1. Prentice Hall EARTH SCIENCE
Tarbuck Lutgens 

2. Distribution of Earth’s Water

3. The Water Cycle
Makes no sense without caption in book

4. 6.3 Water Beneath the Surface
Distribution and Movement of Water Underground
6.3 Water Beneath the Surface
 Much of the water in soil seeps downward until it reaches the zone of saturation.
 The zone of saturation is the area where water fills all of the open spaces in sediment and rock.
• Groundwater is the water within this zone.
• The water table is the upper level of the saturation zone of groundwater.

5. 6.3 Water Beneath the Surface
Distribution and Movement of Water Underground
6.3 Water Beneath the Surface
 Movement
• Groundwater moves by twisting and turning through interconnected small openings.
• The groundwater moves more slowly when the pore spaces are smaller.

6. 6.3 Water Beneath the Surface
Distribution and Movement of Water Underground
6.3 Water Beneath the Surface
 Movement
• Porosity
- The percentage of pore spaces
- Determines how much groundwater can be stored
• Permeability
- Ability to transmit water through connected pore spaces
- Aquifers are permeable rock layers or sediments that transmit groundwater freely

7. Features Associated with Subsurface Water

8. 6.3 Water Beneath the Surface
Springs
6.3 Water Beneath the Surface
 A spring forms whenever the water table intersects the ground surface.
 Hot Springs
• Water is 6–9ºC warmer than the mean air temperature of the locality.
• Water is heated by cooling of igneous rock.
 Geysers
• Intermittent hot springs
• Water turns to steam and erupts.

9. Geyser Eruption Cycle

10. 6.3 Water Beneath the Surface
Wells
6.3 Water Beneath the Surface
 A well is a hole bored into the zone of saturation.
• An artesian well is any formation in which groundwater rises on its own under pressure.
• Pumping can cause a drawdown (lowering) of the water table.
• Pumping can form a cone of depression in the water table.

11. Cone of Depression

12. 6.3 Water Beneath the Surface
Environmental Problems Associated with Groundwater
6.3 Water Beneath the Surface
 Overuse and contamination threatens groundwater supplies in some areas.
• Treating it as a nonrenewable resource
• Land subsidence caused by its withdrawal
• Contamination

13. Groundwater Supplies are Finite!!
The High Plains Aquifer is an example of
Severe groundwater depletion.
Even if pumping were to stop now, it would
take thousands of years to replenish the
groundwater.

14. San Joachim Valley, CA The marks of the utility
pole illustrate the sinking
of 13,400 sq. km over 9
meters because of
the withdrawl of
groundwater for irrigation:
subsidence.
subsidence_Poland.jpg

15. High Plains Aquifer About 27 percent of the
irrigated land in the US overlies
this aquifer system.
It yields about 30 percent of
the nation's ground water used
for irrigation.
It provides drinking water to
82 percent of the people who
live within the aquifer boundary. [2]

16. Groundwater Contamination
Common Sources of Water Pollution:
Sewage from septic tanks.
Farm wastes
Inadequate or broken sewers
Fertilizers, Pesticides, and Highway Salts
Chemicals and Industrial Materials leaking from:
Pipelines
Storage tanks
Landfills
Holding Tanks

17. Groundwater Contamination

18. Groundwater Contamination
Harmful bacteria in aquifer
may be purified by:
Mechanical filtration
Chemical oxidation
Assimilation by other organisms

19. Groundwater Contamination
LANDFILLS: Solid Waste Disposal
Open Air Dumps:
used in US up until 1970, now illegal (standard in rest of world)
release toxins in air and groundwater
Attract vermin, breed disease
Sanitary:
Dig hole, line w/ clay and plastic liner, cover w/ dirt daily
Promotes decomposition, reduces vermin & disease
Still may leak, check groundwater constantly

20. Open-air rubbish dump on coastline, Barrow, Alaska, USA
This dump site
in such fragile
environment
is polluting
groundwater
and spoils the
tundra.

21. Sanitary Landfill

22. Sanitary Landfill

23. US WASTES FACTS
*The US produces more wastes per person than any other nation
in the world (10 to 100 X more!!!) Over 200 metric tons/year!!
** 60% of our wastes end up in landfills, 20% is incinerated, and 20% is recycled.
***The US is guilty of “eco-terrorism”
a. We are the World Leaders of “e” wastes (500 tons/month)
b. We export 80% to Africa and China
c. Children harvest the metal for sale and wade through
the toxic wastes for food. Also contaminates water supply.
d. One desktop = 9 to 12 pounds of lead, mercury, arsenic,
and radioactive isotopes and may also contain a few
grams of silver, gold, and copper. (source: NCSU/Bruck)

24. LANDFILL VIDEO

25. 6.3 Water Beneath the Surface
Caverns
6.3 Water Beneath the Surface
 A cavern is a naturally formed underground chamber.
 Erosion forms most caverns at or below the water table in the zone of saturation.
 Travertine is a form of limestone that is deposited by hot springs or as a cave deposit.

26. Dissolving of Groundwater Creates Caverns

27. 6.3 Water Beneath the Surface
Caverns
6.3 Water Beneath the Surface
 Characteristics of features found within caverns
• Formed in the zone of aeration
• Composed of dripstone
• Formed from calcite deposited as dripping water evaporates
• Common features include stalactites (hanging from the ceiling) and stalagmites (growing upward from the floor).

28. 6.3 Water Beneath the Surface
Karst Topography
6.3 Water Beneath the Surface
 Formed by dissolving rock at, or near, Earth's surface
 Common features
• Sinkholes—surface depressions
- Sinkholes form when bedrock dissolves and caverns collapse.
• Caves and caverns
 Area lacks good surface drainage.

29. Sinkhole Formation

30. Water Contamination
Point Source Pollution-pollution that comes from a known/specific location
Nonpoint Source Pollution- does NOT have a specific point of origin

31. Point Source Pollution
The term "point source" means any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged

32. Continued

33. Nonpoint Source Pollution
Excess fertilizers, herbicides and insecticides from agricultural lands and residential areas
Oil, grease and toxic chemicals from urban runoff and energy production
Sediment from improperly managed construction sites, crop and forest lands, and eroding streambanks
Salt from irrigation practices and acid drainage from abandoned mines
Bacteria and nutrients from livestock, pet wastes and faulty septic systems
Atmospheric deposition and hydromodification

35. Wastewater Treatment