Presentation on theme: "Living in the Environment"— Presentation transcript:
1Living in the Environment Water PollutionG. Tyler Miller’sLiving in the Environment14th EditionChapter 22
2The solution to pollution is dilution. Water, Air, Land ….The solution to pollution is dilution.
3Chapter 22 Key ConceptsTypes, sources, and effects of water pollutantsMajor pollution problems of surface waterMajor pollution problems of groundwaterReduction and prevention of water pollutionDrinking water quality
5Section 1 Key IdeasWhat are major types and effects of water pollution?How do we measure water quality?Point versus Nonpoint sourcesWhat are the major sources of pollution?
6What 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.
7What is water pollution? WHO:3.4 million premature deaths each year from waterborne diseases1.9 million from diarrheaU.S. 1.5 million illnesses1993 Milwaukee 370,000 sick
8What is water pollution? Need to study Table 22-1 Page 492 Infectious Agents: bacteria and viruses often from animal wastesOxygen 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
9What is water pollution? Organic Chemicals: oil, gasoline, plastics, detergents often from surface runoff, industries and cleanersPlant Nutrients: water soluble nitrates, ammonia and phosphates often from sewage, agriculture and urban fertilizersSediment: soils and silts from land erosion can disrupt photosynthesis, destroy spawning grounds, clog rivers and streamsHeat Pollution and Radioactivity: mostly from powerplants
10How do we measure water quality Bacterial Counts: Fecal coliform counts from intestines of animalsNone per 100 ml for drinking>200 per 100 ml for swimmingSources: human sewage, animals, birds, raccoons, etc.See table 22-2 on page 493 for diseases transmitted by contaminated drinking water.
12How do we measure water quality Dissolved Oxygen: BOD Biological Oxygen Demand…the amount of oxygen consumed by aquatic decomposersChemical Analysis: looking for presence of inorganic or organic chemicalsSuspended Sediment water clarity
13How 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
14Types, Effects and Sources of Water Pollution Point sourcesRefer to Tables 22-1 and 22-2 p. 492 and 493Nonpoint sourcesFig p. 494Water quality
15Point and Nonpoint Sources Urban streetsSuburban developmentWastewater treatment plantRural homesCroplandFactoryAnimal feedlotPOINT SOURCESFig p. 494
16Major Sources of Water Pollution Agriculture: by far the leaderSediment, fertilizers, bacteria from livestock, food processing, salt from soil irrigationIndustrial: factories and powerplantsMining: surface mining toxics, acids, sediment
18Section 2-3 Key IdeasFreshwater pollution: What are major problems in streams?Developed versus Developing CountriesLake Pollution: Why are lakes and reservoirs more vulnerable?What is Eutrophication?
19Freshwater Stream Pollution Flowing streams can recover from moderate level of degradable water pollution if their flows are not reduced.Natural biodegradation processDoes not work if overloaded or stream flow reducedDoes not work against non biodegradable pollutants
20What factors will influence this oxygen sag curve? Pollution of StreamsOxygen sag curveFactors influencing recoveryFig p. 496What factors will influence this oxygen sag curve?
21Two Worlds Developed Countries U.S. and other developed countries sharply reduced point sources even with population and economic growthNonpoint still a problemToxic chemicals still problemSuccess Cuyahoga River, Thames River
22Two Worlds Developing Countries: Serious and growing problem Half of world’s 500 major rivers heavily pollutedSewage treatment minimal $$$Law enforcement difficult10% of sewage in China treatedEconomic growth with little $$$ to clean up
23India’s Ganges River Holy River (1 million take daily holy dip) 350 million (1/3rd of pop) live in watershedLittle sewage treatmentUsed for bathing, drinking etc.Bodies (cremated or not) thrown in riverGood news is the Indian government is beginning to work on problem
25Freshwater Lake Pollution Dilution as a solution in lakes less effectiveLittle vertical mixingLittle water flow (flushing)Makes them more vulnerableToxins settleKill bottom lifeAtmospheric depositionFood chain disruptions
26Biomagnifications of PCBs in an aquatic food chain from the Great Lakes. See figure 22-6 on page 498
27Eutrophication of Lakes Eutrophication: nutrient enrichment of lakes mostly from runoff of plant nutrients (nitrates and phosphates)During hot dry weather can lead to algae bloomsDecrease of photosynthesisDying algae then drops DO levelsFish kills, bad odor
41Section 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
42Ocean PollutionOceans can disperse and break down large quantities of degradable pollution if they are not overloaded.Pollution worst near heavily populated coastal zonesWetlands, estuaries, coral reefs, mangrove swamps40% of world’s pop. Live within 62 miles of coast
48Case Study: Chesapeake Bay Largest US estuaryRelatively shallowSlow “flushing” action to AtlanticMajor problems with dissolved O2Fig p. 506
49Preventing and reducing the flow of pollution from land and from streams emptying into the ocean is key to protecting oceans
50Oil SpillsSources: offshore wells, tankers, pipelines and storage tanksEffects: death of organisms, loss of animal insulation and buoyancy, smotheringSignificant economic impactsMechanical cleanup methods: skimmers and blottersChemical cleanup methods: coagulants and dispersing agents
54Section 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
55Solutions: Preventing and Reducing Surface Water Pollution Nonpoint SourcesPoint SourcesReduce runoffClean Water ActBuffer zone vegetationWater Quality ActReduce soil erosionOnly apply pesticides and fertilizers as needed
58NonpointPrevent soil erosion and only apply needed pesticides and fertilizers
59Point SourcesMost 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
60Clean Water Act Sets standards for key pollutants Requires permits for dischargeRequires sewage treatmentRequire permits for wetland destructionDoes not deal with nonpoint sources wellGoal All Waterways fishable and swimable
61Technological Approach: Septic Systems Require suitable soils and maintenance¼ of all U.S. homes have Septic tanksCan be used in parking lots, business parks, etc.Fig p. 510
62Combined 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 overflowsEPA: $100 billion to fix
63Technological Approach: Sewage Treatment Physical and biological treatmentFig p. 511
65Primary: removes 60% of solids and 30-40% oxygen demanding wastes (physically) Secondary: uses biological processes to remove up to 90% of biodegradablesTertiary: advanced techniques only used in 5% of U.S. $$$$Disinfection: chlorine, ozone, UVWhat is not taken out???
69Technological Approach: Using Wetlands to Treat Sewage Fig p. 513
70The Good News Largely thanks to CWA: Between 1972 – 2002 fishable and swimmable streams 36% to 60%74% served by sewage treatmentWetlands loss dropped by 80%Topsoil losses dropped by 1 billion tons annually
71The Bad News45% of Lakes, 40% streams still not fishable and swimmableNonpoint sources still huge problemLivestock and Ag. RunoffFish with toxins
74Section 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?
75Drinking Water Quality Purification of urban drinking waterProtection from terrorismPurification of rural drinking waterSafe Drinking Water ActMaximum contaminant levels (MCLs)Bottled water
76Purification of urban drinking water Surface Water: (like Delaware River)Removed to reservoir to improve clarityPumped to a treatment plant to meet drinking water standardsGroundwater: often does not need much treatment