1. Water Pollution

2. Types and Sources of Water Pollution  #1 problem - Eroded soils  Organic wastes, disease-causing agents  Chemicals, nutrients  Radioactive stuff, heat

3. Point and Nonpoint Sources NONPOINT SOURCES Urban streets Suburban development Wastewater treatment plant Rural homes Cropland Factory Animal feedlot POINT SOURCES

4. Major Problem: Drinking Water  Safe Drinking Water Act  EPA: Maximum contaminant levels (municipal, but not rural and private)  1/2 of world’s people drink polluted water

5. Pollution of Surface Water: Streams  D.O., B.O.D., fecal coliform bacteria count

6. Pollution of Surface Water: Lakes  Cultural eutrophication  Slow turnover  Accumulation of nutrients, excessive plant growth, algae blooms

7. Case Study: The Great Lakes

8. Mississippi River Basin Missouri River Ohio River Mississippi River LOUISIANA Mississippi River Depleted Oxygen Gulf of Mexico Dead Zone

9. Suffocated fish Low dissolved oxygen Decreased fish population Altered food web Thermal Pollution

10. Groundwater Pollution: Sources  Low flow rates  Few bacteria  Cold temperatures Coal strip mine runoff Pumping well Waste lagoon Accidental spills Groundwater flow Confined aquifer Discharge Leakage from faulty casing Hazardous waste injection well Pesticides Gasoline station Buried gasoline and solvent tank Sewer Cesspool septic tank De-icing road salt Unconfined freshwater aquifer Confined freshwater aquifer Water pumping well Landfill

11. Groundwater Pollution Prevention  Monitoring aquifers - expensive  Leak detection systems  Strictly regulating hazardous waste disposal  Protecting recharge areas - aquifer classifications  Protecting recharge areas - aquifer classifications

12. Ocean Pollution: dumping and oil

13. Oil Spills  Sources: offshore wells, tankers, pipelines and storage tanks  Effects: death of organisms, loss of animal insulation and buoyancy, smothering  Significant economic impacts  Short-term cleanup problems - beaches, wildlife  Long-term cleanup problem - persistence (decades)

14. Case Study: Chesapeake Bay  Largest US estuary  Relatively shallow  Slow “flushing” action to Atlantic  Major problems with dissolved O 2

15. Solutions: Preventing and Reducing Surface Water Pollution Nonpoint Sources Point Sources  Reduce runoff  Buffer zone vegetation  Reduce soil erosion  Reduce soil erosion  Water Pollution Control Act (1972)  Water Pollution Control Act (1972)  Clean Water Act (1977) - set effluent standards - secondary treatment  Clean Water Act (1977) - set effluent standards - secondary treatment

16. Technological Approach: Septic Systems  Require suitable soils and maintenance

17. Technological Approach: Sewage Treatment  Mechanical and biological treatment

18. Technological Approach: Advanced Sewage Treatment  Removes specific pollutants

19. Technological Approach: Using Wetlands to Treat Sewage