英语年同等学力英语练习22

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Drinkingwastewater?Theideamaysounddistasteful,butnewfederallyfundedresearchsaysmoreAmericansaredoingso―whethertheyknowornot―andthisreusewillbeincreasinglynecessaryastheU.S.populationexpands.

Treatedwastewaterposesnogreaterhealthrisksthanexistingwatersuppliesand,insomecases,maybeevensafertodrink,accordingtoareportreleasedbytheNationalResearchCouncil.“Webelievewaterreuseisanoptiontodealwithgrowingwaterscarcity,especiallyincoastalareas,”saysJorgDrewes,anengineeringprofessorattheColoradoSchoolofMines.“Thiscanbedonereliablywithoutputtingthepublicatrisk,”hesays,citingtechnologicaladvances.Hesaysit’sawastenottoreusethenation’swastewater,becausealmostallofitistreatedbeforedischarge.Thiswaterincludesstormrunoff(径流)aswellasusedwaterfromhomes,businessandfactories.

Inmanyplaces,thereportsays,thepublicdoesnotrealizeit’sdrinkingwaterthatwastreatedafterbeingdischargedaswastewatersomewhereupstream.Forexample,wastewaterdischargedintotheTrinityRiverfromDallas/FortWorthflowssouthintoLakeLivingston,thesourceforHouston’sdrinkingwater.

Despitethegrowingimportanceofthisreuse,thereportsaysthere’sbeennosystemicanalysisofitsextentnationwidesinceastudybytheU.S.EnvironmentalProtectionAgency(EPA).AlanRobersonoftheAmericanWaterWorksAssociationsayswastewaterreuseis

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