Transcript Document
Water Pollution
G. Tyler Miller’s
Living in the Environment
14th Edition
Chapter 22
Key Concepts
Types, sources, and effects of water pollutants
Major pollution problems of surface water
Major pollution problems of groundwater
Reduction and prevention of water pollution
Drinking water quality
Types, Effects and Sources of Water
Pollution
Point sources
Refer to Tables 22-1 and
22-2 p. 492 and 493
Nonpoint sources
Fig. 22-3 p. 494
Water quality
Point and Nonpoint Sources
NONPOINT SOURCES
Rural homes
Cropland
Urban streets
Animal feedlot
Suburban
development
POINT
SOURCES
Factory
Wastewater
treatment
plant
Fig. 22-4 p. 494
Pollution of Streams
Oxygen sag curve Factors influencing recovery
Fig. 22-5 p. 496
Pollution of Lakes
Eutrophication
Fig. 22-7 p. 499
Case Study: The Great Lakes
Fig. 22-8 p. 500
Groundwater Pollution: Causes
Low flow rates Few bacteria
Low oxygen
Cold temperatures
Hazardous waste injection well
Pesticides
Coal strip
mine runoff
De-icing
road salt
Pumping
well
Waste lagoon
Gasoline
station
Water pumping
well Landfill
Buried gasoline
and solvent tank
Cesspool
septic tank
Sewer
Leakage from faulty
casing
Accidental
spills
Discharge
Confined aquifer
Groundwater
flow
Fig. 22-9 p. 502
Groundwater Pollution Prevention
Monitor aquifers
Find less hazardous substitutes
Leak detection systems
Strictly regulating hazardous waste disposal
Store hazardous materials above ground
Ocean Pollution
Fig. 22-11 p. 504
Case Study: Chesapeake Bay
Largest US
estuary
Relatively shallow
Slow “flushing”
action to Atlantic
Major problems with dissolved O2
Fig. 22-13 p. 506
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
Clean Water Act
Buffer zone
vegetation
Water Quality Act
Reduce soil erosion
Technological Approach: Septic
Systems
Require suitable soils and maintenance
Fig. 22-15 p. 510
Technological Approach: Sewage
Treatment
Physical and biological treatment
Fig. 22-16 p. 511
Technological Approach: Advanced
(Tertiary) Sewage Treatment
Uses physical and chemical processes
Removes nitrate and phosphate
Expensive
Not widely used
Technological Approach: Using
Wetlands to Treat Sewage
Fig. 22-18 p. 513
Drinking Water Quality
Purification of urban drinking water
Protection from terrorism
Purification of rural drinking water
Safe Drinking Water Act
Maximum contaminant levels (MCLs)
Bottled water