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Living in the Environment

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Presentation on theme: "Living in the Environment"— Presentation transcript:

1 Living in the Environment
Water Pollution G. Tyler Miller’s Living in the Environment 14th Edition Chapter 22

2 The solution to pollution is dilution.
Water, Air, Land …. The solution to pollution is dilution.

3 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

4 Water makes us unique and gives life to Earth.

5 Section 1 Key Ideas What are major types and effects of water pollution? How do we measure water quality? Point versus Nonpoint sources What are the major sources of pollution?

6 What is water pollution?
Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or makes water unsuitable for desired usage.

7 What is water pollution?
WHO: 3.4 million premature deaths each year from waterborne diseases 1.9 million from diarrhea U.S. 1.5 million illnesses 1993 Milwaukee 370,000 sick

8 What is water pollution? Need to study Table 22-1 Page 492
Infectious Agents: bacteria and viruses often from animal wastes Oxygen Demanding Wastes: organic waste that needs oxygen often from animal waste, paper mills and food processing. Inorganic Chemicals: Acids and toxic chemicals often from runoff, industries and household cleaners

9 What is water pollution?
Organic Chemicals: oil, gasoline, plastics, detergents often from surface runoff, industries and cleaners Plant Nutrients: water soluble nitrates, ammonia and phosphates often from sewage, agriculture and urban fertilizers Sediment: soils and silts from land erosion can disrupt photosynthesis, destroy spawning grounds, clog rivers and streams Heat Pollution and Radioactivity: mostly from powerplants

10 How do we measure water quality
Bacterial Counts: Fecal coliform counts from intestines of animals None per 100 ml for drinking >200 per 100 ml for swimming Sources: human sewage, animals, birds, raccoons, etc. See table 22-2 on page 493 for diseases transmitted by contaminated drinking water.


12 How do we measure water quality
Dissolved Oxygen: BOD Biological Oxygen Demand…the amount of oxygen consumed by aquatic decomposers Chemical Analysis: looking for presence of inorganic or organic chemicals Suspended Sediment water clarity

13 How do we measure water quality
Indicator Species: organisms that give an idea of the health of the water body. Mussels, oysters and clams filter water

14 Types, Effects and Sources of Water Pollution
Point sources Refer to Tables 22-1 and 22-2 p. 492 and 493 Nonpoint sources Fig p. 494 Water quality

15 Point and Nonpoint Sources
Urban streets Suburban development Wastewater treatment plant Rural homes Cropland Factory Animal feedlot POINT SOURCES Fig p. 494

16 Major Sources of Water Pollution
Agriculture: by far the leader Sediment, fertilizers, bacteria from livestock, food processing, salt from soil irrigation Industrial: factories and powerplants Mining: surface mining toxics, acids, sediment


18 Section 2-3 Key Ideas Freshwater pollution: What are major problems in streams? Developed versus Developing Countries Lake Pollution: Why are lakes and reservoirs more vulnerable? What is Eutrophication?

19 Freshwater Stream Pollution
Flowing streams can recover from moderate level of degradable water pollution if their flows are not reduced. Natural biodegradation process Does not work if overloaded or stream flow reduced Does not work against non biodegradable pollutants

20 What factors will influence this oxygen sag curve?
Pollution of Streams Oxygen sag curve Factors influencing recovery Fig p. 496 What factors will influence this oxygen sag curve?

21 Two Worlds Developed Countries
U.S. and other developed countries sharply reduced point sources even with population and economic growth Nonpoint still a problem Toxic chemicals still problem Success Cuyahoga River, Thames River

22 Two Worlds Developing Countries: Serious and growing problem
Half of world’s 500 major rivers heavily polluted Sewage treatment minimal $$$ Law enforcement difficult 10% of sewage in China treated Economic growth with little $$$ to clean up

23 India’s Ganges River Holy River (1 million take daily holy dip)
350 million (1/3rd of pop) live in watershed Little sewage treatment Used for bathing, drinking etc. Bodies (cremated or not) thrown in river Good news is the Indian government is beginning to work on problem


25 Freshwater Lake Pollution
Dilution as a solution in lakes less effective Little vertical mixing Little water flow (flushing) Makes them more vulnerable Toxins settle Kill bottom life Atmospheric deposition Food chain disruptions

26 Biomagnifications of PCBs in an aquatic food chain from the Great Lakes.
See figure 22-6 on page 498

27 Eutrophication of Lakes
Eutrophication: nutrient enrichment of lakes mostly from runoff of plant nutrients (nitrates and phosphates) During hot dry weather can lead to algae blooms Decrease of photosynthesis Dying algae then drops DO levels Fish kills, bad odor

28 Pollution of Lakes Eutrophication Fig p. 499

29 Eutrophication in Lakes
Solutions: Advanced sewage treatment (N, P) Household detergents Soil conservation Remove excess weed build up Pump in oxygen or freshwater

30 Case Study: The Great Lakes
Pollution levels dropped, but long way to go 95% of U.S. freshwater 30% Canadian pop, 14% U.S. 38 million drink 1% flow out St. Lawrence Toxic fish


32 Section 4: Groundwater Why is groundwater pollution a serious problem?
What is the extent of the problem? What are the solutions?


34 Groundwater Groundwater can become contaminated
No way to cleanse itself Little dilution and dispersion Out of sight pollution Prime source for irrigation and drinking REMOVAL of pollutant difficult

35 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 Buried gasoline and solvent tank Pumping well Cesspool septic tank Gasoline station Waste lagoon Water pumping well Sewer Landfill Leakage from faulty casing Accidental spills Discharge Unconfined freshwater aquifer Confined aquifer Confined freshwater aquifer Groundwater flow Fig p. 502


37 Groundwater Pollution moves in plumes
Soil, rocks, etc. act like sponge Cleansing does not work (low O, low flow, cold) Nondegradables may be permanent

38 Prevention is the most effective and cheapest

39 Groundwater Pollution Prevention
Monitor aquifers Find less hazardous substitutes Leak detection systems Strictly regulating hazardous waste disposal Store hazardous materials above ground


41 Section 5 Ocean Pollution
How much pollution can the oceans tolerate? Coastal zones: How does pollution affect coastal zones? What are major sources of ocean pollution and what is being done? Oils spills

42 Ocean Pollution Oceans can disperse and break down large quantities of degradable pollution if they are not overloaded. Pollution worst near heavily populated coastal zones Wetlands, estuaries, coral reefs, mangrove swamps 40% of world’s pop. Live within 62 miles of coast

43 Mangrove Swamp

44 Estuaries

45 Ocean Pollution Large amounts of untreated raw sewage (viruses)
Leaking septic tanks Runoff Algae blooms from nutrients Dead zones NO DO Airborne toxins Oil spills

46 Ocean Pollution Fig p. 504


48 Case Study: Chesapeake Bay
Largest US estuary Relatively shallow Slow “flushing” action to Atlantic Major problems with dissolved O2 Fig p. 506

49 Preventing and reducing the flow of pollution from land and from streams emptying into the ocean is key to protecting oceans

50 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

51 Oil Spills



54 Section 6: Prevention and Reduction
How can we reduce surface water pollution: point and also nonpoint. How do sewage treatment plants work? How successful has the U.S. been at reducing water pollution? Clean Water Act

55 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 Only apply pesticides and fertilizers as needed

56 Nonpoint Sources Reduce runoff

57 Nonpoint Sources Buffer Zones Near Streams

58 Nonpoint Prevent soil erosion and only apply needed pesticides and fertilizers

59 Point Sources Most developed countries use laws to set water pollution standards. Federal Water Pollution Control Act (Clean Water Act 1972, ’77, ’87) Regulates navigable waterways..streams, wetlands, rivers, lake

60 Clean Water Act Sets standards for key pollutants
Requires permits for discharge Requires sewage treatment Require permits for wetland destruction Does not deal with nonpoint sources well Goal All Waterways fishable and swimable

61 Technological Approach: Septic Systems
Require suitable soils and maintenance ¼ of all U.S. homes have Septic tanks Can be used in parking lots, business parks, etc. Fig p. 510

62 Combined sewer overflow is a problem in many older towns
EPA: 1.8 M to 3.85 M sick from swimming in water contaminated by sewer overflows EPA: $100 billion to fix

63 Technological Approach: Sewage Treatment
Physical and biological treatment Fig p. 511


65 Primary: removes 60% of solids and 30-40% oxygen demanding wastes (physically)
Secondary: uses biological processes to remove up to 90% of biodegradables Tertiary: advanced techniques only used in 5% of U.S. $$$$ Disinfection: chlorine, ozone, UV What is not taken out???


67 Technological Approach: Advanced (Tertiary) Sewage Treatment
Uses physical and chemical processes Removes nitrate and phosphate Expensive Not widely used

68 Sludge disposal…using as fertilizer

69 Technological Approach: Using Wetlands to Treat Sewage
Fig p. 513

70 The Good News Largely thanks to CWA:
Between 1972 – 2002 fishable and swimmable streams 36% to 60% 74% served by sewage treatment Wetlands loss dropped by 80% Topsoil losses dropped by 1 billion tons annually

71 The Bad News 45% of Lakes, 40% streams still not fishable and swimmable Nonpoint sources still huge problem Livestock and Ag. Runoff Fish with toxins



74 Section 7 Drinking Water
How is drinking water purified? High tech way. How can we purify drinking water in developing nations? What is the Safe Drinking Water Act? Is bottled water a good answer or an expensive rip-off?

75 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

76 Purification of urban drinking water
Surface Water: (like Delaware River) Removed to reservoir to improve clarity Pumped to a treatment plant to meet drinking water standards Groundwater: often does not need much treatment


78 Purification of rural drinking water
There can be simple ways to purify water: Exposing to heat and UV rays Fine cloths to filter water Add small amounts of chlorine

79 Safe Drinking Water Act
54 countries have drinking water laws SDWA passed 1974 requires EPA to set drinking water standards Maximum Contaminating Levels (MCLs)

80 Safe Drinking Water Act
Privately owned wells exempt from SDWA SDWA requires public notification of failing to meet standards and fine. MCLs often stated in parts per million or parts per billion

81 Bottle Water U.S. has the world’s safest tap water due to billions of $$$ of investment Bottle water 240 to 10,000 times more expensive than tap water 25% of bottle water is tap water

82 Bottle Water 1.4 million metric tons of bottle thrown away each year
Toxic fumes released during bottling Bottles made from oil based plastics Water does not need to meet SDWA



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