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1Spillsandoverfillsofregulatedsubstances(suchasgasolineordiesel)oftenoccurwhentheproductisbeingdeliveredintoastoragetank.Whenaspilloccurs,itcanseepintothedirt(orsoil)aroundastoragetank,possiblycontaminatinglocalwatersupplies.Contaminationofsoilorwatercanaffectthehealthofpeopleandnegativelyaffectourenvironment.
Inthismodule,youwilllearnaboutthedifferentmethodsofspillandoverfillpreventionforastoragetanksystemandtheregulatoryrequirementsforyourstate.Spillandoverfillpreventionmethodsareintendedtopreventreleasesorspillsfromoccurringduringthedeliveryofproduct,suchasgasolineordiesel,toyourstoragetanksystem.
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2Topreventspillingassociatedwiththetransferofregulatedsubstances,suchasgasolineordiesel,toaneworupgradedstoragetanksystem,stateregulationsrequirethateachowneroroperatormustusespillcontainmentequipment(suchasacatchmentbasin)topreventreleaseofregulatedsubstanceswhenthetransferhosefromthetankertruckisdetachedfromthefillpipe.
Topreventoverfillingassociatedwiththetransferofregulatedsubstances,eachowneroroperatormustuseoverfillpreventionequipmentthatautomaticallyshutsoffflowintothetankwhenthetankisnomorethan95%full,alertsthedeliverydriverwhenthetankisnomorethan90%fullbyrestrictingtheflowofproductintothetankortriggersahighlevelalarmaudibletothetransferoperator.
Alternativespillandoverfillequipmentmaybeusedifitisdeterminedby,andapprovedinwritingbytheOfficeofStateFireMarshalltobenolessprotectiveofhumanhealthandtheenvironmentthanthesemethods.
AUSTthatisfilledbytransfersofnomorethan25gallonsatonetimedoesstillrequirespillcontainment,butdoesnotrequireoverfillprevention.
Wasteoiltanksmustalsobeequippedwithspillcontainmentdevicesatallfillandretrieval
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3Beforeproductisdeliveredtoatank,theowner,operatororpersonincharge(suchasadeliverydriver)shouldmakesurethatthevolumeavailableinthetankisgreaterthanthevolumeofproductbeingtransferredtothetank.
Duringadelivery,theowner,operatororpersoninchargemustconstantlymonitorthetransferofproducttopreventoverfillingandspillingandensurethatdeliveryisbeingperformedinaccordancewithmanufacturerspecifications.
Theowneroroperatormustensurethatspillpreventionequipmentiskeptclean,dryandinspectedmonthly.Priortodispensingproduct,thedeliverydriverorpersoninchargeshouldalsoverifythattheequipmentiscleananddry,beforetransferring.
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4Theowneroroperatormustensurethatallfilllinesforthestoragetanksystemareclearlymarkedtoindicatethetypeofregulatedsubstance,suchasunleaded87ordiesel,beingstored.Itisrecommendedthateachtankisadditionallymarkedtoindicatetanksize.
Thefollowingmethodscanbeusedasproperlabeling: Installingapermanenttagorsignimmediatelyadjacenttothefillpipeswhichstates
thesizeofthetankandthespecifictypeofsubstancestored;or, Applyingacolorcodethatconformstothefollowingrequirements:
ColormarkingsinaccordancewithAPI1637ProductIdentification,mustbepaintedorplacedaroundthefillormanholecoverinamannerthatwillreadilyidentifythesubstanceinthetank;or,identificationinaccordancewithindustrystandardsorbusinesscolorcode
Owners,operatorsorotherresponsiblepartiesarerequiredtoreport,investigate,andcleanupanyspillsandoverfillsthatoccur.
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5Spillbuckets,orspillcatchmentbasins,arelarge,drumshapedcontainersthatsurroundthefillportand,insomecases,thevaporrecoveryporttoastoragetankwhereahoseisconnectedfromtheproductdeliverytrucktothetankduringrefueling.
Spillbucketscanrangeinsize,andifinstalledafterMay1,2003arerequiredtoholdaminimumof5gallonsofproduct.Bucketshavingcapacitiesupto25gallonsarecurrentlyinuse.Spillbucketsareinstalledtocontainorcatchdripsorspillsoffuelthatcanoccurduringproductdelivery.TheirintendedpurposeistheTEMPORARYstorage,orcontainmentofthespilledfueluntilitcanbeproperlycleanedup.
Sometimes,fuelingstationscontainremotefills.Thismeansthatthedeliveryports,includingthespillbuckets,arelocatedawayfromthetopofthestoragetanks.Remotefillsaretypicallyusedatsmallerfacilities,facilitieswithhighervolumeorwheredeliverytruckscannotaccessthetopsofthestoragetanks.
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6SpillbucketsaredesignedtotemporarilycontainproductspillsthatmightoccurandareNOTdesignedtocontainproductforextendedperiodsoftime.Spillbucketsshouldhaveacapacitylargeenoughtocontainanyproductthatmayspillwhenthedeliveryhoseisuncoupledfromthefillpipe,andifinstalledafterMay1,2003arerequiredtoholdaminimumof5gallonsofproduct.
AUSTthatisfilledbytransfersofnomorethan25gallonsatonetimedoes stillrequirespillcontainment,butdoesnotrequireoverfillprevention.
Wasteoiltanksmustalsobeequippedwithspillcontainmentdevicesatallfillandretrievalpoints.
Anyspillbucketrepairedorinstalledisrequiredtobetestedtoensuretheyareliquidtight.Ahydrostatictestmustbeperformedasfollows:1)Containmentistobefilledwithwatertoaheightthatcoversthehighestpenetrationby2inches.2)Minimalbackfillingthatmaybenecessaryforsupportofthecontainmentsumpisallowedpriortothetest.3)Testdurationis30minutesandperformedunderPerformanceAssuranceInspectionTimeandDateCertainrequirementswithnodropinwaterlevel.
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Spillbucketsaretypicallyequippedwithavalvewhichallowsyoutodrainthecontainedproductbackintothetank.Ifwaterordebrisismixedinwiththeproductinthespillbucket,thenyoushouldNOTdrainthismixtureintothetank.Watermaycauseinternaltankcorrosion,dispensingproblems,orincreasetherequirementtoremovethecontaminatedwaterfromthetank.Worstofall,wateranddebriscancontaminatethefuelinthestoragetankandcouldcausedamagetocustomervehicles.
Waterpresentinspillbucketswillalsoreducecapacityandmaycausemetalcomponentstocorrode.
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Yourspillbucketsmaybeequippedwithamanualpumpinsteadofadrainvalvethatallowsyoutopumptheproductbackintothetank.However,asmentionedpreviously,itisnotwisetoallowwaterordebristoenterthetank.Therefore,youshouldpumpthewater,product,anddebrismixtureoutofthespillbucketandplacethewasteinanappropriatedrumatyourfacility.Thenyoucanarrangeforproperdisposal.
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Itisveryimportanttoinspectthelidsofyourspillbucketstoensurethattheyremainingoodconditionandarenotallowingsurfacewatertoenter.Youshouldensurethatwhenthelidstoyourspillbucketsareclosed,thereisagoodsealandaretightlysecured.Somespillbucketshaverubbergasketsontheinsideofthelids.Youshouldensurethattherubbergasketsareingoodconditionandcreatesagoodseal.Inaddition,ensurethespillbucketlidisnottouchingthefillcap,asthiscoulddamagethefillpipe.
Lastly,inspectyourspillbucketstoensurethattheyarestructurallysound.Cracks,holes,ordeformationstothespillbucketswillallowproducttoleakandcontaminatesoiland/orgroundwater.Onlyonegallonoffuelleakingeachweekfromapoorlymaintainedspillbucketcanresultinthousandsofdollarsincleanupcosts.
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Althoughnotrequired,itisrecommendedthatspillbucketsbeinspecteddailytoensuretheyareworkingproperlyandarebeingmaintainedcorrectly(or,thattheyarecleananddry).Theuseofachecklistmightbeausefulreminderofwhattolookforduringadailyinspection.Pleasetakeamomenttoreviewtherecommendedspillbucketoperationandmaintenancechecklist.Itisnotrequiredtouseacontractorforspillbucketinspections,howevertheirexperiencemaybehelpfulinrecommendingappropriatecorrectivemeasures.
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Overfillprotectionequipmentinstalledonundergroundstoragetankshelpspreventyourtanksfrombeingoverfilledduringproductdelivery.Overfillprotectionisdesignedto:
Alertthetransferoperatorwhenthetankisnomorethan90%fullbyrestrictingtheflowintothetankandtriggeringahighlevelaudibleand/orvisualalarm;and
Automaticallyshutoffflowintothetankwhenthetankisnotmorethan95%full.
Wewilldiscussthethreetypesofoverfillprotectionforstoragetanks,whichare:1)Overfillalarms;2)Ballfloatvalves;and3)Automaticshutoffdevices.
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Thefirsttypeofoverfillprotectionisanoverfillalarm.AnoverfillalarmhasasensorlocatedinthestoragetankthatistypicallyconnectedtoamonitoringdevicesuchasanautomatictankgaugeorATG.
Anoverfillalarmprovidesawarningthatcanbeseenand/orheardbythepersondeliveringtheproductwhentheproductinthestoragetankreaches90%ofthetankscapacity,oriswithinoneminuteofbeingoverfilled.
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Pleasetakeamomenttoreviewthebasicoperationandmaintenancechecklistforoverfillalarms.
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Thesecondtypeofoverfillprotectionisaballfloatvalve.Aballfloatvalve,alsocalledafloatventvalve,isinstalledattheventpipeinsidethetankandrestrictsvaporflowintoastoragetankasthetankgetsclosetobeingfull.Theballfloatvalveshouldbesetatadepthwhichwillrestrictvaporflowoutoftheventlineduringdeliveryat90%ofthetankscapacity.Asthetankfills,theballinthevalverises,restrictingtheflowofvaporsoutofthestoragetankduringdelivery.Theflowrateofthedeliverywilldecreasenoticeablyandshouldalertthedeliverypersontostopthedelivery.Forballfloatvalvestoworkproperly,thetopofthetankmustbeairtightsothatvaporscannotescapefromthetank.Everythingfromfittingstodrainmechanismsonspillbucketsmustbetightandbeabletoholdthepressurecreatedwhentheballfloatvalveengages.
Itmaybedifficulttodeterminewhetherornotyouhaveaballfloatvalve,orifitisstillintactandfunctioningproperly.Youmightbeabletofindanextractorportfortheballfloatvalve,asillustrated.Otherwise,youwillneedtolookthroughyourpaperworktodeterminewhetheryourtankhasthisdevice.Youmaywanttoaskyourmaintenancecontractortoinspectthetankstotellyouwhichdeviceyouhave.
Ballfloatventvalvesmustnotbeusedonanytypeofsuctionsystem.
Pleasealsonote:Theuseofaballfloatvalveisnotrecommendedwhenafacilityisequippedwithremotefills.Insituationswhenashutoffdeviceisusedwitharemotefill,atrapdoororsimilardevicemustbeusedbeneaththefilladaptoronthestraightportionofthefillpipetopreventfuelfromshootingupoutofthestraightfillwhentheshutoffvalvecloses.Astandardfillcapisnotsufficienttocontainthepressurecreatedatthestraightfillwhentheshutoffvalvecloses.
Ballfloatvalvesmayalsocompromisetheeffectivenessoftheflappervalveinanautomaticshutoffdevice.Ifballfloatvalvesarepresentorusedwithautoshutoffdevices,theymustbesettoengageat95%fullorhigher(nottoexceed98%)soasnottointerferewiththeoperationoftheautoshutoffdevice.Becauseoftheseshortcomings,ballfloatvalvesarenotapreferredmethodofoverfillprevention.
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Thethirdtypeofoverfillprotectionisanautomaticshutoffdevice.Anautomaticshutoffdevice,alsoknownasaflappervalve,isamechanicaldeviceinstalledinlinewiththedroptubewithinthefillpiperiser.Itslowsdownandthenstopsthedeliverywhentheproducthasreachedacertainlevelinthetank.Itshouldbepositionedsothatthefloatarmisnotobstructedandcanmovethroughitsfullrangeofmotion.Wheninstalledandmaintainedproperly,theshutoffvalvewillstoptheflowoffueltothestoragetankat95%ofthetankscapacityorbeforethefittingsatthetopofthetankareexposedtofuel.
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Pleasetakeamomenttoreviewthebasicoperationandmaintenancechecklistforautomaticshutoffdevices.Youmustuseaspecificallydesignedautomaticshutoffdeviceforoverfillprotectionifyourstoragetankreceivespressurizeddeliveries.Apressurizeddeliveryiswhentheproductbeingdeliveredintothestoragetankisforcedintothetankbysomemechanicalmeans,notgravityfed.
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Containmentsumpspreventreleaseofaregulatedsubstanceintotheenvironment.Theyareusedforconnectionsofpipingfromthetanktothedispenser.
OnorafterMay1,2003,atankcontainmentsumpmustbeinstalledatthetankonallnewtankswithsubmersiblepumpsorAmericansuctionpipingsystems.Atankcontainmentsumpmustbealsobeinstalledwhenanexistingsubmersibleisreplacedwithanothersubmersible,orwhenpiping,flexconnectorsorothertransitionalcomponentsatthesubmersiblearereplaced.
Alltankcontainmentsumpsmustconsistofafactorymanufacturedcontainmentthatisliquidtightonitssides,bottomandatanypenetrationsandiscompatiblewiththesubstanceconveyedbythepiping.Europeansuctionsystemsarenotrequiredtohavethiscontainment.
Fornewdispenserinstallations(wheretherewerenonepreviously),andwhenanexistingdispenserisreplacedwithanotherdispenser,andequipmentatorbelowtheshearvalveisreplaced,underdispensercontainmentmustbeinstalled.Examplesofequipmentatorbelowtheshearvalveincludeflexconnectorsorrisersorothertransitionalcomponentsthatarebeneaththedispenserandconnectthedispensertothepiping.Europeansuctionsystemsarenotexemptfromthisrequirement.
Containmentmustbemonitoredmonthlyforevidenceofareleasefromthetankandpiping,andmustbeinplaceatthesubmersiblepumporotherlocationwherethepipingconnectstothetank,wherethepipingconnectstoadispenser,andwheredoublewalledpipingthatisrequiredconnectswithexistingpiping.
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ThisconcludestheSpillandOverfillmodule.Youshouldnowhaveanunderstandingofcontrolmethodsusedtopreventspillingassociatedwiththetransferofregulatedsubstances,suchasgasolineordiesel,toaneworupgradedstoragetanksystem.Thisisreferredtoasspillprevention.Overfillpreventionreferstothepreventionofreleasesduringtransferofregulatedsubstancesbyrestrictingorstoppingthedelivery.
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