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GEOL100(PlanetEarth)#28-GroundwaterandtheEnvironment

Agricultural fields in Nebraska irrigated with groundwater

GWProblemsandSociety

GW-importantresourceforaridregions(e.g.,southwestUSA,MiddleEast),wherewaterisscarce.Israel/PalesGnianpeacenegoGaGonsinvolvewaterrights.

AralSeaincentralAsia(aridclimate),was4thlargestinlandwaterbody

WaterProblems-Overuse(AralSeaCaseHistory)

In1950sriversdivertedforirrigaGon,AralSeabeganshrinking

AnimatedGraphic:ShrinkingofAralSea1960-2014

WaterProblems-Overuse(AralSeaCaseHistory)By2012,surfaceareaandvolumeofAralSeadecreasedby90%!

DamconstrucGonin2005stabilizedNorthAralSea;SouthAralSeaconGnuestoshrink,easternpartcompletelydryin2014(AralkumDesert)

Aral Sea in 1989 (left) 2014 (right)

WaterProblems-Overuse(AralSeaCaseHistory)EvaporaGonofAralSea↑salinityupto10x(10,000-100,000ppm).Hugeenvironmentalimpact:deadfishingindustry,shoreline10sofmilesfromfishingtowns,toxicduststorms,wetlandsloss,temperatureextremes,drierclimate

2008 dust storm over South Aral Sea

GlobalWaterCrisis(WaterSupply)Today,~1.2billionpeople(~17%ofworldpopulaGon)don’thaveenoughwater(physicalscarcity).MostinMiddleEast,NorthAfrica,China.

Another~1.6billionpeople:economicscarcityofwater,i.e.,countrieslackinfrastructuretotakewaterfromrivers,aquifers.MostinAfrica,India,southeastAsia,SouthAmerica.

Source = United Nations World Water Development Report 4 (2012)

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By2025,forecast~3billionpeople(~40%ofworld'sprojectedpopulaGon)tohavephysicalscarcityofwater.LargeincreasecomingmainlyfromChinaandIndia.

GlobalWaterCrisis(WaterSupply) GroundwaterProblems-FindingGW

Usuallyeasytofind,reachsaturatedzone;

Tofindlargeaquiferforcityhydrogeologistscollect,interpretdata(maps,cross-secGons,testwells,models)

Hydrogeologist examines rock from drill hole

GroundwaterProblems-FindingGWNoscienGficbasistodowsing(waterwitching),involvesdiviningrodthatdeflectsdownward"onitsown"whendowserpassesoverGW.

Dowser holds divining rod in search of groundwater

GroundwaterProblems-IsItRenewable?Dependsonwhetherwaterisremovedfasterthanitisreplaced.Inmanyareasdemand>>supply,calledGWmining.WhatcausesgroundwatermininginsouthwesternUSA?

Groundwater Overdraft (Mining) Map - USA

GroundwaterMiningCaseHistory-OgallalaAquiferHugeaquiferinHighPlains(NB,KS,OK,TX,~400,000km2).

Irrigation water from Ogallala aquifer

OgallalawaterusedforirrigaGon(~170,000wells,highfarmproducGvity).

OgallalafilledwhenglaciersfromlastIceAgemelted~10,000yearsago.

Nowlillerecharge.GWdemand>>supply.

GroundwaterMiningCaseHistory-OgallalaAquifer

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GroundwaterMining-OgallalaAquifer

BeforeGWpumping(1940s),averagesaturatedzonethickness=~200feet.

By1980~5%depleGon;in2008~9%depleGon.

InsomeareasofKS,OK,NM,TX50-100%depleGon

GWMining-OgallalaAquifer

Center-pivot sprinklers

InefficientirrigaGonwithhighevaporaGon(center-pivotsprinklers),governmentpolicy(pricesupportsforwater-hungrycrops),otherrules(useitorloseit)contributedtowaterdeficit.

GroundwaterMining-OgallalaAquifer

Irrigation circles from center-pivot sprinklers

GroundwaterMining-OgallalaAquiferIn1980s,improvementduetobelerwatermanagement(waterwellmeterstopreventoveruse,wastewateruse),newtechnologies(irrigaGonnozzlesapplywatermoredirectlyonplants;↓waterandenergy,↓evaporaGonlossupto98%vs.previousspraysystems.)

ProjecGonsthat25%ofOgallalawaterwillbeusedby2020.

Older inefficient irrigation Modern efficient irrigation

ImpactsofGWWithdrawal-LoweredWaterTableAsGWispumped,WTcandropdeeply.

ChicagohasWT300-500feetbelowsurface.

Needdeeper,moreexpensivewells.

Cross-section

ImpactsofGWWithdrawal-GroundSubsidence

Earth'ssurfacesinksduetoGWpumping.

Cross-section Land surface sinks ↓

After GW pumping

Before GW pumping

saturated zone

Subsidenceirreversible,groundcan'tspringbackevenifGWreturns.

Gofromwater-filledporespacestoair-filledporespaces,allowscompacGon.

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SubsidencemajorprobleminHoustonandGalveston,TX,Venice(Italy),MexicoCity,SanJoaquinValley(centralCA).

ImpactsofGWWithdrawal-GroundSubsidence

LeaningTowerofPisaunderwent↑rateofleaning,differenGalcompacGonfromGWwithdrawal.

Flooded Piazza San Marco, Venice, Italy due to land subsidence

ImpactsofGWWithdrawal-GroundSubsidence

Globally, ~660 million people (9%) lack access to safe water supplies (1990 - 24% drank “unsafe” water) “improved” drinking-water source protects it from outside contamination, particularly fecal matter (World Health Organization, 2015)

GlobalWaterCrisis(WaterQuality) GlobalWaterCrisis(WaterQuality)~2.4billionpeople(32%ofworldpopulaGon)withoutimprovedsanitaGon(in1990-46%ofpopulaGon),ensureshygienicseparaGonofhumanexcretafromhumancontact;poorsanitaGoncauseswaterpolluGonfromfecalmaler(WHO,2015)

~340,000water-relateddeathsarechildrenages0-5(every90secondschilddiesfromwater-relateddisease,WHO,2015)

Eachyear~840,000peoplediefromwater-relateddisease,e.g.,diarrhea,cholera,typhoidfever,dysentery;98%ofwater-relateddeathsoccurindevelopingworld

GlobalWaterCrisis(WaterQuality) GWPolluQon-Pointvs.Non-PointSourcesManysourcesofGWcontaminaGon:pointsources(~small,readilyidenGfiable),non-pointsources(large,diffuseareas)Pointsourceexamples?

Non-pointsourceexamples?

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GWPolluQon-ContaminantPlumeGWpolluGoncangoundetectedlongGme(underground,movesslowly)Oncepollutantentersaquifer,GWflowdispersesintoenlargingcontaminantplume(largeflowingmassofpollutedwater).

PolluGoncanspreadoverlargearea,costlycleanup.

GWPolluQon-LeakyFuelStorageTanksBefore1980,fuelstoragetanksmadeofmetal-corrodes,leaks,contaminatesGW.

Removal of leaking metal underground storage tank for fuel

Fiberglass underground storage tank for fuel

SmallamountoforganicpollutantcontaminateslargeareaofGW.

Leakdetectorsnowrequired.Oldmetalstoragetanksdugup,replacedwithfiberglasstanks.

LoveCanal(NiagaraFalls,NY)-ditch20mwide,3mdeep,1000mlong,developedforhydroelectricpowerinearly1900s(GoogleEarthview).

Aerial view Love Canal area (open area)

HookerChemicalspurchasedin1942,dumped~21,000tonsofchemicalwaste(benzene,dioxin,chloroform,heavymetals)inmetalbarrels,coveredwithdirt;barrelsbrokeduringburial;wastepoureddirectlyindirt.

Hooker Chemicals in 1940s

GWPolluQonCaseHistory:LoveCanal

Priortothedeliveryofthisinstrumentofconveyance,thegrantee(CityofNiagaraFalls)hereinhasbeenadvisedbythegrantor(Hooker)thatthepremisesabovedescribedhavebeenfilled,inwholeorinpart,tothepresentgradelevelthereofwithwasteproductsresulAngfromthemanufacturingofchemicalsbythegrantoratitsplantintheCityofNiagaraFalls,NewYork,andthegranteeassumesallriskandliabilityincidenttotheusethereof.Itisthereforeunderstoodandagreedthat,asapartoftheconsideraAonforthisconveyanceandasacondiAonthereof,noclaim,suit,acAonordemandofanynaturewhatsoevershalleverbemadebythegrantee,itssuccessorsorassigns,againstthegrantor,itssuccessorsorassigns,forinjurytoapersonorpersons,includingdeathresulAngtherefrom,orlossofordamagetopropertycausedby,inconnecAonwithorbyreasonofthepresenceofsaidindustrialwastes.ItisfurtheragreedasacondiAonhereofthateachsubsequentconveyanceoftheaforesaidlandsshallbemadesubjecttotheforegoingprovisionsandcondiAons.

In1953HookersoldlandtoNiagaraFallsSchoolBoardfor$1(advisedthemoflanduse).

Final paragraph of 1953 deed granting Love Canal from Hooker Chemical Co. to City of Niagara Falls for $1

GWPolluQonCaseHistory:LoveCanal

Publicschool,housingdevelopmentbuilt($toschooldistrict).

Map (left) and aerial view (right) of development on Love Canal waste disposal site

Stormsewernetworkbreachedwastecontainers.

GWPolluQonCaseHistory:LoveCanalLoveCanal-symbolofimproperlystoredchemicalwaste.Eventually,wasteseepedintohouses,barrelsemerged.Healthproblems(miscarriages,birthdefects,chromosomedamage).

Emerging barrels of chemical waste

Houses awaiting destruction at Love Canal

GWPolluQonCaseHistory:LoveCanal

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GWPolluQonCaseHistory:LoveCanal,SuperfundBeganfederalprogramSuperfund,purposeofcleaningupworstof40,000abandonedtoxicwastesites.In2004,EPAdeclaredLoveCanal“clean.”

Map of Superfund sites. Red = Current, yellow = proposed, green = cleaned

>2,000hazardouswastesitesinUSAidenGfiedhavinghighpriorityforacGon;manyinindustrialNortheast,northernMidwest.

GWPolluQon-SanitaryLandfillBestanswerforlargewastesite=layersofimpermeableclay,isolatewastefromaquifers.Nowthesesiteswelldesigned,monitored.

GWPolluQon-UrbanPolluQon

UrbanpolluGonintostormsewers.

ReducingUrbanPolluQonIntoSewersDon'tpourusedmotoroil,anGfreeze,paints,pesGcides,hazardouschemicalsdownstormsewerordrain.

RecycleusedmotoroilUsecity-orstate-sponsoredhazardouswastedisposal

ReducingUrbanPolluQonIntoSewersKeepsoil,leaves,grassclippingsoffdriveways,sidewalks,streets.CompostNoferGlizer,herbicide,pesGcide