Chapter 6.4 - Pollution of Freshwater


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Pollution of freshwater

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Chapter 6.4 - Pollution of Freshwater

  1. 2. Chapter: Freshwater at Earth’s Surface Table of Contents Section 3: Wetlands Section 1: Streams Section 2: Lakes and Reservoirs Section 4: Pollution of Freshwater
  2. 3. Pollution Sources— Point Source Pollutants <ul><li>A pollutant is a substance that contaminates the environment. </li></ul><ul><li>Water pollution occurs when substances are added to water that lower its quality. </li></ul>Pollution of Freshwater 4
  3. 4. Pollution Sources— Point Source Pollutants Pollution of Freshwater 4 <ul><li>Pollution that enters water from a specific location is called point source pollution . </li></ul><ul><li>Point sources are fairly easy to control because the location of the pollution source is known. </li></ul>
  4. 5. Nonpoint Source Pollutants <ul><li>Most water pollution doesn’t enter a body of water from sources you can identify. </li></ul><ul><li>When pollution comes from a wide area such as lawns, construction sites, and roads, it is called nonpoint source pollution . </li></ul>Pollution of Freshwater 4
  5. 6. Nonpoint Source Pollutants Pollution of Freshwater 4 <ul><li>Pollutants can be delivered to a body of water by runoff from yards, parking lots and farm fields. </li></ul>
  6. 7. Nonpoint Source Pollutants <ul><li>Nonpoint sources also include pollutants in rain or snow. </li></ul><ul><li>Nonpoint sources are much harder to control because it is hard to tell exactly where the pollution comes from. </li></ul>Pollution of Freshwater 4
  7. 8. Reducing Water Pollution <ul><li>The key to clean water is to reduce the amount of pollutants that enter it. </li></ul><ul><li>Controlling point source pollutants might seem easy-reduce the amount of pollutants at the source. </li></ul>Pollution of Freshwater 4
  8. 9. Reducing Water Pollution <ul><li>Controlling nonpoint source pollution is more difficult. </li></ul><ul><li>Fertilizers, herbicides, and insecticides are sprayed on crops and gardens over large land areas to encourage plant growth and reduce damage from weeds and insects. </li></ul>Pollution of Freshwater 4 <ul><li>These substances can be carried into Earth’s surface freshwater. </li></ul>
  9. 10. Reducing Water Pollution <ul><li>Controlling pollution requires difficult decisions about the types and amounts of pollutants that should be allowed in water. </li></ul><ul><li>Laws that limit pollutants are written carefully to protect the water resource and the economy. </li></ul>Pollution of Freshwater 4
  10. 11. Legislation <ul><li>The Rivers and Harbors Act of 1899 was the first attempt to use legislation to help regulate water pollution. </li></ul><ul><li>This law required that when any work was done in water that ships use for navigation, like dredging the bottom, the wildlife resources of the water must be considered. </li></ul>Pollution of Freshwater 4
  11. 12. Legislation <ul><li>By the late 1960s, water pollution became so bade in the United States that many beaches along the east and west coasts were unhealthy for swimming. </li></ul>Pollution of Freshwater 4
  12. 13. Legislation <ul><li>In 1969, greasy debris floating on a large river in Cleveland, Ohio, caught on fire. </li></ul>Pollution of Freshwater 4 <ul><li>In 1972, the U.S. Congress responded by passing the Federal Water Pollution Control Act. </li></ul>
  13. 14. Legislation <ul><li>Amendments were added to this act in 1977 and 1987, and it was renamed the Clean Water Act. </li></ul><ul><li>These laws put limits on the types of pollution that can be discharged into streams and lakes. </li></ul>Pollution of Freshwater 4 <ul><li>In 1970, Congress created the Environmental Protection Agency (EPA), to enforce water pollution limits. </li></ul>
  14. 15. Legislation <ul><li>The Clean Water Act amendments also provided federal funds for communities and industries to limit their water pollution sources. </li></ul>Pollution of Freshwater 4
  15. 16. Legislation <ul><li>Today, 55 percent of streams and rivers and 46 percent of lakes that have been tested have good water quality. </li></ul>Pollution of Freshwater 4
  16. 17. How can you help? <ul><li>You can do many things to reduce water pollution. Pay attention to how much water you use. </li></ul><ul><li>Just turning off the faucet when you brush your teeth can save more than 19 L of water per day. </li></ul>Pollution of Freshwater 4 <ul><li>Keep your yard and driveway free of pet wastes, oil, and other debris. When it rains, these pollutants run off to streams and lakes. </li></ul>
  17. 18. How can you help? <ul><li>Learn alternate methods to care for your yard and garden, like composting grass clippings. </li></ul><ul><li>Composting yard wastes reduces the amount of fertilizer and other chemicals needed for your yard. </li></ul>Pollution of Freshwater 4
  18. 19. How can you help? Pollution of Freshwater 4 <ul><li>Properly dispose of any hazardous substances, such as used oil, antifreeze, and paint. </li></ul><ul><li>Learn about programs in your community for safe disposal of hazardous waste. </li></ul>
  19. 20. Section Check 4 Question 1 List some sources of nonpoint pollution. Nonpoint source pollutants can come from lawns, construction sites, roads, and farms. Answer NC: 3.07
  20. 21. Section Check 4 Question 2 Which of the following provides funds to communities and industries to limit their water pollution sources? A. Clean Water Act B. Environmental Protection Agency C. Federal Water Pollution Control Act D. The Rivers and Harbors Act NC: 3.08
  21. 22. Section Check 4 Answer The answer is A. The Clean Water Act provides federal funds to keep water sources free of pollution. NC: 3.08
  22. 23. Section Check 4 Question 3 Why is point source pollution easier to control than nonpoint source pollution? NC: 3.07
  23. 24. Section Check 4 Answer Point source pollution enters water from a specific location; therefore, the location of the pollution source is known. Nonpoint source pollution can come from a wide area and the source can be difficult to track down. NC: 3.07