Water Pollution: Causes, Impacts, and Solutions

1. Chapter 14 Water Pollution

2. Water Pollution • 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. These are easily identified • Nonpoint sources- diffuse areas such as an entire farming region that pollutes a waterway. These are more expensive and difficult to clean up.

3. Can you identify which of these is point source Pollution?

4. Categories of Water Pollution • Sewage • disease-causing agents • sediment pollution • inorganic plant and algal nutrients • organic compounds • inorganic chemicals • radioactive substances • thermal pollution • Noise pollution

5. Water Pollution is a Problem Worldwide Half of the world’s major rivers are seriously depleted and polluted They poison surrounding ecosystems Threaten the health and livelihood of people The invisible pollution of groundwater has been called a “covert crisis”

6. Water Pollution Over two-thirds of U.S. estuaries and bays are severely degraded because of nitrogen and phosphorous pollution Every year almost 25% of U.S. beaches are closed at least once because of water pollution Over 73 different kinds of pesticides have been found in the groundwater that we eventually use to drink 1.2 trillion gallons of sewage, storm water and industrial waste are discharged into U.S. waters every year A large number of U.S. rivers are too polluted for aquatic life to survive Americans use over 2.2 billion pounds of pesticides every year, which eventually washes into our rivers and lakes

7. Leading causes of water pollution • Agriculture activities • Sediment eroded from the lands • Fertilizers and pesticides-almost all waters are polluted with pesticides • Bacteria from livestock and food processing wastes • Industrial facilities- heavy metals, corrosive materials organic and non-organic chemicals • Mining- acid drainage pollutes water by leeching out heavy metals

8. Agriculture major source of water pollution • Agriculture is leading source of water pollution in US • Animal wastes and plants residues have high BOD • Chemical pesticides can leach into groundwater • Almost all streams and rivers are polluted with agricultural pesticides

9. Agricultural Runoff is the main cause of the Dead Zone in the Gulf of Mexico; The U.N. documented 250 dead zones worldwide in 2005

10. Sediment runoff from farmland is the highest Pollution from agriculture by weight.

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 and oxygen levels to fall eventually may cause a die-off of all organisms.

12. Solutions to Reduce Eutrophication • Phosphate-free detergents • Planting vegetation to increase nutrient uptake • Treat wastewater • Reduce fertilizer application

13. Different industries add different pollutants • Food processing plants- high BOD • Paper mills- High BOD and toxic compounds • Textile industry-the World Bank estimates that 17-20 percent of industrial pollution comes from textile industry with 72 toxic chemicals being added to water

14. According to Greenpeace, the discharge from these factories includes heavy metals and “hazardous and persistent chemicals with hormone-disrupting properties” were found being discharged from China’ s factories

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

16. More on heavy metals • Lead • Found in old paint, industrial pollutants, leaded gasoline • Mercury • Mercury bioaccumulates in the muscles of top predators of the open ocean

18. Arsenic found naturally in rocks and water • When arsenic is found in water, it may be from natural causes • Highest levels of arsenic in U.S. found in upper Midwest and West • Individual wells dug in Southeast Asia-many are contaminated by arsenic causing arsenic posioning

19. World Mercury Production from Human Activities

20. Pharmaceuticals and Hormones Found in Water

21. Industrial Compounds • Chemicals used in manufacturing • Local examples include PCBs in Hudson River from General Electric Co. and cadmium from foundry in Cold Spring • PCBs cause brain damage, are lethal and carcinogenic

22. Oil Pollution

24. Marine pollution threatens resources • Even into the mid-20th century, coastal U.S. cities dumped trash and untreated sewage along their shores • Oil, plastic, chemicals, excess nutrients make their way from land into oceans • Raw sewage and trash from cruise ships • Abandoned fishing gear from fishing boats In 2006, 359,000 Ocean Conservancy volunteers from 66 nations picked up 3.2 million kg (7 million lbs.) of trash

25. 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

26. Water Pollution from Mining • Acid Mine Drainage-low pH of water causes iron to precipitate from pyrite and cause a rusty red color • Heavy metal contamination and leeching • Mine waste and tailings • Processing chemicals pollution • Sedimentation of waters and erosion

27. Mining often pollutes waters

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

29. Solid Waste Pollution • Much solid waste is garbage • North Pacific Gyre-Great Pacific Garbage Patch • Plastic waste is dangerous to marine animals and humans • Found in the stomachs of dead baby sea birds as parent birds think the small pieces of plastic is phytoplankton.

30. Plastic rubbish deposits

31. Plastic Pollution of Water • Plastics can release harmful chemicals into the water • Plastic is a synthesized organic compound (carbon-hydrogen bonds) that does not decompose • Plastic breaks up into extremely tiny pieces that is mistaken for food by many organisms.

32. Sediment Pollution • Excessive amounts of suspended soil particles • Originates from erosion of agricultural lands, forest soils exposed by logging, degraded stream banks, overgrazed rangelands, strip mines, and construction • Problems • Limits light penetration • Covers aquatic animals and plants • Brings insoluble toxins into waterways

34. Land disturbance results in poor water quality • Clear-cutting, mining, poor cultivation practices • Dramatically changes aquatic habitats, and fish may not survive • Solutions: better management of farms and forests; avoid large-scale disturbance of vegetation

35. Radioactive Substances Contain atoms of unstable isotopes that spontaneously emit radiation Sources Mining Processing radioactive materials Nuclear power plants Natural sources

36. Thermal Pollution Occurs when heated water produced during industrial processes is released into waterways Temperature affects digestive rates, heart rates, and respiration rates Warmer water holds less dissolved oxygen Removing streamside cover also raises water temperature

38. Noise Pollution • Sounds from ships and submarines • Sonar equipment could negatively affect whales, causing them to be beached • U. S. Military exempt from environmental laws related to sonar use

39. Organic Compounds found in Polluted Water

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

41. Why human and animal waste water needs to be treated Pathogens and toxins enter water supply via inadequately treated human waste and animal waste via feedlots Causes more human health problems than any other type of water pollution

42. 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.

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

45. Sewage and pollutants in drinking water • Currently, 1.1 billion people are without safe drinking water • 2.4 billion have no sewer or sanitary facilities • Mostly rural Asians and Africans • An estimated 1.6 to 5 million people die per year from unsafe drinking water

46. Common Diseases from Human Wastewater

47. Major Water Pollutants and Their Sources Table 20-1, p. 532

48. Solutions • Treat sewage • Disinfect drinking water • Public education to encourage personal hygiene • Government enforcement of regulations

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

50. 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. • Test for human and animal waste using fecal coliform bacteria test