Freshwater Pollution

1. Freshwater Pollution

2. Water Pollution • Water pollution – chemical, physical or biological things in the water which degrade the quality of the water and affect the organisms dependent on it • Causes: • Industrialization • Human population boom

3. Major Types of Water Pollution • Pathogens – disease causing organisms • Bacteria, viruses, parasitic worms • Sewage • Organic chemicals – pesticides, fertilizer, gasoline, oil, detergents, etc. • Organic matter – biodegradable remains of animals and plants

4. Major Types of Pollution cont. Inorganic chemicals – acids, salts, toxic metals Toxic chemicals – poisonous chemicals including heavy metals (lead, mercury), industrial and household chemicals Physical agents – heat and suspended solids (soil) Radioactive waste – from power or nuclear processing plants

5. Classification of Pollution • Point pollution – discharged from a single source • Factory, wastewater treatment plant, oil tanker • Easy to regulate and control • Nonpoint pollution – comes from many sources rather than a single specific site • Hazardous materials washed into bodies of water • Difficult to control • 96% of water pollution comes from nonpoint pollution

6. Wastewater Treatment Plants • Wastewater – water that flows down the drain • Treatment plants remove most but industrial wastewater and toxic substances are harder to get rid of • Creates sludge – solid material that remains after treatment • May contain hazardous materials • Incinerated or buried in a landfill

7. Effects of Water Pollution

8. Long Term Effects • Biological magnification – toxic materials work its way through the food chain • Soil tainted with toxins enters producers (sea weed) → lots of seaweed is eaten by small fish → lots of small fish are eaten by one big fish • Big fish has an increased concentration of toxin

9. Biological Magnification

10. Water Pollution and Humans Toxic chemicals can cause cancer, birth defects, damage to reproductive system, nervous system, liver or kidneys Occurs from drinking polluted water or eating fish with accumulated toxins

11. Short Term Effects Toxic chemical or oil spills which instantly kill almost all the living things

12. Artificial Eutrophication • Eutrophic means lots of nutrients • Occurs naturally as organisms die and decompose • Artificial – plant nutrients like phosphorus and nitrogen get into the water • Cause algal blooms • Algae die and use up oxygen • killing fish

13. Thermal Pollution Excessive amounts of heat are added to body of water Water comes from power plants and factories Too much heat releases oxygen – not enough for fish to survive

14. Cleaning Up Water Pollution Clean Water Act – 1972 – goal to make all surface waters clean enough for fishing and swimming by 1983 Led to more, stricter laws on both national and state level Personal and industrial progress

15. Wastewater Treatment Plants • Wastewater – water that flows down the drain • Treatment plants remove most but industrial wastewater and toxic substances are harder to get rid of • Creates sludge – solid material that remains after treatment • May contain hazardous materials • Incinerated or buried in a landfill