The Importance of Water

1
The Importance of Water

• Pollution
• Water Quality
• What Can We Do?

2
Why is there such a fuss about conserving water?

• 80 of the earths surface is covered by water!

3
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!!

4

• Canada has less than 1 of the worlds
  population, but has 22 of the worlds fresh
  water! Lucky us, right?!

5
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

6
Problem Rivers and Lakes contain more substances
than ever before that make water less desirable
for drinking and other uses
7
How did these substances get into the water?
8
(No Transcript)
9
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

10
Manufacturing

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

11
Refining

• Petroleum Products are dumped in the water from
  ships and refineries on shore

12
Sewage

• Have you ever been to Point Pleasant Park in
  Halifax?
• What were some of the things you saw in the
  water?

YUCK!!!!
13
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

14
Tests scientists perform to discover what is in
water
15
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)

16
Dissolved Oxygen cont.

• 5-6ppm dissolved oxygen is required for normal
  growth and activity
• lt3ppm is stressful lt2 is too low for animals and
  plants to survive!

17
Acidity

• Strong acids and bases are both dangerous to have
  in water (theyre corrosive!)
• Can test pH of water with pH paper or with a pH
  probe

18
(No Transcript)
19
Turbidity

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

20
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?