1. 3/16 A/B Day
LEQ: How do we use different measurements to
determine if our hydrosphere is healthy?
1. What is desalination?
2. How does the hydrosphere give us air to breathe?
3. What is the difference between a point- and a non-
point pollutant?
4. Give an example of a point-source pollutant and a
non-point-source pollutant
5. What is one thing you can do to help keep our
hydrosphere clean?

2. Today’s LEQ: How do we use different
measurements to determine if our
hydrosphere is healthy?
By the end of today, you should be able to…
Examine the pH level, turbidity, nitrate
level, oxygen level, and bio-indicators to
determine if a body of water is healthy or
unhealthy!

3. Focus Vocabulary:
141. pH
142. Turbidity
143. Algal bloom
144. Nitrates
145. Bio-indicator

4. What are some physical characteristics
of someone who is sick?

5. Water can be sick too!
What physical characteristics
do you see in the water in each picture?

6. Draw this in your notes:
Good Water Quality Bad Water Quality

7. Unscramble!
Muddy/Murky

8. How are dissolved oxygen and water
temperature related?
Temperature: Dissolved Oxygen:
20° 9 mg/l
Dissolved Oxygen
40° 6 mg/l
60 ° 5 mg/l
80 ° 3 mg/l
As the temperature
increases, the amount
of dissolved oxygen
[increases/decreases].
Water Temperature

9. Good or Bad Water Quality?
Good 
Dissolved Oxygen
Still Pretty
Good 
TERRIBLE! 
Water Temperature

10. Temperature: Cool
Dissolved Oxygen Level: High

11. Temperature: HOT
Dissolved Oxygen Level: LOW

12. Evaluate: Water Health in North Carolina
Cape Fear River Lake Michie
• 25° Celcius • 38° Celcius
(68 ° Farenheit) (100.4 ° Farenheit)
• Dissolved Oxygen: • Dissolved Oxygen:
8 mg/l 2 mg/l
Which body of fresh water is
healthier? How do you know?

13. What is likely the cause of the low oxygen levels in July?
a) High temperatures
b) Lots of algae died
c) More fish are being born
d) Fewer bubbles are in the water

14. Draw this in your notes:
pH Scale: scale from 0-14 that measures
the levels of acids and bases in a liquid

15. BrainPop: pH Scale

16. Draw this in your notes:
pH Scale: scale from 0-14 that measures
the levels of acids and bases in a liquid
Very Neutral  Very
Acidic Basic

17. Healthy Water!
(Neutral)

18. ADD this to your notes:
Good Water Bad Water
Quality Quality
Lots of different
species of algae
Algal Bloom!

19. pH Level: Around 7 (Neutral)

20. pH Level: Very high or very low

21. Evaluate: Water Health in North Carolina
Neuse River Lake Phelps
• pH: 8.1 • pH: 2.4
Which body of fresh water is
healthier? How do you know?

22. ADD this to your notes:
Good Water Bad Water
Quality Quality
Neutral pH
(about 7)
Very high pH or
very low pH

23. Draw this in your notes:
Turbidity: measures how clear or
muddy the water is
High Turbidity = unhealthy Low Turbidity = healthy

24. Turbidity: Low

25. Turbidity: High

26. Which one has the highest turbidity?

27. Which one has the highest turbidity?

28. Which one has the highest turbidity?

29. Evaluate: Water Health in North Carolina
Neuse River Lake Norman
• High turbidity • Low turbidity
Which body of fresh water is
healthier? How do you know?

30. Think-Pair-Share:
Can you think of an
example where too
much of a good thing
becomes a bad thing?!

31. Too Much Algae = BAD!!!!!

32. Nitrates (nutrients from fertilizer) are
washed into hydrosphere
This causes algal blooms (when too
much algae grows in an area)

34. Discovery Education: Nutrient Pollution
While you’re watching…
HOW DO ALGAL BLOOMS
DAMAGE THE
HYDROSPHERE?

35. Nitrates (nutrients from fertilizer) are
washed into hydrosphere
This causes algal blooms (when too
much algae grows in an area)
Algal blooms damage the hydrosphere by:
-using up all of water’s dissolved oxygen
-releasing toxic chemicals
-blocking out sunlight

36. Which water has high levels of nitrates?

37. Which water has high levels of nitrates?

38. ADD this to your notes:
Good Water Bad Water
Quality Quality
Normal algae
levels
Algal Bloom!

39. ADD this to your notes:
Good Water Bad Water
Quality Quality
Low Nitrate
Levels
High Nitrate
levels

40. What months might there
have been an algal bloom?

41. Break down the word:
What do you think a
bio-indicator is?

42. Draw this in your notes:
Bio-indicators: animals that are used
to measure the health of water
Example: Trout can only live in healthy water
Trout in water = healthy No Trout in water = unhealthy

43. ADD this to your notes:
Good Water Bad Water
Quality Quality
Presence of bio-
indicators
No bio-indicator

44. BrainPop: Water Pollution

45. EOG Question:
Which of the following are indicators of a healthy
water system?
a) high nitrates, high chlorophyll, low
temperature
b) low temperature, high dissolved oxygen,
neutral pH
c) low pH, high nitrates, low dissolved oxygen
d) low turbidity, high chlorophyll, high
temperature

46. EOG Question:
What does it mean when a scientist says a
lake has a high turbidity?
a) the water has a lot of particles in it
b) the water is very clear
c) the water is very basic
d) the water can support many
organisms

47. Let’s Practice!
Water Quality Independent Practice

48. Summarizer:
A student takes measurements from a lake in East
Charlotte. The student finds the following:
Turbidity: High
Dissolved Oxygen: low
Temperature: 111 ° Fahrenheit
pH Level: 3.1
Is this a healthy lake or an unhealthy lake? Explain
your answer in 5-7 sentences. BE SURE TO INCLUDE a
prediction about what the lake looks like (Do you
think there are there any bio-indicators? Do you
think there could possibly be an algal bloom?)