Designation:D6634/D6634M−14StandardGuideforSelectionofPurgingandSamplingDevicesforGroundwaterMonitoringWells1ThisstandardisissuedunderthefixeddesignationD6634/D6634M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thisguidedescribesthecharacteristicsandoperatingprinciplesofpurgingandsamplingdevicesavailableforuseingroundwatermonitoringwellsandprovidescriteriaforselect-ingappropriatedevicesforspecificapplications.Theselecteddevice(s)shouldbecapableofpurgingthewellandprovidingvalidrepresentativesamplesofgroundwaterandincludeddissolvedconstituents.Thescopedoesnotincludeproceduresforpurgingorcollectingsamplesfrommonitoringwells,samplingdevicesfornon-aqueousphaseliquids,diffusion-typesamplingdevicesorsamplingfromdevicesotherthanmoni-toringwells.1.2Thisguidereviewsmanyofthemostcommonlyuseddevicesforpurgingandsamplinggroundwatermonitoringwells.Thepractitionershouldensurethatthepurgingandsamplingmethodsused,whetherornottheyareaddressedinthisguide,areadequatetosatisfythemonitoringobjectivesateachsite.1.3Thisguideoffersanorganizedcollectionofinformationoraseriesofoptionsanddoesnotrecommendaspecificcourseofaction.Thisguidecannotreplaceeducationorexperienceandshouldbeusedinconjunctionwithprofessionaljudgment.Notallaspectsofthisguidemaybeapplicableinallcircum-stances.ThisASTMguideisnotintendedtorepresentorreplacethestandardofcarebywhichtheadequacyofagivenprofessionalservicemustbejudged,norshouldthisdocumentbeappliedwithoutconsiderationofthemanyuniqueaspectsofaproject.Theword“Standard”inthetitleofthisdocumentmeansonlythatthedocumenthasbeenapprovedthroughtheASTMconsensusprocess.1.4ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyof...
