1. How do you know water is healthy?

2. Water Quality Standards
Rules set by the Environmental Protection Agency (EPA)
Clean Water Act of 1972 – set laws into place

3. Temperature
Water needs to be a certain temperature to support life Water warmer than 35°C (95°F) is bad for wildlife Colder = Better

4. Turbidity Describes how muddy or cloudy water is
Higher turbidity means too much runoff or algae
Under 25 for Salt
Under 50 for Fresh

5. Dissolved Oxygen Oxygen is needed for animals to survive underwater
Aquatic plants will release oxygen into water & oxygen can also be dissolved into the water from the air
Less than 5 ppm is dangerous

6. pH pH should stay between 5 and 9
A PH scale tells how acidic or basic objects are

8. Other Nutrients Nitrates – No more than 1 ppm
Phosphates – No more than ppm
Comes from fertilizers

9. How does the algae in this river effect the ecosystem?

10. Bio-indicator
Life in or around water that tells scientists about the water quality before any tests are run.
How does the algae act as a bio-indicator in the previous slide?

11. What is the bio-indicator? What can you conclude?