Designation:D5270/D5270M−20StandardPracticefor(AnalyticalProcedures)DeterminingTransmissivityandStorageCoefficientofBounded,Nonleaky,ConfinedAquifers1ThisstandardisissuedunderthefixeddesignationD5270/D5270M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticecoversananalyticalprocedurefordeter-miningthetransmissivity,storagecoefficient,andpossiblelocationofboundariesforaconfinedaquiferwithalinearboundary.Thispracticeisusedtoanalyzewater-levelorheaddatafromoneormoreobservationwellsorpiezometersduringthepumpingofwaterfromacontrolwellataconstantrate.Thispracticealsoappliestoflowingartesianwellsdischargingataconstantrate.Withappropriatechangesinsign,thispracticealsocanbeusedtoanalyzetheeffectsofinjectingwaterintoacontrolwellataconstantrate.1.2TheanalyticalprocedureinthispracticeisusedinconjunctionwiththefieldprocedureinTestMethodD4050.1.3Limitations—Thevaliduseofthispracticeislimitedtodeterminationoftransmissivitiesandstoragecoefficientsforaquifersinhydrogeologicsettingswithreasonablecorrespon-dencetotheassumptionsoftheTheisnonequilibriummethod(seePracticeD4106)(see5.1),exceptthattheaquiferislimitedinarealextentbyalinearboundarythatfullypenetratestheaquifer.Theboundaryisassumedtobeeitheraconstant-headboundary(equivalenttoastreamorlakethathydraulicallyfullypenetratestheaquifer)orano-flow(impermeable)boundary(equivalenttoacontactwithasignificantlylesspermeablerockunit).TheTheisnonequilibriummethodisdescribedinPracticesD4105/D4105MandD4106.1.4Units—ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnoncon-formancewiththestandard.ReportingofresultsinunitsotherthanSI...
