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Chapter 21Chapter 21

Water PollutionWater Pollution

Chapter Overview QuestionsChapter Overview Questions

What pollutes water, where do theseWhat pollutes water, where do thesepollutants come from, and what effects dopollutants come from, and what effects dothey have?they have?

What are the major water pollution problemsWhat are the major water pollution problemsin streams and lakes?in streams and lakes?

What causes groundwater pollution, and howWhat causes groundwater pollution, and howcan it be prevented?can it be prevented?

What are the major water pollution problemsWhat are the major water pollution problemsaffecting oceans?affecting oceans?

Chapter Overview Questions (contChapter Overview Questions (cont’’d)d)

How can we prevent and reduce surfaceHow can we prevent and reduce surfacewater pollution?water pollution?

How safe is drinking water, and how can it beHow safe is drinking water, and how can it bemade safer?made safer?

Core Case Study: Using Nature toCore Case Study: Using Nature toPurify SewagePurify Sewage

Ecological wastewaterEcological wastewaterpurification by apurification by a livinglivingmachinemachine..

Uses the sun and a seriesUses the sun and a seriesof tanks containing plants,of tanks containing plants,snails, zooplankton,snails, zooplankton,

crayfish, and fish (thatcrayfish, and fish (thatcan be eaten or sold forcan be eaten or sold forbait).bait).

Figure 21Figure 21--11

WATER POLLUTION: SOURCES,WATER POLLUTION: SOURCES,TYPES, AND EFFECTSTYPES, AND EFFECTS

Water pollutionWater pollution is any chemical, biological,is any chemical, biological,or physical change in water quality that has aor physical change in water quality that has aharmful effect on living organisms or makesharmful effect on living organisms or makeswater unsuitable for desired uses.water unsuitable for desired uses.

Point sourcePoint source: specific location (drain pipes,: specific location (drain pipes,ditches, sewer lines).ditches, sewer lines).

Nonpoint sourceNonpoint source: cannot be traced to a single: cannot be traced to a singlesite of discharge (atmospheric deposition,site of discharge (atmospheric deposition,

agricultural / industrial / residential runoff)agricultural / industrial / residential runoff)

Table 21-2, p. 495

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Major Water PollutantsMajor Water Pollutantsand Their Effectsand Their Effects

A fecalA fecal coliformcoliformbacteria test is usedbacteria test is usedto indicate the likelyto indicate the likelypresence ofpresence ofdiseasedisease--causingcausingbacteria in water.bacteria in water.


Major Water PollutantsMajor Water Pollutantsand Their Effectsand Their Effects

Water quality and dissolved oxygen (DO)Water quality and dissolved oxygen (DO)content in parts per million (content in parts per million (ppmppm) at 20) at 20°°C.C. Only a few fish species can survive in water lessOnly a few fish species can survive in water less

than 4ppm atthan 4ppm at 2020°°C.C.Figure 21Figure 21--33

Fig. 21-3, p. 496

WaterQuality

Below 4

Below 4.5

DO (ppm) at 20°C

4.5–6.7

6.7–8

8–9

Gravelypolluted

Heavilypolluted

Moderatelypolluted

Slightlypolluted

Good

POLLUTION OF FRESHWATERPOLLUTION OF FRESHWATERSTREAMSSTREAMS

Flowing streams can recover from aFlowing streams can recover from amoderate level of degradable water pollutantsmoderate level of degradable water pollutantsif they are not overloaded and their flows areif they are not overloaded and their flows arenot reduced.not reduced.

In a flowing stream, the breakdown of degradableIn a flowing stream, the breakdown of degradablewastes by bacteria depletes DO and creates andwastes by bacteria depletes DO and creates andoxygen sag curveoxygen sag curve..

•• This reduces or eliminates populations of organismsThis reduces or eliminates populations of organismswith high oxygen requirements.with high oxygen requirements.

Water Pollution Problems in StreamsWater Pollution Problems in Streams

Dilution and decay of degradable, oxygenDilution and decay of degradable, oxygen--demanding wastes and heat in a stream.demanding wastes and heat in a stream.

Figure 21Figure 21--44 Fig. 21-4, p. 497

8 ppm

Biological

oxygendemand

Dissolved

oxygen(ppm)

Types of

organisms

8 ppm

Recovery

ZoneSepticZoneDecomposition

ZoneClean Zone

Fishabsent,fungi,sludgeworms,bacteria

(anaerobic)

Trash fish(carp, gar,leeches)

Clean Normal clean

water organisms

(Trout, perch, bass,

mayfly, stonefly)

Normal clean water

organisms

(Trout, perch, bass,

mayfly, stonefly)

Clean Zone

Trash fish(carp, gar,

leeches)

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POLLUTION OF FRESHWATERPOLLUTION OF FRESHWATERSTREAMSSTREAMS

Most developed countries have sharplyMost developed countries have sharplyreduced pointreduced point--source pollution but toxicsource pollution but toxicchemicals and pollution from nonpointchemicals and pollution from nonpointsources are still a problem.sources are still a problem.

Stream pollution from discharges of untreatedStream pollution from discharges of untreatedsewage and industrial wastes is a majorsewage and industrial wastes is a majorproblem in developing countries.problem in developing countries.

Global Outlook: Stream Pollution inGlobal Outlook: Stream Pollution inDeveloping CountriesDeveloping Countries

Water in many ofWater in many ofcentral China's riverscentral China's riversare greenish blackare greenish blackfrom uncontrolledfrom uncontrolledpollution bypollution bythousands ofthousands offactories.factories.


Case Study: IndiaCase Study: India’’s Ganges River:s Ganges River:Religion, Poverty, and HealthReligion, Poverty, and Health

Religious beliefs, cultural traditions, poverty,Religious beliefs, cultural traditions, poverty,and a large population interact to causeand a large population interact to causesevere pollution of the Ganges River in India.severe pollution of the Ganges River in India.

Very little of the sewage is treated.Very little of the sewage is treated.

Hindu believe in cremating the dead to free theHindu believe in cremating the dead to free thesoul and throwing the ashes in the holy Ganges.soul and throwing the ashes in the holy Ganges.

•• Some are too poor to afford the wood to fully cremate.Some are too poor to afford the wood to fully cremate.

•• Decomposing bodies promote disease and depletesDecomposing bodies promote disease and depletesDO.DO.

Case Study: IndiaCase Study: India’’s Ganges River:s Ganges River:Religion, Poverty, and HealthReligion, Poverty, and Health

Daily, more than 1Daily, more than 1million Hindus inmillion Hindus inIndia bathe, drinkIndia bathe, drinkfrom, or carry outfrom, or carry outreligious ceremoniesreligious ceremoniesin the highly pollutedin the highly pollutedGanges River.Ganges River.


POLLUTION OFPOLLUTION OFFRESHWATER LAKESFRESHWATER LAKES

Dilution of pollutants in lakes is less effectiveDilution of pollutants in lakes is less effectivethan in most streams because most lakethan in most streams because most lakewater is not mixed well and has little flow.water is not mixed well and has little flow.

Lakes and reservoirs are often stratified andLakes and reservoirs are often stratified andundergo little mixing.undergo little mixing.

Low flow makes them susceptible to runoff.Low flow makes them susceptible to runoff.

Various human activities can overload lakesVarious human activities can overload lakeswith plant nutrients, which decrease DO andwith plant nutrients, which decrease DO andkill some aquatic species.kill some aquatic species.

CulturalCultural EutrophicationEutrophication

EutrophicationEutrophication: the natural nutrient: the natural nutrientenrichment of a shallow lake, estuary or slowenrichment of a shallow lake, estuary or slowmoving stream, mostly from runoff of plantmoving stream, mostly from runoff of plantnutrients from the surrounding land.nutrients from the surrounding land.

CulturalCultural eutrophicationeutrophication: human activities: human activitiesaccelerate the input of plant nutrients (mostlyaccelerate the input of plant nutrients (mostlynitratenitrate-- and phosphateand phosphate--containing effluents)containing effluents)to a lake.to a lake. 85% of large lakes near major population centers85% of large lakes near major population centers

in the U.S. have some degree of culturalin the U.S. have some degree of culturaleutrophicationeutrophication..

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POLLUTION OF GROUNDWATERPOLLUTION OF GROUNDWATER

Groundwater can become contaminated withGroundwater can become contaminated witha variety of chemicals because it cannota variety of chemicals because it cannoteffectively cleanse itself and dilute andeffectively cleanse itself and dilute anddisperse pollutants.disperse pollutants.

The drinking water for about half of the U.S.The drinking water for about half of the U.S.population and 95% of those in rural areaspopulation and 95% of those in rural areascomes from groundwater.comes from groundwater.

Fig. 21-7, p. 501

Coal stripmine runoff

Polluted air

Deicingroad salt

Pesticidesand fertilizers

Hazardouswaste

injectionwell

Pumpingwell

Gasoline station

Waterpumping well

LandfillSewer

Buried gasolineand solvent tanks

Cesspool,septic tank

Groundwaterflow

Confinedaquifer

Confined fre

shwater aquifer

Unconfined fre

shwater aquifer

Accidentalspills

Waste lagoonLeakagefromfaultycasing

Discharge


It can take hundreds to thousand of years forIt can take hundreds to thousand of years forcontaminated groundwater to cleanse itself ofcontaminated groundwater to cleanse itself ofdegradable wastesdegradable wastes..

NondegradableNondegradable wasteswastes (toxic lead, arsenic,(toxic lead, arsenic,flourideflouride) are there permanently.) are there permanently.

Slowly degradable wastesSlowly degradable wastes (such as DDT) are(such as DDT) are

there for decades.there for decades.

Fig. 21-8, p. 502

Aquifer

Water well

Migratingvapor phase

Contaminant plume moveswith the groundwater

Free gasolinedissolves ingroundwater(dissolvedphase)

Groundwaterflow

Watertable

Gasolineleakage plume(liquid phase)

Leakingtank

Bedrock


Leaks from a number of sources haveLeaks from a number of sources havecontaminated groundwater in parts of thecontaminated groundwater in parts of theworld.world.

According the the EPA, one or more organicAccording the the EPA, one or more organicchemicals contaminate about 45% ofchemicals contaminate about 45% of municipalmunicipal

groundwater supplies.groundwater supplies.

By 2003, the EPA had completed the cleanup ofBy 2003, the EPA had completed the cleanup of297,000 of 436,000 underground tanks leaking297,000 of 436,000 underground tanks leakinggasoline, diesel fuel, home heating oil, or toxicgasoline, diesel fuel, home heating oil, or toxicsolvents.solvents.

Case Study: Arsenic in GroundwaterCase Study: Arsenic in Groundwater --a Natural Threata Natural Threat

Toxic Arsenic (Toxic Arsenic (AsAs) can naturally occur at high) can naturally occur at highlevels in soil and rocks.levels in soil and rocks.

Drilling into aquifers can releaseDrilling into aquifers can release AsAs intointodrinking water supplies.drinking water supplies.

According to WHO, more than 112 millionAccording to WHO, more than 112 millionpeople are drinking water withpeople are drinking water with AsAs levels 5levels 5--100 times the 10 ppb standard.100 times the 10 ppb standard.

Mostly in Bangladesh, China, and West Bengal,Mostly in Bangladesh, China, and West Bengal,India.India.

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Fig. 21-9, p. 504

Solutions

Groundwater Pollution

CleanupPrevention

Find substitutes fortoxic chemicals

Install monitoringwells near landfillsand undergroundtanks

Require leak detectorson underground tanks

Ban hazardouswaste disposalin landfills andinjection wells

Store harmful liquids inaboveground tanks with leakdetection and collectionsystems

Pump to surface,clean, and returnto aquifer (veryexpensive)

Pumpnanoparticles ofinorganiccompounds toremove pollutants(may be thecheapest, easiest,and most effectivemethod but is stillbeing developed)

Keep toxicchemicals out ofthe environment

Injectmicroorganismsto clean upcontamination(less expensivebut still costly)

OCEAN POLLUTIONOCEAN POLLUTION

Oceans, if they are not overloaded, canOceans, if they are not overloaded, candisperse and break down large quantities ofdisperse and break down large quantities ofdegradable pollutants.degradable pollutants.

Pollution of coastal waters near heavilyPollution of coastal waters near heavilypopulated areas is a serious problem.populated areas is a serious problem.

About 40% of the worldAbout 40% of the world’’s population lives near ons population lives near onor near the coast.or near the coast.

The EPA has classified 4 of 5 estuaries asThe EPA has classified 4 of 5 estuaries as

threatened or impaired.threatened or impaired.

Fig. 21-10, p. 505

Healthy zoneClear, oxygen-richwaters promote growthof plankton and sea grasses,and support fish.

Oxygen-depleted zoneSedimentation and algaeovergrowth reduce sunlight,kill beneficial sea grasses, useup oxygen, and degrade habitat.

Red tidesExcess nitrogen causesexplosive growth oftoxicmicroscopic algae,poisoning fish andmarine mammals.

FarmsRunoff of pesticides, manure, andfertilizers adds toxins and excessnitrogen and phosphorus.

Toxic sedimentsChemicals and toxicmetals contaminateshellfish beds, killspawning fish, andaccumulate in thetissues of bottomfeeders.

Construction sitesSediments are washed intowaterways, choking fish andplants, clouding waters, andblocking sunlight.

Urban sprawlBacteria andviruses fromsewers and septictanks contaminateshellfish beds

Oxygen-depletedzone

Closedbeach

CitiesToxic metalsand oil fromstreets andparking lotspollutewaters;

IndustryNitrogen oxidesfrom autos andsmokestacks,toxic chemicals,and heavy metalsin effluents flowinto bays andestuaries.

Closedshellfish beds

OCEAN POLLUTIONOCEAN POLLUTION

Harmful algal blooms (HAB) are caused byHarmful algal blooms (HAB) are caused byexplosive growth of harmful algae fromexplosive growth of harmful algae fromsewage and agricultural runoff.sewage and agricultural runoff.


Oxygen Depletion in the NorthernOxygen Depletion in the NorthernGulf of MexicoGulf of Mexico

A large zone ofA large zone ofoxygenoxygen--depleted waterdepleted waterforms for half offorms for half ofthe year in thethe year in theGulf of MexicoGulf of Mexicoas a result ofas a result ofHAB.HAB.

Figure 21Figure 21--AA Fig. 21-A, p. 507

MississippiRiver

MississippiRiver Basin

Gulf of Mexico

Ohio River

Mississippi River

Missouri River

TX

MSLA

Depleted oxygen

LOUISIANA

Gulf of Mexico

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Case Study: The Chesapeake BayCase Study: The Chesapeake Bay ––An Estuary in TroubleAn Estuary in Trouble

Pollutants from sixPollutants from sixstates contaminatestates contaminatethe shallowthe shallowestuary, butestuary, butcooperative effortscooperative effortshave reducedhave reducedsome of thesome of thepollution inputs.pollution inputs.


OCEAN OIL POLLUTIONOCEAN OIL POLLUTION

Most ocean oil pollution comes from humanMost ocean oil pollution comes from humanactivities onactivities on landland..

Studies have shown it takes about 3 years forStudies have shown it takes about 3 years formany forms of marine life to recover from largemany forms of marine life to recover from large

amounts ofamounts of crude oilcrude oil (oil directly from ground).(oil directly from ground).

Recovery from exposure toRecovery from exposure to refined oilrefined oil (fuel oil,(fuel oil,gasoline, etcgasoline, etc……) can take 10) can take 10--20 years for marine20 years for marinelife to recover.life to recover.

OCEAN OIL POLLUTIONOCEAN OIL POLLUTION

Tanker accidentsTanker accidentsand blowouts atand blowouts atoffshore drillingoffshore drillingrigs can berigs can beextremelyextremelydevastating todevastating tomarine lifemarine life(especially diving(especially divingbirds, left).birds, left).

Figure 21Figure 21--1313 Fig. 21-14, p. 509

Reduce input of toxic pollutants

Solutions

Coastal Water Pollution

Prevention Cleanup

Use wetlands, solar-aquatic,or other methods to treat sewage

Require at least secondarytreatment of coastal sewage

Sprinkle nanoparticles over anoil or sewage spill to dissolvethe oil or sewage withoutcreating harmful by-products(still under development)

Improve oil-spill cleanupcapabilities

Recycle used oil

Regulate coastal development

Protect sensitive areas fromdevelopment, oil drilling, andoil shipping

Ban ocean dumping of sludge andhazardous dredged material

Ban dumping of wastes andsewage by maritime and cruiseships in coastal waters

Separate sewage and storm lines

Require double hulls for oil tankers

PREVENTING AND REDUCINGPREVENTING AND REDUCINGSURFACE WATER POLLUTIONSURFACE WATER POLLUTION

The key to reducing nonpoint pollutionThe key to reducing nonpoint pollution –– mostmostof it from agricultureof it from agriculture –– is to prevent it fromis to prevent it fromreaching bodies of water.reaching bodies of water.

Farmers can reduce runoff by planting buffersFarmers can reduce runoff by planting buffersand locating feedlots away from steeply slopedand locating feedlots away from steeply slopedland, flood zones, and surface water.land, flood zones, and surface water.

How Would You Vote?How Would You Vote?

Should we greatly increase efforts to reduceShould we greatly increase efforts to reducewater pollution from nonpoint sources evenwater pollution from nonpoint sources eventhough this could be quite costly?though this could be quite costly?

a. No. Most farmers and ranchers can't afforda. No. Most farmers and ranchers can't affordmore regulations.more regulations.

b. Yes. Nonpoint source water pollution is ab. Yes. Nonpoint source water pollution is a

serious environmental and human health threat.serious environmental and human health threat.

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PREVENTING AND REDUCINGPREVENTING AND REDUCINGSURFACE WATER POLLUTIONSURFACE WATER POLLUTION

Most developed countries use laws to setMost developed countries use laws to setwater pollution standards, but such lawswater pollution standards, but such lawsrarely exist in developing countries.rarely exist in developing countries.

The U.S. Clean Water Act sets standards froThe U.S. Clean Water Act sets standards froallowed levels of key water pollutants andallowed levels of key water pollutants andrequires polluters to get permits.requires polluters to get permits.

EPA is experimenting with aEPA is experimenting with a discharge tradingdischarge trading

policypolicy similar to that for air pollution control.similar to that for air pollution control.

Reducing Water Pollution throughReducing Water Pollution throughSewage TreatmentSewage Treatment

Septic tanks and various levels of sewageSeptic tanks and various levels of sewagetreatment can reduce pointtreatment can reduce point--source watersource waterpollution.pollution.


Fig. 21-15, p. 510

Distribution box

Manhole cover(for cleanout)

Vent pipe

Perforated pipe

Drain field(gravel orcrushed stone)

Septic tank

Sludge

Wastewater

Gas

Scum


Raw sewage reaching a municipal sewageRaw sewage reaching a municipal sewagetreatment plant typically undergoes:treatment plant typically undergoes:

Primary sewage treatmentPrimary sewage treatment: a: a physicalphysical processprocessthat uses screens and a grit tank to remove largethat uses screens and a grit tank to remove largefloating objects and allows settling.floating objects and allows settling.

Secondary sewage treatmentSecondary sewage treatment: a: a biologicalbiological

process in which aerobic bacteria remove asprocess in which aerobic bacteria remove asmuch as 90% of dissolved and biodegradable,much as 90% of dissolved and biodegradable,oxygen demanding organic wastes.oxygen demanding organic wastes.


Primary and Secondary sewage treatment.Primary and Secondary sewage treatment.Figure 21Figure 21--1616 Fig. 21-16, p. 511

Raw sewagefrom sewers

Activated sludge

Disposed ofin landfill orocean orapplied tocropland,pasture, orrangeland

Primary Secondary

Grit chamberBar screen Settling tank Aeration tank Settling tankChlorinedisinfection tank

Sludge drying bed

Sludgedigester

Air pump

To river,lake,or ocean

(kills bacteria)

Sludge

8


Advanced or tertiary sewage treatment:Advanced or tertiary sewage treatment:

Uses series of chemical and physical processesUses series of chemical and physical processesto remove specific pollutants left (especiallyto remove specific pollutants left (especially

nitrates and phosphates).nitrates and phosphates).

Water is chlorinated to remove coloration andWater is chlorinated to remove coloration andto kill diseaseto kill disease--carrying bacteria and somecarrying bacteria and someviruses (disinfect).viruses (disinfect).


Sewage sludge can be used as a soilSewage sludge can be used as a soilconditioner but this can cause healthconditioner but this can cause healthproblems if it contains infectious bacteria andproblems if it contains infectious bacteria andtoxic chemicals.toxic chemicals.

Preventing toxic chemicals from reachingPreventing toxic chemicals from reachingsewage treatment plants would eliminatesewage treatment plants would eliminatesuch chemicals from the sludge and watersuch chemicals from the sludge and waterdischarged from such plants.discharged from such plants.

Fig. 21-17, p. 513

Sludge

GroundwaterContaminationHarmful chemicalsand pathogensmay leach intogroundwaterand shallow wells.

OdorsOdors may cause illness orindicate presence of harmful gases.

Livestock PoisoningCows may die after grazingon sludge-treated fields.

Dust ParticlesParticles of dried sludgecarry viruses and harmfulbacteria that can beinhaled, infect cuts or enterhomes.

Surface RunoffHarmful chemicalsand pathogens maypollute nearbystreams,lakes, ponds,and wetlands.

ExposureChildren may walk orplay in fertilized fields.

BUFFERZONE


Should we ban the discharge of toxicShould we ban the discharge of toxicchemicals into pipes leading to sewagechemicals into pipes leading to sewagetreatment plants?treatment plants?

a. No. Many small businesses and manufacturersa. No. Many small businesses and manufacturerscan't afford tougher regulations.can't afford tougher regulations.

b. Yes. Dangerous wastes are still beingb. Yes. Dangerous wastes are still being

released into sewage treatment plants.released into sewage treatment plants.


Natural and artificial wetlands and otherNatural and artificial wetlands and otherecological systems can be used to treatecological systems can be used to treatsewage.sewage.

California created a 65 hectare wetland nearCalifornia created a 65 hectare wetland nearHumboldt Bay that acts as a natural wastewaterHumboldt Bay that acts as a natural wastewatertreatment plant for the town of 16,000 people.treatment plant for the town of 16,000 people.

•• The project cost less than half of the estimated price ofThe project cost less than half of the estimated price ofa conventional treatment plant.a conventional treatment plant.


Water pollution laws have significantlyWater pollution laws have significantlyimproved water quality in many U.S. streamsimproved water quality in many U.S. streamsand lakes but there is a long way to go.and lakes but there is a long way to go.

Some want to strengthen the U.S. CleanSome want to strengthen the U.S. CleanWater Act (CWA) to prevent rather thanWater Act (CWA) to prevent rather thanfocusing on endfocusing on end--ofof--thethe--pipe removal.pipe removal.

Many farmers and developers see the CWAMany farmers and developers see the CWAas limiting their rights as property owners toas limiting their rights as property owners tofill in wetlands.fill in wetlands.

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Should the U.S. Clean Water Act beShould the U.S. Clean Water Act bestrengthened?strengthened?

a. No. Many farmers, ranchers and smalla. No. Many farmers, ranchers and smallbusinesses can't afford additional regulations.businesses can't afford additional regulations.

b. Yes. It will further reduce pollution and protectb. Yes. It will further reduce pollution and protectthe environment and human health.the environment and human health.

DRINKING WATER QUALITYDRINKING WATER QUALITY

Centralized water treatment plants andCentralized water treatment plants andwatershed protection can provide safewatershed protection can provide safedrinking water for city dwellers in developeddrinking water for city dwellers in developedcountries.countries.

Simpler and cheaper ways can be used toSimpler and cheaper ways can be used topurify drinking water for developing countries.purify drinking water for developing countries.

Exposing water to heat and the sunExposing water to heat and the sun’’s UV rays fors UV rays for3 hours can kill infectious microbes.3 hours can kill infectious microbes.

Using Laws to Protect Drinking WaterUsing Laws to Protect Drinking Water

While most developed countries haveWhile most developed countries havedrinking water quality standards and laws,drinking water quality standards and laws,most developing countries do not.most developing countries do not.

The U.S Safe Drinking Water Act requires theThe U.S Safe Drinking Water Act requires theEPA to establish national drinking waterEPA to establish national drinking waterstandards (standards (maximum contaminant levelsmaximum contaminant levels))for any pollutant that may have adversefor any pollutant that may have adverseeffects on human health.effects on human health.

Using Laws to Protect Drinking WaterUsing Laws to Protect Drinking Water

The U.N. estimates that 5.6 millionThe U.N. estimates that 5.6 millionAmericans drink water that does not meetAmericans drink water that does not meetEPA standards.EPA standards.

1 in 5 Americans drinks water from a1 in 5 Americans drinks water from atreatment plant that violated one or moretreatment plant that violated one or moresafety standard.safety standard.

Industry pressures to weaken the SafeIndustry pressures to weaken the SafeDrinking Act:Drinking Act: Eliminate national tests and public notification ofEliminate national tests and public notification of

violations.violations.

Allow rights to pollute if provider cannot afford toAllow rights to pollute if provider cannot afford tocomply.comply.


Should the U.S. Safe Drinking Water Act beShould the U.S. Safe Drinking Water Act bestrengthened?strengthened?

a. No. Rural people, small businesses anda. No. Rural people, small businesses andmanufacturers can't afford more regulations.manufacturers can't afford more regulations.

b. Yes. Strengthening the Act would protect theb. Yes. Strengthening the Act would protect theenvironment and the health of millions of people.environment and the health of millions of people.

Is Bottled Water the Answer?Is Bottled Water the Answer?

Some bottled water is not as pure as tapSome bottled water is not as pure as tapwater and costs much more.water and costs much more.

1.4 million metric tons of plastic bottles are1.4 million metric tons of plastic bottles arethrown away.thrown away.

Fossil fuels are used to make plastic bottles.Fossil fuels are used to make plastic bottles.

•• The oil used to produce plastic bottles in the U.S. eachThe oil used to produce plastic bottles in the U.S. eachyear would fuel 100,000 cars.year would fuel 100,000 cars.

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Should pollution standards be established forShould pollution standards be established forbottled water?bottled water?

a. No. Competition within the free market and thea. No. Competition within the free market and themedia would better solve the problems.media would better solve the problems.

b. Yes. Too many bottled waters contain bacteriab. Yes. Too many bottled waters contain bacteriaand other dangerous contaminants.and other dangerous contaminants.

Fig. 21-18, p. 517

• Prevent groundwater contamination

Solutions

Water Pollution

• Reduce birth rates

• Reduce poverty

• Reduce air pollution

• Practice four R's of resource use (refuse,reduce, recycle, reuse)

• Work with nature to treat sewage

• Find substitutes for toxic pollutants

• Reuse treated wastewater for irrigation

• Reduce nonpoint runoff

Fig. 21-19, p. 517

What Can You Do?

Water Pollution

• Fertilize garden and yard plants with manure orcompost instead of commercial inorganic fertilizer.

• Minimize your use of pesticides.

• Do not apply fertilizer or pesticides near a body of water.

• Grow or buy organic foods.

• Do not drink bottled water unless tests show that yourtap water is contaminated. Merely refill and reuseplastic bottles with tap water.

• Compost your food wastes.

• Do not use water fresheners in toilets.

• Do not flush unwanted medicines down the toilet.

• Do not pour pesticides, paints, solvents, oil, antifreeze,or other products containing harmful chemicals downthe drain or onto the ground.

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