Coliform Count

A test of water potability
Untreated water, e.g., from the Thames:
Typical coliform count ± 2,000 bacteria/100 cm3
Mechanically treated water—Post storage, sedimentation and clarification: ± 10 bacteria/100 cm3
Chemically treated water—disinfection with chlorine or ozone: 0 bacteria/100 cm3 for safely distribution to public