Legionella is a bacteria. Its full name is legionella pneumophila. You find it in both natural and man-made water systems. In lakes, streams and rivers it occurs at levels that are not harmful to humans. But in man-made systems, legionella may grow and spread to the extent that it is potentially lethal.

This is why it’s important to manage legionella risk, to test water systems for the presence of the bacteria, and to take measures to control it. An effective method of controlling legionella is using a specialist water treatment.

Legionella Bacteria

Legionella is a gram-negative bacteria that includes the species L.pneumophilia. This is the bacteria that causes legionellosis.

Gram-negative bacteria have built-in properties that make them more resistant to multiple drugs and most available antibiotics.

These types of bacteria cause various infections including pneumonia.

Legionella and Legionnaire’s Disease

Legionella can cause a pneumonia-like illness, known as legionellosis. Legionellosis causes various illnesses:

• Legionnaires’ disease
• Pontiac fever
• Lochgoilhead fever.

Of these, legionnaires’ disease is the most serious. It is a potentially fatal form of pneumonia, and it can infect anyone.

However, certain groups are more vulnerable to the effects of legionnaires’ disease:

• People 45 years or older
• Smokers and heavy drinkers
• Sufferers of chronic respiratory or kidney disease
• People with cancer
• People who have weak immune systems.

Legionella bacteria infects the lungs and, if left untreated, it can prevent them from functioning normally. When this happens, the lungs cannot pass sufficient oxygen into the blood.

Some people can suffer a severe bacterial reaction to legionella infections, leading to sepsis, where the organs in the body no longer receive enough blood to carry on functioning properly.

Symptoms of legionnaire’s disease include:

• Coughing
• High temperature
• Difficulty in breathing
• Chest pain or discomfort
• Muscle aches and pains.

These symptoms are similar to those associated with pneumonia, flu or chest infections. In more serious cases, people can experience nausea, vomiting, diarrhoea and feeling confused.

Generally, symptoms progress from a dry cough to shortness of breath and experiencing chest pain when breathing.

Legionnaires’ disease gets its name from a 1976 outbreak of the then-unnamed disease at an American Legion convention in Philadelphia.

The disease is relatively rare in the UK, but its consequences can be deadly, and it can spread rapidly given the right conditions.

How Does Legionella Spread?

Legionella grows and multiplies in water systems. The common way that people contract legionnaires’ disease is by breathing in droplets of contaminated water. These droplets are small enough to be in the air and are undetectable.

The bacteria thrives especially in warm temperatures, which is why people in the UK sometimes contract it while travelling abroad.

There are several potential sources of legionella in water systems, including:

• Showers and taps
• Plumbing systems
• Cooling systems and cooling towers
• Hot and cold water systems
• Spa baths, hot tubs, thermal spas and pools
• Decorative fountains
• Humidifiers.

Generally, legionnaires’ disease does not spread from person to person.

How Can Legionella Affect Your Business?

The law requires business owners to assess premises they own or manage for the risk of legionella contamination in water systems.

Some businesses and industries are at greater risk from legionella than others. These include:

• Industrial and manufacturing sites
• Nursing and care homes
• Hospitals and healthcare facilities
• Hotels, spas and hospitality venues.

Various industrial sites will have cooling towers and systems for processing that use water and are complex and challenging to keep safe. Cooling towers can emit spray, for example, which will also travel on the wind, having the potential to infect more people.

Nursing and care homes contain people who are more vulnerable to diseases but also have communal water systems where legionella can breed.

Likewise, hospitals and healthcare facilities combine potentially vulnerable patients with extensive water systems.

The hospitality sector includes plenty of venues with complex water systems and systems such as spas where warm water is in regular use. There can also be periods where systems are not in frequent use, which allows for the build-up of bacteria.

In the property industry, landlords, property owners and property managers have a duty of care to ensure they assess properties for legionella risk. And where properties stand empty for some time there is an increased risk of legionella spreading in water systems.

Business owners and landlords can face prosecution if they fail to identify legionella risk or fail to take appropriate measures to control legionella on their premises.

In 2015, a fatal case of legionella in an Essex care home resulted in the owners, BUPA, facing a £3 million fine. Following the death of an 86-year-old resident in the care home, investigations revealed various management failings, including not monitoring the home’s hot water system and not flushing through the plumbing system as a preventative measure.

Legionella in the workplace

Legionella poses risks in the workplace simply because any water system under certain environmental conditions is a potential source for the growth of the bacteria.

HSE highlights certain water system conditions as containing a reasonable, foreseeable legionella risk. These are:

• Where water is stored or circulated as part of the system

• Water temperature is between 20°C and 45°C

• Conditions are likely to allow bacteria to multiply

• Water contains sources of nutrients such as rust, scale, sludge and organic matter

• Systems can produce water droplets and disperse them over a wide area

• Where employees are more vulnerable to infection.

Under general health and safety law, employers, or those in control of premises, must take suitable precautions to prevent or control the risk of exposure to legionella.

It’s It is their responsibility to carry out an appropriate risk assessment for legionella.

What Does a Legionella Risk Assessment Involve?

A risk assessment for legionella is simply a means of deciding whether a water system presents circumstances for an ideal breeding ground for legionella.

HSE has a code of practice relating to legionella risk assessments. It states that the person responsible for the premises must carry out a suitable and sufficient assessment, which should identify and evaluate potential sources of risk.

The risk assessment should look at the individual nature of the site, and consider the entire water system, not just specific aspects of it, such as cooling towers.

It’s also important to look at any parts of the system that are either currently not in use, or only intermittently in use. These can be problem areas for legionella contamination, allowing for microbial growth to continue unnoticed.

The risk assessment should cover anything on-site that uses water. Factors to consider include:

• The source of the system’s water supply
• The local environment
• Possible sources of contamination
• Normal operating characteristics of the plant, and foreseeable conditions, such as breakdowns or stoppages
• Current control measures
• Any means of disinfection currently in use.

Where the findings of the risk assessment indicate a risk of exposure to legionella, the employer, building owner or manager must consult employees or their representatives.

The next steps are to test for legionella and to put measures in place to prevent or control the risk.

What is Legionella Testing?

Legionella testing must involve the appointment of a competent person to carry out testing on water systems for legionella.

Typically, this will be a water treatment professional, who will take samples, either as a liquid in a sealed sample bottle or as swabs.

Samples are then tested under laboratory conditions to check for the presence of legionella, and if present, at what levels. Legionella testing must be BS 7592 compliant and carried out by a UKAS-accredited laboratory.

How do You Control or Prevent Legionella?

A key aspect of preventing the risk of legionella is to look at the design, maintenance and operation of your water systems:

• Ensure there is proper control of any released water spray

• Avoid water temperatures and conditions that encourage bacterial growth

• Prevent water from stagnating in the system by shortening pipes or removing unused pipework

• Avoid using materials that will encourage the growth of microorganisms

• Keep the water in the system clean

• Add a water treatment to prevent the build-up of bacteria.

How Does Water Treatment Control Legionella?

Biofilm is a thin film of algae that can build up in water systems and pipework, and it helps create conditions where bacteria such as legionella can thrive and multiply.

To control legionella, it’s important to keep water distribution systems clean and to prevent biofilm building up. An effective means of doing this is with water treatment.

There are varying thicknesses of biofilm, but layers of it can house large amounts of bacteria. When free-floating bacteria and organisms encounter surfaces, they start a process that enables them to adhere to these surfaces. They create matrices of multi-cellular materials, and this is what biofilm is made up of.

At a point in this process, the bacteria mature and break away from these matrices, enabling them to form new colonies. In this way, biofilm enables the spread of legionella throughout water systems.

In effect, biofilms are themselves biological systems with the means to multiply, which makes them hard to remove from water systems.

However, without removing them, these systems will always be at risk from bacterial growth. Biofilms are not inherently dangerous to health, but the bacteria that exist within them are more resistant to disinfectants and other chemical agents.

If you can prevent the growth of biofilm, you can help control the spread of legionella.

Which Water Treatment Works for Legionella?

Effective cleaning of pipework to prevent legionella requires a water treatment that will remove biofilm while delivering clean water.

Oxyl-Pro Clean will remove biofilm from pipework and it works to eliminate gram-positive and gram-negative bacteria including legionella, as well as pseudomonas, listeria, fungi and yeasts.

This is an HSE-accepted alternative for disinfection under its L8 code of practice.

Oxyl-Pro has a unique formulation including only food-safe ingredients and based on aseptic-grade hydrogen peroxide.

For more information about Oxyl-Pro and controlling legionella, please call us on +44 1606 851 782, email enquiries@oxylpro.com or complete our contact form.