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Understanding the Legionella Risk in Hotels, Resorts, and B&Bs

Customer experience and comfort are some of the topmost priorities for businesses operating in the hospitality sector. A stressful stay at a hotel will lead to loss of revenue, reputation, and customer loyalty.

Some industries and businesses are at greater risk from Legionnaires’ disease and legionella contamination than others. Unfortunately, the complexity involved in the hotel’s water systems could put guests at risk for contracting Legionnaires disease during their stay.

An outbreak of Legionella in a hotel could result in the severe illness of hotel guests and staff as well as jeopardising the reputation of the hotel. In fact, every year hundreds of reported Legionnaires’ disease cases are associated with a hotel stay.

Several high-profile outbreaks of Legionella have made headlines in the past few years. One of the most recent outbreaks in Ireland took place where Mary Kelleher from Co Cork went to Muckross Park Hotel in Killarney, Co Kerry to celebrate her wedding anniversary ended up in an induced coma after contracting Legionnaires’ Disease after using the hotel’s spa facilities.

Therefore, facilities managers must understand the risks Legionella poses in hotels, where the bacteria can be found and how it can be effectively controlled through a proven water hygiene programme.

How do people contract Legionnaires’ disease?

After Legionella grows and multiplies in a building water system, water containing Legionella can spread in droplets small enough for people to breathe in. People catch Legionnaires’ disease by inhaling small droplets of tainted water, but not from drinking it.

This could be via the water mist from an infected shower outlet, the spray from a water feature or the fine water droplets from a cooling tower, or a hotel hot tub to give a few examples.

However, new evidence suggests that “Aspiration” now appears to be the most common mode of transmission.

Aspiration is the most common way that bacteria enter the lungs to cause pneumonia. Aspiration means choking such that secretions in the mouth get past the choking reflexes and instead of going into the esophagus and stomach, mistakenly, enter the lung. The protective mechanisms to prevent aspiration is defective in patients who smoke or have lung disease.

There is no direct human-to-human transmission.

If an outbreak of Legionnaires’ disease was to occur, it could potentially affect hundreds of people, all of whom had the hotel in common. However, it may take some time before the source of the outbreak was confirmed, thus allowing many people to fall ill as the condition incubates and leaves people at risk of serious illness. Other guests may also be exposed before the source is found.

Where are the key legionella risk areas in a hotel?

The Legionella bacteria exist in rivers, lakes and other places with fresh water, but numbers are usually low because the water temperature in such places is too low for the bacteria to multiply rapidly.

It is the conditions within the building water system that determine whether bacteria remain at a safe level or multiply and become a threat to health. Considering that hotels will have hot and cold water distribution systems i.e. a supply of water to the guest rooms, the water supplied to the rooms may contain the legionella bacteria and as such airborne dispersal of the bacteria can occur when aerosols are created i.e. water is run from an outlet, shower, a flushed toilet.

Below are just some of the areas that Legionella can be found in hotels:

  • Showerheads & taps
  • Indoor Fountains and water features
  • Swimming pools
  • Air conditioning or cooling towers
  • Condensers
  • Food displays that use humidified air
  • Hot tubs or whirlpools
  • Saunas or steam rooms
  • Water storage tanks

Factors that contribute to the risk of contamination

If left untreated or even poorly treated, any part of a water system can be prone to legionella contamination and proliferation.

Many things that happen inside your building can become a breeding ground for Legionella. These are the most common issues.

1.    Water Temperature

The ideal temperature for Legionella growth is a wide range of 20-45°C. But, Legionella can grow in temperatures outside this range. Certain factors increase the risk of having Legionella-friendly temperatures. They include:

  • Setting the water heater too low
  • Long pipes that lose heat as the water moves along
  • Hot and cold water pipes being too close together
  • Places in a water system where hot and cold water may mix
  • Stagnant water, which tends to lose heat
  • Coldwater pipes that are not protected from hot weather

2.    Biofilm

This slimy buildup eats up disinfectant and provides an ideal environment for Legionella to grow. Biofilm can grow on any surface that is exposed to moisture continuously. It doesn’t leave without a fight: biofilm can stay on surfaces and in water systems for years and even decades.

3.    Limescale

When minerals from the hard water collect inside the water systems, a hard, rock-like substance starts to buildup. Scale deposits form a barrier that interferes with the efforts to heat or cool the water, which can lead to unpredictable and/or unacceptable water temperatures.

Limescale along with biofilms supply vital nutrients to the Legionella bacteria and other germs to grow and proliferate.

Read More: How limescale deposits increase the risk of a legionella outbreak

4.    Sediments

Sediment is a collection of minerals and natural materials. It builds up in water that isn’t properly treated or filtered and compromises heating and cooling systems. Sediment brings germs with it that are hard to get rid of, and invites more germs, including Legionella, to grow in its protected environment.

5.    Water pressure changes

If water pressure inside the building water systems is affected for any reason, it may dislodge biofilm and introduce its germs into the rest of the water system.

6.    Stagnation

Standing water encourages biofilm to grow and soaks up more than its fair share of disinfectant. Stagnation can happen when certain fixtures go unused or water usage, in general, is decreased. Dead legs, which are pipes that have low or no flow, are a prime place for Legionella to grow.

7.    pH

Disinfectants can only do their job if the water’s pH is between 6.5 and 8.5. The pH level may change because of pollution, chemicals, and the amount of plant or organic material in water.

COVID-19 Lockdown & Legionella Risk

Water, as a risk, can often be overlooked. People are very conscious of the dangers of elements such as gas and carbon monoxide, but we have to remain aware that water can pose a real health risk also.

As buildings were closed during the national level lockdown, many water systems may not have been in full operation. Water systems are designed to be used and operated and not to sit dormant for long periods, if the water system does not turnover there is a real risk of the water being exposed to conditions that may promote bacterial growth.

During the COVID-19 pandemic, there is also potential for an increased number of people to have susceptibility to Legionnaires’ disease due to a compromised respiratory system during or after infection with the Coronavirus. Extra care is required.

As part of the law outlined in The Safety, Health, and Welfare at Work Act 2005 (S.I. No. 10 of 2005), measures are required to be in place to manage the risk of exposure to Legionella bacteria in the workplace.

Employers, the self-employed and people in control of premises, have a duty to protect people by identifying and controlling risks associated with legionella.

When buildings re-open after lockdown, it is essential that water systems are not simply put back into use. This is because there is potential for increased levels of Legionella and other waterborne pathogens to be present in the system due to low water usage.

When recommissioning a building of any kind, it is wise to create a plan to help you do so. This is the responsibility of the duty holder and responsible person who would normally handle water safety within the building.

Mitigating Legionella Risk in Hotels

The good news is that hotels can reduce the growth of Legionella bacteria and other waterborne pathogens by implementing a water hygiene program. A complete water hygiene program will assess the water systems at the hotel and come up with site-specific actions for maximizing water safety.

A complete approach, from construction through to ongoing maintenance, will improve the efficiency of water systems, as well as safeguarding staff, guests and reputation.

The primary method used to control the risk from Legionella is water temperature control.

Water services should be operated at temperatures that prevent Legionella growth:

  • Hot water storage cylinders (calorifiers) should store water at 60°C or higher
  • Hot water should be distributed at 50°C or higher (thermostatic mixer valves need to be fitted as close as possible to outlets, where a scald risk is identified).
  • Coldwater should be stored and distributed below 20°C.

A competent person should routinely check, inspect and clean the system, in accordance with the risk assessment.

Stagnant water favours Legionella growth. To reduce the risk you should remove dead legs/dead ends in pipe-work, flush out infrequently used outlets (including showerheads and taps) at least weekly and clean and de-scale shower heads and hoses at least quarterly.

Cold-water storage tanks should be cleaned periodically and water should be drained from hot water cylinders to check for debris or signs of corrosion.

Design systems to minimise Legionella growth, by:

  • Keeping pipework as short and direct as possible
  • Adequately insulating pipes and tanks
  • Using materials that do not encourage the growth of Legionella
  • Preventing contamination by fitting tanks with lids and insect screens

This list is not exhaustive, but it should give you a sense of the challenges you face ensuring that your hotel doesn’t suffer from a damaging outbreak of Legionnaires’ disease.

Legionella Risk Assessments for Hospitality Industry

In Ireland, under occupational Health and Safety legislation, there is a legal obligation on employers to carry out a risk assessment in relation to legionella prevention and control in the workplace and where a risk is identified the appropriate control measures should be put into place and a risk management plan adopted.

Legionella risk assessment is a vital part of an effective strategy for the minimisation of risks associated with legionella proliferation in water systems within buildings.

The risk assessment needs to be completed by someone who is competent to do so. ACoP L8 & HPSC’s National Guidelines for Control of Legionellosis in Ireland tell us that this person should have the ability, experience, instruction, information, training and resources to be able to carry out the work and should know:

  • The potential sources of legionella and the risks they present;
  • Measures to adopt, including the precautions to take to protect the people concerned, and their significance;
  • Measures to take to ensure that the control measures remain effective, and their significance.

The risk assessor will need to be someone with specialist knowledge and understanding of the risk associated with dangers in hotel water systems, invariably this will be an independent consultant.

Book a Consultation

Celtic Water Solutions is a leading water hygiene service provider in Ireland offering a complete range of services including an initial legionella risk assessment, any remedial works needed, legionella testing, ongoing monitoring for tasks, water tank cleaning, and even training around this troublesome bacteria.

We are your one-stop shop for all legionella safety.

All our work is completed in strict accordance with HPSC’s National Guidelines for Control of Legionellosis in Ireland and UK HSE ACoP L8.

With our advanced water treatment and management service, you can be assured that you will effectively control Legionella at your hotel, keeping your guests safe and your site compliant.

For more information, book a free consultation.
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