1. 11.2 Water Use and Management
Page 296

2. How many people lack access to clean, reliable water?
1 Billion!

3. Global Water Use Agricultural Residential Industrial
The amounts vary depending on area, but there are 3 major uses of water:
Agricultural
Residential
Industrial

4. #1 - Residential water use
Biggest amount differences in this worldwide
Look at figure 5 on page 297
Which of the three main uses of water do
most of the countries use?
Agriculture
Look at table 1.
What is the biggest use of residential water?
Lawn and pools

5. Water Treatment
Water that is treated and made safe enough to drink is called POTABLE.
Things it removes:
1. Mercury, lead, arsenic – from pollution or naturally
Pathogens – organisms that cause illness or disease.
- Could be from being contaminated by sewage or animal feces.
Ex. Bacteria, viruses, protozoa, parasitic worms

6. Pop Quiz! Not really…
Try putting steps to water treatment in the right order! When you’re finished lets check them together.

7. Water Treatment Steps:
First Filtration – remove large organisms and trash
Coagulation – Alum is rapidly mixed to form sticky globs called Flocs. Bacteria and other impurities cling to the it and settle to the bottom.
Second Filtration – Layers of sand, gravel and coal filter
Chlorination – chlorine added to prevent bacteria growth
Aeration – air is forced thru water which releases gas & reduces odor and improves taste.
Additional Treatment – fluoride may be added for teeth or lime/sodium to soften water.

8. Water Treatment Video

9. #2 - Industrial Water Use
Most water is used to cool power plants!
19% of water used in the world.
Used to:
manufacture goods
Dispose of waste
generate power
ex – 1,000L = 1 kg aluminum
500,000L = car

10. #3 – Agricultural Water Use
67% of world wide water use
80% of water used in AGR. Evaporates before it reaches the plant roots.
In the U.S. the most common method is inefficient.

11. What % of water is used for industry?
B. 50%
C. 86%
D. 19%

12. Water that is safe enough to drink is called?
Pathogens
Potable
Reservoir
watershed

13. What is the first step to treating water?
Coagulation
Filtration
Chlorination
aeration

14. Water Management
Water Diversions – rivers can be diverted to carry water great distances that need it. (AQUADUCT)
Dams are built across a river to control the flow and Reservoirs build up behind it. Benefits: generate electricity, flood control, drinking, irrigation Cons: flooded ecosystems, blocks sediment to land below, breakage = death.

15. Water Conservation
1. In Agriculture: Drip irrigation – delivers water to roots 2. In Industry: Plans devised to conserve. The biggest is recycling cooling water and wastewater. 3. At home: low flow toilets/showers, water lawns at night, xeriscaping, turn off water when shaving/brushing teeth, wash only when full loads, etc.

16. Solutions for the future
Transporting Fresh Water
Ships can tow water from where available to where its needed in large plastic bags.
We are looking at doing this in alaska to CA.
Towing Icebergs to areas, but we don’t know how to efficiently do this yet.
Desalinification = process of removing salt from salt water. It consumes lots of energy which makes it expensive & therefore not an option for many.