1. Chapter 21 Water Pollution

2. Types of Water Pollution  Water pollution  Any physical or chemical change in water that adversely affects the health of humans and other organisms 1. Sewage 2. disease-causing agents 3. sediment pollution 4. inorganic plant and algal nutrients 5. organic compounds 6. inorganic chemicals 7. radioactive substances 8. thermal pollution

3. 1. Sewage  Causes 2 serious environmental problems: 1. Enrichment  Fertilization of water by high levels N and P 2. Increase in Biological Oxygen Demand (BOD)  BOD-amount of oxygen needed by microorganisms to decompose biological wastes  BOD Dissolved Oxygen (DO)

4. Sewage

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

6. Sewage: Eutrophication  Eutrophic  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:  Typhoid, cholera, bacterial dysentery, polio, and infectious hepatitis India

8. 3. Sediment Pollution  Excessive amounts of suspended soil particles. From:  erosion of agricultural lands lands  logging  degraded stream banks  overgrazing  mining  construction

9. 4. Inorganic Plant and Algal Nutrients  Ex: N and P  Sources:  Human and animal wastes, plant residues, atmospheric deposition, and fertilizer runoff  It Causes:  Enrichment, bad odors, and a high BOD

10. Inorganic Plant and Algal Nutrients: The Dead Zone Hypoxia

11. 5. Organic Compounds  Chemicals that contain carbon atoms  Natural examples: sugars, amino acids, and oils  Human-made examples: pesticides, solvents, industrial chemicals, and plastics, medication Dangerous!

12. Volatile Organic Compounds in Groundwater

15. Los Angeles

16. Seal Beach, CA

17. Depicts 60,000 plastic bags, the number used in the US every five seconds.

20. 2 million bottles the number used by Americans every 5 minutes!

21. 6. Inorganic Chemicals  Contaminants that contain elements other than carbon (ex: acids, salts, heavy metals)  Do not degrade easily  Examples:  Lead-  Mercury-

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

23.  Why is this bad?  Temperature affects reproductive cycles, digestion rates, and respiration rates  Warm water holds less DO than cold water 8. Thermal Pollution  Factories release heated water into waterways

24. Two Types of Water Pollution 1. Point Source Pollution  Water pollution that can be traced to a specific origin 2. Non-point Source Pollution  Pollutants that enter bodies of water over large areas rather than being concentrated at a single point of entry

25. Water Pollution from Agriculture  Agriculture is leading source of water pollution in US  Animal wastes and plants residues have high BOD  Chemical pesticides  Almost all streams and rivers are polluted with agricultural pesticides Important* There is little regulation!

26. Municipal Water Pollution

27. Industrial Wastes in Water  Different industries generate different pollutants  Food processing plants- high BOD  Paper mills- High BOD and toxic compounds  Green Chemistry

28. Groundwater Pollution

29. Water Pollution in Other Countries  Lake Maracaibo, Venezuela  Po River, Italy  Ganges River, India

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

31. Purification of Drinking Water  Treated water distributed to customers

32. 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

33. Municipal Sewage Treatment

34. Laws Controlling Water 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