What is legionella? 

Legionella is a bacterium that is always available in any source of water. The bacteria spread through small droplets which can be ingested by people nearby the water, for instance when taking a shower. Consequently, they can contract Legionnaires’ disease or Pontiac fever. Compared to COVID-19 for instance, the mortality rate for Legionnaires’ disease is way higher. 10% of healthy people die and the rate increases for the elderly and people with underlying diseases. 

How does legionella grow? 

In temperatures below 15 degrees and beyond 65 degrees, Legionella will not be able to multiply. In the quest to do cost-saving installations, cold and hot water pipes are always laid quite close to each other. Thus, the hot water pipes tend to warm up cold water pipes. Even though hot water pipes are beyond 65 degrees, the cold-water pipes might be warmed up enough to create suitable conditions for Legionella to grow. It is therefore quite common to find legionella in cold water pipes even though the cold water most of the time is colder than 15 degrees. 

What problems can it cause? 

Some long-distance routes like Bulk-carriers carrying iron-ore from Brazil to China may have 30 days at sea. Many crew are of Philippino and Indian descents and they require Visa in order to get onshore in South Africa. A legionella outbreak onboard will then prove catastrophic, as the next possible port of disembarkation will be Singapore. As a result, the crew are not able to receive emergency treatment. 

In 2021 there have been two cases where the captain of a ship died on board and the port of disembarkation refused the ship. The ship Vantage Wave lost their Romanian captain en route to China from India, and was stuck in Asian waters while no one wanted to accept the ship. Additionally, Evergreen's Ital Libera lost their captain to COVID-19 on board and the crew was stuck at great risk of being infected themselves. The virus spread and several crew members diseased.  

How do you prevent legionella? 

For facility owners who has Legionella infestations, Chlorines in normal dosing will never solve the problem due to the marine growth. Alternatives are hot-water (65 degrees) flushing, but most installations are too big so one will never be able to flush the entire system at 65 degrees. 

Waterworks provides a safe and cost-effective disinfection system that prevents Legionella bacteria from growing by dosing biocides into the water. The system is virtually maintenance-free once it has been installed. Read more about our service or contact us for more information.