1. Chapter 22 Water Pollution

2. Types of Water Pollution
Any physical or chemical change in water that adversely affects the health of humans and other organisms
Eight categories
____________________
_____________________

3. 1. Sewage Wastewater from drains or sewers
Causes 2 serious environmental problems:
1. _____________________
Fertilization of water by high levels N and P
2. Increase in Biological Oxygen Demand (BOD)
__________________________________________________________________________________
____ _______________

4. Sewage

5. Sewage: Eutrophication
Oligotrophic
Unenriched, clear water that supports small populations of aquatic organisms

6. Sewage: Eutrophication
Slow-flowing stream, lake or estuary enriched by inorganic plant and algal nutrients such as phosphorus

7. 2. Disease-causing Agents
Infectious organisms that cause diseases
from wastes of infected individuals
Examples:
____________________________________________________________________________
India

8. 3. Sediment Pollution
Excessive amounts of suspended soil particles. From:
_____________________
Why Is This Bad?
Limits light penetration
Covers aquatic animals and plants
Brings insoluble toxins into waterways

10. 4. Inorganic Plant and Algal Nutrients
N and P that stimulate the growth of plants and algae
Harmful in large concentrations
Sources:
__________________________________________________________________________
Causes:

11. Inorganic Plant and Algal Nutrients: The Dead Zone

12. 5. Organic Compounds Chemicals that contain carbon atoms
Dangerous!
Chemicals that contain carbon atoms
Natural examples: sugars, amino acids, and oils
Human-made examples: _____________________________________

13. Volatile Organic Compounds in Groundwater

14. 6. Inorganic Chemicals
Contaminants that contain elements other than carbon
Do not degrade easily
Examples:
Lead-
Mercury-
Found in old paint, industrial pollutants, leaded gasoline
bioaccumulates in the muscles of top predators of the open ocean

15. 7. Radioactive Substances
Unstable isotopes that emit radiation
Sources:
Mining
Processing radioactive materials
Nuclear power plants
Natural sources

16. 8. Thermal Pollution Factories release heated water into waterways
Why is this bad?
Organisms affected
________________________________________________________________________
____________________________________

17. Two Types of Water Pollution
1. Point Source Pollution
__________________________________________________________________________
2. Non-point Source Pollution
_______________________________________________________________________________________________________________
_____________________________________

18. Water Pollution from Agriculture
Agriculture is ____________________
Animal wastes and plants residues have high BOD
Chemical pesticides
Almost all streams and rivers are polluted with agricultural pesticides
Important****
There is NO regulation!!!!

19. Municipal Water Pollution

20. Industrial Wastes in Water
Different industries generate different pollutants
Food processing plants- high BOD
Paper mills- High BOD and toxic compounds
Many industries recover toxins before they go into the waste stream
Green Chemistry

21. Groundwater Pollution

22. Water Pollution in Other Countries
Lake Maracaibo, Venezuela
Po River, Italy
Ganges River, India
Used for bathing and washing clothing
Sewage and industrial waste discharged into river
Ganga Action Plan initiated by government
Construction of 29 sewage treatment plants

23. Purification of Drinking Water
In US most municipal water supplies are treated

24. Purification of Drinking Water
Treated water distributed to customers

25. Purification of Drinking Water
Chlorine Dilemma
Chlorine byproducts are linked to numerous cancers, miscarriages and birth defects
Peru
Fluoridation
Prevents tooth decay
Linked to cancer, kidney disease

26. Municipal Sewage Treatment

27. Laws Controlling Water Pollution
Citizen Watchdogs to Monitor Pollution
Safe Drinking Water Act (1974)
Set uniform federal standards for drinking water including maximum contaminant level
Clean Water Act (1972)
EPA sets up and monitors National Emissions Limitations
Effectively improved water quality from point sources