2. The Importance of Water Pollution Water Quality What Can We Do?

3. Why is there such a fuss about conserving water? 80% of the earth’s surface is covered by water!

4. Where is this water? 97.2 % is in the oceans (* as we all know salt water is undrinkable!!!) 2.15% is locked in glaciers and icecaps That leaves us with less than 1%; 0.65% to be exact!!

5. Canada has less than 1% of the world’s population, but has 22% of the world’s fresh water! Lucky us, right?!

6. We need water To drink To use for washing To use for cooking For industrial processes (manufacturing) To irrigate crops For recreation Sewage treatment, waste disposal

7. Problem: Rivers and Lakes contain more substances than ever before that make water less desirable for drinking and other uses

8. How did these substances get into the water?

10. Farming  Herbicides and pesticides: *they get washed into nearby lakes and other sources of water  Soil nutrients are deposited into water through erosion and poor farming practices

11. Manufacturing Manufacturing plants release harmful air pollutants called dioxins Bodies of water absorb these dioxins from the polluted air above them!

12. Refining Petroleum Products are dumped in the water from ships and refineries on shore

13. Sewage Have you ever been to Point Pleasant Park in Halifax? What were some of the things you saw in the water? YUCK!!!!

14. Needs Humans We need clean water that we can drink safely. The water must be free of living things and chemical poisons! It must be filtered, processed, and purified. Animals Aquatic animals need dissolved oxygen for breathing Need a clean water environment free of pollutants

15. Tests scientists perform to discover what is in water

16. Dissolved Oxygen The level of dissolved oxygen in water is a very important indicator of water quality WHY? Water gets oxygen from two places: From the air above the water From plants in the water (photosynthesis)

17. Dissolved Oxygen cont. 5-6ppm dissolved oxygen is required for normal growth and activity <3ppm is stressful; <2 is too low for animals and plants to survive!

18. Acidity Strong acids and bases are both dangerous to have in water (they’re corrosive!) Can test pH of water with pH paper or with a pH probe

20. Turbidity Turbidity is the measure of how cloudy water is If the water is too cloudy, sunlight is blocked from reaching aquatic plants

21. Reflection How can we conserve water as individuals? As a city? What changes do humans have to make to prevent water from becoming so polluted?