Groundwater Terms & Myths

Groundwater Terms:

  • Aquifer: an underground formation that contains significant amounts of moveable water.
    • Unconfined aquifer: An aquifer that is not bound above or below by impermeable rock, but rather by the water table. Groundwater in these aquifers is primarily driven by the force of gravity with the water generally flowing downhill.
    • Confined aquifer: An aquifer that is bounded by impermeable rock and the driving force is pressure. If the confining pressure can raise the water level above the surface in a water well, it is referred to as a flowing artesian well.
  • Discharge: The process by which groundwater exits the subsurface, which may be through the pumping of a well for domestic purposes, or through natural flow into streams, rivers, marshes, lakes and oceans.
  • Recharge: The process of surface water entering the subsurface and accumulating within the saturated zone.
  • Residence Time: The amount of time groundwater remains in the subsurface, which may vary from as a little as a week to as much as 10,000 years.

Groundwater Myths:


  • moves rapidly
  • migrates thousands of miles
  • has no relationship with surface water
  • removed from the earth is never returned
  • is mysterious and occult
  • is not a significant source of water supply