RussellAvenueSlipTechnicalReport

PreparedbyJennyC.Fisher,CourtneyL.Winter,SandraL.McLellan

SchoolofFreshwaterSciencesUniversityofWisconsin-Milwaukee

Summary:TheMcLellanlabhasmonitoredthepresenceandabundanceoffecalindicatorbacteria(FIB)andhumanfecalbacteriaintheRussellAvenueslipsince2008.Thecombinedseweroverflow(CSO)outfallthatdischargesintotheslipmaybeasourceofsewageundernon-CSOconditions.ThesourceofhumanindicatorsdetectedneartheRussellAvenueslipwasinvestigated.Fieldvisitsweredonetotrackthestormwaterandsanitarypipesthatwereinproximityoftheslip.PreviousdatawasexaminedtoidentifypatternsofhumanfecalbacterianeartheRussellAvenueslipandtheirrelationshiptorainfallandlakeconditions.SamplingwasconductedalongatransectfromtheRussellAvenuesliptoSouthShorebeach,withintensivesamplingperformedduring2014-2015bathingseasons.ThesedatawereanalyzedtodetermineiftheRussellAvenueCSOoutfallisasourceoffecalbacteriatothebeach.TheslipisdefinitelyasourceofhumanfecalbacteriatothebeachunderCSOconditions.However,althoughsporadichighlevelsofhumanmarkerswereobservedintheslipundernon-CSOconditions,acorrespondingelevationofhumanmarkerswasnotnecessarilyseenattheYachtClubsamplelocationoreithertheexistingorproposedbeachlocations.Lowlevelsofhumanindicators(nearthelimitofmethoddetection)wereoftenpresentattheexistingbeachlocationwhennohumanmarkerswereobservedintheslip.Thus,aminorsourceofhumanfecalinputsstillneedstobeidentified.Introduction:ThepresenceofthehumanindicatorsBacteroidales(HB)andLachnospiraceae(Lachno2)hasbeenusedasevidenceofhumanfecalcontamination.SouthShoreBeachandtheRussellAvenue(RA)slipsamplingsiteshaveahistoryofhumanindicatorspresentduringnotonlyCombinedSewerOverflow(CSO)events,butduringrainandbaselineconditionsaswell.Determiningthesourceofthehumanindicatorsisachallengebecausethereisnoclearspatialortemporalpatternpointingtoaspecificlocationoforiginationorsetofinfluentialconditions.Ourinvestigationattemptedtoanswerthefollowingquestions:1)whatarethepotentialcontributorsofhumanfecalpollutiontotheRAslip?2)istheRACSOoutfallacontinuousorvariablesourceofsewagetotheenvironment,andwhatfactorsdrivethesefluxes?3)istheRACSOoutfallthesourceofthehumanfecalbacteriafoundatSouthShoreBeach?and4)whatareotherpossiblesourcesofhumanfecalcontaminationatSSBeach?TheRAsliphasacombinedseweroverflow(CSO)outfalllocatedonthesouthwall.Humanindicatorshavebeendetecteddirectlyattheoutfall’sopeninginthesurfacewaterandatthemouthoftheslip.(Samplesdesignated“RUSSAVE50”arecollectedintheslipdirectlyinfrontoftheCSOoutfall,eitheratthesurfaceorslightlysubmerged;“RUSSAVE100”samplesarecollectedattheveryendoftheslipwhereLakeMichiganwatermixesin.)However,thepresenceofhumanindicatorsisvariableoverbothshortandlongtimescales,anditisunclearwhetherornottheRAslipisasourceofcontaminationtothesamplesitesadjacenttotheyachtclubandSouthShorebeach.Anumberofotherpotentialsourcesofhumanfecalcontaminationarelocatedinproximity:amarinalocatedbetweentheRAslipandextendstojustsouthofSouthShoreBeachandfilledwithdockedwatercraftsduringthesummer;ayachtclubwithrestroomfacilities;anoutfalllocatedtothesouthatBayViewParkthathasalsobeenfoundtohaveasewagesignal;dailyeffluentfromtheJonesIslandWRF;andSouthShorePavilion,whichwasoriginallyconstructedover80yearsagoandmayhavefailinglateralsorsewerconnections.TheRAslipislocateddownhillfromapark,wheretherearepavedparkinglots,residentialhousingandapartmentcomplexes.Multiplesourcescouldcontributetothehumanfecalcontaminationthatisultimatelydetectedatthebeach.IfasewagesourcetotheRAslipcanbeidentified,investigationsintowhetheritisaconstantsourceorifspecificconditionssuchasweatherorlakelevelconditionsaffectthesesources,shouldbepursued.

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TheMcLellanLabhastwosamplesiteslocatedbytheoutfallintheRAslip,aswellastwoalongtheshorelinebytheSouthShoreYachtClub,threeatSouthShoreBeachandthreeatapreviouslyproposed“newbeach”(alsocalled“RockyBeach”),locatedapproximately150mfurthersouth(Figure1).SouthShorebeachexperiencesasignificantnumberofwarningsandclosuresduetoelevatedlevelsofEscherichiacoli(E.coli)eachsummerduringthebathingseason,withthecurrentlocationofthebeachtypicallyhavingsignificantlyhigherlevelsthanattheproposedlocationforanewbeachtothesouth(Figure2).BoxesinFigure2showthequartileranges(25-75%)forE.coliCFU/100mLforthetwobeachesfromthe2013-2015bathingseasonsunderbaseline(norain),lightrain,andheavyrainconditions.Onaverage,araineventresultsinE.coliconcentrationsexceedingtherecreationalwaterqualitystandardof235CFU/100attheexistinglocation,butnotattheproposedsite.NotethatCSOeventswereexcludedfromthisdataset.

Infallof2015,weconductedaseriesoffieldinvestigationstoidentifythesourceofthehumanfecalbacteriaanddetermineifweatherorlakeconditionsaffecttheconcentrationsofthesebacteria.SincehumanindicatorshavebeendetectedpreviouslyneartheRAoutfall,onesourceofhumanfecalindicatorbacteria(HFIB)maybecomingfromstormwaterconnectionstotheoutfall.Investigationsweredonetointensivelyexaminethesewerinfrastructureinproximityoftheslip.Comparisonsbetweenrainfallandlakelevelsoverthespanofsamplecollectiondateswereusedtoidentifyifanycorrelationsexist.MilwaukeeMetropolitanSewerageDistrict(MMSD)facilitatedtrackingnumeroussanitaryandstormwaterpipeslocatedintheareaabovetheRAslip(seeFigure3).Watercollectionbybothgrabsamplesandanautomatedsamplerwereusedtodetermineifhumanindicatorswerepresentandatwhatconcentration.

Figure2.E.coliconcentrationsatSouthShorebeachfortheexistingandproposedlocationsunderdifferentweatherconditions(2013-2015).

Russell Ave-Yacht Club-South Shore Beach Sampling Transect

SSYC1

SS “old”

SS “new”

RUSSAVE50

RUSSAVE100

SSYC2

O1

O3O2

N1

N3N2

Figure1.MapofRussellAveSlip,YachtClub,andSouthShoreBeachsamplingsites

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PotentialContributorsofHFIBtotheRussellAvenueSlipWiththeassistanceofMMSD,weexploredtheflowinsanitaryandstormwatersewerpipesneartheRASlip,thestructureoftheNearSurfaceCollector(NSC)anditsconnectiontotheCSOoutfall,anadditionaloutfallintheslipacrossfromtheCSOoutfall,andpotentialconnectionstotheoldKKRiverFlushingtunnelatthewestendoftheslip.

Stormwaterandsanitarysewerflows.ThefirstaccesspointtothestormwatersystemisamanholeonthecornerofEastOntarioStreetandSouthShoreDriveasshowninFigure3.Here,thereisa15”stormwaterpipethatdischargesintotheoutfallstructurebelowthegateforthenearsurfacecollector.Duringtheinitialvisit,themanholeatthefirstaccesspointwasopenedtoidentifypipesleadinguptothissiteanddeterminethedirectionfromwhichtheyarecoming.Onepipe,originatingfromthenorthonSouthShoreDrive,drainstothissite.Apipecomingfromthewesthadbeen

bulkheaded(blockedwithcement),aswellasanotherbulkheadedpipefromthenortheastthatwasfromcurbsidecatchbasins.MMSDinstalledanautomatedsampleratthislocationonOctober21,2015andcollectedwaterduringraineventsonOctober28,2015andNovember6,2015.

MMSDaidedinasecondinvestigationonDecember7,2015thatexaminedthe24”sanitarysewerpipeadjacenttothe15”stormwaterpipethathousedthesampleratsiteSLM05A.ThissanitarysewerpipeservesalargeapartmentcomplexonthecornerofSouthShoreDriveandLincolnMemorialDrive.

DuringthisvisititwasconfirmedthatthesanitarypipefromtheapartmentbuildingflowsnorthintoanothersanitarypiperunningwestalongLincolnMemorialDrive,paralleltotheCSOsystem,andshowednoconnectiontothestormwaterpipes.SevenothernearbymanholeswereinvestigatedaspotentialsourcesofhumanfecalcontaminationtotheRAoutfall,butwereeliminatedduetoeitherlackofflow,orflowinthewrongdirection.

Dyetestingwasperformedonaterminalmanhole(likelythefirstinthelineofthestormwatersystem,oranoverflow?)attheintersectionofRussellAve.andLincolnMemorialAve.,locatedin

thegrassdirectlyabovetheKKFlushingTunnel;butnodyewasobservedintheslip,andwaterflowedwestintotheCSOsystem.Avisualinspectionofthismanholewasperformedwithasubmersiblecamera(Dec8,2015)andprovidedevidencethattherewasnoconnectionoropeningtotheeast.

NearSurfaceCollector.AninitialexaminationoftheNSCprovidedvisualizationofthesystemcomponents,includingthegateleadingtotheCSOoutfall.Standingwaterwasvisibleonbothsidesofthechamber--fromlakewaterintrusionontheoutfallside,andpresumablystormwater-sanitarysewageonthecollectorside.ThegateoftheRussellAvenueCSOfromtheNSCshouldremainclosedunlessthereisaCSOeventinwhichtheinlinestoragesystem(“deeptunnel”)reachescapacity.MMSDrecordsshowthattheRACSOoutfalldischargedfivetimesfrom2011-2015:6/21/11(1MG),4/10/13(1MG),4/18/13(1MG),6/18/14(0.5MG),and4/10/15(1MG).Residualcombinedsewage/stormwaterinthetunnelbetweentheNSCandCSOoutfallmaythereforebearesidualsourceofhumanindicatorsthatwouldbeexpectedtodecreasewithtimefromthemostrecentCSOandcouldbedrivenbylocalseicheandchangesinlakelevels.

RASlipStormwaterOutfall.WeinvestigatedanadditionaloutfallonthenorthsideoftheRAslipasanotherpotentialsourceofsewagecontamination.WetrackedthepipesleadingtothisoutfallwiththeMMSDfieldcrew,andfoundthattheoutfalldrainsaverylimitedareaincludingtwoparkinglotstothenorth.BasedonMMSDmapsandfield

Figure3.OntarioStreetandS.ShoreStreetmanholes,includinglocationofinlinesampler(SLM05A).Imagesource:MilwaukeeMetropolitanSewerageDistrict

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observations,onlystormwaterlinesconnecttothisoutfall.OnesamplecollectedfromthatoutfallinAug.2015revealedhighFIBconcentrationsbutnohumanfecalindicators.

KKFlushingTunnel.TheKKFlushingTunnel,locatedatthewesternendoftheRAslip,formerlyservedtotransportLakeMichiganwatertoanupstreamlocationoftheKKRiverinordertodisplacedirtywaterandsewagethatwouldstagnatethereduringperiodsoflowflow.Assuch,thetunnelshouldbefilledwithlakewaterandshouldnotbeasourceoffecalpollutiontotheslip.However,decreasinglakelevelscouldresultinaneffluxofwaterfromthetunnelalongareducedpressuregradient,potentiallycontaminatingtheslipwithanyfecalbacteriathatwereintroducedtothetunnelupstream.Thisscenariohasalowlikelihoodofoccurrence,butwasexaminedtoeliminateallpossiblesources.Autilitymanholethatprovidedaccesstotheflushingtunnelwasobserveddirectlyabovetheflushingtunnel,atthebottomofahill~10mbelowtheterminalstormwateroutfallonRussellAveandLincolnMemorialdescribedabove.Themanholewasboltedtopreventopening,likelyduetotheprobabilityofsurchargefromthatmanholeduringhighlakelevels.

ContributionsfromUpstreamSources(SamplingandAnalysisResults)

InlinesamplingupstreamofRAoutfall.Duringthetimeframethattheautomatedsamplerwassetup,tworaineventsoccurredthattriggeredcollectionfromsamplingsiteSLM05A.Followinga0.53”raineventonOctober27th,and0.34”ofrainonOctober28th,thefirstsetofinlinesampleswerecollectedonOctober28.Thesecondcollectiondate(November6,2015)occurredafter0.24”ofrain.Theautomatedsamplercollectedtwosamplesoneachdate,oneaftertheinitialrainfall(“firstflush”),labeledSLM05A01,followedbyasecondcollectionashorttimelater,SLM05A02(Figure4andTable1).

Sampleswerecollectedfromallthreesites(SLM05A,RUSSAVE50andRUSSAVE100)onOctober28th,2015.ThelattertwowerecollectedasgrabsamplesbytheMcLellanlab.OnlyinlinesampleswerecollectedonNov6.The“firstflush”fromSLM05Ashowedhigheramountsoffecalcontaminationduringbothrainevents,whichwouldbeexpectedasthatcontainsanyremnantsoffecalmatterthatmayhavebeensittingwithinthepipes.ThewatersamplescollectedfromEastOntarioStreetandSouthShoreDrive,atsamplesiteSLM05A,hadhighconcentrationsoftheHBmarkerpresentandverylow(limitofdetection)concentrationsofLachno2.Webelievethatthistypeofmismatchinhumanindicatorsistypicallyduetoraccoonwaste.OnOctober28,thesamplesiteRUSSAVE50,whichisrightoutsidetheCSOoutfall,hadnodetectablehumanindicators.SamplesiteRUSSAVE100,attheendoftheslip,hadonlylowlevels(atthelimitofdetection)oftheHBmarker(Table1).Duringthesecondfieldvisit,raccoonstoolwasfoundinastormwaterpipejustupstreamofwheretheautomatedsamplerwasinstalled.ThusitislikelythatthisfecalmaterialcontributedtothepositiveHBbutnegativeLachno2results.RaccoonwastewouldnotexplaintheresultsonNovember6,2015andintheRAslipsincebothmarkersweredetectedatsimilarlevels.

Figure4.HumanindicatormarkerdensitiesinA)stormwater(inlinesampling)andRAslip,Oct.28andB)stormwater,Nov6.

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Table1.HumanindicatorresultsfromRussellAvenueslipandSLM05AsamplesitesonOct28andNov6samplingdates.

SamplingSites

HB Lachno2

October28,2015

SLM05A01 9280 225SLM05A02 740 0RUSSAVE50 0 0RUSSAVE100 225 0

November6,2015 SLM05A01 405 624SLM05A02 BLD 0

NearSurfaceCollector.WaterwascollectedfromtheNSConDecember7,2015andanalyzedonlyforE.coli,enterococcus,andfecalcoliformsbyplatecountsandhumanindicatorsbyqPCR.Alloftheseindicatorswereatornearzero(1fecalcoliform/100mLwasdetected),suggestingthatthewatercontainedtherepresentlydoesnotharborsignificantlevelsofsanitarysewage.

RASlipOutfall.Wewereunabletocollectsamplesfromthenon-CSOoutfallthatdrainstotheRAslipduringourfallsampling,butonesamplewascollectedonAug102015,alongwithsamplesfromRUSSAVE50andRUSSAVE100.Thisoutfallwasnegativeforhumanindicators,buthadhighlevelsofE.coliandenterococci,asdidthetwositeswithintheslip(Figure5).Thisisunlikelytobeasourceofhumanindicatorsingeneral,asitappearstobemorenewlyconstructed

pipesandonlydrainsparkinglots.ItmaybeconsistentsourceofFIBduringraineventsthough.

KKFlushingTunnel.ThemanholetothetunnelwasremovedonDec7,2015andvisuallyexamined.Thisstructureledtoachamberthatwasfilledwithwaterandalargeamountoffloatingtrash,includingfoodwrappersandalargetacklebox.Theoriginoftheseitemsislikelyfromtheslip,confirmingthatthereisflowfromthelake/slipintothetunnel.FIBcountsintunnelwaterwereextremelylow,rangingfrom0-8CFU/100mL.Whilethisonesamplecannotruleouttheflushingtunnelasasourceofhumanfecalinputs,itseemsunlikely.TheabsenceofhumanindicatorsforthisandNSCwaterwasconfirmedwithqPCR.

RussellAveCSOOutfallisaVariableSewageSource

HistoricalDataTrends.WecompiledallavailablehumanindicatordataonsamplescollectedfromRussellAvebetween2011and2015.ThroughaSeaGrantproject(2014-2015),theRAslipwassampledfrequentlyduringthebathingseason.OnlyoneCSOeventoccurredduringthesummersampling(Table2).ACSOeventalsooccurredinAprilbothyearspriortocommencingsummersampling.In2014theoutfallappearedtobeavariablesourceofsewage,testinghighlypositiveforbothHBandLachno2immediatelyfollowingaCSOevent(highlightedinorange),withpositiveandnegativeresultsoccurringintermittentlyuntilAugust,afterwhichonlyoneweaklypositiveresultforRUSSAVE100wasobserved.Theoveralltrendappearedtobeadecreaseinthequantityofhumanindicators(whenpresent)withtimepost-CSO,

Figure5.EnterococciandE.colicountsforthenon-CSOoutfallandsiteswithintheRAslip

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suggestingthattherecouldberemnantsfromtheJuneCSOeventthatslowlywashedout.In2015,nosummerCSOoccurred,andnoobvioustrendswerepresent.Humanindicatorswerenegativeoratdetectionlimitsforthemajorityofsamples.AblendingeventoccurredonNovember18thatwouldnothaveresultedinreleasesfromtheCSOoutfall.However,HFIBlevelswerethehighestrecordedin2015,suggestingthatdischargefromtheblendingeventtotheharbormaybeapotentialsourceofHFIBtotheslipinadditiontotheCSOoutfall.

Table2.HumanindicatorqPCRresultsfromRussellAvenueslip2014-2015.Dataiscolor-codedbyeventtype:grey=rain,red=CSO,orange=postCSO,green=blending,non-shaded=baseline.

HB (Bacteroidales)

Lachno2 (Lachnospiraceae)

Date RUSSAVE 50 RUSSAVE100 RUSSAVE 50 RUSSAVE 100 6/9/14 736 607 347 607

6/11/14 301 355 682 355 6/12/14 4275 3157 3376 3157 6/17/14 416 490 399 490 6/18/14 13249793 4353781 35196512 4353781 6/19/14 14169 17173 23437 17173 6/20/14 8489 7712 9470 7712 6/23/14 226 BLD 273 BLD 6/24/14 0 0 0 0 6/27/14 0 0 0 0 7/1/14 2901 1741 1642 1741 7/2/14 BLD BLD 0 BLD 7/7/14 0 BLD 360 BLD

7/14/14 1107 675 586 675 7/15/14 694 591 482 591 7/16/14 329 BLD BLD BLD 7/17/14 BLD 0 0 0 7/22/14 0 0 0 0 8/1/14 0 0 0 0 8/7/14 0 233 0 233

8/21/14 0 0 0 0 8/22/14 0 0 0 0 8/28/14 0 0 0 0 9/9/14 0 0 0 0

9/10/14 0 0 0 0 9/11/14 0 0 0 0 4/10/15 NOT SAMPLED 5/21/15 0 0 109 0 5/26/15 BLD BLD 0 BLD 6/1/15 597 BLD 275 BLD

6/12/15 BLD 0 BLD 0 6/19/15 0 0 0 0 6/23/15 0 0 0 0 6/29/15 0 0 0 0 7/7/15 0 0 0 0

7/13/15 0 0 7/14/15 0 0 0 0 7/23/15 0 BLD 0 BLD 7/24/15 0 BLD 0 BLD 7/25/15 696 696 865 696

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7/26/15 0 0 0 0 7/27/15 0 0 0 0 7/30/15 554 554 8/5/15 2752 524 3567 524

8/10/15 0 BLD 0 BLD 8/11/15 3012 0 4968 0 8/17/15 0 226 0 226 8/18/15 262 0 0 0 8/31/15 0 BLD 0 BLD

10/20/15 0 0 0 10/22/15 0 0 0 0 10/28/15 0 0 0 0 11/18/15 1080 2772 5055 2772 11/19/15 8626 7564 7756 7564

EffectsofRainEvents.SamplesweretakenfromtheRAslipduringbaseline(norain),lightrain,heavyrain,andpostraineventstodetermineiftherewasarelationshipbetweenprecipitationamountandtheconcentrationofindicators.Thequestiontobeansweredwas:doesraindrivesewagecontamination;andifso,doheavierrainsresultinhigherHFIBlevels?Itwouldbeexpectedthatifthesourceofthehumanfecalbacteriatotheoutfallwerecomingfromasanitarypipe,itwouldbepresentduringwetanddryperiodsbecausethecontaminationsourcewouldbeconstant.Raincouldeitherincreaseflowsinthepipe,drivingsewageoutwardintotheslip,ordiluteaconsistentsewagesignal.

Undernearlyallconditions,humanindicatorsweredetectable,butbelowthethresholdtobeconsideredpositiveforsewage.Wehavepreviouslyusedaminimumthresholdforconcernbecausehumanmarkersareprevalentalmostubiquitouslyatlowlevelsinurbanwaterssuchasrivers.Thesethresholds(1000CN/100mlforHBand1500CN/100mlforLachno2)areshowninFigure6asthedashedblueandredlinesonthegraphs.Onaverage,RUSSAVE50hadastrongsewagesignalonlyduringandimmediatelyafterCSOevents.Whensamplestakenduringtheseeventsareremoved,themeanvaluesforhumanmarkersarebelowthethresholdlevelunderallconditions.Furthermore,theconcentrationofhumanmarkersunderdifferentconditionsdidnotcorrelatewithFIB,suggestingthatfreshsewageisnotthesourceoftheFIB.Fordetaileddataonindividualsamplingdays,seeAppendixA,whichincludestransectplotsofallsamplingdatesforwhichqPCRwasrunforhumanfecalmarkers.Baseline,heavyrain,andpostrainconditionsshowedsimilartrendsinhumanfecalindicatorabundance,withaveragevaluesbelowthethresholdtobeconsideredsewagecontaminationbutwithintherangeofquantification.ConcentrationsatRUSSAVE50generallytendedtobehigherthanRUSSAVE100,whichsuggestcontaminationisoriginatingfromtheRAslipbutthatthecontaminationmayberesidualsewagefromthemostrecentCSOevent.

LakeLevelImpacts.Wealsoexploredthepossibilitythatlakewaterlevelscouldaffecttheconcentrationofindicatorspresentintheslip,withthehypothesisthatlowerlakelevelswouldcorrelatetohigherHFIBconcentrations.ThetunnelleadinguptotheCSOisfilledwithlakewatertosupportthetunnel,sothewaterlevelsbetweentheCSOgateandoutfallopeningmayfluctuatewiththelake’swaterlevels.Ahigherlakelevelshouldforcelakewaterbackintothepipe,fillingitcompletely;butlowlakelevelsmightresultinoutflowofwater.LakeleveleffectsontheCSOoutfallcanbevisualizedonadailybasis;onsomedaystheoutfalliscompletelysubmergedandonothers,theopeningispartiallyvisible.

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Samplescollectedattheslipfrom2011-2015wereanalyzedforHBandLachno2markersandcomparedtomeanlakelevelstodetermineifanycorrelationexists(Figure7).Amongtheyearssampled,2015hadthehighestwaterleveland

Figure6.FIBandHFIBconcentrationsattheRussellAvenueslipunderdifferentweatherconditions(norain/baseline,lightrain,heavyrain(>0.5”),andpostrain).

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thelowestconcentrationsofhumanindicators.Thelake’swaterlevelhasbeengraduallyincreasingoverthepastfouryears,whichmaybethecauseoflowerincidenceofHFIBintheslipin2015,inadditiontotheabsenceofasummerCSOevent.LowerhumanindicatorpresenceduringhigherwaterlevelsmaybebecausethelakewaterinsidetheCSOoutfallistoohightoallowoutflowofresidualcontamination.Theseresultscanbeverifiedbycontinuedcollectionofsamplesunderdifferentlakelevels.Blendingevents(showningreeninFigure7)areincludedtoshowthatdischargesfromriversand/oreffluentfromJonesIslandmayreachtheslipduringhighflowstormevents.

PotentialImpactsonSouthShoreBeach

SouthShorebeachexperiencesfrequenthealthadvisoriesandclosingduetoelevatedE.colilevels(>235CFU/mL).Shorebirdssuchasgeeseandgullscontributealargeportionofthispollution,butthewadingzoneoftenhasdetectableHFIBaswell.ThesourceoftheHFIBisstillunknown,buttheRACSOoutfallmaybeapotentialsource,evenduringnon-CSOevents.AtransectfromtheRAslip,totheSouthShoreYachtClub,alongtheexistingbeachlocationandtheproposedbeachlocation(seeFigure8A-BforE.colicounts)wassampledfrequently(~weekly)throughoutthe2014-2015bathingseasons.Platecountassays(enterococciandE.coli)weredoneforallsamples,andselectedsampleswerealsoanalyzedforHFIB.

Figure7.LakeMichiganwaterlevelsandhumanfecalmarkerconcentrationsattheRussellAvenueslip.Lakelevelsaregiveninfeet;humanmarkersareshownaslog10copynumberper100mL

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Figure8.TransectplotsofE.coliCFU/100mLinwatersamplesfromtheRussellAvenueSliptoSouthShorebeachforallsamplingdaysinA)2014andB)2015.EPAregulationsforhealthadvisory(235CFU/mL)andbeachclosing(1000CFU/100mL)areshownasdashedlines.

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Figures9A-9CprovideadditionalinformationonHFIBontherangesofHFIBfromsamplescollected2011through2015underA)CSO,B)baselineandC)rainconditions.(TransectplotsshowingFIBandHFIBforindividualsamplingdaysareavailableinAppendixA.)IftheRACSOoutfallwereaconsistentsourceofsewagethatcontributedtoHFIBatSouthShorebeach,trendsshouldshowsignificantlyhigherconcentrationsatRUSSAVE50,slightlylowerconcentrationsatRUSSAVE100duetomixingwithlakewater,andcontinuallylowerHFIBlevelsfromtheYachtClubsites,tothe“SSOLD”sitestothe“SSNEW”beach.However,thistrendwasobservedonlyunderCSOconditions(Figure7A).EvenduringCSOevents,theYachtClubsampleshadlowerHFIBconcentrationscomparedto“OldBeach,“suggestingthatthereisanadditionalsourceofHFIBtothebeach.TheCSOconditionsprovideareferencefortruesewagecontamination,whichcanberecognizedbycloselycoupledHBandLachno2concentrations,withslightlyhigherLachno2comparedtoHB.Underbaselineconditions,themedianHFIBconcentrationswereactuallyhigherthanmedianvaluesmeasuredintheRAslip,andthetwoHFIBwerenotcloselymatched.Medianvaluesatallsiteswerealsotypicallynearthelimitofdetectionfortheassays.ThissuggeststhatsewageissporadicallyenteringtheRAslipfromtheCSOoutfall,butitisunlikelythattheCSOoutfallisthelow-levelsourceofFIBobservedfrequentlyatthebeachlocations.AninterestingobservationisthattheSouthShoreBeachsitesSSOLD3andSSOLD2(closesttothemarinaandboatramp)wererarelynegativeforHFIBunderrainconditions,suggestingeitheranadditionaltracesourceofhumansewage,orcross-reactionsfromanimalfecalmaterialwithbothhumanassays.Alternativesources(SSBeachPavilionlaterals,parkinglotbathrooms,yachtclubpumpstation)shouldbeinvestigatedfortheirimpactsonthebeach.

Figure9A.Humanindicatorconcentrations(CN/100mL)forallsitesinRussellAvenueSliptoSouthShoreBeachtransect(2011-2015).A)DataforsamplescollectedduringCSOevents:amaximumof200,000isusedtoshowdetailinbeachsamples;maximumvaluesfortheslipwere>1,000,000.Boxesshowtheinterquartilerange(25-75%),withthedarklinerepresentingthemedianvalue.Whiskersextendto1.5*IQR,andallothervaluesareshownasoutliers.

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Figure9Band9C.Humanindicatorconcentrations(CN/100mL)forallsitesinRussellAvenueSliptoSouthShoreBeachtransect(2011-2015).DataforsamplescollectedduringB)baseflowandC)rainevents.Notethatthemaximumvaluesonfigures9Band9Care~2ordersofmagnitudelowerthaninfigure9A.

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JonesIslandEffluentandHarborasHFIBSource

MillionsofgallonsoftreatedeffluentarereleasedfromJonesIslandWWRFeveryday.Effluentissanitizedthroughchlorination,whichshouldreduceoreliminatethegrowthofbacteriacontainedintheeffluent.However,thisprocessdoesnotdestroyDNA,andislesseffectiveatinactivatingGrampositivebacteria(e.g.,Lachnospiraceae)comparedtoGram-negativebacteria(e.g.,E.coli).DependingonflowvolumesandmovementofcurrentswithintheMilwaukeeHarbor,JIeffluentmaybetransportedsouthtowardtheRAslipandSouthShoreYachtClub.Thismightresultinlow

viablecountsforE.coli,butdetectionofhumanmarkers.ConcentrationsofhumanmarkersatSouthGap,theharborlocationclosesttotheRASlip,tendedtobelowerthaneffluent,aswouldbeexpectedfromdilution.ThissourceshouldbefurtherinvestigatedfurtherforthepotentialforresidualsignaltoreachtheYachtClubandexistingbeachlocation.

ConclusionsandRecommendations

SourcestoRACSOoutfall.TheresultsofthetwofieldinvestigationsconcludedthatthehumanfecalcontaminationislikelynotcomingfromasourceabovetheRussellAvenueCSOoutfallstructure.Therewasanextensivesearchofnearbystormwaterandsanitarysewers,noneofwhichappearedtobeapotentialsourceofcontamination.Asmentionedpreviously,itislikelythattheindicatorsdetectedininlinesamplesduringthelightraineventswerearesultofcross-reactionwithbacteriaintheraccoonfecesobservedinthepipesonthesecondvisit.However,theinitialsamplingshowingthepresenceofbothmarkersremainsunexplained;butlevelsarenotatypicalforthemajorityofstormwaterpipesinthecity.ThelowlevelscombinedwiththelargedilutioneffectintheCSOoutfallstructurecouldpartiallyexplainsome,butnotalloftheoccurrencesindetectinghumanmarkers.NegativeHFIBresultsfromthestormwateroutfall,KKFlushingTunnelandevenwithintheNSCsuggestthattheoutfallisnotaconsistentsourceofhumanfecalindicatorstotheslip.

EffectofLakeLevels.Basedon2014summerdatafollowingtheJuneCSOevent,theHFIBdetectedarelikelycomingfromremnantsinthetunnelbetweentheNearSurfaceCollectorandtheCSOoutfall,essentiallytheremainsofcombinedsewagereleasedduringaCSOevent.Sincethelakewaterisindirectcontactwithwaterinsidethetunnel,anyfecalcontaminationmayeventuallymakeitswayoutintothelakeasthelakelevelfluctuates.ContinuingtomonitortheRussellAvenueoutfallandslipmayleadtodiscoveringanycorrelationsbetweenthedataandlakelevels.

IstheRAOutfallthesourceofsewageatSouthShoreBeach?TheoutfallislikelythesourceofhighHFIBconcentrationsatthebeachfollowingaCSOevent,butdoesnotappeartobeaconsistentsourceofHFIBduringeitherrainfallorbaselineconditions.Futureworkcharacterizingwholemicrobialcommunitiesfromtheoutfallandthebeachesmayhelptoclarifyifandwhentheoutfallimpactsthebeach,andifthereareother,moredominantsourcesofsewageimpactingthebeach.

Figure3.CopynumbersofHFIB/100mLinJonesIslandEffluent,atthePierheadsinMilwaukeeHarbor,andattheSouthGapsouthernopeninginthebreakwaterwallnearRASlip.Harborsamplesweretakenundernon-CSOconditions.

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“New”vs.“Old”Beaches.Onecleartrendinthedataisthatanyimpactsfromfecalpollution--humansewage,gulls,wildlife,orunknowninputs—arelowerattherockybeach~150msouthofthecurrentswimmingbeach.ThistrendhasbeenobservedconsistentlyforoveradecadeinbothstudiesbytheMcLellanLabandtheCityofMilwaukeeHealthDepartment.Wehypothesizethatthisisdueinparttodistancefrompotentialsources(shorebirds,yachtclub,RAslip,JonesIsland),butheavilyinfluencedbythehigherdegreeofwaterexchangeatthissite.Duringswimmingseason,alongshorecurrentsdominatewatermovementatSSBeach,essentiallymovingwaternorthandsouthinanarrowbandnearthewadingzone.However,attheproposedbeachlocation(“SSNew”),theopeninginthebreakwaterwallallowswatertoflowdirectlytowardthecenterofthebeachandcreateanoffshoretransportofpollution.

Recommendations.Yearsofdataandobservationrevealacomplexproblemthatislikelyacombinationofseveralfactors,includingtimefrommostrecentCSOevent,lakelevels,windandcurrentdirection,andotherconfoundingsources(possiblyboat/marinawaste).Hydrologicmodelingoftheslipcoupledwithconsistentsamplingmayhelptobetteridentifyiftheslip(fromtheoutfall)isasource,orifitisreceivingcontaminationfromothersourcesthatbecometrappedwithintheslip.

EachsummertherearemanysailboatsdockedthroughoutthemarinaneartheRussellAvenueslipandnearby,SouthShoreYachtClubprovidesawastepumpingstation.Theseboatsandpumpingstationmaybepotentialsourcesofcontaminationbothtotheslipandtothebeach.Collectingsamplesclosertostationedyachtsorthepumpingstationmayhelpidentifyleaks.Anotherpotentialwaytoruleoutboatwasteasapotentialsourcewouldbetosampleaftericethawinspring,beforethewatercraftsaredocked,withcontinuoussamplingintofallaftertheyhavebeenremoved.Duringthesetimeframestherewillbenouseofthepumpingstationandallwatercraftwillbeoutofthewater,eliminatingthepresenceofapotentialsource.BoatsusingmarinasonCalifornia’scoast,suchasintheSanDiegomarina,aremandatedtoaddfluoresceintotheirsanitarytanks,includinganyboatsvisitingthemarina.ThisrequirementcouldbepursuedthroughtheCountyParks.

Finally,werecommendthattheswimmingbeachbemoved150msouthtoreducethepotentialforhumanexposuretopollutioninputs.Thiswouldresultinasignificantlyhighernumberofswimmingdaysduringtheseasonandhealthrisksfromlowlevelsofsewagewouldbediminished(i.e.ondayswhereFIBiswithinlimits),andwouldalsoresultineconomicandsocialbenefittotheBayViewcommunity.

References:

NationalOceanicandAtmosphericAdministration.Tides/Waterlevels.Dateaccessed:December23,2015.<http://www.co-ops.nos.noaa.gov/waterlevels.html?id=9087057>

WeatherUnderground.WeatherHistory.Dateaccessed:December,232015.<http://www.wunderground.com/history/airport/KMKE/2015/11/6/DailyHistory.html?req_city=Milwaukee&req_state=WI&req_statename=Wisconsin&reqdb.zip=53207&reqdb.magic=1&reqdb.wmo=99999>