1. Water & Water Pollution
Chapters 20-21

2. Household Water Use

3. Household Water Use Activity Daily Consumption Brushing teeth 19-39 L
Washing hands/face
4-8 L
Showering
75-80 L
Taking a bath L
Dishwasher
56-60 L
Toilet flushing
16-21 L (per flush)

4. Use the table on the previous slide & calculate your average daily water consumption

5. Household Water Use Average person uses 300 L daily
Small percentage is for drinking and cooking

6. Industrial Water Use 44% of all fresh water is used by industry
Power source
Coolant
Disposes waste
15,000 L used to produce steel for 1 washing machine

7. Agricultural Water Use
Single largest consumer of water in US (47%)
Irrigation
Flood irrigation (flooding flat land)
Furrow irrigation (water into ditches near crops)
Overhead irrigation (sprinklers)

8. Types of Irrigation

9. Effects of Water Use on Ecosystems
Dams, draining swamps, changing stream courses
Damages habitat

10. Las Vegas

11. Las Vegas
Water from Lake Mead
Created by Hoover Dam
Slowly depleting

12. Lake Mono, CA Mineral-rich water from surrounding mountains
As water evaporates, it leaves the minerals behind
1940 they started diverting this water to other areas
Increased salt concentration
Affects algae & shrimp, which feeds gulls & other migratory birds

13. Water Sources

14. Surface Water Streams Lakes Ponds Melting snow Rain Melting ice caps
Colorado River

15. Aquifers
Water that has seeped down into the spaces between soil particles and eventually into the bedrock to become groundwater
Top of the saturated layer of rocks is the water table
Wells are used to access the aquifer

16. Aquifers

17. Overdraft Water gets used faster than it is replenished
Salt water can get into an aquifer & make the water unpotable
Bedrock that stores the water can weaken
Land may sink or “subside”

18. Water Treatment

19. Removing Salts Desalination
Can be used for drinking, cooking, and irrigation

20. Distilling Heat water to boiling Water vapor is collected & cooled
Liquid fresh water is collected

21. Reverse Osmosis
Salt water gets forced through a strainer that traps the salt and only lets fresh water pass
The pores in the membrane are too small for salt to pass through

22. Freezing Salt water gets frozen It separates into ice and salty slush
The ice can be melted for fresh water

23. Water Purification Removes harmful chemicals & microorganisms
Makes water potable
Sedimentation
Filtration
Aeration
Sterilization

24. Sedimentation & FIltration
Coagulation- chemicals added to water to make sediments clump together
Sedimentation- particles settle to the bottom
Filtration- sent through a fine filter

25. Aeration & Sterilization
Water may still contain dissolved gases or bacteria that cannot be filtered out
Aeration- exposing it to air by spraying it into the air, where it mixes with “good” bacteria that break the bad stuff down
Sterilization- the added “good” bacteria are killed through extreme heat or very small concentrations of chlorine/ozone

26. Water Pollution

27. History of Water Pollution
19th century people would dump garbage into the most convenient waterway
In London, the smell of the River Thames was so bad, that Parliament had to close on several occasions!

28. History of Water Pollution
This build up of bacteria and pollution led to the spread of several dangerous diseases:
Cholera
Typhoid fever (killed 90,000 in Chicago in 1885)
dysentary

29. History of Water Pollution
Ocean dumping is still a common practice today!

30. Top 2 Sources of Water Pollution
1st: Runoff from Agriculture
2nd: Sewage

31. It goes untreated before dumping in many developing countries.
Sewage
Contains organic waste from humans and industry
Toilets
Sinks
Washing machines
It goes untreated before dumping in many developing countries.

32. Sewage
The US dumps approximately 8.9 trillion Liters of sewage into the ocean every year

33. Sewage-Treatment Plant
Processes raw sewage before it is dumped
Solid waste = Sludge

35. Pathogens Disease-causing organisms
Pathogens carried by water result in more human illness and death than any other environmental factor

36. Schistosomiasis Microscopic worms Enter through skin
Attack liver, bladder & intestines
Africa, Middle East, Egypt

37. Malaria Passed through bite of infected mosquito
Not directly through water
Attack liver
Dirty Water = breeding ground for bugs

38. Types of Pollutants

39. Chemical Pollutants
Toxic chemicals
Directly harmful to living things

40. Inorganic Chemicals
Usually by-products of metal treatment and plastic production
Acids
Salts
Heavy metals (high mass number)
Mercury
Lead

41. Mad Hatters Disease
Mercury from the softening of materials used to make hats
Tremors
Hallucinations
Anxiety
Insanity
2:05

42. Mercury Poisoning Usually from plastics factories
Runoff gets into waterways & fish absorb it
Early signs: local animals behaving strangely
Brain damage, paralysis, liver, kidney damage

43. Mercury Poisoning Fish w/ high levels of mercury: Shark Swordfish
Largemouth bass
Tuna
Mahi mahi

44. Organic Chemicals
Gasoline
Oils
Plastics
Pesticides & fertilizers

45. Eutrophication
Lakes and ponds can be changed by excess plant nutrients
From fertilizers and other organic wastes
Overgrowth of algae & decomposing bacteria
Lowers the available oxygen in the water
Fish numbers decline

47. Eutrophication