Designation:D4105/D4105M−20StandardPracticefor(AnalyticalProcedure)forDeterminingTransmissivityandStorageCoefficientofNonleakyConfinedAquifersbytheModifiedTheisNonequilibriumMethod1ThisstandardisissuedunderthefixeddesignationD4105/D4105M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticecoversananalyticalprocedurefordeter-miningtransmissivityandstoragecoefficientofanonleakyconfinedaquiferunderconditionsofradialflowtoafullypenetratingwellofconstantflux.ThispracticeisashortcutprocedureusedtoapplytheTheisnonequilibriummethod.TheTheismethodisdescribedinPracticeD4106.1.2Thispractice,alongwithothers,isusedinconjunctionwiththefieldproceduregiveninTestMethodD4050.1.3Limitations—Thelimitationsofthispracticeareprimar-ilyrelatedtothecorrespondencebetweenthefieldsituationandthesimplifyingassumptionsofthispractice(see5.1).Furthermore,applicationisvalidonlyforvaluesofulessthan0.01(uisdefinedinEq2,in8.6).1.4AllobservedandcalculatedvaluesshallconformtotheguidelinesforsignificantdigitsandroundingestablishedinPracticeD6026.1.4.1Theproceduresusedtospecifyhowdataarecollected/recordedorcalculated,inthisstandardareregardedastheindustrystandard.Inaddition,theyarerepresentativeofthesignificantdigitsthatgenerallyshouldberetained.Theproce-duresuseddonotconsidermaterialvariation,purposeforobtainingthedata,specialpurposestudies,oranyconsider-ationsfortheuser’sobjectives;anditiscommonpracticetoincreaseorreducesignificantdigitsofreporteddatatobecommensuratewiththeseconsiderations.Itisbeyondthescopeofthisstandardtoconsidersignificantdigitsusedinanalyticalmethodsforengineeringdesign.1.5Units—ThevaluesstatedineitherSIUnitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesineachsystemmaynotbeexactequivalents;thereforeeachsystemshallbeusedindependentlyofth...
