1. Freshwater Resources
Unit C
Chapter 2

2. Earth’s Waters
Most of Earth’s water is 97% percent salt water that is found in oceans.
Only 3% is fresh water.
76% ice masses
.037% atmosphere (water vapor in a gaseous form.
Less than 1% is fresh water available for human use.
Some of the Earth’s fresh water is deep underground.

3. Distribution of Water on Earth

4. Freshwater available for human use
Earth’s water supply
Actual % on Earth
Oceans
Glaciers/Icecaps
Groundwater
Atmosphere
Freshwater Lakes
Saline lakes/Inland Seas
Soil Moisture
Rivers
Easily available amount of freshwater*

5. Freshwater available for human use
Earth’s water supply
Actual % on Earth
Oceans
97.2%
Glaciers/Icecaps
2%*
Groundwater
.62%*
Atmosphere
.009%*
Freshwater Lakes
.008%*
Saline lakes/Inland Seas
.001%*
Soil Moisture
Rivers
.0001%*
Easily available amount of freshwater*
2.6291%

6. Why is water so important???
Our bodies are more than ½ water – our bodies need it to survive!
We use it for many things….

7. Almost everything you do requires water….
Showering, brushing teeth, washing dishes and clothes,…
And even eating a pizza!
Farms need water to grow the tomatoes and wheat for your pizza, the cheese comes from a cow that drank water and the grain is grown using water.

8. The major ways people use water:
* Farming – about 40% of water used in the U.S. goes toward crops and livestock
Irrigation: supplying water to land (from aquifers, rivers, or lakes) to grow crops

9. The major ways people use water:
Industry – water used to:
Cool down machines
Separate chunks of coal when mining
Example:
Process of making 1 car can require about 50x the car’s weight in water – the process begins with the mining of minerals and ends with the final washing as the car rolls out of the factory

10. The major ways people use water:
Transportation
Recreation

11. The major ways people use water:
Fisheries & Aquaculture
The science and business of raising and harvesting fish in a controlled situation.
Negative: Can cause pollution!
Positive: Helps maintain population of fish in rivers & lakes

12. The major ways people use water:
ENERGY
Dams
Hydroelectric dam: as water rushes through, the dam turns turbines that generate electricity.
May also be used to create a reservoir
Potential problem:
Blocks flow of rich soil to valley below dam
Fish cannot reach breading grounds – “fish ladder”
Locks

13. Locks
Lock system video

14. Society depends on clean and safe water
Fresh water can contain a variety of harmful substances and organisms – some are present naturally, others are there because of pollution.
When the concentration of these substances are high, they can harm people

15. Society depends on clean and safe water
Substance
Common Source
Max Allowed in Parts Per Million
Copper
Natural deposits; household pipes
1.3
Cyanide
Various factories
0.2
Lead
0.015
Mercury
Natural deposits; refineries & factories; landfills; crop fields
0.002
Nitrite
Water running off fertilized fields; sewage leaks; natural deposits 1
EPA sets standards for safe, clean drinking water
Water providers test water in their area and compare with EPA standards

16. Treatment of Drinking Water
Clean water - how it's made

17. Sewage Systems
Collects and treats wastewater from a city or town

18. Sources of water pollution
Point-source pollution
Pollution is easy to spot and laws can be enforced to stop it

19. Sources of water pollution
Nonpoint-source pollution
Runoff from streets, lawns, construction sites, etc

20. Sources of water pollution
Homes
Cities
Sewage
Farms
Shipping, Boating, & Oil Transport

21. Water pollution can be PREVENTED
Factories can maintain pipelines and equipment
Inspect transportation to ensure there are no leaks
Reduce amount of toxic waste from industries
Construction companies can design projects to reduce pollution that new construction can cause
New techniques in farming
Choose organic foods
Proper disposal of chemicals

22. Water shortages threaten society
Global problem
Overuse can cause water shortages
Americans use an average of gallons of water each day!

23. Conservation Use less water Reuse water Recycle water
There are so many things we can do!