1. © Cengage Learning 2015 LIVING IN THE ENVIRONMENT, 18e G. TYLER MILLER SCOTT E. SPOOLMAN © Cengage Learning 2015 20 Water Pollution

2. © Cengage Learning 2015 Spring and summer – huge inputs of nutrients from the Mississippi River basin Depletion of dissolved oxygen in the Gulf of Mexico’s bottom layer of water –Contains little marine life –Disrupts nitrogen cycle Case Study: The Gulf of Mexico’s Annual Dead Zone

3. © Cengage Learning 2015 Fig. 20-1a, p. 544 Mississippi River Basin Missouri River Ohio River Mississippi River

4. © Cengage Learning 2015 Fig. 20-1b, p. 544 Mississippi River GULF OF MEXICO

5. © Cengage Learning 2015 Water pollution causes illness and death in humans and other species, and disrupts ecosystems Sources: –Primarily agricultural activities, industrial facilities, and mining –Growth of both the human population and our rate of resource use makes it increasingly worse 20-1 What Are the Causes and Effects of Water Pollution?

6. © Cengage Learning 2015 Water pollution –Change in water quality that can harm organisms or make water unfit for human uses Point sources –Located at specific places –Easy to identify, monitor, and regulate Water Pollution Comes from Point and Nonpoint Sources

7. © Cengage Learning 2015 Nonpoint sources –Broad, diffuse areas –Difficult to identify and control –Expensive to clean up Water Pollution Comes from Point and Nonpoint Sources (cont’d.)

8. © Cengage Learning 2015 Leading causes of water pollution –Agriculture activities Sediment eroded from the lands Fertilizers and pesticides –Industrial facilities Inorganic and organic chemicals –Mining Erosion and toxic chemicals Water Pollution Comes from Point and Nonpoint Sources (cont’d.)

9. Fig. 20-2, p. 545

10. © Cengage Learning 2015 Fig. 20-3, p. 546

11. © Cengage Learning 2015 Infectious disease organisms –Contaminated drinking water –An estimated 1.6 million people die every year, mostly under the age of five Major Water Pollutants Have Harmful Effects

12. © Cengage Learning 2015 Table 20-1, p. 547

13. © Cengage Learning 2015 Streams and rivers around the world are extensively polluted –However, they can cleanse themselves of many pollutants if we do not overload them or reduce their flows –Adding excessive nutrients to lakes from human activities can disrupt their ecosystems, and prevention of such pollution is more effective and less costly than cleaning it up 20-2 What Are the Major Water Pollution Problems in Streams and Lakes?

14. © Cengage Learning 2015 Dilution Biodegradation of wastes by bacteria takes time Oxygen sag curve –Breakdown of biodegradable wastes by bacteria depletes oxygen Streams Can Cleanse Themselves, If We Do Not Overload Them

15. © Cengage Learning 2015 Fig. 20-6, p. 549 Point source Pollution- tolerant fishes (carp, gar) Fish absent, fungi, sludge worms, bacteria (anaerobic) Types of organisms Normal clean water organisms (Trout, perch, bass, mayfly, stonefly) Pollution- tolerant fishes (carp, gar) 8 ppm Normal clean water organisms (Trout, perch, bass, mayfly, stonefly) Dissolved oxygen (ppm) 8 ppm Biochemical oxygen demand Recovery Zone Clean Zone Septic Zone Decomposition Zone Clean Zone

16. © Cengage Learning 2015 1970s – water pollution control laws Successful water clean-up stories –Ohio Cuyahoga River, U.S. –Thames River, Great Britain Contamination of toxic inorganic and organic chemicals by industries and mines Stream Pollution in More-Developed Countries

17. © Cengage Learning 2015 Half of the world’s 500 major rivers are polluted –Untreated sewage –Industrial waste Water often used for human activities Stream Pollution in Less-Developed Countries

18. © Cengage Learning 2015 Fig. 20-7, p. 550

19. © Cengage Learning 2015 Less effective at diluting pollutants than streams –Stratified layers Little vertical mixing –Little of no water flow –Can take up to 100 years to change the water in a lake –Biological magnification of pollutants Too Little Mixing and Low Water Flow Makes Lakes Vulnerable to Water Pollution

20. © Cengage Learning 2015 Eutrophication –Natural enrichment of a shallow lake, estuary, or slow-moving stream –Caused by runoff into lake that contains nitrates and phosphates Oligotrophic lake –Low nutrients; clear water Cultural Eutrophication Is Too Much of a Good Thing

21. © Cengage Learning 2015 Cultural eutrophication –Nitrates and phosphates from human sources –Farms, feedlots, streets, parking lots –Fertilized lawns, mining sites, sewage plants During hot weather or droughts –Algal blooms –Increased bacteria; anaerobic bacteria –More nutrients Cultural Eutrophication Is Too Much of a Good Thing (cont’d.)

22. © Cengage Learning 2015 Prevent or reduce cultural eutrophication –Remove nitrates and phosphates –Diversion of lake water Clean up lakes –Remove excess weeds –Use herbicides and algaecides –Pump in air Cultural Eutrophication Is Too Much of a Good Thing (cont’d.)

23. © Cengage Learning 2015 Fig. 20-8, p. 551

24. © Cengage Learning 2015 Nitrates discharged from the Mississippi have nearly tripled since 1950 –Nitrogen cycle disrupted –Blue-green algae blooms Flood-control along the Mississippi –Flow faster; increase sediment pollution Fish kills Revisiting The Gulf of Mexico: An Extreme Case of Cultural Eutrophication

25. © Cengage Learning 2015 1960s – many areas with cultural eutrophication 1972 – Canada and the United States Great Lakes pollution control program –Decreased algal blooms –Increased dissolved oxygen –Increased fishing catches –Better sewage treatment plants Case Study: Pollution in the Great Lakes

26. © Cengage Learning 2015 Pollution control program (cont’d.) –Fewer industrial wastes –Bans on phosphate-containing household products Problems still exist –Raw sewage and biological pollution –Nonpoint runoff of pesticides and fertilizers –Atmospheric deposition of pesticides and Hg Case Study: Pollution in the Great Lakes (cont’d.)

27. © Cengage Learning 2015 Continuing problems –Urban sprawl and runoff –Biological pollution Zebra mussels –Atmospheric deposition of pollutants Case Study: Pollution in the Great Lakes (cont’d.)

28. © Cengage Learning 2015 Fig. 20-11, p. 553

29. © Cengage Learning 2015 Chemicals used in agriculture, industry, transportation, and homes can spill and leak into groundwater and make it undrinkable –There are both simple ways and complex ways to purify groundwater used as a source of drinking water, but protecting it through pollution prevention is the least expensive and most effective strategy 20-3 What Are the Major Pollution Problems Affecting Groundwater?

30. © Cengage Learning 2015 Aquifers provide drinking water for about half of the U.S. population and 95% of Americans who live in rural areas Common pollutants –Fertilizers and pesticides –Gasoline –Organic solvents –Fracking Pollutants dispersed in a widening plume (diffusion) Ground Water Cannot Cleanse Itself Very Well

31. © Cengage Learning 2015 Slower chemical reactions in groundwater due to: –Slow flow – contaminants not diluted –Less dissolved oxygen –Fewer decomposing bacteria –Low temperatures Ground Water Cannot Cleanse Itself Very Well (cont’d.)

32. © Cengage Learning 2015 Fig. 20-12, p. 554 Polluted air Hazardous waste injection well Pesticides and fertilizers Deicing road salt Coal strip mine runoff Buried gasoline and solvent tanks Pumping well Gasoline station Cesspool, septic tank Water pumping well Waste lagoon Landfill Sewer Accidental spills Leakage from faulty casing Discharge Freshwater aquifer Groundwater flow

33. © Cengage Learning 2015 China – 90% of urban aquifers are contaminated or overexploited U.S. – FDA reports of toxins found in many aquifers Nitrate ions –Can turn into cancer causing chemicals Slowly degrading wastes Non-degradable wastes Groundwater Pollution Is a Serious Hidden Threat in Some Areas

34. © Cengage Learning 2015 Rocks rich in arsenic can contaminate wells Long-term exposure can lead to: –Skin, lung, bladder cancer Treatment –Nanoparticles of rust Case Study: Arsenic in Drinking Water

35. © Cengage Learning 2015 Reservoirs and purification plants Process sewer water to drinking water Expose clear plastic containers to sunlight (UV) The LifeStraw PUR – chlorine and iron sulfate powder There Are Many Ways to Purify Drinking Water

36. © Cengage Learning 2015 Bottled water can be useful but expensive The U.S. has some of the world’s cleanest drinking water Bottled water less regulated than tap water Use of bottled water can create environmental problems Case Study: Is Bottled Water a Good Option?

37. © Cengage Learning 2015 1974 – U.S. Safe Drinking Water Act –Sets maximum contaminant levels for any pollutants that affect human health Health scientists –Strengthen the law Water-polluting companies –Weaken the law Using Laws to Protect Drinking Water Quality

38. © Cengage Learning 2015 Most ocean pollution originates on land and includes: –Oil and other toxic chemicals –Solid waste, which threaten fish and wildlife and disrupt marine ecosystems Key to protecting the oceans –Reduce the flow of pollution from land and air and from streams emptying into ocean waters 20-4 What Are the Major Water Pollution Problems Affecting Oceans?

39. © Cengage Learning 2015 Municipal sewage from less-developed countries are often dumped into oceans without treatment Deeper ocean waters –Dilution –Dispersion –Degradation Ocean Pollution Is a Growing and Poorly Understood Problem

40. © Cengage Learning 2015 U.S. coastal waters –Raw sewage – viruses –Sewage and agricultural runoff: NO 3 - and PO 4 3- –Harmful algal blooms –Oxygen-depleted zones Ocean Pollution Is a Growing and Poorly Understood Problem (cont’d.)

41. Fig. 20-15, p. 559 Industry Nitrogen oxides from autos and smokestacks, toxic chemicals, and heavy metals in effluents flow into bays and estuaries. Cities Toxic metals and oil from streets and parking lots pollute waters; sewage adds nitrogen and phosphorus. Urban sprawl Bacteria and viruses from sewers and septic tanks contaminate shellfish beds and close beaches; runoff of fertilizer from lawns adds nitrogen and phosphorus. Construction sites Sediments are washed into waterways, choking fish and plants, clouding waters, and blocking sunlight. Farms Runoff of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus. Red tides Excess nitrogen causes explosive growth of toxic microscopic algae, poisoning fish and marine mammals. Closed shellfish beds Closed beach Oxygen-depleted zone Toxic sediments Chemicals and toxic metals contaminate shellfish beds, kill spawning fish, and accumulate in the tissues of bottom feeders. Oxygen-depleted zone Sedimentation and algae overgrowth reduce sunlight, kill beneficial sea grasses, use up oxygen, and degrade habitat. Healthy zone Clear, oxygen-rich waters promote growth of plankton and sea grasses, and support fish.

42. © Cengage Learning 2015 North Pacific Garbage Patch –Two rotating gyres –On or just beneath the water surface Tiny plastic pieces harmful to wildlife No practical way to clean up Case Study: Ocean Garbage Patches: There Is No Away

43. © Cengage Learning 2015 Fig. 20-17, p. 560 PACIFIC OCEAN Hawaii Russia Alaska United States China Japan Canada

44. © Cengage Learning 2015 Crude and refined petroleum –Highly disruptive pollutants Largest source of ocean oil pollution –Urban and industrial runoff from land 1989 – Exxon Valdez, oil tanker 2010 – BP Deepwater Horizon in the Gulf of Mexico Ocean Pollution from Oil

45. © Cengage Learning 2015 Volatile organic hydrocarbons –Kill many aquatic organisms Tar-like globs on the ocean’s surface –Coat animals Heavy oil components sink –Affect the bottom dwellers Ocean Pollution from Oil (cont’d.)

46. © Cengage Learning 2015 Faster recovery in warm water with rapid currents –In cold, calm waters recovery can take decades Methods of preventing oil spills –Double hulls Ocean Pollution from Oil (cont’d.)

47. © Cengage Learning 2015 Fig. 20-19, p. 561

48. © Cengage Learning 2015 Spill from deep-sea oil drilling – 1 mile deep –Released 4.9 million barrels of crude oil –Contaminated vast areas of coastline –Caused by equipment failure and poor decisions Government developed new standards for offshore drilling procedures Case Study: The BP Deepwater Horizon Oil-Rig Spill

49. © Cengage Learning 2015 Reducing water pollution requires that we: –Prevent it –Work with nature to treat sewage –Use natural resources far more efficiently 20-5 How Can We Deal with Water Pollution?

50. © Cengage Learning 2015 Reduce flow of pollution from land –Land-use –Air pollution –Linked to energy and climate policy Reducing Ocean Water Pollution

51. © Cengage Learning 2015 Fig. 20-21, p. 563 Coastal Water Pollution PreventionCleanup Require secondary treatment of coastal sewage Improve oil-spill cleanup capabilities Separate sewage and storm water lines Use nanoparticles on sewage and oil spills to dissolve the oil or sewage (still under development) Ban dumping of wastes and sewage by ships in coastal waters Strictly regulate coastal development, oil drilling, and oil shipping Use wetlands and other natural methods to treat sewage Require double hulls for oil tankers Solutions

52. © Cengage Learning 2015 Agriculture –Reduce erosion –Reduce the amount of fertilizers –Plant buffer zones of vegetation –Use organic farming techniques –Use pesticides prudently –Institute tougher pollution regulations for livestock operations Reducing Surface Water Pollution from Nonpoint Sources

53. © Cengage Learning 2015 1972 – Clean Water Act 1987 – Water Quality Act Experimenting with a discharge trading policy that uses market forces What are some achievements of the Clean Water Act? Case Study: The U.S. Experience with Reducing Point-Source Pollution

54. © Cengage Learning 2015 How do septic tank systems work? Wastewater or sewage treatment plants –Primary sewage treatment Physical process –Secondary sewage treatment Biological process with bacteria –Tertiary or advance sewage treatment Special filtering processes Bleaching, chlorination Sewage Treatment Reduces Water Pollution

55. © Cengage Learning 2015 Many cities violate federal standards for sewage treatment plants –Federal law requires primary and secondary treatment Exemptions from secondary treatment There are health risks of swimming in water with blended sewage wastes Sewage Treatment Reduces Water Pollution (cont’d.)

56. © Cengage Learning 2015 Fig. 20-23, p. 565 Manhole cover (for cleanout) Septic tank Gas Distribution box Scum Wastewater Sludge Drain field (gravel or crushed stone) Vent pipe Perforated pipe

57. © Cengage Learning 2015 Fig. 20-24, p. 566 PrimarySecondary Chlorine disinfection tank Bar screenGrit chamberSettling tankAeration tankSettling tank To river, lake, or ocean Raw sewage from sewers Sludge Activated sludge (kills bacteria) Air pump Sludge digester Disposed of in landfill or ocean or applied to cropland, pasture, or rangeland Sludge drying bed

58. © Cengage Learning 2015 Remove toxic wastes before water goes to the municipal sewage treatment plants Reduce or eliminate use and waste of toxic chemicals Use composting toilet systems Wetland-based sewage treatment systems –Work with nature We Can Improve Conventional Sewage Treatment

59. © Cengage Learning 2015 Developed countries –Bottom-up political pressure to pass laws Developing countries –Little has been done to reduce water pollution –China Small sewage treatment plants How can we avoid producing water pollutants in the first place? There Are Sustainable Ways to Reduce and Prevent Water Pollution

60. © Cengage Learning 2015 Fig. 20-26, p. 568

61. © Cengage Learning 2015 Fig. 20-27, p. 570

62. © Cengage Learning 2015 There are a number of ways to purify drinking water, but the most effective and least costly strategy is pollution prevention The key to protecting the oceans is to reduce the flow of pollution from: –Land and air –Streams emptying into ocean waters Three Big Ideas

63. © Cengage Learning 2015 Reducing water pollution requires that we: –Prevent it –Work with nature in treating sewage –Use natural resources far more efficiently Three Big Ideas

64. © Cengage Learning 2015 Dead zones disrupt ecological interactions between species in river and coastal systems We can use solar energy to purify water and reduce waste We can use natural nutrient cycles to purify water Tying It All Together: Dead Zones and Sustainability