Assertion: e. coli | /r/ObjectUse | used as indicator
Facets:
value: in the field of water purification
type: LOCATION
value: commonly
type: TEMPORAL
Source sentences:
text: E. coli is commonly used as an indicator in the field of water purification.
text: The reason why E. coli is used as an indicator is due to a significant larger amount of E. coli in human feces than other bacterial organisms.