1. Water Pollution Unit 14

3. Pollution Water pollution: change in water quality that makes it unsuitable for use: chemical, biological, or physical

4. Sources of Pollution Point-source: discharge of pollutants from a specific location -pipes, ditches, sewers -easily identified, monitored, regulated Nonpoint-source: scattered release of pollutants -cannot be traced to single site -often runoff from large areas of land -64% of all water pollution in US

5. Leading Sources of Pollution Agriculture: leading source -runoff: sediments, inorganic fertilizers/pesticides, manure, salts. Industry: from manufacturing -acids, heavy metals, pesticides, gasoline, oil, PCBs-polychlorinated biphenyls, solvents Mining: erosion -runoff carries sulfuric acid, arsenic, cyanide (gold), heavy metals from rock

6. Types and Effects of Pollutants Infectious agents: disease-causing pathogens -bacteria, viruses, protozoa, parasites -major source: human, animal wastes -effects: mild-fatal diseases -detection: counting coliform bacteria/100ml of water -WHO, EPA: 0 colonies for drinking water; 200 colonies for swimming

7. Table 21-2, p. 495

8. Coliform Count A fecal coliform bacteria test is used to indicate the likely presence of disease-causing bacteria in water. Figure 21-2

9. Types and Effects of Pollutants(cont’d) Oxygen-demanding wastes: depletes dissolved O₂ (DO) by aerobic bacteria -biodegradable animal wastes, plant debris, aerobic bacteria -major source: sewage, feedlots, paper mills -effects: suffocation of aquatic organisms -Biological Oxygen Demand (BOD): O₂ needed by aerobic decomposers to break down organic matter/ 5 days at 20⁰C

11. Types and Effects of Pollutants(cont’d) Plant nutrients: excessive growth of algae. -nitrates (NO₃), phosphates (PO₄) -major sources: sewage, animal feedlots, inorganic fertilizers -effects: O₂ depletion/animal suffocation

12. Fig. 21-3, p. 496 Water Quality Below 4 Below 4.5 DO (ppm) at 20°C 4.5–6.7 6.7–8 8–9 Gravely polluted Heavily polluted Moderately polluted Slightly polluted Good

13. Types and Effects of Pollutants(cont’d) Inorganic and organic chemicals: add toxins -inorganic- acids, bases, salts, metals -organic- oil, gasoline, plastic, cleaners -major sources: inorganic- organic- -effects: damages human health, wildlife -detection: chemical water analysis; indicator species presence (organic) industry, households, farms

14. Types and Effects of Pollutants(cont’d) Sediments: fine particles -soil, silt -major sources: erosion -effects: disrupt photosynthesis, food webs, destroy spawning grounds of benthic species, clogs harbors, lakes

15. Types and Effects of Pollutants(cont’d) Thermal: runoff of heated waste water -heated effluents -major sources: electric power and industrial plants -effects: lower DO levels, thermal shock in species

16. Types and Effects of Pollutants(cont’d) Heavy metals: high density metals -lead, mercury, arsenic -major sources: unlined landfills, household chemicals, mining refuse, industry -effects: cause cancer, disrupt immune, endocrine systems

17. Pollution of Rivers and Streams O₂-demanding wastes (sewage, feedlot runoff) create an oxygen sag curve: occurs when bacteria break down wastes, depleting O₂ Fast moving water recovers from moderate levels of degradable wastes via dilution Slow moving water (drought, damming) cannot recover from high concentrations of wastes No water can dilute PCBs, pesticides, non- degradable wastes (heavy metals)

18. Fig. 21-4, p. 497 8 ppm Biological oxygen demand Dissolved oxygen (ppm) Types of organisms 8 ppm Recovery Zone Septic Zone Decomposition Zone Clean Zone Fish absent, fungi, sludge worms, bacteria (anaerobic) Trash fish (carp, gar, leeches) Clean Normal clean water organisms (Trout, perch, bass, mayfly, stonefly) Normal clean water organisms (Trout, perch, bass, mayfly, stonefly) Clean Zone Trash fish (carp, gar, leeches)

19. Developed Countries 1970’s pollution laws restricted point-source discharge, increased wastewater treatment plants -Cuyahoga River: went from combustible to clean -Thames River: smelly sewer to commercial fishing and waterfowl breeding area Continued problems: nonpoint-source runoff, intentional dumping, malfunctioning sewage equipment

21. Developing Countries Half of globe’s 500 rivers are heavily polluted: -cannot afford wastewater treatment (raw sewage dumped directly in water) -lack/do not enforce laws restricting toxic discharging China: 300 million people lack clean water (liver, stomach cancers leading causes of death) Latin America, Africa: most urban surface water is severely polluted with toxins, garbage

22. Global Outlook: Stream Pollution in Developing Countries Water in many of central China's rivers are greenish black from uncontrolled pollution by thousands of factories. Figure 21-5

23. Case Study: India’s Ganges River Religious beliefs, cultural traditions, poverty, and a large population cause severe pollution of the Ganges River in India. – Very little of the sewage is treated. – Hindu believe in cremating the dead to free the soul and throwing the ashes in the holy Ganges. Some are too poor to afford the wood to fully cremate. Decomposing bodies promote disease and depletes DO.

24. Case Study: India’s Ganges River (Daily, more than 1 million Hindus in India bathe, drink from, or carry out religious ceremonies in the highly polluted Ganges River) Figure 21-6

25. Pollution Of Freshwater Lakes Less effective dilution of pollutants. -Lakes and reservoirs are often stratified; undergo little vertical mixing. -Low flow makes them susceptible to runoff. Harmful chemicals are biomagnified as they pass through food webs.

26. FYI:Cultural Eutrophication Unnatural input of plant nutrients in lakes -excess phosphates, nitrates runoff from cropland, lawns, feedlots, untreated sewage Nutrients create algal blooms -block solar radiation needed for photosynthesis -encourage growth of aerobic bacteria -leads to decreased DO; leads to decreased biodiversity (EPA: 85% of large US lakes are at some level of eutrophication)

27. Case Study: The Great Lakes Cultural eutrophication: sewage (point source), fertilizers and detergents (nonpoint source) Industrial pollution: PCB’s, mercury (coal-burning plants), pesticides Removal of riparian (river) buffer vegetation Biological pollution: Zebra mussels, (1972: Great Lakes Water Quality Agree- Ment- $20 billion to restore Great Lakes basin ecosystem)

28. Case Study: The Great Lakes

29. Case Study: Lake Washington Cultural eutrophication: pollutants from Seattle wastewater Community succeeded in diverting wastewater into Puget Sound 10 years later, water clarity improved, fish populations rebounded

30. Remediation/Prevention of Cultural Eutrophication Mechanical removal of lake weeds Pumping O₂ into water to decrease depletion Increasing riparian zones to prevent excess nutrients from entering water Removal of PO₄ and NO₃ from wastewater in advanced treatment plants (all remediation measures are more expensive than prevention)

31. Groundwater Pollution (remember, groundwater is source of drinking water for 50% of US; 70% or more for globe) Pollution sources: solvents, pesticides, fertilizers, leaking fuel tanks Few methods of naturally degrading/diluting pollutants due to slow flow, low pop.s of aerobic bacteria Nondegradable wastes may remain in water for decades or permanently

32. Fig. 21-7, p. 501 Coal strip mine runoff Polluted air Deicing road salt Pesticides and fertilizers Hazardous waste injection well Pumping well Gasoline station Water pumping well Landfill Sewer Buried gasoline and solvent tanks Cesspool, septic tank Groundwater flow Confined aquifer Confined freshwater aquifer Unconfined freshwater aquifer Accidental spills Waste lagoon Leakage from faulty casing Discharge

33. Groundwater Pollution: Arsenic Natural sources: rock, soil surrounding aquifer Human sources: mining, ore processing Safe standard: less than 10 ppb (even this is considered too high by WHO) Health risk: Long-term exposure-premature death from cancers of skin, bladder, lungs (more than 112 million people are drinking water with As levels 5-100 times the 10 ppb standard- mostly in Bangladesh, China, and West Bengal, India)

34. Groundwater Pollution: Nitrate Ions Human source: contamination of aquifer with nitrate fertilizers Health risk: once in body, nitrates (NO₃) convert to nitrites (NO₂¯) -in adults, nitrites can form organic compounds that lead to cancers of stomach, bowel, bladder -in infants, nitrites interfere with ability of RBCs to carry O₂ which leads to fatal “blue baby syndrome”

35. Groundwater Pollution: MTBE Human source: 1979 gasoline additive MTBE (methyl tertiary butyl ether), entered aquifer from leaking gas tanks Health risk: suspected carcinogen (law suits against oil companies have resulted in phase out of additive, but plumes of MTBE will stay in groundwater for decades)

36. Fig. 21-8, p. 502 Aquifer Water well Migrating vapor phase Contaminant plume moves with the groundwater Free gasoline dissolves in groundwater (dissolved phase) Groundwater flow Water table Gasoline leakage plume (liquid phase) Leaking tank Bedrock

37. Fig. 21-9, p. 504 Solutions Groundwater Pollution CleanupPrevention Find substitutes for toxic chemicals Install monitoring wells near landfills and underground tanks Require leak detectors on underground tanks Ban hazardous waste disposal in landfills and injection wells Store harmful liquids in aboveground tanks with leak detection and collection systems Pump to surface, clean, and return to aquifer (very expensive) Pump nanoparticles of inorganic compounds to remove pollutants (may be the cheapest, easiest, and most effective method but is still being developed) Keep toxic chemicals out of the environment Inject microorganisms to clean up contamination (less expensive but still costly)

38. Preventing Groundwater Pollution Find substitutes for toxic chemicals Keep toxic chemicals out of environment Install monitoring wells near landfills and underground tanks Require leak detectors on underground tanks Store harmful liquids in aboveground tanks with leak detection and collection systems

39. Clean Up of Groundwater Pump to surface, clean, and return to aquifer (very expensive) Inject microorganisms to clean up contamination (less expensive but still costly) Pump Pump nanoparticles of inorganic compounds to remove pollutants (may be the cheapest, easiest, and most effective method but is still being developed)

40. Rates of Waste Dilution Freshwater’s ability to cleanse degradable waste (fastest to slowest): 1.River 2.Lakes, ponds 3.Aquifers

41. Providing Clean Drinking Water Laws that regulate, monitor drinking water Recycling, purifying wastewater (Ca, Texas) Collecting water in clear containers, allowing UV radiation from sun to kill pathogens Nanofilters for water bottles or plastic straws Use of forests, wetlands for natural filtration

43. Water Quality Legislation 1977 Clean Water Act (Federal Water Pollution Act) -regulates point-source pollution from municipal sewage plants, industries -1987 Water Quality Act- amended Clean Water Act to separate storm water/sewage lines 1974 US Safe Drinking Water Act- requires EPA to set standards of max containment levels for health harming pollutants 2002 Public Health Security and Bioterrorism Preparedness and Response Act- assess water supply’s vulnerability to intentional attack

44. Water Quality Testing Techniques Physical Tests: Temperature: impacts solubility of O₂, less DO is found in hot water -most fish kills occur in summer -removal of riparian areas increases temp -coal-burning, nuclear plant create thermal pollution

45. Water Quality Testing Techniques (cont’d) River/Stream Flow Velocity: -fast-flowing water diffuses O₂ faster than slow-moving water Turbidity: measure of cloudiness by suspended solids in a water column -sedimentation, algal blooms prevent photosynthesis at base of food chain. -measured by Secchi disk

47. Water Quality Testing Technique (cont’d) Chemical Tests: pH: measures hydrogen ion concentration to determine acidity/alkalinity -most organisms are best in pH btw 6-9 Dissolved Oxygen (DO): amount of available O₂ (regulates aquatic biodiversity) -most organisms are stressed if DO falls below 5ppm -highest in cold, fast moving water with lots of phytoplankton

48. Water Quality Testing Technique (cont’d) Nitrates/Nitrites/Phosphates: indicate fertilizer runoff, septic leaks, sewage Hardness: indicates metal cations- Mg²⁺, Ca²⁺ -may mean increased solubility of heavy metals or ability to buffer aquatic systems

49. Water Quality Testing Technique (cont’d) Biological Tests: Fecal coliform: indicates septic tank leaks, animal waste runoff Biological Assessment: populations of specific organisms are monitored for water health -benthic microinvertebrates- mayflies, caddisflies, copepods (small crustaceans) -fish species- some species are sensitive to DO levels (trout)

51. Ocean Pollution Oceans can dilute, disperse, degrade large amounts of degradable wastes. Coastal areas (mangroves, estuaries, and coral reefs) have greatest impact from dumped wastes. -extensive colonies of viruses (ear, eye, throat infections) -”floatables” (plastics) injure animals, leach harmful chemicals into water -Agricultural runoff can create red tides- toxin secreting diatoms

52. Ocean Pollution -hypoxia: lower DO due to eutrophic coastal conditions; “dead zones” (decomposing bacteria love these); Oil pollution: leaks of crude oil (from ground) or refined petroleum (gasoline) -largest source: urban, industrial runoff -VOCs: volatile organic compounds kill larval forms of ocean organisms -oil reduces buoyancy, insulation of marine mammals, birds (results in heat loss, drowning) (study Sources of Ocean Pollution diagram)

53. Harmful Algal Bloom Oil Clean Up of Penguin

54. FYI OCEAN OIL POLLUTION Tanker accidents and blowouts at offshore drilling rigs can be extremely devastating to marine life (especially diving birds, left). Figure 21-13

55. Fig. 21-A, p. 507 Mississippi River Mississippi River Basin Gulf of Mexico Ohio River Mississippi River Missouri River TX MS LA Depleted oxygen LOUISIANA Gulf of Mexico

56. Fig. 21-10, p. 505 Healthy zone Clear, oxygen-rich waters promote growth of plankton and sea grasses, and support fish. Oxygen-depleted zone Sedimentation and algae overgrowth reduce sunlight, kill beneficial sea grasses, use up oxygen, and degrade habitat. Red tides Excess nitrogen causes explosive growth of toxicmicroscopic algae, poisoning fish and marine mammals. Farms Runoff of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus. Toxic sediments Chemicals and toxic metals contaminate shellfish beds, kill spawning fish, and accumulate in the tissues of bottom feeders. Construction sites Sediments are washed into waterways, choking fish and plants, clouding waters, and blocking sunlight. Urban sprawl Bacteria and viruses from sewers and septic tanks contaminate shellfish beds Oxygen-depleted zone Closed beach Cities Toxic metals and oil from streets and parking lots pollute waters; Industry Nitrogen oxides from autos and smokestacks, toxic chemicals, and heavy metals in effluents flow into bays and estuaries. Closed shellfish beds

57. Case Study: The Chesapeake Bay Largest estuary in US; 17 mil people live in its watershed Receives point-source, nonpoint-source pollution from 9 major rivers (141 tributaries) -point-source: phosphates from sewage, industry -nonpoint-source: runoff of fertilizers, manure from agricultural, urban, suburban areas Low DO has resulted in reduced pop.s of commercially and ecologically valuable species (oysters, crabs, fish)

58. Chesapeake Bay (cont’d) Remediation: banning phosphate detergents, upgrading sewage treatment plants, wetlands restoration (which do you think should come first?)

59. Fig. 21-14, p. 509 Reduce input of toxic pollutants Solutions Coastal Water Pollution PreventionCleanup Use wetlands, solar-aquatic, or other methods to treat sewage Require at least secondary treatment of coastal sewage Sprinkle nanoparticles over an oil or sewage spill to dissolve the oil or sewage without creating harmful by-products (still under development) Improve oil-spill cleanup capabilities Recycle used oil Regulate coastal development Protect sensitive areas from development, oil drilling, and oil shipping Ban ocean dumping of sludge and hazardous dredged material Ban dumping of wastes and sewage by maritime and cruise ships in coastal waters Separate sewage and storm lines Require double hulls for oil tankers

60. Reducing Pollution: Water Treatment (Urban areas in developed countries rely on primary and secondary wastewater treatment) Primary sewage treatment: physical; removes floating debris, allows solids to settle out as sludge -removes 60% of suspended solids -does not remove pathogens, salts, nitrates, medications,

61. Reducing Pollution: Water Treatment Secondary sewage treatment: biological; aerobic bacteria remove dissolved, biodegradable O₂-demanding waste -water is bleached to remove infectious agents -since chlorination can be harmful to health, ozone, UV light is sometimes used -does not remove pesticides, medications

62. Reducing Pollution: Water Treatment Advanced/tertiary treatment: physical and chemical -removes nitrates, phosphates

63. Further Treatment 1.Separate pipes for runoff of storm water and sewage 2.Treat sludge for toxins (organic/inorganic), use as fertilizer 3.Require industry to remove waste before it reaches municipal sewage line 4.Use natural, artificial wetlands to degrade, filter sewage 5.Use septic tank with large drainage field to degrade, filter rural sewage

64. Fig. 21-15, p. 510 Distribution box Manhole cover (for cleanout) Vent pipe Perforated pipe Drain field (gravel or crushed stone) Septic tank Sludge Wastewater Gas Scum

65. Fig. 21-18, p. 517 Prevent groundwater contamination Solutions Water Pollution Reduce birth rates Reduce poverty Reduce air pollution Practice four R's of resource use (refuse, reduce, recycle, reuse) Work with nature to treat sewage Find substitutes for toxic pollutants Reuse treated wastewater for irrigation Reduce nonpoint runoff

66. Fig. 21-19, p. 517 What Can You Do? Water Pollution Fertilize garden and yard plants with manure or compost instead of commercial inorganic fertilizer. Minimize your use of pesticides. Do not apply fertilizer or pesticides near a body of water. Grow or buy organic foods. Do not drink bottled water unless tests show that your tap water is contaminated. Merely refill and reuse plastic bottles with tap water. Compost your food wastes. Do not use water fresheners in toilets. Do not flush unwanted medicines down the toilet. Do not pour pesticides, paints, solvents, oil, antifreeze, or other products containing harmful chemicals down the drain or onto the ground.

67. Exam Focus Sources of water pollution -which is largest, most difficult to treat? Types of pollution, sources Water-bourne diseases Major human activities responsible for pollution Measure that tells most about water health Oxygen sag curve; know diagram What Biological Oxygen Demand (BOD) measures

68. Exam Focus (cont’d) Cultural eutrophication Natural sources of groundwater pollution; manmade sources of groundwater pollution Why groundwater pollution is difficult to remediate (why doesn’t biodegradation happen) Ways to prevent groundwater pollution Order (rates) in which surface, groundwater clean themselves

69. Exam Focus Purpose of sewage treatment -primary (physical…) -secondary (biological…) Affect of nitrates, phosphates on DO, “dead zones” Water quality laws (focus on Clean Water Act) From Unit 4: oligotrophic lake traits (clear, but low in nutrients)