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

• IMPERMEABLE- liquid 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!!!