Ground Water Infiltration

Let’s learn about groundwater! The Groundwater Story Animation

Infiltration – water seeping into the ground

Water Infiltrating into ground Infiltration

Zones of Sub-Surface Groundwater Zone of Saturation – layer of soil completely saturated with water (no air spaces) Zone of Aeration – layer of soil under Earth’s surface Pores contain both water and air

Water Table – Lies on top of zone of saturation Water Table – Lies on top of zone of saturation. It is the interface between the zone of saturation and zone of aeration. Reflects the shape of the land above All open spaces below are filled with water

Saturation

Level of water table will rise and fall due to changes in amount of rainfall. The more rain there is the higher the water table. The less rain, the lower.

Pores filled with mostly AIR Pores filled with WATER

Groundwater Animation

Level of Water Table Rises and Falls

The Water Table Groundwater flows from areas where the water-table is high, to areas where it’s low.

Groundwater Review with Tim & Moby!

What might affect the water being able to get into the ground?

Steep Slope vs. Gentle Slope Run-off = Water that is unable to infiltrate into the ground so it “runs off” the surface usually ending in the ocean or a lake. More Runoff Less Runoff

There will be less infiltration and more run off if There is a greater gradient – steeper slope. The ground is already filled with water The ground is frozen. The water falls too quickly for the ground to absorb it. We’ve paved over the ground with our sidewalks and streets.

What determines how much water the ground can hold? Porosity!

Porosity – the percentage of pore space Water is found in the pores between particles of rock. The more pores there are, the more water can be held

High Porosity Low Porosity

1. Shape of Particle B A Low Porosity High Porosity

Which bunch has higher porosity, the strawberries, or grapes?

2. Packing Higher Porosity

3. Sorting Well Sorted A High Porosity Unsorted B Low Porosity

Is the total amount of pore space in ‘A’ bigger or smaller than ‘B’? They are equal! Size does not affect porosity! A B Bigger pores, but fewer of them Smaller pores, but more of them

What determines how fast the water can travel through the ground What determines how fast the water can travel through the ground? Permeability!

Permeability The ability of material to allow water to pass through it. The rate at which water passes through the material is the permeability rate. Not as fast – pores are not as well connected Very slow – pores are not well connected. Fast – pores are well connected

The higher the porosity, the higher the permeability

The more connected the pores are the faster the permeability. Even though large particles and small particles have the same amount of pore space, large particles are better connected. This allows the water to travel through faster. permeability size

Permeability In Action

Porosity & Permeability P & P

Capillary Action The upward movement of water against gravity to “feed” vegetation through root hairs

Occurs because water is sticky (positive Hydrogen's and negative Oxygen attract) The smaller the pores, the higher the water rises

Capillary Action Water will rise the highest in the thinnest tube

Long Island’s Water

Where do we get our drinking water from???

Have you noticed water towers like these before?

Aquifers Underground layer of sediment or rock capable of yielding fresh water

There are 3 aquifers underneath Long Island: Upper Glacial – our water table (lakes, streams, puddles) Magothy – Biggest Aquifer. This is where we get our drinking water from (water is hundreds of years old!) Lloyd - This is our deepest aquifer and it contains the oldest and cleanest water (water is thousands of years old!)

Animations Permeability Animation Water Table Animation Water Cycle

Groundwater Sources

Water Pollution

What is Pollution? Pollution occurs when concentration of substances in the environment become large enough to have an adverse (negative) effect on humans, plant, and animal life.

How do we pollute?

How can water deep underground become polluted?

Groundwater contamination from Septic Systems When Septic Tanks break or leak, the sewage infiltrates into the flow of groundwater. If the leak is close to the house, the drinking water from the well may be contaminated.

Improper Disposal of chemicals, oil pesticides and other wastes

Contamination from Deicing Salts

Garbage Trucks dumping trash at a Landfill

Modern Landfill

Contamination from Landfills                                                    

Contamination from cemeteries and animal burials Avoid high water table for burial site and use watertight caskets in cemeteries