Post on 23-Jan-2021
RainWaterHarvestingAuthors:
OwenManningDanielKiley
HannahDemetryAlishaSchroederJennaVonnahmeDavidBruewerCarolineCollins
TheOhioStateUniversity
ENGR4692.01May8,2017
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Abstract
Lackofsafedrinkingwaterindevelopingcountriesisoneoftheworld’smostsignificanthealthissues.Thisproblemiscausedbycontaminatedsourcesofwater,lackofhealtheducationincommunities,andshortageofresourcestothoseinneed.Thesolutiontothisproblemmustbeonethatlastsandisnotonlyeffectivebutalsosustainable.InworkingwithMayanFamilies,thekeytomovingtowardsthebestsolutionwillbeinestablishingastrongrelationshipfocusedonteamworkandcommunication.AsignificantgoalfortheservicelearningtripistoleavetheorganizationandcommunityinPanajachel,Guatemalawiththeproperresourcesandknowledgesothattheycanrecreateaworkingrainwatercollectionsystem.
Thedesignprocessfortherainwatercollectionsystemdiscussedinthisreportincludesdefiningtheproblem,gatheringinformation,experimenting,choosingthebestidea,andtesting.ThegroupcycledthroughthisprocessinordertoarrivetoaconclusionforMayanfamilies.TherecommendationforarainwatercollectionsysteminPanajachel,Guatemalaisaflushsystem.ThissystemusesmultiplePVCflushpipestodiscardofthedirtywaterthatisfirstcollectedwhenrainbeginstofallonadirtyroof.Thenumberofflushpipesrequireddependsontheareaoftheroof.Thedesignisfurtherdetailedinthereportalongwiththeprocessofarrivingtotheflushsystemastheconclusion.Incountry,theobjectiveistoimplementaprototypedesignoftheflushsystemandevaluateitsperformancewhilegaininguserfeedback.Benefitsofthisdesignincludeeaseofuse,costofmaterial,andabilitytointegratethedesignwithexistingfiltersusedbyMayanfamilies.Overall,theflushsystemprovestobeastrongcandidateforthesolutiontothelackofcleanandaccessiblewaterinGuatemala.
TableofContentsBackgroundandIntroduction……………………………………………………………………1InfluencingFactors……………………………………………………………………………..…….4MethodologyandResults……………………………………………………………………....…7Implementation………………………………………………………………………………..……...20Conclusion…………………………………………………………………………………………….…..22ReferencesandAppendix………………………………………………………………………….23
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BackgroundandIntroductionProjectMotivation
ThemotivationbehinddesigningarainwaterharvestingsystemistocollectcleanwaterthatisunavailabletoresidentsofGuatemalabecauseofpollutioninbodiesoffreshwater.Thesebodiesofwaterwereoncethesourceofcleanwaterbuttherearenownogovernmentregulatedsourcesoffreshwater.Rainwaterisapossiblesourceofcleanwaterbecausethesourcedoesnotinvolveacostforthepeopleusingit.
Rainwatercollectionsystemsareviablemethodsforstoringwaterthatcanbeusedinvariouswaysandhavebeenimplementedworldwide.Therainwaterisoftenusedtowatergardensindryseasons,bathe,washdishes,andinsomecasesitisusedfordrinkingwater.ManycommunitiesinGuatemalarelyondirtystreamsastheirsourceofwatertoaccomplishthesetasks.Itiscommonformanyofthesestreamstodryupaftertherainyseason,leavingmanyyoungchildrenandwomentowalkseveralkilometerstoaccesswater.Uganda’sPrimeMinisterAmamaMbabazisays,“Lackofaccesstosafewaterandsanitationfacilitieshasadetrimentalimpactonthehealth,productivityandgeneralsocio-economicprogressofourpeople,especiallythechildren”(Baguma).TheseconcernsapplytotheGuatemalanpeopleaswell.Childrencanbepulledoutofschoolorotherresponsibilitiesbecausetheyhavetoretrievewaterfortheirfamilies.Rainwatercollectionsystemshavethepotentialtobeareliablesourceofwater,evenindryseasons,thatcanbeusedbyindividualfamiliestoalleviatetheproblemofaccesstowater.
Thisprojectwillbecompletedinordertoprovidefamilieswiththecleanwaternecessarytoperformdailytasks.ThecustomerofthisprojectwillbetheMayanFamiliesorganizationwhowillthendeterminewheretodistributethesolutions.Thestakeholdersinthisprojectarethedesigners,MayanFamiliesaswellasthefamilieswhowillbeusingtherainwatercollectionsystem.BackgroundInformation
WateraccessibilityinGuatemaladiffersgreatlybyregionandpopulationdensity.AccordingtoUNICEF,asof2015,97%ofurbanGuatemalahasaccesstowaterpumpeddirectlytoareaseasilyaccessibletoresidents.Inruralareas,however,only71%ofthepopulationhasaccesstopumpedwater,with22%percentofthepopulationdependingonanotherwatersource,and6%dependingonsurfacewatercollection.Surfacewater,collectedfromsuperficialstreams,ponds,andrivers,istypicallymuchlesssafethanwaterofothersources,asitisexposedtopollutionfromsewage,animals,andfarmrunoff.ThisleavesalargenumberofGuatemalansvulnerabletounsafewaterfordailyuseandconsumption.
MuchoftheareasurroundingLakeAtitlanisconsideredrural.Inthepast,LakeAtitlansuppliedcleandrinkingwatertoresidentsoftheregion.However,in2009,researchersconfirmedthepresenceoftoxicstrainsofcyanobacteriainthewaterofLakeAtitlan.Thesetoxins,resultingfromsewagedrainageandphosphorus-basedfertilizerscancauseillnessinhumans.Manyresidentsoftheareanowdependonothersuperficialsourcesofwatersuchastreamsandpondsforfreshwater.However,most
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ofthesesourcesalsocontaindangerouspollutants,leavingmanydependentuponrainwatercollectionforwaterconsumption.
Guatemalahastwodefiningseasonsforrainfall,dryandrainyseasons.DryseasonisfromNovemberthroughAprilandtherainyseasonisfromMaytoOctober.AccordingtodatacollectedbyTheWorldBankGroupbetween1990and2012,theaveragerainfallduringthedryseasonis3.09inchespermonthandtheaveragerainfallduringtherainyseasonis13.53inchespermonth.Usinga500squarefootcatchmentsurface,ifeverydropiscollected,963gallonscanbecollectedpermonthduringthedryseasonand4,214gallonspermonthcanbecollectedduringtherainyseason.Generously,theaveragefamilyinaruralthirdworldcountryusesabout10gallonsofwaterperday.Giventhis,arainwatercollectionsystemthatcancollectjustonethirdoftherainfallduringdryseasoncansupportanentirefamily'smonthlywateruse.GeneralRainwaterHarvestingSystems
Rainwatercollectionmaynotseemlikeanentirelycomplextask,buttherearemanydifferentcomponentsinvolved.Additionally,ittakesallcomponentsworkinginharmonyforasystemtobeeffective.Ifasystemlacksstrengthinonecomponent,itismorelikelytofail.Theuniversalcomponentsofrainwaterharvestingincludethecatchmentarea,storagearea,andconveyancebetweencatchmentandstorage.
Thecatchmentareaistheareathatfirstcomesincontactwiththerainwater.Thishastraditionallybeenrooftops,butmanyothermethodshavebeendevelopedaswell.Importantfactorsofthecatchmentareaincludematerialandslope.Thematerialofthecatchmentarea,andtheentiresystem,needstobeonethatdoesnotabsorbimpuritiesorcollectedwater.Ifthecatchmentareabecomescontaminated,theentirecollectedwatersupplyisatriskofcontamination.
Theconveyancesystemisresponsibleformovingtherainwaterfromthecatchmentareatothestoragearea.Itiscommonforthecatchmentareaandthestorageareatobeseparatedbysomedistanceforpracticalityreasons,therefore,itisnecessaryfortheintermediateconveyancesystem.Mostcommonlyisagutterstylesetupandoraclosedtubingsystem.Importantfactorsoftheconveyancesystem,similartothecatchmentarea,includethematerialandslope.Ifthematerialabsorbedimpuritiesortheslopeisnotsteepenoughthenbacteriacangrowandruinthesample.
Thethirdandfinalcomponentisthestorageunit,oftenreferredtoasacistern.Therearemultiplewaystostorecollectedwater.Storagecanbeaboveorbelowground,madeoutofmanydifferentmaterials,comeinvariousshapesandsizes,andincludedifferentadditionalaspects.Somesubcomponentsofastorageunitincludeventilation,inletandoutletports,overflow,andcoverage.Storageunitsareanintegralpartoftherainwaterharvestingsystem.
Themostcommonsystemusedtodayistherooftopguttersystem,whichisseenonmosthomesandbuildings.Wateriscollectedbytherooftopsintwoways:byslopingtheroofstowardstheouteredgesintoexternalguttersorbyslopingroofsinwardstowardstheinternalguttersoroutletswithinthemainroofarea.Theseoutletsthenleadtopipesthatcarrythewatertothegroundorastoragecontainer.Thissystemoperatesviagravityanddoesnotusepumps.Theslopesoftheroofinfluencethewatertorundownspecificallybeingpusheddownbygravity.Theguttersaretypicallymadeofmetal,butcanbemadeofwoodorPVC.However,woodenguttersrequirealotofmaintenanceandarenotverydurable.
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Anotherrainwatercollectionsystemistheinvertedrooftop.Inthissystem,aportionoralloftheroofisangledinwardtocreateaV-shape.Thebottomvertexofthe‘V’isangleddownwardastoenablegravitytobethemechanismthatdrivesthewaterdownwardandthroughthepipe.Thispipethenleadstoacisternorbarreltokeepforstorage.Thistypeofsystemcanbemadeusingcurrentdesignsofroofsoritcanbemadeasitsownstandingstructure.Thiscanbedoneusingmetalorwoodenpolestoholdupaplasticsheetthatisinverteddownwardstocollectwater.Theplasticmustbesolarresistantinordertoslowthedeteriorationofthesheet.
Hillsidecollectioninvolvesharnessingthelandscapetocollectwaterbyplacingpipesorastoragecontaineratthebottomofahillandallowingtherainwatertofallintoit.Thiswaterisnotverysanitaryhoweverbecauseitcontainssedimentsformthedirtandgrass.FiltrationandPVCpipesmustbeusedinordertomakethewaterbetterqualityandremovesomeofthesediment.Nopumpsareusedinthissystemandthematerialusedismetalforthepipesandfiltration.
RainwaterHarvestinginAmericaandGuatemala
Americaisaverydevelopedcountrywitharegulatedwatersystemavailableinthevastmajorityofthecountry,ruralareasincluded.Thereforerainwaterharvestingiscommonlyusedindividuallyinhomes.TheharvestingofwaterintheU.S.normallytypicallyusesgravitytofeedthewaterintothestoragecontainerusingmechanismslistedindetailabove.Theprocessofgettingthewateroutofthestoragecontainercaneitherbethroughgravityorbypumps.Gravitycanallowforwatertoflowoutofaspouteasily.Pumpscanpushthewateroutofthestoragecontainerandupintopipelinesthatleadtosinksandbathrooms.Pumpsaremoreexpensive,buttheytakeawaythemanualneedtotransportwater,makingitreadilyavailablewhenneeded.Americahasavarietyofwaysthatrainwatercanbeharvestedandtransported.ManyofthesemechanismsandstylescanbeusedtoinfluenceideasinGuatemala.
OnemethodofrainwatercollectionimplementedinGuatemalaisasemi-undergroundstoragetank.Materialsneededincludecement,sand,wiremesh,andsteelbars.Suchatankistypicallycapableofholdingover2000gallonsofwaterthatisdirectedtothetankfromguttersonnearbyhouses.Despiteitslargestoragecapacity,thismethodisverycostly.Othercollectionsystemsmightincludeseveral50gallonplasticstoragetanksconnectedtoguttersonslantedroofs.Holesofabout1inchindiametercanbecutoutofaflowerpottobeusedasafiltersothatlargerdebrisortwigsdonotgetintothestoragesupply.Ifthewateristobemadepotable,manyadditionalstepsmustbeconsideredandtestedinordertosanitizethewaterofalgaeorbacteria.Lastly,freestandingsystemscanbemadetocatchtherainwaterinsteadofusingtheroofandgutters.Thesesystemsoftenprovetobelesseffectivebutmightbethebestoptionforsomecommunitiesdependingongeographyandhousestyleinthatarea.Itisimportantfortheengineeringteamtoconsiderallfactorsandtoworkcloselywiththeresidentssothatthecorrectproblemisbeingsolved.Theteamhopestocomparethevariousmethodsdescribedaboveandprovideextensiveresearchanddeepthoughtintowhichmethodismosteffective.
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InfluencingFactorsDesignConstraints
Therearenumerousfactorsthatwillconstraintherainwatercollectionsystemanddefinehowthesystemneedstobedesignedandimplemented.Thecollectionandstoragemechanismsmustbecleanandmustbeabletobecleanedinorderforthewatercollectedtobeusefulforthefamilies.Thecleanlinessofthestoragemechanismisespeciallyimportantbecausestoringstagnantwaterforextendedperiodsoftimecouldbecomeahealthrisktothepeopleinthecommunitiesiftheproperprecautionsarenottaken.Thecostofthecollectionsystemisanimportantaspecttoconsider.Iftheunitistooexpensivetojustifybuildingandinstalling,thenitisessentiallyandfunctionallyuseless.Therainwatercollectionmustbeaffordableinordertojustifyusingit.ThetimespentinGuatemalaisanotherconstraintonthedesign.TherewillnotbeenoughtimewhilethegroupispresentinGuatemalatoinstallthesystem,sotheteammustensurethattheinstructionsareclearenoughforotherstocompletetheinstallationthemselves.Thedesignalsomustbeintuitiveenoughthattheteamwillnotneedtoassisttheusers.ThedesignalsoneedstobeabletobebuiltwithmaterialsreadilyavailableinGuatemala.Thisisimportantnotonlyforkeepingtheinitialinstallationcostslowbutalsoforloweringtherepaircosts.Italsoensuresthatifapartneedsreplacing,theuserswillnotneedtowaitforittobeshippedfromfaraway.Additionally,therainwatercollectionsystemneedstodesignedtobeusedforasinglehome.Thismeansthattheunitmustnotbetoobig.Italsoneedstorequirerelativelyfewpeopletooperate,asindividualhouseswouldnotbeabletosupportdesignsthatrequiremultiplepeopletooperate.ThedesignalsomustnotrequireexcessivemodificationstothecurrenthouseholdsinGuatemala.Alltheseconstraintswereconsideredintheprocessofdesigningtherainwatercollectionunit.
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Table1:DesignRequirements
UserNeed Whatareyougoingtomeasure
Howtomeasureit(units)
GoodValue BetterValue
Affordable Initialcost Quetzal <1428.57 <714.29
Operating/maintenancecosts
Quetzalperyear <142.89 <71.43
Easeofuse Timetobuild Hours <12 <6
Stepsrequiredforuse
Number 2 1
Lowmaintenance Timetomaintain Hours/week <1 <.5
Powerless Powerrequired Watts 0 0
Healthandsafety Closedcollectionsystem
Yesorno Yes Yes
Sharpedges Number 0 0
Effectiveness Amountofwatercollected
Percentageofrainfall
60% 75%
Particlesinwater(sticks,leaves,etc.)
Particles <5 0
Durability Timeinuse Years 3 5
Oneofthemostcriticalcomponentsoftherainwaterapparatusisthatitcanbeaffordedby
families.Withoutcompromisingqualityanddurabilityoftheproductandincomparingtoprevioustechnologies,itwasdeterminedthat$200wouldbeareasonablepriceforthecostofthematerialsandinstallation.$100wouldbeanevenbettervaluethatwouldstillallowforqualityproduct.Productscanbedesignedtobesimpleyetdurable,andwiththismaintenancecostsshouldnothavetoexceed$10-$20peryear.Themaintenanceprocessesrequiredwouldincludesurfacecleaningandroutinechecksonparts,neitherofwhichwouldhavemuchadditionalcost. Asmentionedabove,simplicitywasamainconsiderationinthedesignrequirements.Inordertoattractusers,theproductmustbeeasytosetupandeasytouse.Setupshouldbeaccomplishableoverthecourseofafewdayswhentakingintoaccounthoursdevotedtojobs.Atargetinstallationtimewouldbebetween6-12hours,atimespanthatwouldallowforuserstobuildtheapparatusoverthecourseofoneweekeveniftheyworkedduringtheday.Theproductshouldrequireseveralhoursofsetup,however,toensuredurability.Additionally,userswillbemoreattractediftheapparatusdoesnot
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involvefurtherstepsthantypicalwatercollectionfromastreamorlocalsource.Forthisreason,thenumberofstepsinvolvedinthewatercollectionprocess,suchasapumpingmotionortransferringfromonevesseltoanother,oughttonotexceedtwoandwouldbebestifitwereaone-stepprocess. Withpeopleleadingverybusylives,itisessentialthattimeduringtheweekisnotwastedonmaintenance.Asmentionedabove,awell-builtproductwillminimizethetimerequiredformaintenancedowntheroad.Theonlyforeseeableprocessesformaintenancewouldbecleaningtheapparatusandensuringallcomponentsareproperlyinplace.Thesetwoprocessesshouldnotexceedonehourperweek,andabettermodelwouldbeanapparatusrequiringlessthanonehalfhourofmaintenanceperweek.Awell-designedapparatusoughttonotrequireanyexternalpowerinput.Theproductshouldbefueledbygravitationalforcesandusenaturalelementstoaccomplishthetaskofraincollection. Theapparatusmustbeefficientincapturingwaterthatisreadyforuse.Inresearchingaveragerainfallandamountofwaterrequiredbyfamilies,itwasdeterminedthatbetween60-75%ofrainfallsurroundingalocalhomemustbeeffectivelycapturedbytheapparatustosupportthisneed.Thesystemmustpromoteahighqualityofrainwaterbeingcollectedtoothatisfreeofdebris.Afiltrationsystemshouldbeabletosiftoutlargerobjectsliketwigsandleaves,leavingwatermostlyfreeoftheseparticles.Ifonlyfiveparticlesentertheraincatchment,notmuchtimeneedstobedevotedtoremovingthem.Inanidealsystem,nodebrisofthisnaturewouldmakeitallthewaythroughthesystemtothecatchmentvessel. Thisproductcertainlyneedstolast.Withanyinvestment,peoplewanttoseelongevityoftheproductspurchased.Consideringtheextremepovertyandsignificantpercentageofwagesgoingtowardthisproduct,itmustbeabletolastfor3-5years.
Notonlyshouldthesystembecost-effectiveandwell-constructed,butthesystemshouldalsobesafe.Nosharpedgesshouldbeinvolvedinthedesignsoastonotcutusersoftheproduct.Furthermore,thefeedintothevesselcapturingthewaterandthevesselitselfshouldnotbeexposedtotheair.Thiswillminimizehealthrisksassociatedwithnaturalelementsandanimals,namelymosquitos.
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MethodologyandResultsProblemFrame
TheproblemfacedbytheteamwastocomparerainwatercollectionsystemsanddesignanappropriaterainwatercollectionsystemtobeusedbyfamiliesinGuatemala.Thesystemhadtobedesignedforindividualfamilyuseandthushadtobeaffordableforasinglefamily.Italsohadtobeascompactaspossibleandbedurableenoughtowithstandseveralyearsofuse.Additionally,allcomponentsneededtobepermanent.Itcouldnotincludepartsthatneedtobereplacedeveryfewmonths,asmanyfamilieswouldnotbeabletoaffordthem.
ExplanationofIdeationPhase
Inordertocreateaneffectivedesignsolution,theteamspentalotoftimeundertheideationphase.Thisphaseincludesbrainstorming,analysis,andexperimentation.Tocompletethebrainstormingportion,theteamcompletedextensiveindividualandgroupbrainstormingusingvarioustechniquessuchasbisociationtopicsandcreativeconstraints.Afterbrainstorming,theteamfocusedonanalysisandexperimentationofthepopularideascreatedduringbrainstorming.Theseideaswereanalyzedforprosandcons,usingaPughchartwhenapplicabletocomparemultipleideas.Fortheexperimentationportionoftheideationphasetheteamusedtheexperimentationofothers,beingthatexperimentationoptionswerelimited.Finally,theteamplannedwhichideaswouldmoveontothenextimplementationphasebasedonaboveresults.
Theteambeganthedesignprocesswithindividualbrainstorming.Todothis,theteamfollowedthesuggestionsoftheprovidedcreativecapacitybuildingdesignworkbook(CreativeCapacityBuilding,D-Lab,MIT,2009).Theworkbooksuggestedstartingwithcreativeideagenerationindividually,usingtechniquessuchasbisociationtopicsandcreativeconstraints.Bisociationtopicstakeaseeminglyunrelatedtopicandforcesittoberelatedinsomewaytothedesigninmind.Theobjectiveofusingbisociationtopicsistoshedlightonafactorthatmaynothavebeenmadeawaretoyouinthefirstplace.Forexample,oneteammemberrelatedacoffeecuptotherainwaterharvestingsystem.Indoingso,theteammemberrealizedthatitispossibleforarainwaterharvestingsystemtobestandalone,anideapreviouslyunconsidered.Thesecondtechniqueforideagenerationusedwascreativeconstraints.Thistechniqueprovideduniqueconstraintsforteammemberstocreateadesignunder.Forexample,onecreativeconstraintgivenwas,“Makethesystemportable”.Similartobisociationtopics,creativeconstraintsexpandedthethinkingofeachmember,exposingadifferentsetofideasthroughwildcreativity.
Afterindividualbrainstorming,theteamcametogethertobrainstormasagroup.Sinceeachmemberhadindividuallyresearchedandcreatedasetofideasalone,theteamdecidedtousePost-Itnotestovisuallydisplaythemostprominentideas.Eachmemberwasinstructedtowritethekeyaspectsanddesignsofrainwaterharvestingcollectionsystemstheyhaddiscovered,thenstickthemonthewall.Thenallthepost-itnoteswerecollectedintosimilarcategoriesbasedonthesefactors.Thisprojecthighlightedwhichideasandmodelsweremostpopular,Figure1belowforreference.
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Figure1:GroupBrainstorming
Afterthepost-itnoteswerecategorized,thegrouphadtheideaofdividingintosubteamsin
ordertobetterfocusonspecificsectionsofthesystem.Intheimageyoucanseethatthemaincategorieswerecatchment,storage,andsanitation.Theteamthendecidedtoresearchagaincollectivelyinthesubgroups,narrowingthefocustotheabovepopularideas.Thesepopularideaswereanalyzedandsomeexperimentedinordertotobetterunderstandeachwithhopesofcomingtoaconclusiononwhichisthebestsolution.
Catchment
Therainwaterwillbecollectedasrunofffromtheroofofthehouseinaguttersystem.Becausemanyofthehousesintheareadonothaveguttersalreadyinstalled,theteamneededtodesignaguttersystemforimplementation.Thetwochoicesthegrouphadwereinstallingapre-madeguttertothehousehold,orbuildingonewithPVC.Thebenefitsofusingapre-madegutterwouldbethatitwouldultimatelyrequirelessworktoinstallontothehousehold.Unfortunatelyguttersmaynotbereadilyavailableinthearea,andapre-madegutterwouldrequiremoreworkthanaPVCguttertoinstalltheflushsystemonto.Thisiswhythegroupdecidedtouseapieceof3-inchPVCpipecutlengthwisetomakethegutter,asitwouldrequirefewerspecializedpartsthanthepremadegutter.BecausethegutterwillbemadefromPVC,onlypre-madePVCconnectorsarenecessarytoconnecttotheGuttertotheflushsystem.
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Table1:PughChartcomparingtwogutterdesigns
Criteria PVCGutter StandardGutter
Specific Amountofwater 0 0
Easeofconnection 0 -
Builddifficulty 0 +
General Cost 0 -
Availability(x2) 0 -
Total 0 -3
Thegroupdidnotconductphysicalexperimentstodeterminewhichdesigntouse.Insteadwe
cametoourconclusionsbycontactingRogerDzwonczyk,AprofessoratOSUandahumanitarianengineerwhohadbuiltarainwatercollectionsystembefore.Thegroupwenttohishouseandinspectedhisprototypeandaskedhimquestions.Hisrecommendationwasthatifnopre-madegutterisavailable,buildingoneoutofPVCisanacceptablesubstitute. Themaindesignofthegutterwillbea3-inchdiameterPVCpipecutlengthwise.Thegutterwillbethelengthofthehouseandwillbetilteddownslightlytomakethewaterflow.OneitherendwillbePVCcapsthatwillbegluedonforsecurity.Attheendthatistilteddowntobeclosesttotheground,therewillbeaPVCteethatemptiesintotheflushsystem.TherewillbeaholecutinthePVCpiletoallowthewatertoflowintotheflushsystem.Theguttercanbeconnectedtothehosebythesamepoststhataresupportingtheflushsystemtubes.Theguttercanbescrewedontothosepostsinasimilarmattertohowtheflushtubesarebeingconnectedtothem.
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Figure2:Basicsketchofgutterdesignconcepts
Therainwaterwillbecollectedviaa“flush”system.Thissystemfiltersoutthewaterproduced
inthefirst20minutesofrainfallthatcontainsanysedimentthatiswashedoffoftheroof.OncetherainwaterfallsandistakenthroughtheguttersystemitencountersasystemofPVCpipes.Everypipebesidesthelastoneservestocollectwaterthatcontainssediment.AseachPVCpipefillswithwater,atennisballrisesandcapsthepipe,blockingmorewaterfromenteringthatparticularpipe.Onceeachpipehasbeenfilled,thesedimentthatwaspresentontheroofisexpectedtobeinthefirstpipesleavingcleanwatertoenterthestoragetank.
ThismethodwasintroducedtoourteambecauseithadbeenimplementedbyRogerDzwonczyk,anOhioStateprofessorwhoworkedonrainwatercollectioninHonduras.Hisgroupledaprojectthereverysimilartotheonebeingpresentedcurrently.Histeamcompletedextensiveresearchandduetothesocioeconomicsimilarities,theteamisconfidenthisdesignwouldalsoworkbestinGuatemala.Priortodecidingtomoveforwardwiththisdesign,theteamdidnotconsidertheneedforextractingthesedimentfromtheinitialrainfallandinsteadtheteamwasconsideringasystemwithasinglepathwayofwaterfromthecatchmentareatothestoragetank.Onebenefitofthisinitialconceptisthattherearefewerpartstomaintain;however,theflushsystemproductivelyusestheadditionalpartstoprovidecleanerwatertothefamilyforwhichthissystemwillbeimplemented.Again,nophysicalexperimentsweremadetoexplorethisoptionbutrathertheteamvisitedRogerDzwonczykandlearnedmoreabouthissetbackswhenimplementingtheflushsystem.Inordertodeterminehowmanydivergentpipesareneeded,thesurfaceareaoftheroofincludinganyadditionalareaaddedbycurvaturemustbecalculated.Theequivalentvolumeistheminimumamountofwaterthatshouldbecollectedpriortowaterbeingcollectedinthestoragetank.
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Storage
Oneofthefactorsthatwasdebatedforthedesignoftherainwatercollectionsystemwaswhetheronelargestoragecontainerormultiplesmallercontainersweretobeused.Welackedtheresourcesforconductingourownexperiments,sotheexperimentaldataourteamcollectedinvolvedlookingupotherpeople’sexperimentsandanalyzingtheirdata.Onemanbuiltalargesingularcisternoutofanoldroadculvert.Basedonhisresults,itwasdeterminedthatanaveragelargecisterncanholdupto11,000gallons.However,dependingontheirsize,theycanholdupto10gallonsto100,000gallons.An8ft.by5ftcylindricalpieceofmetalisbeneficialbecauseitcaneasilybehandledbyafewpeopleandholdsalargeamountofwater.Forqualitywater,ascreenorstrainershouldbeusedupontheinputofthewaterintothecisterninordertopreventdebrisfromstayinginthewaterandsmallanimalsandmosquitoesfromenteringtheinside.Thelidneedstobeheavyorhaveweightsappliedtoitsothatitcanwithstandheavywinds.Acounterbalancecanbehookeduptotheoutsideofthecisternsothatthewaterlevelontheinsidecanbemeasuredaswellasatrapdoortoseetheinsideofthecistern.Anoverflowpipeneedstobeinstalledtopreventthecisternfrombursting.Theoutletoftheoverflowneedstobeacoupleoffeetawayfromthecisternsoasnottodisruptthesoilatwhichthecisternisrestingupon.Theoutletthatpeoplecancollectthewaterfromisgravityfed.Italsotakeswaterfromthetopofthewaterlineastonothaveanysedimentatthebottomofthetankcomeout.
Thematerialofthecisterncanbeeithermetal,plastic,orconcrete.Concreteandmetalarethemostdurable,butplasticisthecheapest.Concreteandmetalarethemostefficientinkeepingtheinsidedarksonoalgaecangrow.ConcretecontainslimewhichcanraisethepHinrain,whichisnaturallyacidic,makingitmoresafetouse.Metalcaneasilybereplacedandbeusedoutofrecycledmaterials.Thus,metaliseasiertouseinthemakingofalargecisternbecauseitischeaperthanconcreteandmoreavailable.Thebenefitsofalargecisternarethatitstoresalotofwaterinasmallarea.Itisverydurablebecauseitislargeandsturdyenoughtowithstandweatherconditionsofmassiverainstormsandwind.Itisverylowmaintenancesonotalotofefforthastogointocleaningitandthewaterqualityisveryclean.Theconsofthecisternarethatitisexpensivecomparedtootherformsofwaterstorageandithasafairlycomplexdesign.
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Table2:MaterialOfCisternPughChart
Criteria Datum:ExistingSysteminGuatemala(TileTub)
Option1:Metal/Steel
Option2:Concrete
Option3:Plastic
Opaque 0 + + 0
Weight 0 0 0 -
Deterioration 0 0 + -
Weather-Proof 0 0 + -
CleanlinessofStoredH2O
0 + ++ +
EaseofRepairs 0 + - 0
Cost 0 0 - +
Durability 0 + + -
Total 0 4 4 -2
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Figure3:Design
Theothermaindesignlookedatforthestoragecontainerwastheuseofmultiplesmaller
containers.Thesmallercontainersaretypicallydrumbarrelsthatholdabout55gallonseach.Theguttergoesdownintoanentryholetooneofthestoragecontainers.Thisentryholehasastrainerorscreeninitinordertofilteroutsedimentandpreventmosquitoesorsmalleranimalsfromentering.ThebarrelsareconnectedtoeachotherthroughaPVCpipeandtieintoamanifoldsystem.Amanifoldsystemisoneinwhichthewaterflowsintothemainbarrelandthenisevenlydistributedintoeachbarrel.Thisenablesallthebarrelstobeconnectedandwatertoflowoutofacollectiveoutlet.Theoutletforallthewaterisinthemiddleofthemanifoldsystemandisoperatedbythetwistingofaknob.Thesystemneedstoincludeanoverflowoutlettopreventthesystemfrombursting.Theoutletisahoselocatedatthetopofoneofthebarrelsthatalsocontainsscreentopreventmosquitoesorotherbugsfromentering.Inadditionthetopsofthebarrelsshouldhaveholeswithscreensoverthemcutouttorelievepressureinthebarrel.ThebarrelssitatopcinderblockssothatthePVCpipesinthemanifoldsystemhaveaccesstothebottomofthebarrels.Thiswaythebarrelcanfillfromthebottomupandallowsforthewatertobeevenlydistributed.Thepipesenteringthebottomofthebarrelshavetobeprettylong
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andgohighintothebarrelsothatthewaterthatcomesoutdoesnothavethesedimentthatsettlesatthebottom.
Thematerialofthebarrelistypicallyplasticbecauseitisthecheapest.However,theplasticneedstobeopaquesothatnosunlightcanpenetrateandallowforalgaetogrow.Thebarrelscanbemadeofmetal,butthisismoreexpensivethanplasticandtheplasticcanbeadjustedmoreeasily.ThebenefitsofamultiplesmallercontainersarethatitholdsmorewaterthanthesystemalreadyinplaceinGuatemala.Thewaterqualityisalotmorepureandthereisnoenergyuseincollectingordistributingofthewater.Thesystemiseasytouseandrequireslowmaintenance.Thepartsthatmakeupthesystemareallrelativelycheapandthesystemitselfdoesnotrequirealotoftimetosetup.Theconsofthisdesignarethatitisacomplexdesignandthatitisnotverydurable.Sincethebarrelsaretypicallyplasticitmeanstheyarelightweight.Ifnotenoughwaterisinthebarrelstoholdthemdown,weatherconditionslikestrongwindinstormscouldknockthemovereasilyordeterioratetheplasticexterior.
Figure4:DesignwithMultipleGallonTanks
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ThisPughChartbelowcomparestheonelargecisterndesignandmultiplesmallerbarrelstothesystemcurrentlyimplementedinGuatemala.
Table3:PughChartforPrototypeDesign
Criteria Datum:ExistingsysteminGuatemala(VeryLittleCollectionanda
WaterFilter)
Option1:OneLargeCistern
Option2:MultipleSmallerBarrels
Volume 0 ++ +
FlowRate 0 + +
PurityofWater 0 ++ +
Power-Needed 0 + +
EaseofCleaning 0 + 0
Cost 0 -- -
Simplicity 0 - --
EaseofUse 0 ++ +
Durability 0 + 0
Safety 0 + +
Maintenance 0 ++ +
Total 0 10 4
Sanitation
Anotherimportantfactorinthedesignofarainwatercollectionsystemissanitation.Inparticular,thedesignmusthavetheabilitytosanitizewatersothatitispotable.ThisrequirementwassetbyMayanFamilies,thepartneringorganizationinGuatemalathatisworkingwiththeengineeringteam.Thetwomosteffectivesystemstosanitizewaterfordrinkingistheuseofceramicfiltersorchlorinetablets.
Filtrationusingaceramicfilterfunctionsaccordingtoasimpleprinciple.Smallporesinthesolidsurfaceallowwatertoseepthrough,butleaveanythinglargerthan0.5micronstoaccumulateonthesurface.Mostceramicfiltersarecapableofremovingbacteriaandhavecauseduptoa70%reductionindiarrhealdiseasesincountrieslikeGuatemala(CDC2012).Additionally,thesedevicesaresimpletouseandareaonetimecost.ThePottersforPeacedesignshownbelowiscurrentlythemostwidelyusedceramicfilterandholds8-10Lofwater.
16
Figure5:PottersforPeaceCeramicFilter
Notabledrawbacksintheimplementationofceramicfiltersincludemaintenance,
ineffectivenesstowardviruses,andlackofchlorineresidualprotection.Thismeansthatthewaterhaspotentialtobecomerecontaminated.However,thisisaviableoptionforcleanwaterandshouldbeconsideredwhenresearchingrainwatercollectionsystems. Anotherhighlyeffectivemeasureusedinthepurificationofdrinkingwateristheuseofchlorinetablets.Chlorinetabletsactaspurifiersbydissolvingovertimeintothewater,killingoffharmfuldisease-causingorganisms,andpreventingagainstfuturecontamination.Chlorineinteractswithwatermoleculesandmicroorganisms,andtheotherchlorinemoleculesthatremainunboundareleftasresidualtoprovidecontinuousdisinfection(Oram2014). Therearemanypositivestochlorinesolutions.Chlorinetabletsarehighlyeffectiveinneutralizingmostpathogenicbacteriaandviruses,solutionsareverysmallandaffordable,andtheyhavetheabilitytocontinuedisinfectionlongafterinitialcontactwiththewater(CDC2014).Thispreventswaterfrombeingcontaminatedfromfactorssuchasdirtycontainersoranimals. However,therearealsomanydownsidesassociatedwiththechlorinetablets.Themostsignificantonesincludetheintroductionofaforeignodorandtasteintowater,limitedeffectivenessinneutralizingprotozoa,andintensequalitycontrolandregulationtoensureproperchlorinelevels(CDC2014).Overall,chlorinesolutionsareveryeffectiveinreducingproblematicissueslikediarrheaanddisease-causingbacteriaevenafterinitialintroductionthesolution,buttheireffectivenessisnottotalsincemanyprotozoaandsomevirusescanwithstandtheinjectionandtheyareassociatedwithnegativeimpactsonwatertaste.Akeytakeawayisthatthissolutionwouldbehighlyeffectivewhencoupledwithafiltrationdevicebutmaynotbecompletelydependableonitsown. Akeyexperimentthatwouldneedtobeconducted,asitcannotbequantified,istheimpactofchlorinetabletsonwatertaste.Anexperimentwouldbedevisedinwhichusersoftheproductwouldfirsttakeadrinkoftheirtypicalwatersourcewithoutthechlorinesolution.Theywouldthentakeadrinkofthewateraffectedbythechlorinetablet.Participantswouldthenbeaskedtorespondbydescribingthetasteofwaterbyusingoneofthefivefollowinganswers:“betterthancurrentwater,minimaldifferenceandwoulddrink,nodifference,minimaldifferencebutwouldnotdrink,worsethan
17
currentwater.”Thisdatawouldbecollectedinordertodeterminewhethertheuserswouldbeacceptingoftheadditionofchlorinetabletsintheirwater.
Figure6:TypicalChlorineTablet
ThefigurebelowisaPughChartthatcomparesthemethodsofsanitationofrainwaterinquestion.ThismethodallowstheteamtocomparethemethodsagainstthesamecriteriawithrelationshiptothecurrentmethodofsanitationinGuatemalanow.
Table4:SanitationPughChart
Criteria Datum: Generic
Filter Option 1: Chlorine
Tablet Option 2: Ceramic
Filter
Generic
Cost 0 - 0
Ease of Use 0 + 0
Size 0 0 0
Specific
Available 0 0 0
Taste of Water 0 - 0
Ease of Integration into
Design 0 0 +
Effective (measure turbidity of
water) 0 + +
TOTAL 0
0 2
18
Anotherfactorinneedofconsiderationisthemodeofimplementingsanitationdevices.Thesolutioncouldeitherbedirectlyintegratedintothewatercollectionsystemoritcouldbeacomponentthatrequiresadditionalstepstoperformpurification.Consideringthetwosanitationoptionsprovidedabove,ceramicfiltersandchlorinetablets,therearefouroptionstoconsider.
Thefirsttwooptionswouldinvolvetheceramicfilter.Theceramicfiltercouldbeattachedtothedownspoutbeforethewaterentersthestorageunit.Theotheroptionistohaveasysteminwhichwaterfromthestoragebasinispouredthroughaceramicfilterpriortouse.Therearestrongincentivesforimplementingthefilterrightintothedesigntolimitstepsandtoreducetimepervolumeofwaterfiltered.However,thisoptionmostlikelywouldnotbefeasibleduetothetimerequiredforwatertopassthroughthemembrane.Thisholdupwouldcreateoverflowandbackflowwhererainfallwouldnotbeabletoenterthestoragetankanddisruptthesystemoverall.Forsafetyanddurabilitypurposes,theceramicfilterwouldneedtobeusedseparately.
Inconsideringthechlorinetablets,thetabletscouldeitherbeplaceddirectlyinthecollectionbasinortheycouldbeplacedinaseparatecontainerinwhichwaterfromthecollectionbasinistransferredto.Thepositiveinplacingthetabletsdirectlyinthecollectiontankisthatwaterisimmediatelysanitizedatthesourceandpreventscontaminationlaterintheprocess.Additionally,fewerstepsarerequired.However,thismaynotbefeasibleduetofluctuatingvolumesofwaterinthecollectionunit.Regulatingchlorinelevelsisimperativeforhumanhealth,andthiscanonlybeaccomplishedifwaterlevelsarepredictable.Sincethevolumeofwaterinthecollectionunitarevariableandatthewillofrainfall,thisisnotviable.Rather,chlorinetabletsoughttobeusedinaseparatecontainerinwhichwaterlevelscanbepredictedandmeasuredeffectivelyatalltimesindependentofrainfall.Inconclusion,regardlessofthefiltrationsolutionselected,itisnecessarytoimplementitseparatefromthecollectionsystem.Table2belowshowstheresultsofthesecomparisons.
19
Table5:SanitationIntegrationPughChart
Criteria Datum IntegratedCeramic
SeparateCeramic
IntegratedChlorine
SeparateChlorine
General EaseofUse
0 + + + +
NumberofSteps
0 + - + -
TimeRequired
0 - 0 + 0
Safety 0 - + -- +
Durability 0 - + 0 +
Specific Longevity 0 0 0 + +
%Purified
0 + + + +
Total 0 0 3 3 4
Uponfurtherresearch,MayanFamiliesinformedthegroupthatusersoftherainwatercollectionsystemareprovidedwithSawyerwaterfilters.Additionally,MayanFamiliessuggestedthatuserswouldnotfeelcomfortableusingchlorinetabletsorchemicalsanitationmethods.Withthisinformationaswellasthevariableeffectivenessanddurabilityqualitiesoftheceramicfiltersinmind,itisproposedthattheSawyerwaterfiltersbedirectlyimplementedintothedesignoftherainwatercollectionsystem.Thiscouldbeaccomplishedbyattachingthecomponenttothecollectionbucketasanoutletspout.MovingForward
Thegroupdecidedtousetheflushsystembecauseitprovidescleanerwatertothecisterns.ThePughchartdiscussingtheflushsystemshowsthis.ThoughMayanFamiliesprovideswaterfilterstothefamilies,thefiltersoftenbreakduetointakeofturbid,dirtywater.ThecostofrepeatedlyreplacingthesefiltersastheydeteriorateislargeenoughtojustifytheincreaseininitialcostthattheextraPVCneededfortheflushsystemcause.
ThegroupchosetocontinuewiththemultiplecisternsbecauseitismorefeasibletodoinGuatemalathanonelargecistern.ManyfamiliesinGuatemalaalreadyhavebarrelsforcollectingwater,sothegroupdecideditwasbettertomakeasystemtoconnectthebarrelsalreadytherethantocreateanewlargerbarrel.
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Implementation Catchment
Theteamdecidedtouseflushsystemastheformofcatchmentsystemfortherecommendeddesign.TheteamrecommendsusingaguttermadeofPVConesideofthehousetocollectwaterfromtheroof.ThewaterwillthenbeconveyedthroughaslantedPVCpipeintoverticalflushpipes.Theflushpipeswillbeattachedtowoodenboardsthroughtheuseofmetalclamps.Theboardswillthembenailedtothehouseforsupport.Waterfromtheinitialrainfallwillfallintothefirstpipeuntilitisfull.Itwillthenfallintothefollowingpipes,fillingeachinorder.Whenallofthepipesarefull,thewaterwillbeconveyedintothestoragecistern.ThenumberofflushpipesusedwillbedependentonthesizeoftheroofandthesizeofthePVCpipesused.ThePVCpipeswillbeconnectedtooneanotherthroughtheuseofPVCglueandPVCconnectors.
Thematerialsfortheflushsystemandguttersinclude:approximately120inchesof3”SCH40PVCtobeusedfortheguttersandtheflushpipes,PVCendcapstobeusedattheendsoftheguttersandpipes,2’’SCH40PVCpipetobeusedatthetopofeachflushpipetostopthetennisball,tennisballsfortheflushpipes,3to2inchPVCconnectors,90degree3”PVCconnectors,PVCYconnectors,2’’x4’’woodboardand4’’metalclampringstoconnecttheflushsystemtothehouse,andconcretescrewsandjackets.CommonequipmentusedwillincludeasawtocutthePVCpipes,adrilltoconnectthepipestothehome,screwdrivers,andPVCglue.ResultsfromFlushExperimentation
ThegroupperformedtestsatOhioStatetoensurethatitwasfeasibletobuildaworkingprototypeonceinGuatemala.ThegroupmemberspracticedcuttingPVC,bothlengthwiseandwidthwise,withdifferentsawstolearnwhichsawwouldbethebesttouse.Thegroupdecidedthatusingamiterboxsawwouldbethebestforcuttingthepvc,becauseitisrigidenoughtohelpensurestraightcuts.ThegroupalsodevelopedthetechniqueforcuttingthePVClengthwise.ThegroupdecidedthatonehalfofthePVCshouldbecutatatime.Also,afterthePVCstartstogetacutgoingdownthemiddle,thecutshouldbewedgedopentorelievestress.Fromtheseexperiments,thegroupdecidedthattitisperfectlyfeasibletobuildafunctioningprototypewhileinGuatemala.Storage
Forthestoragecomponentoftherecommendeddesign,theteamwentwithamultiplecisternstylestorage.Specifically,theteamrecommendsathreebarrelsystemusinggravitytotransportthewaterbetweenbarrels.Thebarrelsareverticallysupportedbytwobyfours,stackedontopofeachothertominimizespaceconsumption.Theflushsystemwilldepositthewaterintotheinitialbin,whichfeedsallthewaytothebottombarrelthroughconnectingpipes.Fromthere,variousfilterscanbeconnectedtoanyofthebarrels,specificallyMayanFamiliesrecommendsSawyerfilters,whichwillbediscussedfurtherbelow.
21
Figure:MultipleCisternStyleStorageSketch
Thematerialsneededforthismultiplecisternstoragesystemincludethreelargebarrelsofthe
samesize,multiplepiecesoftwobyfoursthatcanbeusedassupportstructures,screwstoconnectthesupportstructuretothebarrels,PVCprimerandglue,aswellastwoconnectionpipes,madeoutofcurvedPVCfittings.ThetoolsneededtobuildthisstructureincludeaPVCcuttingsaw,asaworbladetocutthebarrels,andascrewdriverorpowertool.Mostofthesetoolscoincidewiththetoolsneededtobuildtheflushsystem.Sanitation
Theteamwaslookingatincludingafilterwithintherainharvestingsystems.UponcommunicationwithMayanFamilies,theteamwasinformedthatSawyerFiltersareprovidedtoeachfamily.ThespecificproductMayanFamiliesuseisthe‘WaterPurifierBucketAdapterKit.’Thiskitincludesahole-cutter,SawyerPointZeroTwo0.02MicronAbsoluteInclineWaterPurifier,adapter,hose,filtercleaner,andfilterhanger.Thebenefitofthispurifieristhatitcanprovideupto170gallonsofcleanwaterperday.Thesetupofthiswaterfilterisveryeasy.Acleanbucketorplasticcontainerneedstobeobtainedandthentheuserusesthehole-cuttertodrillahole1.5inchesfromthebottomofthecontainer.Thehoseandfiltercanbeconnectedtothecontainerbyplacingtheconnectorontheinsidewhilethefilterandhoseareontheoutsideandscrewingthemtogether.Whenthecontainerisfilledwithwater,thefilterjusthastobebelowthewaterlineandgravitywillfeedthewaterthroughthefilterandoutthehoseforuse.Thisrequiresthecontainerofwatertobeonanelevatedsurfacesothatthefiltercanhang.Iftheuserdoesnotwanttoextractanywater,theysimplyhavetohangthefilterabovethewaterlinetopreventanywaterfromcomingout.Thisfiltercanbeimplementedintothemultiplecisternstoragebydrillingaholeintooneofthebarrelsusingtheholecutterprovided.Thehoseandfiltercanthenbeattachedandpurewatercanbeextractedfromthebarrelsafterrainwateriscollected.Thecombinationoftheflushsystemandthefilterwillensureforverycleanwaterthatissafeandsanitarytouseforactivitiessuchascleaninganddrinking.
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Conclusion QuickSummaryofProcess
Overthecourseofthepastthreemonths,thegrouphasengagedinresearchonthecurrentsituationandsolutions,brainstormingpotentialideas,andevaluatingtheoptionsbasedontheircapacitiestomeetspecificneedsinordertoproposearecommendedsolutionforarainwatercollectionsystemtobeusedbyMayanFamiliesinGuatemala.Thegroupbroughtupsolutionsforcatchmentsystemsthatincludedusageofstandalone,regulargutter,andPVCpipingsystems.Storagesolutionsthatevaluatedtheusageofsingle-cisternversusmulti-cisternsystemsaswellasthematerialsforthecontainerswereconsidered.Lastly,sanitationsystemsintheformofceramicfilters,chlorinetablets,andSawyerwaterfiltersprovidedbyMayanFamilies.Completesystemideasweresynthesizedfromthesecomponentsafterindividualevaluation,andaflushsystemusingamulti-barrelstoragedevicewithanintegratedSawyerwaterfilterisproposed.ExplanationofFinalDecision
Multiplereasonsledtothedecisionoftheteamtousetheflushsystem.Theinitialrainfallcollectedbyarainwatercollectionsystemneedstobedivertedfromstoragebecauseitcontainsallofthepollutantsthataccumulateonthecollectionsurface.Theflushsystemisthemostsimpleandinexpensivewaytodivertrainfallwithoutmanuallabor.Thisleadstoimprovedwaterqualitywhencomparedtoaconveyancesystemwithoutflushes.Inaddition,theflushsystemstillusestheroofasthecatchmentarea.Thisfeatureisthemostreasonablewaytocollectwaterandbestimplementswhatisalreadypresentincountry.Lastly,theteamdecidedtomoveforwardwithmultiplecisternstylestorageformultiplereasons.Forone,itisaneffectivesolutiontotheproblemathand.Barrelsareareadilyavailableresourceincountry.Currently,thatiswhatisinusebythevillagersfortheirathomecollection.Theteamanalyzedthatthiswasamuchmorefeasibleoptioncomparedtobuildingalargesinglecistern.Additionally,thissystemcanactasanadditionalflushsystem.Thecleanestwaterwillbeattheuppermostbarrelwhiletheinitiallycollectedwater,aswellassediment,willsettletothebottombarrell.Thiswillallowtheusertochoosetousethebottombarrelasnondrinkingwaterandthetoptwoasfilterconnections,ifdesired.Thissystemiseasytobuildandusesinexpensiveyetdurablematerials.FutureworkneededtocompleteProject
Havingthedesigninmind,thenextstepistoimplementthesystemincountry.ItemswillbepurchasedintheUSpriortotraveling,andthenthesystemwillbereplicatedinGuatemalaafterdeterminingwhichproductsareavailableincountry.Measuringthedimensionsofthehomeroofsystemtobeusedforinstallationwillprovidethedatanecessaryindeterminingflushsystemspecifics.Inparticular,surfaceareaoftheroofwillprovidethemeansforcalculatingvolumerequiredthroughPVCpipeinstallationinordertosuccessfullyutilizetheflushfiltrationsystemoperations.Thesystemwillbeinstalledandevaluatedbasedonperformancecriteriasuchaspercentageofrainfallcollectedandcleanlinessofthewater.Thesystemwillalsobeevaluatedbasedonuserpreferences.
23
AppendixA:WorksCited
AllianzRiskConsulting.RoofDrainageSystems.Rep.Vol.9.N.p.:AllianzGlobalCorporate&Specialty,
2012.Print.
Baguma,David,SyedAljunid,JamalHashim,HelmutJung,andLoiskandlWillibald."Rainwaterand
HealthinDevelopingCountries:ACaseStudyonUganda."UnitedNationsUniversity.United
NationsUniversity,11Oct.2012.Web.28Feb.2017.
"CountryHistoricalClimate-Guatemala."ClimateChangeKnowledgePortal.TheWorldBankGroup,
n.d.Web.28Feb.2017.
EILIreland."RainwaterHarvestingGuatemala."YouTube.YouTube,01Nov.2011.Web.28Feb.2017
"GuatemalaRainHarvestandWaterDistributionProject-EngineersWithoutBorders."GoogleSites.
N.p.,n.d.Web.28Feb.2017
"LakeAtitlanIsinCrisis."LakeAtitlanHealthCyanobacteriaResource.N.p.,21Aug.2015.Web.28Feb.
2017.
Morgan,Peter.RainWaterHarvestingintheHomeStead.Rep.N.p.:Aquamor:Researchand
Development,2015.Print.
Oram,PGMr.Brian."ChlorinationofDrinkingWater."WaterResearchCenter.WaterResearchCenter,
2014.Web.29Mar.2017.
Pushard,Doug."RainwaterPumpsorPressureTanks."RainwaterPumpsorPressureTanks.
HarvestH2O,2016.Web.25Feb.2017.
24
"RoofDrainageSystems."TechTalk9(2012):n.pag.AllianzGlobalCorporate&Specialty,July
2012.Web.28Feb.2017.
"SafeWaterSystem."CentersforDiseaseControlandPrevention.CentersforDiseaseControland
Prevention,23Apr.2014.Web.29Mar.2017.
"WHO/UNICEFJointMonitoringProgramme:Documents."WHO/UNICEFJointMonitoring
Programme(JMP)forWaterSupplyandSanitation.N.p.,n.d.Web.28Feb.2017.
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AppendixB:SampleCalculations
CatchmentArea(meters^2)ofroof:
VolumeofFirstFlush(Liters):
HarvestedWater(gallons)basedonrainfallandroofsize:
WaterCollected(gallons)=(CatchmentArea(ft^2))*(Rainfall(in))*(0.623)
26
AppendixC:TeamSchedule
PrototypeSchedule April
Day 4 5 6 7 8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
6
1
7
1
8
1
9
CreatePartsList
Researchpartpricesatdifferent
hardwarestores
SubmitpartslisttoRachelandhave
approved
Gotohardwarestoreandbuyparts
Buildgutter
Buildflushpipes
Attachguttertoflushpipes
Attachflushpipestostoragetanks
Troubleshoot