Legionnaires disease is a potentially fatal form of pneumonia that is caused by Legionella bacteria which can be found in many natural fresh water resources. However, it can also be present in the water systems of domestic and commercial buildings.

Very small amounts of Legionella are commonly found in water, however, it will only become a serious issue when it breeds. This can lead to the potentially fatal Legionnaires disease if contracted. If not properly maintained, hot water systems can encourage the growth of Legionella as the bacteria breeds well in warm stagnant water.

The following recommendations can help to prevent Legionnaires disease in hot water systems:

Maintain Hot Water Temperature

Hot water should be stored at 60°C or higher at all times. Often homeowners reduce the temperature as they think it will reduce energy usage or turn off their hot water tank altogether when going away for some time. This can create favourable conditions (temperatures between 25° and 50°C) for Legionella bacteria to breed.

It is, therefore, important to maintain the hot temperature of at least 60°C in water systems and refrain from turning off the water heater. Please note; even cold water tanks can reach up to 25°C if in direct sunlight or warm environments, posing the same risk.

Remove ‘dead legs’ in pipe work

‘Dead legs’ in pipe work will store water, resulting in it becoming stagnant and Legionella is likely to grow faster. This can also lead to an increase in scale build up and biofilm within the pipes. It is the perfect breeding ground for Legionella bacteria to accumulate. You should aim to keep pipe work short and direct.

Maintain Hot Water Tanks

Regular maintenance including flushing out and cleaning water tanks should be done to help prevent the growth of Legionella. Hot water tanks should be cleaned with disinfectant after being flushed.

If you have a large tank and don’t use up the water stored in it frequently, you can end up with the old water staying in the tank for long periods of time, increasing the chances of bacteria growth. Regular chlorination is also needed for hot water tanks and helps to eliminate bacteria.

Water Testing

Water samples should be frequently analysed for Legionella to check that the bacteria count is low. Landlords and employers are legally required to carry out water testing when their property features hot or cold-water systems and wet cooling systems. Please note; all systems may have some Legionella bacteria present so it is key to measure any colony count is at a safe level.

Risk Assessment

Managing the risks associated with Legionella is a legal requirement for commercial property owners and landlords. The risk assessment is easy to do and can be carried out internally or by an external specialist.

The risk assessment should include:

· Description of the system, management responsibilities, and training of key personnel
· Any identified potential risk sources
· Means of preventing risk or controls used to limit risks
· Monitoring, inspection and maintenance procedures
· Records of results, inspections and checks
· Plans for reviewing the risk assessment regularly

Expert Legionella Testing solutions

If you would like to find out more about Legionella Testing, contact the team at Smartwater Testing. Full discretion is assured, whatever the test results show up and although we only provide a test and report service, we do work with water treatment specialists. With your permission, we can forward your test results to them for their advice and recommendations. Get in touch to find out more and order your testing kit online today.