1. Water Pollution Chapter 19 “Today everybody is downwind or downstream from somebody else.” William Ruckelshaus

2. Key Concepts Types, sources and effects of water pollution Major pollution problems of surface water Major pollution problems of groundwater Reduction and prevention of water pollution Drinking water quality

3. Types and Sources of Water Pollution Point sources Nonpoint sources Biological oxygen demand Water quality Fig. 19-3 p. 485

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

5. Pollution of Streams Oxygen sag curveFactors influencing recovery

6. Pollution of Lakes Fig. 19-7 p. 491 Eutrophication Slow turnover Thermal stratification

7. Case Study: The Great Lakes

8. Low flow rates Few bacteria Groundwater Pollution: Sources Cold temperatures Fig. 19-10 p. 494 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

9. Groundwater Pollution Prevention Monitoring aquifers Leak detection systems Strictly regulating hazardous waste disposal Storing hazardous materials above ground

10. Ocean Pollution

11. Case Study: Chesapeake Bay Fig. 19-14 p. 500 Largest US estuary Relatively shallow Slow “flushing” action to Atlantic Major problems with dissolved O 2

12. Oil Spills Sources: offshore wells, tankers, pipelines and storage tanks Effects: death of organisms, loss of animal insulation and buoyancy, smothering Significant economic impacts Mechanical cleanup methods: skimmers and blotters Chemical cleanup methods: coagulants and dispersing agents

13. Solutions: Preventing and Reducing Surface Water Pollution Reduce runoff Buffer zone vegetation Reduce soil erosion Clean Water Act Water Quality Act Nonpoint sourcesPoint sources

14. Technological Approach: Septic Systems Require suitable soils and maintenance

15. Technological Approach: Sewage Treatment Mechanical and biological treatment

16. Technological Approach: Advanced Sewage Treatment Removes specific pollutants

17. Technological Approach: Using Wetlands to Treat Sewage

18. Drinking Water Quality Fig. 19-11 p. 495 Bottled water Safe Drinking Water Act Maximum contaminant levels