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WATER QUALITY
What is quality water?
Is it suitable for a particular use? Ecosystem Drinking Recreation Agriculture
based upon its selected Physical, Chemical, and Biological properties
Ecosystem health Biological: flora and fauna species
Benthos macroinvertebrates Bottom dwellers lacking a backbone, i.e.
Worms, larvae, clams, snails, water striders
Range of Tolerance
Chp 18 .11. When was the Clean Water Act signed into law? 2. What was a goal of the Clean Water Act? 3. List one area of water pollution that has gotten
worse in the past 40 years. 4. Give an example of point source and non-point
source water pollution. 5. List a waterborne disease. 6. What does BOD test for?7. What can lower the DO of a body of water? 8. How can oxygen be added to water? 9. What is the term to describe a body of water that
has low biological productivity? 10. What is cultural eutrophication? 11. Describe an ecological harm caused by cultural
eutrophication.
Oxygen demanding wastes Example: Organic matter Source: sewage, lawn clippings.
Oxygen is required to convert stored energy in organic matter to ATP (cellular respiration).
As O2 dissolves in H2O , energy is releasedO2 + 80% Saturation > 100% saturation + heat.If the system is heated, H2O will not dissolveCool the water , then O2 dissolves.
During the summer, where could the water become anoxic? Why?
A lake becomes stratified in the summer .Prevents mixing of nutrients and oxygen
Why are there large algae blooms in the fall?
Nutrient enrichment Example: N & P Source: Ag. & Urban fertilizers, sewage, manure Eutrophication: Things change. Dead Zones Excess Nitrogen in drinking water:
methemoglobinemia
Infectious agents: Pathogens
Bacteria: Cholera: watery diarrhea that can kill in hours. 3-5 million affected, 100,000 deaths
Virus: Polio: paralyzes muscles, enters through mouth 99% reduction since 1988. Only four
countries are endemic for it. Protist: Giardiasis : severe diarrhea
Coliform testing: Guilt by association
Chemicals: Organic Organic: C-C bonds, C-H bonds Example : Fossil fuels, detergents,
pharmaceuticals DDT: Silent Spring
Miracle chemical: killed lice in WWII Later used to kill mosquitoes
Bio-accumulated in tissues Biomagnified through food chain
Chemicals Inorganic materials Metals: mercury, lead, cadmium
Weathered from rocks into the water. Coal releases mercury into the
atmosphere, which then diffuses on to the water.
Shark, Tilefish, Mackerel, Kingfish, Swordfish
Mercury: causes neurological impairments. Pregnant women should eat 1 can light
tuna/ 3 days Non-metalic: Road salt, arsenic Acids: H2SO4
Other pollutants
Sediments Thermal Radiation
Clean Water Act
1948 30% of Americans had access to municipal sewage treatment that may have only removed chunks
NPDES : 10% of pollution comes from industrial point source
91% rivers, 88% lakes are fishable and swimmable
Navigable waters no longer include some tributaries.
Clean Water Act
Sediments, nutrients & pathogens pose problems
Non-point sources account for 75% of water pollution
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