Water PollutionWater Pollution

Questions for Today:Questions for Today:

• What are examples of point and nonpoint What are examples of point and nonpoint pollution sources for water?pollution sources for water?

• What are the Major Types of Water Pollutants What are the Major Types of Water Pollutants and Diseases transmitted in Water?and Diseases transmitted in Water?

• What are two measurements used to What are two measurements used to determine clean waters in lakes and rivers?determine clean waters in lakes and rivers?

• Compare and Contrast Oligotrophic Lakes Compare and Contrast Oligotrophic Lakes with Eutrophic Lakes.with Eutrophic Lakes.

Questions for Today:Questions for Today:

• What major sources of pollution for What major sources of pollution for ground water?ground water?

• What laws are in effect for our What laws are in effect for our drinking water?drinking water?

• What are major sources of pollution What are major sources of pollution for ocean water?for ocean water?

Sources of Water PollutionSources of Water Pollution

• Remember:Remember:– Point sources are pollutions sources Point sources are pollutions sources

where you can identify the sole polluter where you can identify the sole polluter and/or pollutantand/or pollutant

– Nonpoint sources are sources where you Nonpoint sources are sources where you cannot identify the polluter or the cannot identify the polluter or the pollutant can come from many pollutant can come from many anonymous sources.anonymous sources.

Top Three pollutersTop Three polluters

• Agricultural ActivitiesAgricultural Activities– Sediment eroded from agricultural landsSediment eroded from agricultural lands– Fertilizers and pesticidesFertilizers and pesticides

• Industrial WastesIndustrial Wastes– Organic and inorganic wastesOrganic and inorganic wastes– HeatHeat

• MiningMining– Erosion of Sediments and Toxic ChemicalsErosion of Sediments and Toxic Chemicals

Top areas of nonpoint Top areas of nonpoint pollutionpollution

• Parking LotsParking Lots– Prevent absorption of water back into Prevent absorption of water back into

the water tablethe water table– Increases flooding and erosionIncreases flooding and erosion

• PlasticPlastic– Polymers are forever!Polymers are forever!

Major Water PollutantsMajor Water Pollutants

• Aside from the different chemicals, inorganic Aside from the different chemicals, inorganic and organic, that enter our water supply, and organic, that enter our water supply, infectious disease is one of the major water infectious disease is one of the major water pollutants.pollutants.– Identified over 500 types of diseasesIdentified over 500 types of diseases

• The World Health Organization (WHO)The World Health Organization (WHO)– Each year, approximately 3.2 million people die Each year, approximately 3.2 million people die

prematurely from water-borne infectious diseases.prematurely from water-borne infectious diseases.– 1 child every 18 seconds die due to diarrhea alone!1 child every 18 seconds die due to diarrhea alone!

Water QualityWater Quality

• Two of the biggest measures for Two of the biggest measures for water quality are:water quality are:– Dissolved OxygenDissolved Oxygen

•Amount of Oxygen ready to use in the waterAmount of Oxygen ready to use in the water

– Biochemical Oxygen DemandBiochemical Oxygen Demand•Amount of Oxygen needed for organic Amount of Oxygen needed for organic

growth.growth.

– When both measurements are graphed When both measurements are graphed we get a oxygen sag curve.we get a oxygen sag curve.

Oligotrophic vs EutrophicOligotrophic vs Eutrophic

• Oligotrophic lakes are lakes with low Oligotrophic lakes are lakes with low nutrient, clear water, BIG fish, and nutrient, clear water, BIG fish, and Cold, High DO, low BODCold, High DO, low BOD

• Eutrophic Lakes high nutrient, Eutrophic Lakes high nutrient, murky/brackish water, small fish and murky/brackish water, small fish and bugs, warm, Low DO, High BODbugs, warm, Low DO, High BOD

• Oligotrophic lakes -> Eutrophic LakesOligotrophic lakes -> Eutrophic Lakes– Cultural EutrophismCultural Eutrophism

Major sources of groundwater Major sources of groundwater pollutionpollution

• Remember that half of the US Remember that half of the US Drinking water comes from Drinking water comes from groundwater sources like aquifers.groundwater sources like aquifers.

• Common Pollutants include:Common Pollutants include:– HydrocarbonsHydrocarbons– Inorganic ChemicalsInorganic Chemicals– Organic SolventsOrganic Solvents

Major Sources of GW Major Sources of GW PollutionPollution

• The ProblemThe Problem– Once contaminant hits the water supply, Once contaminant hits the water supply,

the GW is essentially ruined.the GW is essentially ruined.– Groundwater flows slower than surface Groundwater flows slower than surface

water so it cannot naturally biodegrade water so it cannot naturally biodegrade the pollutant as well as a river or the pollutant as well as a river or stream.stream.

Laws protecting our WaterLaws protecting our Water

• U.S. Safe Drinking Water Act of 1974U.S. Safe Drinking Water Act of 1974– Requires the EPA to establish a Maximum Requires the EPA to establish a Maximum

Contaminant Level for any contaminant Contaminant Level for any contaminant entering our water.entering our water.

• Clean Water ActClean Water Act– Many provisions guarding our water Many provisions guarding our water

suppliessupplies– Requires treatment facilities for municipal Requires treatment facilities for municipal

water and regulates the amount of water and regulates the amount of pollutants entering our water.pollutants entering our water.

Pollution in the OceanPollution in the Ocean

• Most of the Open Oceans are Most of the Open Oceans are considered “clean” due to the considered “clean” due to the vastness and the deep waters.vastness and the deep waters.

• Most of the pollution problems are Most of the pollution problems are located closer to the coastlines and located closer to the coastlines and shores due to agricultural runoff and shores due to agricultural runoff and access to sunlight.access to sunlight.

Fig. 20-15, p. 548

Industry Nitrogen oxides from autos and smokestacks, toxic chemicals, and heavy metals in effluents flow into bays and estuaries.

Cities Toxic metals and oil from streets and parking lots pollute waters; sewage adds nitrogen and phosphorus.

Urban sprawl Bacteria and viruses from sewers and septic tanks contaminate shellfish beds and close beaches; runoff of fertilizer from lawns adds nitrogen and phosphorus.

Construction sites Sediments are washed into waterways, choking fish and plants, clouding waters, and blocking sunlight.

Farms Runoff of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus.

Red tides Excess nitrogen causes explosive growth of toxic microscopic algae, poisoning fish and marine mammals.

Toxic sediments Chemicals and toxic metals contaminate shellfish beds, kill spawning fish, and accumulate in the tissues of bottom feeders.

Oxygen-depleted zone Sedimentation and algae overgrowth reduce sunlight, kill beneficial sea grasses, use up oxygen, and degrade habitat.

Healthy zone Clear, oxygen-rich waters promote growth of plankton and sea grasses, and support fish.

Closed shellfish bedsClosed

beach Oxygen-depleted zone

Ocean PollutionOcean Pollution

• Aside from Agricultural, a major pollutant Aside from Agricultural, a major pollutant is oil that is leaked off of rigs and tanker is oil that is leaked off of rigs and tanker ships and industrial and city runoff.ships and industrial and city runoff.

• The Exxon Valdez crash in 1989The Exxon Valdez crash in 1989– Cost roughly 6.5 billion dollarsCost roughly 6.5 billion dollars

• The Prestige Crash in 2002The Prestige Crash in 2002• The BP Oil SpillThe BP Oil Spill• Industrial Runofff accounts for 37% of the Industrial Runofff accounts for 37% of the

oil pollution in the oceanoil pollution in the ocean

Gulf of Mexico and PollutionGulf of Mexico and Pollution

• The Gulf Coast has some of the worst The Gulf Coast has some of the worst water in the nation due to it’s low DO water in the nation due to it’s low DO count.count.– Why?Why?– How many states drain waste into the How many states drain waste into the

Gulf of MexicoGulf of Mexico