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