1. Water Pollution Chapter 20

2. Point Sources of Pollution Water discharged from industry Water discharge of treated sewage Point sources – pollutants directly discharged into bodies of water

3. Nonpoint Sources of Pollution Nonpoint sources – pollutants that come from many different sources and are difficult to identify; diffuse into soil (or air) and the plume seeps into bodies of water or runoff into bodies of water

4. Fig. 20-11, p. 542 Hazardous waste injection well 10 Pumping well Gasoline station Water pumping well Discharge Unconfined freshwater aquifer Confined freshwater aquifer Confined aquifer Principal Sources of Groundwater Contamination in the U.S. 2 4 6 3 5 11 1 9 8 7

5. Principle Sources of Groundwater Contamination 1.Pesticides and fertilizers 2.Buried gasoline and solvent tanks 3.Accidental industrial spills 4.Industrial waste lagoons and reservoirs 5.Hazardous waste wells 6.Landfills 7.Cesspools and septic tanks 8.Sewer 9.Salt for de-icing roads 10.Coal strip-mining 11.Polluted air 12.Saltwater intrusion

6. Groundwater Contamination  Groundwater cannot cleanse itself of degradable wastes as quickly as surface water because: 1.Slower flow (less than 0.3 meters per day) 2.Lower DO-dissolved oxygen (O 2 promotes decomposition) 3.Smaller populations of decomposing bacteria 4.Colder temperatures slow down reactions  Non-degradable wastes, such as lead, DDT, MTBE and arsenic, remain permanently.

7. Contamination of Rivers, Lakes, and Streams Polluted rivers and streams recover rapidly; lakes recover slowly. Sources of pollution in rivers, lakes, and streams: 1.Industry and mines 2.Agriculture and feedlots 3.Human sewage and garbage 4.Drought and warm weather

8. Contamination of Rivers, Lakes, and Streams Problems caused by excess pollution: 1.Contaminated drinking water 2.Health hazards and disease 3.Biomagnification of harmful chemicals 4.Habitat destruction 5.Fish kills 6.Algal blooms (cultural eutrophication)

9. Even though it is vast, the ocean still has pollution problems: 1.Dead Zones – O 2 depleted (hypoxic) areas caused by algal blooms Polluting Oceans - Coastal areas are affected most by ocean pollution; deeper waters, oceans can dilute, disperse, and degrade large amounts of pollutants

10. Even though it is vast, the ocean still has pollution problems: 1.Dead Zones – O 2 depleted (hypoxic) areas caused by algal blooms 2.Oil pollution – caused by runoff and tanker accidents/spills Polluting Oceans - Coastal areas are affected most by ocean pollution; deeper waters, oceans can dilute, disperse, and degrade large amounts of pollutants

11. MAJOR OIL SPILLS  1989: Exxon-Valdez (oil tanker) Hit rocks and released 10.8 million gallons of oil into Prince William Sound, Alaska

12. MAJOR OIL SPILLS  2010: Deepwater Horizon (drilling platform) Explosion damaged underwater pipes and caused sea- floor gusher to flow into ocean for 3 months, spilling 210 million gallons of oil (into the Gulf of Mexico.)

13. Polluting Oceans  Major environmental problems - VOC’s: (volatile organic compounds) kill aquatic organisms & larvae Floating tar globs: kill seabirds and marine mammals (coat feathers and fur) Heavy oil components: sink to floor and harm bottom dwellers

14. Polluting Oceans  Economic impact - Damages to: fishing and tourism industries Clean-up costs: $4 billion Exxon-Valdez $20 billion Deepwater (estimated)

15. Polluting Oceans  Cleaning up oil spills: 1.Floating booms 2.Skimmers 3.Absorbent materials 4.Chemicals 5.Fires 6.Bacteria that degrade oil

16. Polluting Oceans  Prevention of oil spills is the key: Use tankers with double hulls

17. Major Water Pollutants Have Harmful Effects - Pathogens  BACTERIA Sources: Human and animal wastes Human effects: Examples – typhoid fever, cholera, bacterial dysentery  VIRUSES Sources: Human and animal wastes Human effects: Examples – Hepatitis B Diarrhea, vomiting, etc. Enlarged liver, jaundice

18. Major Water Pollutants Have Harmful Effects - Pathogens  PROTOZOANS Sources: Human and animal wastes Human effects: Examples – Amoebic dysentery  PARASITIC WORMS Sources: Human and animal wastes Human effects: Examples – Schistosomiasis Diarrhea, vomiting, etc. Anemia, chronic fatigue

19. Major Water Pollutants Have Harmful Effects  BIODEGRADABLE ANIMAL WASTES Sources: Sewage and feedlots Environmental effects: Deplete DO  BIODEGRADABLE PLANT WASTES Sources: Pulp mills, food processing plants Environmental effects: Deplete DO

20. Major Water Pollutants Have Harmful Effects  NITRATES and PHOSPHATES Sources: Fertilizer runoff, sewage treatment Environmental effects: Excessive algal growth (decreased photosynthesis & DO) Human effects: cancers, blue baby syndrome

21. Major Water Pollutants Have Harmful Effects  OIL, GAS, and ORGANIC SOLVENTS Sources: Industry, households Environmental effects: Toxic to aquatic systems Human effects: Toxic, carcinogenic Example: MTBE (methyl tertiary butyl ether) Gasoline additive used since 1977 Carcinogen Has been phased out since 2005, but has already contaminated aquifers across the country

22. Major Water Pollutants Have Harmful Effects  PESTICIDES Sources: Farms, households Environmental effects: Toxic to aquatic organisms and wildlife Human effects: poisonous, possible lethal  ACIDS and BASES Sources: Agriculture, industry, households Environmental effects: Alters pH

23. Major Water Pollutants Have Harmful Effects  SALINE Sources: Saltwater intrusion, salt for de-icing roads, salinization runoff Environmental effects: Harmful to aquatic species and plants Human effects: Gastrointestinal issues  SOIL and SILT Sources: Runoff from agriculture and mining Environmental effects: Disrupts photosynthesis

24. Major Water Pollutants Have Harmful Effects  LEAD, MERCURY, ARSENIC Sources: Mining, industry, landfills Environmental effects: Toxic to aquatic organisms Human effects: Toxic, lethal, carcinogens  PLASTICS Sources: Garbage Environmental effects: Harmful to aquatic animals

25. Major Water Pollutants Have Harmful Effects  HEAT Sources: Power and industrial plants Environmental effects: Harmful to aquatic organisms, decreases DO  PCB’s (polychlorinated biphenyl) Sources: Used from 1929-1977 in lubricants, hydraulic fluids, insulation, paints, fire retardant fabrics, adhesives, etc. Human effects: Carcinogen

26. Using Laws to Protect Drinking Water Quality 1.1972: Clean Water Act  Set water quality standards for allowed levels of pollutants in surface water  Established monitoring, enforcement and management plans 2.1974: Safe Drinking Water Act  Sets maximum contaminant levels for pollutants in drinking water that affect human health

27. Major Water Pollutants Have Harmful Effects  10% of world’s population lacks access to clean drinking water  3.4 million people (mostly children) die each year from water-related diseases

28. Drinking Water Treatment

29. Wastewater Sewage Treatment

30. effluent Sludge is disposed of in landfill, ocean, cropland, pasture, rangeland

31. Solutions: Septic Tank System 1 2 3 4 5 6 1.Sewage is discharged into a septic tank 2.Grease and oil rise to the top 3.Solids fall to the bottom - decomposed by bacteria

32. Solutions: Septic Tank System 1 2 3 4 5 6 4.Wastewater is discharged into a field through small holes in pipes 5.Soil filters out some pollutants 6.Soil bacteria decompose biodegradable materials