Designation:D5092/D5092M−16StandardPracticeforDesignandInstallationofGroundwaterMonitoringWells1ThisstandardisissuedunderthefixeddesignationD5092/D5092M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticedescribesamethodologyfordesigningandinstallingconventional(screenedandfilter-packed)groundwa-termonitoringwellssuitableforformationsrangingfromunconsolidatedaquifers(thatis,sandsandgravels)togranularmaterialshavinggrain-sizedistributionswithupto50%passinga#200sieveandasmuchas20%clay-sizedmaterial(thatis,siltyfinesandswithsomeclay).Formationsfinerthanthis(thatis,silts,clays,siltyclays,clayeysilts)canbemonitoredbutthewellmaynotyieldsufficientwaterrequiredforsampling,andfinefilterpackandscreenrequirementsaredifficultandcostlytoinstall.Useofcoarserfilter/screensinfineformationswillresultinwellswithunstablefilterpacksandassociatedelevatedsampleturbiditythatmayadverselyaffectsampleaccuracyanddataqualityobjectives.Thispracticeisnotapplicableinfracturedorkarstrockconditions,butmaybeapplicableforotherporousrockformations.1.2Therecommendedmonitoringwelldesignandinstalla-tionprocedurespresentedinthispracticearebasedontheassumptionthattheobjectivesoftheprogramaretoobtainrepresentativegroundwatersamplesandotherrepresentativegroundwaterdatafromatargetedzoneofinterestinthesubsurfacedefinedbysitecharacterization.1.3Thispracticewhenusedoncoarsegrainedsandandgravelaquifers,incombinationwithproperwelldevelopment(D5521),propergroundwatersamplingprocedures(D4448),andproperwellmaintenanceandrehabilitation(D5978),willpermitacquisitionofgroundwatersamplesfreeofartifactualturbidity,eliminatesiltationofwellsbetweensamplingevents,andpermitacquisitionofaccurategroundwaterlevelsandhydraulicconductivitytestdatafromthezonescreenedbythewell.Forwellsinstalledinfine-grai...
