1. Bell Ringer
Runoff soaks into the ground through [ permeable / impermeable ] rock layers into an unconfined aquifer. It first flows through the zone of [ aeration / saturation ] and ends up with other water in the zone of [ aeration / saturation ].

2. Today
5.6 Notes – Water Use
California Heist

3. Water Use

4. Freshwater Only 2.5% of Earth’s water is fresh water
The rest (____%) is ____ water
97.5
salt

5. Freshwater Of the Earth’s freshwater:
70% is frozen in glaciers or ice caps (so not available for human use)
30% is groundwater
0.3% is surface water (lakes, rivers, etc.)
Much of Earth’s fresh water is not available for human use

6. Freshwater
Of all the water on Earth, only % is available to humans, so we need to protect the water we do have!
Water Conservation – the preservation and protection of water resources
Using less water and keeping water free of pollution

7. Freshwater Use in the US
Almost half of the US’s freshwater is used for thermoelectric power
Review: The US’s main source of electricity is burning __________
To produce electricity, fossil fuels are burned to heat up a vat of ______ to produce steam to turn a ________
fossil fuels
water
turbine

8. Freshwater Use in the US
Which of these energy sources could we use without having to heat up a vat of water?
natural gas
solar energy
bacterial
digestion
coal
petroleum/oil
wind energy
geothermal
energy
burning biomass
hydroelectric
power

9. Freshwater Use in the US
Conservation – using alternative energy sources that do not require large vats of water

10. Water Usage About 1/3 of the US’s freshwater is used for irrigation
Irrigation – watering crops to promote growth

11. Water Usage
Irrigation is an extremely wasteful practice because nearly 80% of the water used is lost to evaporation or seeping into the ground rather than watering the plants

12. Freshwater Use in the US
Conservation – using trickle irrigation
Trickle irrigation – pipes trickle out small amounts of water over a long period of time instead of a burst of water in a short period of time
Water is better able to soak into the roots
However, trickle irrigation is significantly more expensive than traditional irrigation

13. Freshwater Use in the US
Less than 10% is used domestically (in homes)
However, this is the place where YOU can make the biggest change

14. Freshwater Use in the US
The average American uses about gallons of water a day!
What are some ways we use water in our homes?
In comparison, the average African family uses only gallons a day!

15. Freshwater Use in the US
Conservation
Low-flow toilets use less water per flush (1.6 gallons instead of 5-7 gallons)
However, most consumers find that it doesn’t effectively remove toilet paper or solid waste, so they end up flushing twice ( = 3.2 gallons)
Dual-flush toilets have two options for flushing: half flush for liquid waste and full flush for solid waste
Uses less water than a traditional toilet, but is more expensive

16. Other Methods of Conservation:
Use high-efficiency washing machines (determines how much clothes are in the washer and adjusts the water level accordingly)
Only run full loads in dishwasher
Take shorter showers
Turn off faucets when not in use (like while you’re brushing your teeth)
Fix any leaky faucets
Just one leaky faucet can waste 350 gallons a year!

17. Overuse of Aquifers
The current rate of freshwater use is greater than ever before
This has put bodies of freshwater, especially underground aquifers, in danger

18. Overuse of Aquifers
If groundwater is pumped faster than it is recharged (naturally refilled), the water table will drop below the drilled wells, creating a cone of depression
Cone of Depression – sinking of a water table around a well

19. Overuse of Aquifers
Subsidence – the sinking of the land around an overused aquifer (like a deflated balloon)

20. Overuse of Aquifers
Saltwater Intrusion – when overpumping in coastal areas caused saltwater to be pulled into the freshwater aquifer
Contaminates the fresh water, making the aquifer unusable

21. Overuse of Aquifers Possible Solution:
Desalination – the process of removing salt from salt water in order to use the water
However, not very effective and very expensive, so not a viable solution

22. Freshwater Availability
Water is not evenly distributed around the world or even in the US, so some areas have abundant supply while others do not have enough to support their needs

23. Freshwater Availability
Eastern US – abundant supply, so able to use water in a variety of ways (cooling, hydroelectric power, etc.)
Western US – very little precipitation, so water is primarily used for irrigation

24. Freshwater Availability
In California, cities have to get water shipped in from other locations to meet the needs of their populations

25. Freshwater Availability
Worldwide, water availability is an even more serious situation, especially in northern Africa, the Middle East, India, and Australia

27. You have just bought a house and hire a company to drill a well for you. They come back with four proposals. Which one do you choose?

28. What is good about Well 1?
Clean water, no pollution
What is bad about Well 1?
Shallow, won’t last long

29. What is good about Wells 2&3?
Deep, won’t run out
What is bad about Wells 2&3?
Can become polluted (Well 2 from industrial waste, Well 3 from sewage)

30. Which well would you choose?
What is good about Well 4?
Clean water, no pollution
What is bad about Well 4?
Going to be really expensive to drill
Which well would you choose?