Microbiology
Coliforms
A broader indicator group used to assess water quality.
What is Coliforms?
Coliform bacteria are a group of organisms used as a general indicator of water quality and system integrity.
Why test for it?
Coliforms can indicate ingress or biofilm in a system even when E. coli is absent, so they are usually tested together.
Where can it come from?
- Ingress into pipework or storage tanks
- Biofilm within distribution systems
- Environmental sources
How is it measured?
Determined by membrane filtration or defined-substrate culture, reported per 100 mL.
What does my result mean?
A coliform detection without E. coli usually points towards system or sampling conditions rather than faecal contamination.