Ground Water. Makes up 0.397% of Earth’s Water. - song

Ground Water

Ground Water• Makes up 0.397% of Earth’s Water.

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Ground Water Vocabulary

• Porosity – a measure of the % of pores

(open spaces) in a material• Permeability– a measure of how easy it is

to force water to flow through a porous material

More Vocab• Aquifer-– An underground formation that is capable of

transmitting H2O.

• Water Table– the surface between the saturated zone and the

unsaturated zone (zone of aeration)

• Unsaturated Zone (Zone of Aeration)-– the zone above the H2O table where all the pores

are filled with air.• Saturation Zone (Zone of Saturation)-– the zone beneath the H2O table where all the

pores are filled with H2O

How Water Tables Change

Types of Aquifers• Unconfined Aquifer-– an aquifer that has a free connection upward to the

surface • Confined Aquifer-– aquifers that are isolated from the surface by an

overlying layer of impermeable material called an AQUICLUDE or confining layer • Aquiclude:

- Impermeable layer separating the unconfined and confined aquifer

animation

Recharge Area• Recharge – water that falls as

precipitation and infiltrates the ground to become groundwater.

• Recharge Area– The area where

permeable soil allows water to seep into the ground.

• Discharge Area– place where groundwater

becomes surface water

• Spring-– when groundwater simply bubbles up at the surface of

the ground. Naturally occurring• Wells– place where groundwater is withdrawn for use in

homes, farms, and industry. Human made• Artesian Well-– well in which H2O rises above the level it was

encountered. Must be confined and recharge must exert enough pressure to allow H2O to flow upward

Groundwater Flow• Ground water moves through subsurface material much like

run off– Except a lot more slowly– If the soil is mostly sand or gravel, it can move 5 ft/day

• Like streams and rivers, ground water moves from high areas to low areas

• Gaining Stream-– When ground water is

discharged to the surface water.

• Losing Stream– When water is lost from the

surface water to the ground around it.

Water Level Declines• Water pumped from the ground-water system causes

the water table to lower and alters the direction of ground-water movement.

• Notice that some water that flowed to the stream no longer does so, thereby reducing the amount of stream flow.

Ground Water Contamination• Piezometers-– wells installed to monitor water

level and water quality• Plume-– a concentration of contaminants

that flows along the same path as ground water

What properties of water make it unique?

• Water can dissolve more substances in greater quantities than any other liquid. – However, this means that water

can be easily be contaminated• Most groundwater

contaminates enter the system from the surface, not at points deep within the aquifer.

•Human activities at or near the land surface can contaminate groundwater by moving through the unsaturated zone to the water table. •Then contamination can continue to move within the saturated zone and discharge area.

Sources of groundwater contamination include:

fertilization•misuse of pesticides•oil spills•leaky landfills•leaky septic system •leaky underground storage tanks

•Different chemicals react differently with different soils. •Contaminated groundwater may pollute surface water•Contaminated surface water can pollute groundwater•Water quality can vary within the aquifer

Septic System