WATER POLLUTIONMADE BY

GROUP 1

What is water pollution?Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or makes water unsuitable for desired usage.

What is water pollution?WHO[WORLD HEALTHORGANIZATION]

survey:3.4 million premature

deaths each year from waterborne diseases

1.9 million from diarrhea

U.S. 1.5 million illnesses1993 Milwaukee

370,000 sick

Major Sources of Water PollutionAgriculture: by far the

leaderSediment, fertilizers,

bacteria from livestock, food processing, salt from soil irrigation

Industrial: factories and powerplants

Mining: surface mining toxics, acids, sediment

TopicFreshwater pollution: What are major

problems in streams?Developed versus Developing CountriesLake Pollution: Why are lakes and reservoirs

more vulnerable?What is Eutrophication?

Freshwater Stream PollutionFlowing streams can

recover from moderate level of degradable water pollution if their flows are not reduced.

Natural biodegradation process

Does not work if overloaded or stream flow reduced

Does not work against non biodegradable pollutants

Two WorldsDeveloped CountriesU.S. and other developed

countries sharply reduced point sources even with population and economic growth

Nonpoint still a problemToxic chemicals still

problemSuccess Cuyahoga River,

Thames River

Two WorldsDeveloping Countries:Serious and growing

problemHalf of world’s 500 major

rivers heavily pollutedSewage treatment

minimal $$$Law enforcement

difficult10% of sewage in China

treatedEconomic growth with

little $$$ to clean up

India’s Ganges RiverHoly River (1 million

take daily holy dip)350 million (1/3rd of

pop) live in watershedLittle sewage treatmentUsed for bathing,

drinking etc.Bodies (cremated or

not) thrown in riverGood news is the Indian

government is beginning to work on problem

Freshwater Lake PollutionDilution as a solution in

lakes less effectiveLittle vertical mixingLittle water flow

(flushing)Makes them more

vulnerableToxins settleKill bottom lifeAtmospheric depositionFood chain disruptions

Eutrophication of LakesEutrophication: nutrient

enrichment of lakes mostly from runoff of plant nutrients (nitrates and phosphates)

During hot dry weather can lead to algae blooms

Decrease of photosynthesis

Dying algae then drops DO levels

Fish kills, bad odor

Pollution of LakesEutrophication Eutrophication

Fig. 22-7 p. 499

Eutrophication in LakesSolutions:Advanced sewage

treatment (N, P)Household detergentsSoil conservationRemove excess weed

build upPump in oxygen or

freshwater

Case Study: The Great Lakes•Pollution levels dropped, but long way to go

•95% of U.S. freshwater

•30% Canadian pop, 14% U.S.

•38 million drink

•1% flow out St. Lawrence

•Toxic fish

GroundwaterGroundwater can

become contaminatedNo way to cleanse itselfLittle dilution and

dispersion Out of sight pollutionPrime source for

irrigation and drinkingREMOVAL of pollutant

difficult

Groundwater Pollution: Causes Low flow rates Low flow rates Few bacteria Few bacteria

Cold temperatures

Cold temperatures

Coal strip mine runoff

Pumping well

Waste lagoon

Accidental spills

Groundwater flow

Confined aquifer

Discharge

Leakage from faulty casing

Hazardous waste injection well

Pesticides

Gasoline station

Buried gasoline and solvent tank

Sewer

Cesspool septic tank

De-icing road salt

Unconfined freshwater aquifer

Confined freshwater aquifer

Water pumping well Landfill

Low oxygen

Low oxygen

Fig. 22-9 p. 502

Section 5 Ocean PollutionHow much pollution can the oceans tolerate?Coastal zones: How does pollution affect

coastal zones?What are major sources of ocean pollution

and what is being done?

Ocean PollutionOceans can disperse and

break down large quantities of degradable pollution if they are not overloaded.

Pollution worst near heavily populated coastal zones

Wetlands, estuaries, coral reefs, mangrove swamps

40% of world’s pop. Live within 62 miles of coast

Ocean PollutionLarge amounts of

untreated raw sewage (viruses)

Leaking septic tanksRunoffAlgae blooms from

nutrientsDead zones NO DOAirborne toxinsOil spills

Ocean Pollution

Fig. 22-11 p. 504

Case Study: Chesapeake Bay

Largest US estuary

Largest US estuary

Relatively shallow Relatively shallow

Slow “flushing” action to Atlantic

Slow “flushing” action to Atlantic

Major problems with dissolved O2 Major problems with dissolved O2

Fig. 22-13 p. 506

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