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