1. Chapter 14 Water Pollution

2. Water pollution- the contamination of streams, rivers, lakes, oceans, or groundwater with substances produced through human activities and that negatively affect organisms. Point sources- distinct locations that pump waste into a waterway. Nonpoint sources- diffuse areas such as an entire farming region that pollutes a waterway.

4. Human Wastewater Water produced by human activities such as human sewage from toilets and gray water from bathing and washing clothes or dishes.

5. Three reasons scientists are concerned about human wastewater: Oxygen-demanding wastes like bacteria that put a large demand for oxygen in the water Nutrients that are released from wastewater decomposition can make the water more fertile causing eutrophication Wastewater can carry a wide variety of disease- causing organisms.

6. Cultural Eutrophication Cause-->bloom--> die off--> aerobic bacteria-->DO down--> anaerobic bacteria -->hydrogen sulfide gas (toxic) Prevention Limit phosphate (detergent) Advanced waste water treatment Soil conservation Cleanup Dredging, remove excess weeds, pump air into lakes

7. Biochemical Oxygen Demand (BOD) BOD- the amount of oxygen a quantity of water uses over a period of time at a specific temperature. Lower BOD values indicate the water is less polluted and higher BOD values indicate it is more polluted by wastewater.

8. Oxygen Demanding Wastes organic waste decomposed by aerobic bacteria can be determined by BOD BOD: amount of O 2 consumed by decomposers in 5 days at 20 o C

9. Mississippi River Basin Missouri River Ohio River Mississippi River LOUISIANA Mississippi River Depleted Oxygen Gulf of Mexico

10. Fig. 19.2, p. 478 Water Quality Good8-9 DO (ppm) at 20˚C Slightly polluted Moderately polluted Heavily polluted Gravely polluted 6.7-8 4.5-6.7 Below 4.5 Below 4

11. Eutrophication Eutrophication is an abundance of fertility to a body of water. Eutrophication is caused by an increase in nutrients, such as fertilizers. Eutrophication can cause a rapid growth of algae which eventually dies, causing the microbes to increase the BOD.

12. Oxygen Sag Curve

13. Fig. 19.3, p. 479 Clean ZoneDecomposition Zone Septic ZoneRecovery ZoneClean Zone Normal clean water organisms (Trout, perch, bass, mayfly, stonefly) Trash fish (carp, gar, Leeches) Fish absent, fungi, Sludge worms, bacteria (anaerobic) Trash fish (carp, gar, Leeches) Normal clean water organisms (Trout, perch, bass, mayfly, stonefly) 8 ppm Dissolved oxygen Biological oxygen demand Oxygen sag 2 ppm 8 ppm Concentration Types of organisms Time of distance downstream Direction of flow Point of waste or heat discharge

14. Common Diseases from Human Wastewater Cholera Typhoid fever Stomach flu Diarrhea Hepatitis

15. Pathogens Disease causing agents bacteria, viruses, protozoa, parasitic worms lack of clean drinking water causes 80% of diseases in developing countries coliform bacteria WHO recommends 0 colonies/100 ml drinking water EPA recommends 200 colonies/100ml swimming water

16. Treatments for Human and Animal Wastewater Septic systems- a large container that receives wastewater from the house.

17. Fig. 19.14, p. 494 Household wastewater Perforated pipe Distribution box (optional) Septic tank Manhole (for cleanout) Drain field Vent pipe Nonperforated pipe Gravel or crushed stone

18. Treatments for Human and Animal Wastewater Sewage Treatment Plants- centralized plants in areas with large populations that receive wastewater via a network of underground pipes.

19. Sewage Treatment Primary: mechanical-let solids settle out, screens filter out Secondary: aerobic bacteria remove 90% of organic waste Trickling filters:sewage seeps through crushed stone (bacteria and protozoa ) 202 in WC Or Activated sludge: bacteria rich sludge and air bubbles Doesn’t do much for removal of chemicals

20. Fig. 19.15, p. 494 Raw sewage from sewers Bar screen Grit chamber Settling tankAeration tankSettling tank Chlorine disinfection tank Sludge Sludge digester Activated sludge Air pump (kills bacteria) To river, lake, or ocean Sludge drying bed Disposed of in landfill or ocean or applied to cropland, pasture, or rangeland Primary Secondary

21. Sewage Treatment Advanced Removes nitrates and phosphates, expensive May use reverse osmosis or flocculation (ppt) Chlorinated water may cause 7-10% of cancer in US Ozone or UV can be used as a substitute Sludge as fertilizer May lead to health problem (metals) Natural methods, using bacteria and plants is better than secondary treatment

23. Solutions Technology Septic tanks are used by 25% of all US homes, should be cleaned out every 3-5 years 1200 US cities (including Wilmington) have combined wastewater, stormwater pipelines

24. Treatments for Human and Animal Wastewater Manure lagoons- large, human-made ponds line with rubber to prevent the manure from leaking into the groundwater. After the manure is broken down by bacteria, it is spread onto fields as fertilizers.

25. Chesapeake Bay Point sources e.g. sew treatment plants--> 60% of phosphates Nonpoint sources --> 60% of nitrates Air pollution --> 35% nitrates Commercial fishing, decline since 1960’s due to overfishing, pollution and disease

26. Chesapeake Bay 1980’s, Chesapeake Bay program (ICM) Composed of state, fed, indust, sport, envir, etc Results: P levels down 27%, N down 16%, So submerged veg up 75%

27. Fig. 19.13, p. 490 Drainage basin No oxygenLow concentrations of oxygen PENNSYLVANIA NEW YORK WEST VIRGINIA MARYLAND DELAWARE NEW JERSEY ATLANTIC OCEAN VIRGINIA Cooperstown Harrisburg Baltimore Washington Richmond Norfolk Chesapeake Bay

28. Heavy Metals and Other Substances that can threaten human Health and the Environment Lead Arsenic Mercury Acids Synthetic compounds (pesticides, pharmaceuticals, and hormones)

30. Minamata disease Identified in 1959 Affects nervous system, first evident in cats then humans. Insoluble metallic mercury was dumped in Bay, bacteria converted it to soluble methylmercury It worked its way up the food chain Worldwide reaction helped to spark the environmental movement

31. Mad Hatters Disease Mercury was used in production of felt from fur for hats Workers worked with fumes in confined spaces for the long work day Characterized by erratic behavior, memory loss and shyness (Alice in Wonderland)

32. World Mercury Production Mostly from coal combustion

34. Acid Mine Drainage Groundwater in mines becomes acidic (low pH) Metal atoms dissolve in acid (Fe, Cu, Al, etc) Low pH water mixes with neutral water and yellow or red iron cmpds precipitate

36. Study of 139 streams in US by USGS Next page: percentage of streams with indicated contaminant

38. Sources of oil in the ocean Consumption of petroleum = water bottles, etc

39. Oil Pollution

40. Oil Spill Victim

42. Exxon Valdez March 24, 1989, Prince William Sound Double hull could have prevented spill Best technology can only recover 11-15% Oil Protection Act, 1990 is ineffective

43. Oil in Oceans 1. In normal operations, 1000x more oil is spilled per year than the Exxon Valdez (1989) (11 million gallons) 2. Oil from oil changes=20x Valdez 3. Gulf oil leak, 2010 (206 million gallons)

44. Oil in Oceans Cleanup? Mechanical methods Booms, skimmer boats, absorbent pads (on beaches) Chemical methods: coagulating agents, dispersing agents, fire, natural action

45. Ways to Remediate Oil Pollution Containment using booms to keep the floating oil from spreading. Chemicals that help break up the oil, making it disperse before it hits the shoreline. Bacteria that are genetically engineered to consume oil

46. Other Water Pollutants Solid waste pollution (garbage) Sediment pollution (sand, silt and clay) Thermal pollution Noise pollution

50. Water Laws Clean Water Act- (1972) supports the “protection and propagation of fish, shellfish, and wildlife and recreation in and on the water”. Issued water quality standards that defined acceptable limits of various pollutants in U.S. waterways.

51. Water Laws Safe Drinking Water Act- (1974, 1986, 1996) sets the national standards for safe drinking water. It is responsible for establishing maximum contaminant levels (MCL) for 77 different elements or substances in both surface water and groundwater.

54. Pathogens disease causing agents bacteria, viruses, protozoa, parasitic worms lack of clean drinking water causes 80% of diseases in developing countries coliform bacteria (eg E. Coli) from human waste, indicates possible pathogens

55. Organic Chemicals Oil, gasoline, pesticides, plastics, antifreeze

56. Sediment From erosion mostly Clouds water, blocks photosynthesis Buries feeding, spawning sites for fish Clogs shipping lanes, rotors in hydroelectric dams, reservoirs behind dams

57. Thermal Pollution Solubility of O 2 down, respiration up, so less DO At startup or shutdown of power plant for repair, thermal shock Some call it thermal enrichment since it extends fishing season, etc

58. Problems of Lakes Stratified water Little vertical mixing so little DO on bottom Acid deposition Little dilution b/c little mixing DDT, PCBs (polychlorinated biphenyls) Can be biomagnified