What Is Legionella

  • Legionella bacteria which can cause serious respiratory illness and even death 
  • Over 50 species and 70 serogroups identified
  • Only around half of species cause any disease, much of it non-serious
  • Legionella Longbeacgae notable dangerous species found in soil
  • The most problematic species are water-based
  • The most dangerous of all waterborne species is Legionella pneumophila
  • The most dangerous serogroup of Legionella pneumophila is serogroup 1
  • Legionella pneumophila serogroup 1 responsible for the vast majority of deaths from Legionnaires’ disease globally (where data exists)


  • Serious pneumonia-like respiratory illness
  • Pontiac fever, milder flu-like illness from the same bacteria
  • 1 in 10 of those who acquire Legionnaires’ disease die
  • Similar symptoms to COVID-19 but 10x more fatal

Where is the risk?




Medical Facilities

Why Test For Legionella

  • Legionella is found practically everywhere
  • Legionella is ber resilient
  • VBNC dormant forms when ‘shocked’ by chemical or heart treatment
  • Hides in biofilm so can be resistant to biocides and heat treatments
  • Total eradication / complete sterility impractical
  • typical treatments and risk management techniques are not 100% effective
  • Therefore testing is an absolute necessity to manage risk when reopening

Our Work

Get In Touch

To find out more about our Legionella Services call or email InDepth Water Management now on 0818 77 22 22 or email us at info@indepth.ie. Or you can also reach us on our Contact Us page. We offer a 24/7 Emergency Call Out Service Nationwide.