Assertion: aquifer's water | /r/HasProperty | held for many centuries
Facets:
value: beneath the earth's surface
type: LOCATION
Source sentences:
text: The water in an aquifer can be held beneath the Earth's surface for many centuries: Hydrologists estimate that the water in some aquifers is more than 10,000 years old (meaning that it fell to the Earth's surface as rain or snow roughly 6,000 years before Egypt's Great Pyramid of Giza was built).