WaterResearch36(2002)3023–3028 Regrowthandsurvivalofindicatormicroorganismsonthe surfacesofhouseholdcontainersusedforthestorageof drinkingwaterinruralcommunitiesofSouthAfrica MaggyN.B.Momba*,P.Kaleni Department of Biochemistry and Microbiology, University of Fort Hare, P/Bag x1314, Alice 5700, South Africa Received12March2001;receivedinrevisedform10October2001;accepted20December2001 Abstract ThepresentstudycoveredtworuralcommunitiesofSouthAfrica:NceraandNtselamanzivillages.Rawwaterfrom NcerariverisusedbythecommunityofNceravillagefordrinking,whilethecommunityofNtselamanzireceivestheir drinking water from Alice purification system. Treated water is supplied to the community by a public standpipe system. In rural communities of South Africa, many households use polyethylene (PE) and galvanized steel (GS) containersforthestorageoftheirdrinkingwater.Toinvestigatetheregrowthandsurvivalofindicatormicroorganisms onthesurfaceofhouseholdcontainersduringthestorageofdrinkingwater,PEandGSslidesweresuspendedinthe appropriate household containers for a period of 48h. This period of 48h was chosen as the study period because resultsfromthequestionnaireindicatedthatthelargestpercentage(62%)ofhouseholdsstoretheirwaterforthatlength oftime.Theexperimentwasperformedtotestdrinkingwaterasitiscollectedandstoredbyruralcommunities.No disinfectionofhouseholdcontainersorslideswasdoneduringthestudyperiod.Attachedcoliphages(F-RNA(FP)and somatic phage (SP), coliform bacteria (total coliform (TC), presumptive Escherichia coli (EC), Salmonella (Sal) and Clostridium perfringens (CP) were measured during the study period. With the exception of CP, attached indicator microorganisms consisted of TC, presumptive E. coli and Salmonella,somaticandF-RNAcoliphages,althoughthe yield(averagecount)forthelastfourgroups(EC: o1–3cfucm 2 ,Sal: o1–15cfucm 2 ,FP: o1–7pfucm 2 ,SP:o1– 7pfucm 2 )waslowerthanthatofTC(3–183cfucm 2 ).However,thelowestyieldofindicatormicroorganismswas noted for presumptive E. coli. Whereas the occurrence and survival of TC was noted on the surface of household containersduringtheentireperiodoftheexperimentalstudy,otherindicatormicroorganismsoccurredfromtimeto time.Theregrowthofindicatormicroorganismsoccurred48haftertheexposureofslidestobothtypesoftestwaters. ThislengthoftimemostlyresultedintheregrowthofTC(withanincreaseinbacterialcounts)whilethepersistenceof other indicator organism groups on the surface of the slides was apparent. A comparison between PE and GS containersshowedthatmoreTC(averagecount)regrewonPEthanonGScontainers(forriverwater,PE:from36to 55cfucm 2 ,GS:from25to26cfucm 2 ;forstandpipewater,PE:from147to183cfucm 2 ,GSfrom3to4cfucm 2 ). This study revealed that both types of household containers supported the growth and survival of indicator microorganismsduetothebadqualityoftheintakewaterbeforestorage.Thestorageofdrinkingwaterfor48hmainly resultedintheregrowthofTC.Nevertheless,thepersistenceofotherindicatormicroorganismswasobservedonthe surfaceofhouseholdcontainers. r 2002ElsevierScienceLtd.Allrightsreserved. Keywords: Regrowth;Survival;Indicatormicroorganisms;Householdcontainers;Drinkingwater *Correspondingauthor.Tel.:+27-40-60-22173;fax:+27-40-65-31-669. E-mail address: mmomba@ufh.ac.za(M.N.B.Momba). 0043-1354/02/$-seefrontmatter r 2002ElsevierScienceLtd.Allrightsreserved. PII:S0043-1354(02)00011-8