1. Chapter 11 Environmental Science
Water
Chapter 11
Environmental Science

2. Water Resources
Section 11.1

3. The Water Cycle
Water Cycle: water molecules circulating between the Earth’s surface and the atmosphere.
It involves condensation, evaporation, transpiration, and precipitation.

4. Global Water Distribution
71% of the Earth’s surface is covered in water
97% of that water is salt water in ocean and seas
77% of the fresh water on Earth is frozen in icecaps and glaciers
Fresh water is a limited resource because there is only about 3% usable freshwater.

5. Surface Water Surface Water: Is fresh water on Earth’s land surface.
Lakes, streams, rivers, and wetlands.
Water is used for drinking, agriculture, power, and transportation.

6. River Systems vs. Watersheds
River are formed by:
Rain and snow draining down from mountains and hills.
Small streams come together to form rivers
A river system is a flowing network of surface water.
Amazon is largest river system.
What is a watershed:
The area of land that is drained by a river.
Pollution in a watershed can pollute the river.
Amount of water varies depending on precipitation and melting snow.

7. Groundwater
Ground water: water beneath the Earth’s surface in sediment and rock formations.
Water table is where rock and soil are saturated with water.
Water table varies in wet regions vs. dry regions.

8. Aquifers Aquifer: an underground formation that contains groundwater.
Consist of rock, sand, and gravel where water can accumulate.
It is an important water source for many cities and for agriculture.

9. Porosity vs. Permeability
Is the percentage of the total volume of a rock that has spaces or pores.
The more porous a rock, the more water it can hold
The ability of rock or soil to allow water to flow through it.
Example: granite, sandstone, and limestone are permeable but clay is impermeable.

10. The Recharge Zone
Recharge Zone: An area of the Earth’s surface from which water percolates down into an aquifer. Water enters an aquifer through the aquifer’s recharge zone.
Environmentally sensitive because of pollutants.
Size is affected by permeability of the surface above the aquifer. They can be blocked by structures.

11. Wells Well: a hole that is dug or drilled to reach groundwater.
Are drilled to extend below water table.
Droughts and removing groundwater faster than it is recharged leads to wells drying up.

12. That is all of 11.1
Time for a reading quiz.

13. Water Use and Management
Section 11.2

14. Global Water Use Residential (drinking, washing, cooking, toilets)
Industrial (manufacture goods, dispose of waste, and generate power)
Agricultural (most of the fresh water used worldwide is used to irrigate crops)

15. Water Treatment
Water is treated physically and chemically to make it potable or safe to drink
Mercury, arsenic, and lead are removed by adding chlorine.
Pathogens: organisms that cause illness or disease are also removed.

16. Water Management Projects
Aqueducts or huge canals are used to bring water from mountains to dry areas.
Reservoirs or artificial lakes are used for recreation or drinking water
Dams are structures built across a river to control the river’s flow.

17. Benefits and Consequences of Dams
Flood control
Drinking water
Irrigation
Recreation
Industry
Electrical energy
People can be displaced
Entire ecosystems can be destroyed
Farmland below dam becomes less productive
Dam failure can lead to death.

18. Water Conservation Agriculture: drip irrigation systems
Industry: recycling of cooling water and wastewater
Residential: shorter showers, low-flow toilets/showers, turn water off when brushing teeth, wash full loads, and water lawns sparingly.

19. Solutions for the future
Desalinization: removing salt from salt water. (very expensive)
Transporting water: ships transfer bags of fresh water or towing icebergs. (hard to find efficient way…)

20. That is all for 11.2
Time for a reading quiz.

21. Water Pollution
Section 11.3

22. Water Pollution
Water pollution: the introduction of chemical, physical, or biological agents into water.
Two causes are industrialization and rapid human population growth.

23. Two Sources of Water Pollution
Point-Source Pollution
Nonpoint-Source Pollution
Comes from many different sources
Difficult to identify and trace.
Examples: road or agricultural runoff, polluted precipitation, water runoff.
Pollution discharged from a single source.
Easier to identify and trace.
Examples: leaking tank or unlined landfill.

24. Physical Water Pollutants
Pathogens: disease causing organisms
Organic matter: feces, food wastes
Organic chemicals: pesticides, fertilizers, plastics
Inorganic chemicals: acids, bases, salts
Heavy metals: lead, mercury, cadmium, arsenic
Physical agents: heat and suspended solids

25. Wastewater
Wastewater: water that contains waste from homes or industry.
Most wastewater can be treated but some toxic substances require further treatment.
Sewage sludge is the solid material that remains after treatment
Hard to dispose of so sludge can be used for fertilizer and to make bricks.

26. Artificial Eutrophication
Eutrophication is when phosphates and nitrates enter the water from sewage and fertilizer runoff.
Can be caused naturally or by humans.
Causes algal blooms that eventually die and causes the water to becomes oxygen depleted.

27. Thermal Pollution
Thermal pollution: when the temperature of a body of water increases.
When power plants use water in their cooling systems and then discharge warm water back into lake or river.
Causes large fish kills and aquatic organisms suffocate.

28. Groundwater Pollution
Groundwater pollution: when polluted surface water percolates down.
Pesticides, fertilizers, and petroleum are groundwater pollutants.
Other sources: leaking underground water tanks, septic tanks, and unlined landfills

29. Cleaning Up Groundwater Pollution
Why it’s a challenging problem:
Aquifers recharge very slowly
Pollution can cling to the materials that make up an aquifer

30. Ocean Pollution Dumped wastewater and garbage pollute the ocean.
Majority of pollution caused by land activities
Oil spills (37 million gals)
More oil enters from nonpoint sources in cities and towns ( million gals)

31. Water Pollution and Ecosystems
Water pollution: can have immediate effects or lead to biomagnification.
biomagnification: the buildup of pollutants at higher levels as it travels up the food chain.

32. Cleaning up Water Pollution
Clean Water Act (1972): make all surface water fit for fishing/swimming by 1983.
Marine Protection, Research and Sanctuaries Act (1972): to control the dumping of sewage waste/toxic chemicals
Safe Drinking Water Act (1975):to protect groundwater/surface water from pollution
Comprehensive Environmental Response and Compensation and Liability Act (1980):
makes owners/operators/customers of hazardous
waste responsible for the clean up.
Water Quality Act (1987): support state and
local effort to clean polluted runoff.
Oil Pollution Act (1990): protects US waterways
from oil pollution.

33. That is all for 11.3
Time for a reading quiz