LO Water resources

1. Describe a water molecule and its characteristics

• Water (H₂O) is a dipole molecule: the oxygen end is slightly negative, and hydrogen ends are slightly positive.

• It can exist in three states: solid, liquid, and vapor.

• Dissolves most polar molecules, making it the “universal solvent.”

• Crucial for temperature regulation of Earth and organisms.

2. Relay the tiered pricing system in Athens-Clarke County

• Athens-Clarke County charges ~$6.63 per 1,000 gallons.

• This tiered system encourages conservation by increasing prices with usage levels.

3. Compare municipal water prices to bottled water prices

• Municipal water (Athens): ~$0.0066 per gallon.

• Bottled water: ~$1.22 per gallon or more.

• Bottled water can be ~185 times more expensive than tap water, despite often coming from the same sources.

4. Draw the water cycle: know where the most and least water reside

• Most water is in oceans (97.5%) – not drinkable.

• Glaciers and polar ice caps hold most of Earth’s freshwater (2%).

• Only 0.5% of water is liquid freshwater (rivers, lakes, groundwater).

• The atmosphere holds only 0.001%, but has the fastest turnover.

5. Relate to the percent of the world’s water that is liquid and fresh

• Only 0.5% of Earth’s water is liquid freshwater and available for human use.

• Groundwater makes up 0.62% of total water, with ~50% of the U.S. population depending on it.

6. Combine issues of water shortages and contamination with political issues and water rights

• Global demand for water is increasing 2.3% annually.

• 2 billion people lack access to clean drinking water; 2.5 billion lack sanitation.

• Water contamination sources include pesticides, septic systems, and landfills.

• Example: Florida v. Georgia (2020) lawsuit over water use from shared rivers (dismissed by the Supreme Court).

• Water rights involve ecological values, intergenerational justice, and indigenous sovereignty.

7. Understand the consequences of water stress in several types of aquifers

• Water stress = water withdrawal vs. water availability.

• Ogallala Aquifer (High Plains): vast but overdrawn due to irrigation.

  • Consequences: lower yields, dry wells, soil degradation.

  • Solutions: drip irrigation, crop rotation, terracing, reduced irrigation area.

8. Discern between dug wells and drilled wells

• Dug wells: shallow, wide, often hand-dug, higher contamination risk.

• Drilled wells: narrow, deeper, made with drilling equipment, more secure from contaminants.

9. Weigh the environmental costs and social drawbacks from building dams against the benefits

• Benefits: Water storage, hydropower, flood control, recreation.

• Costs: Habitat disruption, displacement of communities, sedimentation, loss of biodiversity.

10. Explain the difference between point source and nonpoint source pollutions. Generate examples of each

• Point source pollution: Comes from a single, identifiable location (e.g., factory pipe, sewage outfall).

• Nonpoint source pollution: Comes from diffuse sources (e.g., agricultural runoff, urban stormwater).

• Example: Dalton, GA carpet industry pollutes via multiple discharge points.

11. Understand how nutrients can be pollution and describe the science behind eutrophication and oxygen sag

Plant nutrients (nitrate, phosphate) from fertilizers lead to eutrophication:

• Excess nutrients → algae blooms → algae die → decomposition consumes oxygen → oxygen sag.

• If DO (dissolved oxygen) drops <2 ppm, aquatic life suffocates.

12. Describe, in detail, the process of wastewater management using pit privies, septic tanks, and municipal treatment

a. Pit Privies:

• Basic, non-electric toilets using aerobic decomposition.

• Require regular emptying and bulking agents (e.g., wood shavings).

b. Septic Tanks:

• Common in rural areas.

• Solids settle in the tank; liquids filter into drain fields.

• Can fail and lead to contamination if not maintained.

c. Municipal Wastewater Treatment:

1. Primary Treatment: Physical removal of solids.

2. Secondary Treatment: Biological degradation of organics (aeration).

3. Tertiary Treatment: Removes nutrients (e.g., nitrates), often using chemicals or wetlands.

4. Disinfection: Chlorine or UV to kill pathogens.

5. Sludge Management: Filtering, drying, composting.