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Water Pollution Chapter 19. “Today everybody is downwind or downstream from somebody else.” William Ruckelshaus. Key Concepts. Types, sources and effects of water pollution Major pollution problems of surface water Major pollution problems of groundwater
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Water PollutionChapter 19 “Today everybody is downwind or downstream from somebody else.” William Ruckelshaus
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
Fig. 19-3 p. 485 Types and Sources of Water Pollution • Point sources • Nonpoint sources • Biological oxygen demand • Water quality
NONPOINT SOURCES Rural homes Cropland Urban streets Animal feedlot POINT SOURCES Suburban development Factory Wastewater treatment plant Point and Nonpoint Sources
Pollution of Streams • Oxygen sag curve • Factors influencing recovery
Fig. 19-7 p. 491 Pollution of Lakes • Eutrophication • Slow turnover • Thermal stratification
Groundwater Pollution: Sources • Low flow rates • Few bacteria • Cold temperatures Hazardous waste injection well Pesticides Coal strip mine runoff De-icing road salt Buried gasoline and solvent tank Cesspool septic tank Pumping well Gasoline station Waste lagoon Water pumping well Sewer Landfill Leakage from faulty casing Accidental spills Discharge Unconfined freshwater aquifer Confined aquifer Fig. 19-10 p. 494 Confined freshwater aquifer Groundwater flow
Groundwater Pollution Prevention • Monitoring aquifers • Leak detection systems • Strictly regulating hazardous waste disposal • Storing hazardous materials above ground
Fig. 19-14 p. 500 Case Study: Chesapeake Bay • Largest US estuary • Relatively shallow • Slow “flushing” action to Atlantic • Major problems with dissolved O2
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
Reduce runoff Buffer zone vegetation Reduce soil erosion Clean Water Act Water Quality Act Solutions: Preventing and Reducing Surface Water Pollution Nonpoint sources Point sources
Technological Approach: Septic Systems • Require suitable soils and maintenance
Technological Approach: Sewage Treatment • Mechanical and biological treatment
Technological Approach: Advanced Sewage Treatment • Removes specific pollutants
Fig. 19-11 p. 495 Drinking Water Quality • Bottled water • Safe Drinking Water Act • Maximum contaminant levels