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 Reduction and prevention of water pollution Drinking water quality

Types and Sources of Water Pollution Point sources Nonpoint sources Biological oxygen demand

Fig. 19-3 p. 485

Water quality

Point and Nonpoint Sources

NONPOINT SOURCES Rural homes Urban streets Suburban development POINT SOURCES Wastewater treatment plant Cropland Animal feedlot Factory

Pollution of Streams Oxygen sag curve Factors influencing recovery

Pollution of Lakes Eutrophication Slow turnover Thermal stratification

Fig. 19-7 p. 491

Case Study: The Great Lakes

Groundwater Pollution: Sources Low flow rates Few bacteria Cold temperatures

Coal strip mine runoff Hazardous waste injection well Pesticides De-icing road salt Pumping well Waste lagoon Gasoline station Water pumping well Landfill Accidental spills Buried gasoline and solvent tank Cesspool septic tank Sewer Leakage from faulty casing Discharge Confined aquifer Groundwater flow

Fig. 19-10 p. 494

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

Ocean Pollution

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

Fig. 19-14 p. 500

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

Solutions: Preventing and Reducing Surface Water Pollution

Nonpoint sources Point sources

Reduce runoff Buffer zone vegetation Reduce soil erosion Clean Water Act Water Quality Act

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

Technological Approach: Using Wetlands to Treat Sewage

Drinking Water Quality

Bottled water Safe Drinking Act Water Maximum contaminant levels

Fig. 19-11 p. 495