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How does a flood relate to an aquifer?. A flood occurs when an aquifer is completely saturated and water cannot move downward POTABLE : drinkable water. Subsidence is when the aquifer is over pumped and the ground slowly compacts. This sinkhole is 300 ft in diameter, and 18 feet deep. - PowerPoint PPT Presentation
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How does a flood relate to an aquifer?
• A flood occurs when an aquifer is completely saturated and water cannot move downward
• POTABLE: drinkable water
• Subsidence is when the aquifer is over pumped and the ground slowly compacts
Sinkholes don’t just come from over pumping groundwater…
• This sinkhole is 300 ft in diameter, and 18 feet deep.
• Formed from salt mining.
• Note the person in the lower left corner for size reference.
• Formed from oil drilling.
SALT WATER INTRUSION
• What’s going on here?• Ever noticed this at the beach?
• So… what is this caused by again?– Aquifer depletion!– Sinkholes!
Two main types of freshwater pollution1. Point Source: Pollution that comes from a known and specific location
EX) Factory pipes, tail pipe, leaking land fill, leaking storage tank
2. Non-Point: does not have a specific point of originEX) Runoff - water that flows over the land rater
than seeping into the ground.
Eutrophication- Nutrients enter surface water & too many nutrients cause
environmental problems-Large amounts of phosphates & nitrates promote
runaway growth of algae and plants- Open water is choked with plant growth. - Plants die – increase in the # of decomposing bacteria
- Oxygen in water decreases
WATER POLLUTION
Sources of Water Pollution1. Agriculture
2. Municipal:Contains salts, asbestos, chlorides, copper, cyanides, grease, lead, zinc, hydrocarbons, motor oil, organic wastes, phosphates, sulfuric acid
3. Industrial -Toxic compounds, sludge - Some industries are
cleaning water before they discharge it
RESOURCE DEGRADATION = pollution!Controlling Water Pollution- 1898 Rivers and Harbors Act - First legislation to address water pollution
- Individual states were responsible for enforcing laws on water pollution
- Studies not accurate- People not held accountable for pollution
Rachel Carson- wrote the book Silent Spring- Brought water pollution problems to the
common man in terms they could understand- Helped lead to water pollution control act
1972 FEDERAL WATER POLLUTION CONTROL ACT
- Set water-quality standards for all 50 states- Provides a vision of water quality standards and a means of
measuring improvement - Does not set laws for enforcement
- Many states have improved their water quality, but there are still problems- Sewage treatment, soil erosion, removal of toxic chemicals, and
heavy metals- Cancer causing agents identified in drinking water
"Clean Water Act"
TYPE EXAMPLES SOURCES EFFECTS INFORMATION
Disease organisms
Bacteria, viruses Waste from animals
Typhoid, cholera, dysentery
Chicago 1885- 90,000 deathsDirect dumping banned in US
SewageAnimal/human
manure and plant debris that
bacteria decompose
Sewage, animal feedlots, water
treatment plants or the lack of
them
Great amounts of bacteria can remove oxygen from water killing fish. Also
causes algal blooms and possible
eutrophication
-Industrialized societies have sewage treatment plants-Many unindustrialized
societies dump waste directly into water sources.
-encourages the growth of disease organisms
Organic Chemicals
Oil spills, plastics,
pesticides, fertilizers
Oil spills, leakage from ships, runoff from roads, improper disposal
Deplete oxygen, animal contamination
-largest Spill: Persian Gulf War ‘91
hundreds of thousands of metrics tons of oil spilled
intentionally- Exxon Valdez – 42,000
metric tons of crude
Inorganic chemicals
Acids, toxic metals
Industrial effluent, urban
runoff, household cleaners
Poisons fresh alter and sicken those who drink
it
-Lead & mercury levels in fresh water ecosystems enter human food web easily and cause brain, liver & kidney
damage-Acid rain
-Japan 1950- mercury poisoning- 8,000 people
paralyzed or brain damaged
PlantFertilizers
Water soluble
compounds with nitrate, phosphorous
ions
Sewage, manure,
farm/garden runoff
Spurs rapid growth of algae that decay and deplete water’s
oxygen…fish die
Largest source of runoff pollution
Sediment Soil Erosion
Disrupts aquatic food webs, clogs lakes & reservoirs, reduces photosynthesis of
aquatic plants
- over time the water may fill with sediment causing fresh water ecosystems to
fill with sediment and become a meadow over
time
Radioactive substances
Radon, uranium
Nuclear power plants, ore mining & processing
Cancers, birth defects, genetic
mutations
1973 & 1950 radioactive spills from sites- thousands
exposed to high level radiation
Thermal pollution
Large increase in
water temperature
Power plants/industry
Increase in fish metabolism requiring
them to consume more oxygen- water holds less dissolved
oxygen
-Nuclear power plants pull in cold water and release
water 10-15 degrees higher. - Industrial use
Municipal Sewage Treatment Waste water undergoes several treatments at a sewage
treatment plant to prevent environmental and public health problems. The treated water is then discharged
into rivers, lakes or the ocean.
Process:1. Primary Treatment
A. Removes suspended & floating particlesB. Screening & gravitational settling
1. Solid material that settles out is known as primary sludge2. Does not eliminate the inorganic & organic compounds
remaining in the wastewater.
2. Secondary TreatmentA. Uses microorganisms to decompose the suspended organic
material1. Trickling filters: wastewater trickles through rock beds
containing bacterial which degrade the organic material2. Activated sludge process: Wastewater is aerated and
circulated through bacteria rich particles.3. Particles and microorganisms are allowed to settle out
forming Secondary Sludge** Water is clear and free of organic wastes such as sewage**
Primary and Secondary Treatment
Individual Septic Systems• Many private residences use individual septic
systems instead of municipal sewage treatment.– Household sewage is piped into the septic tank – Particles settle to the bottom– Grease and oils form a scummy layer where bacteria
decomposes it– Waste water containing suspended organic and inorganic
material flows into the drain field through a network of perforated pipes set in trenches of crushed stone• Purified wastewater then percolates into the groundwater or evaporates from the soil
Do you see how there could be a contamination problem here?
Septic SystemsThe septic tank works much like primary treatment in municipal sewage treatment- sewage from the house is piped to the septic tank, where particles settle to the bottom
Wastewater containing suspended organic and
inorganic material flows into the drain field and gradually seeps into the soil
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