SpringBoxDesignandConstruction

CE5993

Acknowledgment:Acknowledgment:LaurenFry

Civil & Environmental EngineeringCivil&EnvironmentalEngineeringMichiganTechnologicalUniversity

Unprotected SpringUnprotectedSpring

Figure1.UnprotectedspringinthevillageofBilikBikot,Cameroon.Beforei f h i b h i ll d ll i hiconstructionofthespringbox,thespringwaterwasallowedtocollectinthis

openpool.Waterstagnated,peoplewereabletodipdirtybucketsinthepool,andthespringwasamosquitobreedingarea.

WaterRelatedDiseases

(Cairncross andFeachem,1993)

Choosing a SpringChoosingaSpring

Why people choose a specific source:Whypeoplechooseaspecificsource: Waterlookscleanerandtastesbetter. Itiscloserthanothersources. Theflowisconstantandsufficient.

Other considerations:Otherconsiderations: Actualwaterquality(bacteriafree?Taste,odor) Abilityforwatertodrainy Reliabilitythroughdryseason Accessibilityy

Preparation of the SpringPreparationoftheSpring

Atypicalarrangementofanunimprovedspring.Toprepareforspringboxconstruction,theimpermeablelayerofsandorsoilshouldberemovedatthespringpool,downtotheimpermeablelayer.

Spring Box Design: Profile ViewSpringBoxDesign:ProfileView

(Filtermaybeomittedfromdesign.)

Spring Box Design: Plan ViewSpringBoxDesign:PlanView

(Filtermaybeomittedfromdesign.)

Slow Sand FiltrationSlowSandFiltration

Foraslowsandfiltertofunction,thesandshouldhaveaneffectivegrainsizeof0.15to0.30mmanduniformitycoefficient(D60/D10)lessthan5. D60isthesievesizethatallows60%ofthesandtopassand

D10 i th i i th t ll 10% tD10isthesievesizethatallows10%topass. Minimumheightofthesandlayershouldbe0.5m,andthe

rateoffiltrationshouldbenofasterthan0.1to0.23/ 2/h (Vi h t l 1987)m3/m2/h(Visscher etal,1987).

Forafiltrationrateof0.1m/hthroughacleanfilter,theminimumheadoverthefilteris5cm(Tchobanoglous andB t 2003)Burton,2003).

Evenwithasmallspringoutputlike1.7L/min,thesurfaceareaofthefiltermuststillbeatleast1.0m2.

Rapid Sand FiltrationRapidSandFiltration

Filter may be omitted to save money or as aFiltermaybeomittedtosavemoney,orasacompromise,rapidsandfiltrationmaybeusedused.

Forrapidfiltration,verycoarsesandorsmallgravel is usedgravelisused.

Inthiscasethefilterisdesignedtobei l 0 5 l b 1 5 id b 1approximately0.5mlongby1.5mwideby1

mhigh,withfiltermediaheightof0.4m.

ReservoirReservoir Thereservoirshouldbesizedbasedontheoutputofth i d t i i th t f tthesourceinordertomaximizetheamountofwaterthatisstoredovernight. Forexample,ifaspringhasamaximumoutputof6L/min,p , p g p / ,

assumingthatnoonedrawswaterbetween6:30pmand5:30am(11hoursoffilling),thereservoirsizewouldbe3.96m3.

Size may be restricted by available materials and funds, however.Sizemayberestrictedbyavailablematerialsandfunds,however. Reservoirwallsaremadeofsteelreinforcedconcrete. Floorshouldbeslopedandmadewithsmoothedconcrete.

Allsurfacesinsidethereservoirshouldbesmoothedt ll f i l itoallowforeasiercleaning.

Typical Construction BudgetTypicalConstructionBudget

Typical Construction BudgetTypicalConstructionBudget

Typical Maintenance ScheduleTypicalMaintenanceSchedule

Itisveryimportantthatthecommunityandmanagementcommitteearey p y geducatedandtrainedontheimportanceofmaintenancesotheprojectissustainableinthelongterm.

Measuring Spring DischargeMeasuringSpringDischarge

Weirusedtodeterminetheoutputofthesprings.Awelderwashired to produce this weir from a flat piece of metal roofing materialhiredtoproducethisweirfromaflatpieceofmetalroofingmaterial.Allyieldandheadmarkingswerealsoengravedonthemetal(MannandWilliamson,1973).

ConstructionConstruction

(Filtersizelimitedbymaterials.)

Typical Construction ScheduleTypicalConstructionSchedule

Completed SpringboxCompletedSpringbox

Completed SpringboxCompletedSpringbox

Overflowpipebendsdowntopreventchildrenfrombreakingit.

Common Construction ProblemsCommonConstructionProblems Accidentallydiggingthroughtheimpermeablelayermaycause

water to be lost from the springwatertobelostfromthespring. Whenfillingthewoodenformswithconcrete,unevenpressuremay

causethewallstograduallytiltduringplacement. When filling the primary filtration and capture area there is a Whenfillingtheprimaryfiltrationandcapturearea,thereisa

possibilityforblockingtheveinsaugmentingthespring.Besurethattheveinsarenotblockedbymud.C i th i filt ti d t ith th ft it Coveringtheprimaryfiltrationandcaptureareawithearthafteritisfilledwithrocksmaybeappropriateinsomeplaces,butwheresoilisveryfine,theearthmayendupfilteringthroughtherocksd bl k h l l h handblockingthegravellayerentrance.Inthiscase,theprimary

filtrationandcaptureareacanbefilledwithrocksandcoveredwithaplastictarporotherimpermeablematerialbeforecoveringwithearth.

ReferencesReferences Cairncross, S., and R.G. Feachem. Environmental Health Engineering in the Tropics: an

Introductory Text, Second Edition. Chichester: John Wiley and Sons, 1993. Fry, L. "Spring Improvement as a Tool for Prevention of Water-Related Illness in Four

Villages of the Center Province of Cameroon," M.S. Report, Civil & Environmental Engineering, Michigan Technological University, 137 pages, 2004.

Fry, L., J.R. Mihelcic, D.W. Watkins, Improving public health by improving water supply: y, , , , p g p y p g pp yresults from springbox projects in Cameroon. Journal of Engineering for Sustainable Development: Energy, Environment, Health, 2006.

Huisman L., De Azevedo Netto J.M., Sundaresan B.B., Lanoix J.N., and Hofkes E.H. SmallCommunity Water Supplies: Technology of Small Water Supply Systems in DevelopingCommunity Water Supplies: Technology of Small Water Supply Systems in DevelopingCountries. IRC Technical Paper Series #18. The Hague, The Netherlands: IRC InternationalWater and Sanitation Centre, 1981.

Tchobanoglous, G. and F. L. Burton. Wastewater Engineering: Treatment and Reuse. Metcalf& Eddy Boston: McGraw Hill 2003& Eddy. Boston: McGraw Hill, 2003.

Visscher J.T., Paramasiram R., Raman A., and Heijnen H.A. Slow Sand Filtration forCommunity Water Supply: planning, design, construction, operation, and maintenance.Technical Paper Series #24. The Hague, The Netherlands: IRC International Water andS i i C 1987Sanitation Centre, 1987.