1. WATER QUALITY

2. Water Quality Describes the health of a water system
Is determined by the balance between physical, chemical, and biological variable.

3. Indicators of Water Quality
Physical Indicators: temperature, turbidity, water movement
Chemical Indicators: dissolved oxygen pH
nitrates & phosphates
salinity
Biological Indicators: macroinvertebrates

4. POTABLE WATER VS. SAFE WATER
Potable Water is drinkable!!!!
Safe water is only good for bathing, cleaning, etc…

5. TEMPERATURE Determines the kind of organisms that can live there
Aquatic species have preferred water temperature ranges within which they will survive
Cannot tolerate water temperatures below 32°F
Very few can handle temperatures above 97°F

6. Changes in Temperature
CAUSES
source of water
time of year
suspended sediment
depth of water
shade from shoreline vegetation
EFFECTS
Aquatic life may become susceptible to disease
Extreme changes can result in death

7. TURBIDITY Measure of how clear the water is
The more suspended solids there are in a water sample, the less transparent it is

8. CHANGES IN TURBIDITY CAUSES EFFECTS
Increased levels of phytoplankton
Sediment from erosion
Sediments stirred up by bottom dwellers
Waste discharge
Algae growth
Urban runoff
EFFECTS
Increases the absorption of sunlight
Makes the water temperatures warmer
Dissolved Oxygen levels decrease
Fish may die

9. The rate and amount of water flow
WATER MOVEMENT
The rate and amount of water flow

10. Changes in Water Movement
CAUSES:
Rainstorms
Droughts
Seasons
Shoreline vegetation
Irrigation
Industry
dams
EFFECTS:
Faster moving water can dissolve pollution better
Determines the type of aquatic life
Determines the amount of sediment
Determines the amount of dissolved oxygen (DO)

11. DISSOLVED OXYGEN (DO)
Amount of oxygen dissolved in water that is available for chemical reactions and for use by aquatic organisms

12. DISSOLVED OXYGEN (DO)
DO balance in water is important for the survival of certain microorganisms and higher organisms such as zooplankton and fish
DO enters water during photosynthesis by aquatic plants
DO also enters the water through diffusion from the air around the water

13. LEVELS OF DISSOLVED OXYGEN (DO)
DO levels vary throughout the day as well as throughout the year
Average DO level is 9.0 ppm
Must be 4-5 ppm to support a diverse population of fish

14. CHANGES IN Dissolved Oxygen LEVELS
EFFECTS
If DO levels get low, sensitive animals may move away, weaken, or die
If DO level is high in potable water, it usually tastes better
CAUSES
Turbulent actions such as waves, rapids, etc…
Water depth
Plant growth

15. pH How acidic or basic water is
Controls many chemical & biological processes
Impacts other materials in the water such as iron, aluminum, ammonia or mercury (acidic water can make some these poisonous)

16. pH Scale pH scale goes from 0 to 14
Substances with a pH from 0 to 6 are ACIDIC
Substances with a pH from 8 to 14 are BASIC
Substances with a pH of 7 are NEUTRAL
Surface freshwater:
Swamps:
as low as 4.3
Salt Water:
7.7 to 8.1

17. CHANGES IN pH CAUSES EFFECTS Natural conditions Fertilizers
Farm runoff
Dumping of waste
EFFECTS
Most aquatic life will die if the pH changes to a level outside of their optimal range

18. NITRATES AND PHOSPHATES
Major sources of nitrates in surface water include runoff contaminated with fertilizers, septic tank leakage, sewage, and erosion of natural deposits.
Phosphates usually come from human and animal waste, laundry, cleaning, and industrial effluents.

19. LEVELS OF NITRATES
Potable Water = 10 mg/L
Fish = below 90 mg/L

20. CHANGES IN LEVELS OF NITRATES
CAUSES
Fertilizer runoff
Manure pits
Leaks in septic systems
Animal waste
Car exhaust
EFFECTS
Increase in plant production
Increase in fish population
Overcrowding
Decrease in Dissolved Oxygen
Death in fish

21. BIOINDICATORS Macroinvertebrates found living in water
Macroinvertebrates are easy to collect & identify
Macroinvertebrates are sensitive to pollution
Variety of macroinvertebrates= GOOD QUALITY
Very few and no variety of macroinvertebrates= POOR QUALITY

22. CHANGES IN BIO-INDICATORS
CAUSES
Change in pH
Change in temperature
Change in Dissolved Oxygen
Change in nitrate levels
EFFECTS
Change in the variety of macroinvertebrates
Change in the number of macroinvertebrates