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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
