Who am I?
• I am a compound found naturally in
Earth
• I control the Earth’s climate
• I am necessary for all life
• I am the universal solvent
• I am continuously recycled
• I defy gravity
• I am not a metal
• I have no nutrients
• Who am I?
Groundwater
Groundwater
• Makes up 23% of Earth’s freshwater.
• 12% Shallow (we can reach)
• 11% Deep (out of our reach)
Underground Layers
When precipitation occurs, water often
seeps down into the soil and trickles down
in between particles of soil and through
cracks and spaces in layers of rock.
Permeable and Impermeable
Permeable layers allow water to
travel through them.
Ex: sand, soil, gravel
Impermeable layers do not allow
water to travel through them.
Ex: clay, granite
Permeability
• Rate that liquids go
through pore spaces
• Increases with
porosity (NOT
ALWAYS TRUE)
– Holes must connect
• IMPERMEABLEliquid can’t get
through
Permeable and Impermeable
Pores- the spaces between rock
which water can move through.
Different kinds of rock have
different-sized pores.
Trapped water
When water reaches an impermeable layer,
it is trapped and cannot go any further.
The water begins to fill up the spaces above
the layer.
Saturated Zone
The area of permeable rock or soil that is
totally filled with water.
Water Table
The top of the saturated zone.
Knowing the depth of the water table tells
you how deep you must dig to reach the
groundwater layer.
Unsaturated zone
• The layers of rocks and soil
above the water table.
Aquifer
Any underground layer of rock or sediment
that holds water is called an aquifer.
People often obtain drinking water from
aquifers.
Water may stay in an aquifer for thousands
of years before it well ever come to the
surface!!!