Frequently Asked Questions

The Legionella bacteria are surprisingly widespread in all systems of natural water, such as ponds and pools, lakes, rivers and reservoirs. In order for people to become infected, however, conditions must be conducive, and this is not often the case.

Bacteria levels can multiply and reach dangerous levels in purpose-built water systems where the temperature is between 20 and 45° Celsius. Below 20°C and the bacteria are dormant, above 60 the cannot survive. Stagnant water also favours growth, so systems must be kept in frequent use and be flushed regularly for the risk of Legionnaires’ disease to be averted.

The most common water systems where these conditions proliferate are:

– Hot and cold water systems
– Cooling towers
– Spa pools
– Evaporative condensers

These can be either in a professional, industrial or domestic environment.

Legionnaires disease is contracted when people inhale small particles or droplets of water that contain the bacteria and are suspended in the air.

There is a greater risk of Legionnaires disease:

– When the temperature of the water in the system is between 20 and 45 degrees celsius
– When conditions for the creation and dispersal of breathable water droplets are favourable, such as in cooling towers and domestic water systems
– When water is stored and re-circulated
– When there are deposits that support or encourage growth of the bacteria by providing a nutrients – such as scale, sludge, rust and organic matter

Blue Fish Water Management specialises in carrying out risk assessments to the water systems in your company or on your premises, ensuring the health and safety of your workers, tenants and patrons, as well as your business reputation. Each assessment identifies and assesses sources of risk and gives advice on how to manage those risks.

Legionnaires’ disease, a potentially fatal form of pneumonia, is one of a cluster of diseases that are all caused by a bacterium known as Legionella. The Legionella bacteria are not uncommon in ponds, lakes, pools, rivers, lakes, reservoirs and other systems of natural water. However, it is rarely the case in these natural systems that conditions for bacterial growth are conducive.

When people do become infected and there is a breakout of the disease, it tends to be in purpose-built systems where water is maintained at high enough temperatures to encourage bacterial multiplication. Examples of these systems include industrial and domestic versions of cooling towers, evaporative condensers, hot and cold water systems, and spa pools.

The Legionella bacteria thrive in the following conditions:

– When water temperature is somewhere between 20 and 45 degrees Celsius
– When water is re-circulated in your system
– Where there are deposits such as rust, scale, sludge or organic matter – these provide nutrients that support or encourage the growth of the bacteria

Legionnaires’ disease can be contracted through the inhalation of minute droplets of bacteria-infected water suspended in the air. These airborne droplets might come from a shower or tap, or could also be dispersed through the air-conditioning. Everyone is at risk of infection, but particularly the elderly and those people with a weak immune system.

Symptoms can develop anywhere between two days and two weeks after exposure to the bacteria. The disease is easily treated by antibiotics if it discovered in good time.

The symptoms of Legionnaires’ disease are actually very similar to the symptoms of influenza (the common flu) and include:

– A high temperature, fever and chills
– A sore throat and niggling cough
– Aches and pains in the muscles, headaches
– Occasionally diarrhoea and mental confusion

Legionnaires’ disease is not contagious and therefore is not spread from one person to another, and cannot even be contracted from drinking contaminated water.

If you have developed the symptoms above and are concerned you may have contracted Legionnaires’ disease, see your GP as soon as you can. It is difficult to get a Legionnaires’ disease diagnosis because of the similarity of the symptoms to the flu. Your GP will arrange for a urine or blood test, which will be able to tell if you have Legionnaires’ disease or not.

If you believe that you may have contracted your illness at work, then you must report this fact to your manager, plus anyone connected with your work’s health and safety and/or occupational health department. Your company has a legal requirement to report instances of Legionnaires’ disease that may have been contracted within their premises to the Health and Safety Executive.

Blue Fish Water Management specialises in performing risk assessments for companies and buildings, making sure that health and safety standards are upheld and that your workers, patrons or tenants are as safe as your business reputation. And also, having your water checked is your legal duty.