Designation:D6771–02StandardPracticeforLow-FlowPurgingandSamplingforWellsandDevicesUsedforGround-WaterQualityInvestigations1ThisstandardisissuedunderthefixeddesignationD6771;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoversthemethodforpurgingandsam-plingwellsanddevicesusedforground-waterqualityinvesti-gationsandmonitoringprogramsknownaslow-flowpurgingandsampling.Thismethodisalsoknownbythetermsminimaldrawdownpurgingorlow-stresspurging.Thismethodcouldbeusedforothertypesofground-watersamplingprogramsbuttheseusesarenotspecificallyaddressedinthispractice.1.2Thispracticeappliesonlytowellssampledatthewellhead.1.3Thispracticedoesnotaddresssamplingofwellscon-tainingeitherlightordensenon-aqueous-phaseliquids(LNA-PLsorDNAPLs).1.4Thispracticeoffersasetofinstructionsforperformingoneormorespecificoperations.Thisdocumentcannotreplaceeducationorexperienceandshouldbeusedinconjunctionwithprofessionaljudgment.Notallaspectsofthispracticemaybeapplicableinallcircumstances.ThisASTMstandardisnotintendedtorepresentorreplacethestandardofcarebywhichtheadequacyofagivenprofessionalservicemustbejudged,norshouldthisdocumentbeappliedwithoutconsiderationofaproject’smanyuniqueaspects.Theword“standard”inthetitlemeansthatthedocumenthasbeenapprovedthroughtheASTMconsensusprocess.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:D4750TestMethodforDeterminingSubsurfaceLiquidLevelsinaBoreholeorMonitoringWell(ObservationWell)2D5088PracticeforDecontaminationofFieldEquipmentUsedatNon-RadioactiveWasteSites2D5092PracticeforDesignandInstallationofGr...
