droplets (e.g. showers, taps, pools, air conditioning systems, humidifiers) could be a potential Legionella hazard.

All buildings with water systems that could harbour Legionella bacteria must have a Legionella risk assessment as a key part of their overall water hygiene risk assessment. The legal requirements and guidance for these assessments are detailed in the following legislation:

• The Health and Safety at Work Act 1974
• The Management of Health and Safety at Work Regulations 1999
• The Control of Substances Hazardous to Health (COSHH) regulations 2002
• The Health and Safety Executive (HSE) Approved Code of Practice ACoP L8: “Legionnaires Disease: The Control of Legionella Bacteria in Water Systems”
• The HSE’s Health and Safety Guidance HSG274: “Legionnaires Disease Technical Guidance”
• BS 8580-1:2019 “Water Quality – Risk Assessments for Legionella Control – Code of Practice”

What does a Legionella risk assessment involve?

The methodology for carrying out a Legionella risk assessment is laid out and explained in the ACoP L8 document and the HSG274 document. The appointed Responsible Person, who can be a contractor or someone within the business who has full knowledge of the building’s facilities, will carry out this Legionella risk assessment. 

Here’s a quick explanation of all of the steps that must be included in the Legionella risk assessment:

1. An assessment of risk to staff, visitors or residents

Although Legionella could pose a threat to all people and must always be taken seriously, some groups are more at risk of death or serious health complications if they contract Legionnaires’ disease. For example, people over 45, smokers, heavy drinkers, those with chronic respiratory or kidney diseases, those with heart disease and anyone with a weakened immune system (such as cancer patients) will be particularly at risk.

This means that the level of risk will vary for different businesses or residential buildings. Settings such as hospitals and care homes will naturally contain higher risk individuals, so the risk assessment in these buildings must reflect the higher level of danger.

2. Details of management processes

The existing water safety plan must also be reviewed to ensure that it’s up-to-date with current Legionella risks. Who is responsible for managing Legionella risk, what is currently being done and will these processes need to be amended or updated to account for increases or decreases in overall risk?

3. Identification of roles and responsibilities

In the water safety plan, a Responsible Person must be appointed to oversee the day-to-day management of water hygiene and Legionella risk. Often, the Responsible Person will be someone within the business or the building’s management company who has in-depth knowledge of all the water systems installed on the premises.The plan should also include what kind of training they’ve had to educate them on Legionella risk.

There are no exact rules on who can be appointed to oversee the Legionella risk assessment, but the ACoP L8 does stipulate 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.” The Responsible Person can carry out the risk assessment if they’re sufficiently competent, or business owners could choose to hire contractors or a facilities management company to undertake the assessment.

4. Evaluation of your on-site assets and their condition

During the Legionella risk assessment, all water systems and assets on the premises must be inspected and evaluated for Legionella risk. High-risk systems are of particular concern, such as:

• Hot and cold water systems
• Cooling systems with cooling towers, evaporative condensers or dry/wet cooling systems
• Spa pools
• Showers and taps that aren’t used frequently or consistently

Lower risk systems, such as those that draw cold water directly from a wholesome mains supply (no stored water tanks), will still need to be assessed, but they may not need the same elaborate control measures as higher risk systems.

The assessor will need to determine if all pipes are adequately insulated and all water tanks are fully enclosed and undamaged to prevent the ingress of bacteria. They will also need to watch out for any stagnant water or deposits that can act as a source of nutrients for Legionella, such as sludge, rust, algae or other organic matter and biofilms. Systems will need to be maintained, cleaned and repaired to eliminate these risk factors, which can include removing dead ends in pipework and flushing out infrequently used systems on a regular basis to get rid of stagnant water.

To be effective, this evaluation must be in-depth and comprehensive. This means evaluating all parts of each water system, not just the higher risk areas like cooling towers. If Legionella were present in any part of the system, this could be a serious health hazard for anyone in the building. 

To show that all systems have been fully evaluated, the Responsible Person should take photographs of all system components. It’s also advisable to create a schematic diagram of all systems showing where the greatest risk is located.

5. Water temperature checks

In addition to poorly maintained water systems, stagnant water and organic matter in pipes and tanks, specific water temperatures can also increase the risk of Legionella pathogens. These pathogens thrive at temperatures between 20°C and 45°C, so storing water or operating water services at these temperatures can be very risky.

To mitigate this risk and ensure it’s as low as reasonably practicable (ALARP), you need to regulate the temperature of your hot and cold water systems. Cold water should be kept below 20°C in storage tanks and at outlets, and hot water should always be kept above 50°C. Legionella is dormant at temperatures below 20°C and it cannot survive at temperatures above 50-60°C.

Therefore, as part of your Legionella risk assessment, water temperature must be checked at all outlets and storage tanks. If the current temperatures are conducive to the survival and growth of Legionella, this must be rectified immediately.

6. Methods to control the risk of exposure

As briefly mentioned above, methods must be implemented to control the risk of Legionella exposure as soon as hazards are identified. The Legionella risk assessment must lead to the introduction of new safety measures if necessary and also evaluate the efficacy of current safety measures.

These methods will include:

• Regulating the temperature of all water systems – avoiding temperatures between 20°C and 45°C.
• Flushing out infrequently used systems on a regular basis (i.e. weekly) to eliminate stagnant water.
• Avoiding the use of materials that harbour bacteria or provide nutrients for microbial growth.
• Controlling the release of water spray, as inhaling contaminated water droplets is how Legionnaires’ disease is contracted spreads.
• Using water treatment techniques to maintain the cleanliness of the water.
• Maintaining and repairing systems and components when necessary.

7. An assessment of record keeping and monitoring processes

If an employer has fewer than five employees, they have no legal obligation to record the findings from the Legionella risk assessment. However, we would recommend that all business owners create detailed records as a reminder of what’s been assessed and what measures were recommended to improve on-site safety.

These records should include:

• Who is responsible for conducting the risk assessment
• Any significant findings
• Photographs and schematic diagrams
• Details about the state of operation of each water system
• The dates and results of any inspections or tests

In addition to creating new records, old record keeping and monitoring processes should be assessed to ensure that all current and historical data is correct. This will show evidence of proactive management in response to previous risk assessments, helping you avoid potential legal trouble following a Legionella outbreak.

8. Defined score matrix

To make it easier to assess the efficacy of your water hygiene measures, it’s important to use a defined scoring system within your report. This will help you identify issues that are urgent, non-urgent or something to keep an eye on for the future.

Having a scoring system is particularly essential if you hire a facilities management company to perform your Legionella risk assessment. They should provide you with a score and explain what this means to help you decide which issues need to be urgently addressed and which systems need to be monitored more closely.

9. List of recommended actions

In addition to providing a score, the Responsible Person or the facilities management company should provide a list of recommended actions to reduce your risk of Legionella outbreaks. These actions could also be accompanied by a traffic-light system to represent their urgency, with red lights indicating that an action must be performed as soon as possible. 

Recommendations should not be ordered by cost or difficulty to fix. Health and safety is the most important factor, and resources should be allocated appropriately to tackle the most urgent issues first.

How often should a Legionella risk assessment be carried out?

Although the above methodology is tailored to the risk of Legionella, the same steps can be carried out as part of a wider water hygiene risk assessment, which will also take other risks like P. aeruginosa outbreaks and scalding into account.

Business owners and landlords need to carry out water hygiene risk assessments and Legionella risk assessments to comply with health and safety legislation, but there isn’t a set timeframe for completing these assessments. We recommend that you assess water hygiene every two years, or whenever there’s a change to the overall risk (e.g. you install new water systems, there’s a change to key personnel or there are now vulnerable people who could be affected).

Who can carry out a Legionella risk assessment?

Since the ACoP L8 only stipulates that the person carrying out the risk assessment should be “competent”, you could appoint your own Responsible Person to do it – or you could do it yourself. We recommend that the Responsible Person in charge of the assessment should undertake prior training and education about Legionella and also have in-depth and up-to-date knowledge of all of the water systems on the premises.

For the best results, you could hire an experienced facilities management company to perform your Legionella risk assessment or water hygiene risk assessment. Having a reputable company evaluate your water systems will give you peace of mind and help you ensure that you’ve identified all potential risks. Plus, getting an outside opinion can help you notice things you may have missed in the past, making your health and safety measures even more effective.

If you want an expert opinion on your water hygiene risks, get in touch with Thermatic Technical FM. We provide a full range of water hygiene compliance and maintenance services to help you meet the HSE ACoP L8 requirements. Book a water hygiene or Legionella risk assessment today to keep your staff and customers safe.