Legionella Managing The Risk in Buildings

Managing Legionella Post COVID-19 Lockdown

Legionella Risks Global outbreaks of COVID-19 (Coronavirus) have resulted in the compulsory closure of a number of large buildings such as schools, universities, leisure facilities and office blocks at a scale previously not seen. Now, as these buildings start to re-open after the imposed lockdown, there is a genuine risk that they could have become a breeding ground for another infection – Legionnaires’ disease (Legionella). The long periods of inactivity in buildings, a result of the COVID-19 lockdown, has greatly increased the risk of the Legionella pneumophilia bacteria developing in large water tanks and pipework. The bacteria survives in the biofilm that gathers on pipe and tank surfaces and likes to feed on the sludge and sediment that builds up there. Legionnaires’ disease, or Legionella as it is more commonly known, is caused by inhaling water droplets, via hot tubs, showers and … Read more

Shower head with water spray

Legionella Control in Hot and Cold Water Systems

Hot and cold water systems in buildings supply fresh water for cooking and cleaning and other functions such as heating. Systems that supply hot and cold water range in size scale and complexity. Water is usually distributed throughout buildings through a pipework system. Hot and cold water systems need careful management, particularly in public buildings such as healthcare premises to reduce the risk exposure to legionella. Legionella bacteria is responsible for Legionnaires’ disease, an uncommon but serious lung condition.  It can be caught by inhaling droplets of water from hot tubs, shower heads or heating systems. Temperature control of hot and cold water systems plays an important part in reducing the risk of legionella bacteria within the system. Where possible, cold water systems should be maintained at a temperature below 20°C.  Stored hot water temperatures should be at least 60°C.  … Read more



Legionella is a bacteria found in water that can cause Legionnaires’ disease – a severe pneumonia infection – or Pontiac fever, also known as legionellosis, according to the CDC. An estimated 10,000 to 18,000 people are infected annually in the United States, according to the Legionella.org, but it is rarer in the UK, with most infections transmitted in travel, according the National Health Service. The legionella bacterium spreads through inhalation of contaminated water droplets. It cannot be spread person to person and does not lead to infection in all cases of exposure. While it is found naturally in fresh water, exposure can cause illness. It grows best in warm water, particularly cooling towers used in air-conditioning units for large buildings. Symptoms of Legionnaires’ disease are typically flu-like, including a persistent cough, fatigue, high fever (39.5°C or 103°F), headaches or muscle … Read more

Legionnaires’ Disease – Managing the Risks

Legionnaires’ disease has been in news headlines once again following a deadly outbreak in the south-west of Edinburgh. Although the source of the bug had not been identified, the Health and Safety Executive (HSE) served an improvement notice on a company for alleged failures to adequately control the risk of legionella in a cooling tower. Given the right conditions, Legionella bacteria can grow in any workplace and the Health and Safety Commissions L8 Regulations detail the management required to reduce the risk. If you have responsibility for the management of water systems at your facility, Comark has products that will make that task easier. Comark’s N5001 Auditor is a hand held instrument for logging, monitoring and managing data. Specifically designed for use in HACCP, due diligence and health and safety systems, the instrument can be programmed for almost any task … Read more