Glossary
CFU per litre
Colony-forming units per litre, the unit a laboratory uses to report how many live, culturable Legionella bacteria it grew from a water sample. UK guidance for hot and cold water systems commonly treats counts above around 100 CFU/L as needing review and resampling, with higher counts (commonly above about 1,000 CFU/L) prompting more urgent action, but your risk assessment and lab set the exact response.
Covered in depth
Articles that use this term
- Inside the lab: how Legionella culture testing works
- Choosing a UKAS-accredited lab for Legionella testing
- Total viable count (TVC) explained: what microbiological monitoring tells you that a Legionella test doesn't
- Germany's TrinkwV and DVGW W551, France and the Netherlands: European Legionella regimes compared to the UK
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"CFU per litre, Legionella glossary." Legionella.io. https://legionella.io/glossary/cfu-per-litre/
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