1. Water Quality

2. Indicators of Water Quality
Dissolved Oxygen
Nitrates
Turbidity pH
Bioindicators

3. What is Water Quality?
Water Quality – A term used to describe the health of a water system.
How would you describe a healthy water system?

4. Is the Water Safe?
Potable Water – Water that is safe for humans to drink and use with low risk of immediate or long-term harm.
Nonpotable Water – Water that is not safe to drink or use.

5. Dissolved Oxygen
Dissolved Oxygen – The amount of oxygen dissolved in a water system.
What is the source of dissolved oxygen in water?

6. Dissolved Oxygen
Dissolved Oxygen – The amount of oxygen dissolved in a water system.
What is the source of dissolved oxygen in water?
Plants!

7. DO Levels Average Level: 9.0 ppm (parts per million)
Must be 4–5 ppm to support diverse population of fish

8. What changes the DO Levels?
Turbulent actions (waves, rapids)
Water depth and Temperature change *Cold water holds more DO*
Plant growth

9. Nitrates
Nitrates – The amount of nitrogen compounds in a water system that allows for plant and algae growth.
Nitrates are FOOD for plants, but TOO MUCH can destroy a water system!
Increased Nitrates cause
Algal Blooms, which cause
Fish Kills!

10. What adds Nitrates to the water?
Fertilizer runoff (both farm and home)
Manure pits and animal waste
Leaks in septic systems
Rain trapping car exhaust

11. Algal Blooms Increased Nitrates cause Algal Blooms, which cause
Fish Kills!
How does this happen?
Increase of Nitrates in the water cause Algae to grow.
Algae covers the surface and blocks sunlight.
Other plants die and Bacteria increases.
Bacteria use all the Dissolved Oxygen in the water.
No Dissolved Oxygen causes fish to die! 

12. Turbidity: measure of the degree to which water loses its transparency due to the presence of suspended particulates
How cloudy the water is.

13. Results of High Turbidity
High turbidity increases the absorption of sunlight thus making the water warmer. Warmer water has lower levels of dissolved oxygen causing fish and larvae to die.

14. pH pH – The measure of how acidic or basic a substance is.
pH scale:
Acidic Neutral Basic
*Some acids and bases are used in everyday life, while others can be very harmful to humans and ecosystems.

15. pH Levels Lakes, river, etc.: 6 - 9 (varies around neutral)
Swamps: (acidic)
Salt Water: (basic)

16. What causes changes in pH?
Natural conditions (bacteria in swamps)
Dumping of waste (batteries)
Farm runoff (lime)

17. Results of pH changes Most aquatic life cannot survive changes in pH!!
Ocean acidification – When the ocean becomes acidic, it prevents mollusks and crustaceans (like clams, mussels, crabs, etc.) from developing shells.

18. Bioindicators
Bioindicators – Macroinvertebrates found living in water (they tend to remain in one place) that are sensitive to pollution.
Examples:

19. What causes changes to Bioindicator populations?
Changes in: pH
Nitrates
Temperature
Dissolved Oxygen
*Lack of a large number of different varieties of bio-indicators is indicative of poor water quality and/or pollution.

20. Water Quality and Pollution Video