Assertion: aquifer | /r/HasProperty | useful
Facets:
value: in a spring
type: TEMPORAL
value: for society's activities
type: PURPOSE
value: in a well
type: LOCATION
value: economically
type: DEGREE
Source sentences:
text: Aquifers are subsurface zones of rocks that yield water in sufficient quantities to be economically useful for society's activities.
text: An aquifer is a collection of water underneath the surface, large enough to be useful in a spring or a well.