1. Water Quality, Indicators, and Usage
8. E and 4
Water Quality, Indicators, and Usage

2. How is the health of a water system determined?
Balance between physical, chemical, and biological factors
Physical variables include: temperature, turbidity, and water movement.
Chemical variables include: dissolved oxygen and other gases, pH, nitrates, pollution, and salinity.

3. Physical, Chemical, and biological factors
Both natural and man-made forces are constantly changing these variables. Freshwater systems are of particular concern because they are the source of most of the potable water consumed by humans.
Testing for the occurrence of chemicals and other factors that can influence water quality, such as nutrients and pesticides in water resources is a normal part of public health maintenance and stewardship of freshwater resources.

4. Potable Water
Water that is safe to drink is called potable water, or drinking water, in contrast to safe water, which can be used for bathing or cleaning.
In the United States, the Environmental Protection Agency sets maximum levels for the 90 most commonly occurring contaminants.

5. How does temperature affect the health of a water system?
Affects the ability of water to act as a solvent
Warm water dissolves…
more solid substance
less important gases (oxygen, carbon dioxide)
Aquatic life requires specific temperatures to survive in their habitat
Human impact on water temperature
Global Warming
Factory Discharge
Chemical Reactions

6. How does turbidity affect the health of water systems?
The measure of clarity of water
The more dirt suspended in the water the higher the turbidity (less transparent)
Impact of high turbidity…
Blocks out sun
High water temperatures
Plants and algae cannot perform photosynthesis
Water is not clean to consume

7. How does water movement affect the health of a water system?
Erosion: gradual wearing away and movement of land surface materials due to the movement of water and wind
Stagnant (not moving) water
Levels of dissolved oxygen drop
anaerobic bacteria can grow
The Power of Erosion

8. How do dissolved gases affect a water system?
Aquatic life needs oxygen to survive
Oxygen (solute) is dissolved in water (solvent)
Movement of water and aquatic plants
Temperature = Dissolved Gases
Temperature = Dissolved Gases
Think about chugging a cold soda vs. a warm soda, which one has more bubbles?
Dissolved Oxygen and Gases- Soda Example

9. How does dissolved oxygen (DO) affect water systems?
DO is a measure of the amount of oxygen in water that is available for chemical reactions and for use by aquatic animals
Gets in the water because oxygen is a product of photosynthesis
DO levels decline
sensitive animals may move away, weaken, or die.
High DO levels in potable (drinkable) water usually make it taste better
Measuring Dissolved Oxygen

10. How do other dissolved chemicals affect the water?
Phosphates
Stimulate growth of producers
causes water flow to slow down
increase in sediment
Enter water through…
Human/animal waste
Laundry
Cleaning/industrial waste
Nitrates
Fertilizer
Sewage
Erosion
Increased algae growth which can lead to eutrophication

11. How does pH affect a water system?
Controls many chemical and biological processes that occur in water
A measure of acidity
Acid = pH of 1-6
Base = pH of 8-14
Neutral = pH of 7
Variances in pH cause…
Pollution
Death of aquatic animals

12. How does salinity affect water systems?
Salinity: A measure of dissolved salts in water
Freshwater animals cannot survive in salt water and salt water animals cannot survive in freshwater environments.
How does salt enter the environment?
Minerals get washed into the environment due to surface runoff and erosion.
Human Impact: salted roads during the winter

13. How is the health of a water system determined?
Biological Factors
Components of a water system that indicate the health of the water.
Living organisms in the water indicate the health of the water, depending on the use of the water.

14. What are bioindicators?
Organisms that are studied to indicate the quality of water such as water flow, pollution, and vegetation
They indicate the health or sickness of their environment
The higher the biodiversity, the healthier the environment
Poor water quality is indicated by a few or one type of macroinvertebrates in one place.

15. What is water quality?
Describes the chemical, physical, and biological characteristics of water
Described in terms of the propose for which the water is used.
Potable water- safe to drink
Safe water- can be used for bathing and cleaning

16. What are water quality standards?
Outline the water quality pollution control program for a body of water
Identify uses of body of water
Establishes how to protect uses
Establishes provisions for to protect and preserve in long term
Mandated by local, regional and federal agencies
Drinking water standards: benchmarks established to determine the quality of water

17. What legislation is in place to protect our freshwater?
Clean Water Act- 1972
Safe Drinking Act – 1974
Everyone in the developed world has the right to safe drinking water
1970- concern shifted to industrial waste and water contamination
Water treatment plants adapted
Water treatment: the process used to remove contaminants from water and make it usable for humans.
Focus on conservation of water systems

18. How is water treated? Water flows through mixers Clumping agents
Disinfecting chemicals
Clarifying pool
Lumps of dirt sink to bottom
Filter smaller particles of dirt
Coal, sand, gravel
Chlorine
Added to kill last of the bacteria

20. What are the types of pollution?
Point-source pollution
The specific place or thing can be identified as a source of a specific water contamination
Example: pollution from factory
Non-point source pollution
Both the water and air pollution from diffuse (spread out or disseminating) sources
Example: Smog, pollution comes from cars, factories, etc. in a city

21. What is stewardship?
The act of being responsible for overseeing and protecting, caring for, and preserving something
What makes someone a good steward of water?