Water Pollution

1. Water Pollution • introduction of waste matter or chemicals that are harmful to organisms living in the water or to those that drink or are exposed to the water. • the two underlying causes of water pollution are industrialization and rapid human population growth.

2. Water Pollution • Developed countries some water is still dangerously polluted. • In developing parts of the world, water pollution is a big problem because polluted water may only be available • Sources: • point : actual pipe, source • nonpoint : runoff from land

3. Wastewater • water that contains wastes from homes or industry. • treatment plant make the water clean enough to return to a river or lake • most waste biodegradable

4. Sewage Sludge • the solid material that remains after wastewater treatment • dangerous concentrations of toxic chemicals makes it hazardous • If the toxicity can be reduced to safe levels • used as a fertilizer • combined with clay to make bricks

5. Eutrophication is a natural process • 1. Organic matter builds up in a body of water • 2. Oxygen levels decrease, • 3. Types of organisms change • A body of water can become a swamp or marsh.

6. Artificial Eutrophication • process that increases the amount of nutrients in water through human activities • major causes : fertilizer and phosphates in detergents.

7. Thermal Pollution • temperature increase in a body of water caused by human activity that has a harmful effect on water quality • can cause large fish kills • total disruption of an aquatic ecosystem

8. Groundwater Pollution • Usually from polluted surface water that percolates down • Any pollution of the surface water in an area can affect the groundwater. • Pesticides, herbicides, chemical fertilizer, and petroleum, industrial wastewater • Leaking underground storage tanks are a major source of groundwater pollution

9. Cleaning Up Groundwater Pollution • Oof the most challenging environmental problems in the world. • Groundwater recharges very slowly • hundreds of years to recycle aquifer water and purge contaminants • pollutants can cling to the materials that make up an aquifer, continue to cause problems

10. Ocean Pollution • Often dumped directly into the ocean • At least 85 percent pollutants comes from activities on land • oil, toxic wastes, and medical wastes • Sensitive coastal ecosystems, such as coral reefs, most effected

11. Oil Spills • Each year, about 37 million gallons of oil from tanker accidents are spilled into the ocean. • 5 percent of oil pollution in the oceans • Most of the oil that pollutes the oceans comes from cities and towns..

12. Water Pollution and Ecosystems • Biomagnification : accumulation of pollutants at successive levels of the food chain. • Alarming consequences for organisms at the top of the food chain • One reason why U.S. states limit the amount of fish people can eat from certain bodies of water

13. Cleaning Up Water Pollution • The Clean Water Act of 1972 designed to “restore and maintain the chemical, physical, and biological integrity of the nation’s waters.” • surface water clean enough for fishing and swimming by 1983 (not met) • lakes fit for swimming increased by 30 percent, • many states have passed stricter water-quality standards.

14. Marine, Protection, Research, and Sanctuaries Act of 1972: laws against ocean dumping. • Oil Pollution Act of 1990 : requires all oil tankers traveling in U.S. waters to have double hulls by 2015 as an added protection against oil spills