Water
Resources and Pollution
Chapter 10
The Hydrosphere
Important properties of Water
1.
Hydrogen bonds between molecules of water are strong forces of
attraction.
2.
It exists as a liquid over a wide temperature range (0o C to 100o C) or
(32o F to 212o F)
3.
It has a large storage capacity for heat without a large change of
temperature
4.
It takes a lot of heat to evaporate liquid water because of the strong
attraction between molecules.
5.
Liquid water can dissolve a variety of compounds
1.
2.
3.
4.
Helps to flush waste from tissue
Helps to carry dissolved nutrients to tissue
All-purpose cleaner
Helps to remove and dissolve water soluble wastes
Water properties continued
5.
It has a high surface tension which causes the surface to contract and
to adhere to and coat solids, high wetting ability. (Capillary action)
6.
Water expands when freezes. (Change from liquid to solid phase)
1. Benefits fish
2. Breaks rocks, pipes, etc.
3.
Water is the lifeblood of the Ecosphere.
Water Cycle -revisited
Surface Runoff
Groundwater
Water Usage
Freshwater shortages
4.
5.
6.
7.
Dry climate
Drought – low precipitation, high evaporation
Desiccation – drying out of the soil due to deforestation
Water stress – increased withdraw of water due to increased numbers
of people
8. 40% of world population experience chronic water shortages.
9. 2025, 2.8 billion in 48 countries will face severe water stress, by 2050, 4 to 7
billion people may face severe water shortages.
Water in the U.S.
Increase water supplies
1.
2.
3.
4.
5.
Build dams and reservoirs
Bring in surface water from another area (aqueducts)
Withdraw groundwater
Convert salt water to fresh water (desalination)
Improve the efficiency of water use
Dams and Reservoirs
Water Transfer
Groundwater withdraw
Reduce waste in irrigation
Too much water
Reduce Flood risks
6.
7.
8.
9.
Channelization
Artificial levees and embankments
Flood control dams
Floodplain management
10. Flood frequency curves
11. Prohibit building on floodplains
12. Elevate certain buildings
13. Floodways to channel the flood waters
14.
Federal Flood Disaster Protection Act of 1973
Water Pollution
15.
Disease-causing agents (pathogens)
16. Coliform bacteria – indicator of quality of water
1. Drinking water – 0 colonies/100 ml
2. Swimming pools – 200 colonies/100 ml
3.
Oxygen-demanding wastes
4. Organic wastes
5. Biological oxygen demand (BOD) the amount of dissolved oxygen needed by
aerobic decomposers to break down the organic materials in a certain volume of
water over a 5-day incubation period at 20oC (68oF)
Water pollution continued
6.
Water-soluble inorganic chemicals
1. Acids, salts, compounds of toxic metals, Hg, Pb
2.
Inorganic plant nutrients
3. Nitrates and phosphates, cause algae blooms, deplete dissolved
oxygen, fish kills
4.
Organic chemicals
5. Oil, gasoline, plastics, pesticides, etc.
6.
Sediment or suspended matter
7. Largest class by weight
Water pollution continued
8.
9.
Water-soluble radioactive isotopes
Thermal pollution
10.Heat from water used to cool industrial equipment or from power
generation
11. Genetic pollution
12.Non-native species
Oxygen Sag Curve
Cultural Eutrophication
Groundwater pollution
Preventing contamination is considered the only effective way to protect groundwater
resources.
1.
Monitoring aquifers near landfills and underground tanks.
2.
Requiring leak detection systems for existing and new underground tanks used to
store hazardous liquids.
3.
Requiring liability insurance for old and new underground tanks used to store
hazardous liquids
4.
Banning or more strictly regulating disposal of hazardous wastes in deep injection
wells and landfills.
5.
Storing hazardous liquids above ground in tanks with systems that detect and
collect leaking liquids.
Exxon Valdez oil spill
Coastal waters protection
6.
7.
8.
Encourage or require separate sewage and storm runoff lines in coastal urban areas.
Discourage ocean dumping of sludge and hazardous dredge materials.
Protect sensitive and ecologically valuable coastal areas from development, oil drilling, and oil
shipping.
9.
Use ecological land-use planning to control and regulate coastal development.
10.
Require double hulls for all oil tankers by 2003.
11.
Recycle used oil.
12.
Reduce genetic pollution from non-native aquatic species by using heat to kill organisms in ballast
water or developing filters to trap the organisms when ballast water is taken into or discharged from a
ship.
Coastal waters cleanup
13. Improve oil spill cleanup capabilities.
14. Require at least secondary treatment of coastal sewage, or
use wetlands, solar aquatic, or other environmentally acceptable
methods.
Water pollution Acts in the U.S.
15.
16.
17.
Water Pollution Control Act of 1972
Clean Water Act – 1977
1987 Water Quality Act
18. Form basis of U.S. efforts to control pollution
19. Make surface waters safe for fishing and swimming by 1993
20. Restore and maintain the chemical, physical, and biological integrity of the
nation’s waters
21.
Discharge Trading Policy
Septic tanks
Sewage treatment plants
Advanced Sewage Treatment
Drinking water purification
22. Settling ponds to remove solids
23. Sand filters to remove fine grain sediments
24. Carbonate treatment to remove various inorganic salts from the water
(hardness)
25. Treatment for bacteria and other water born organisms
26. Chlorine
27. Bromine salts
28. Ozone
29. Iodine
30. UV treatment