ASTM_D_5299_-_D_5299M_-_18.pdf

Designation:D5299/D5299M18Standard Guide forDecommissioning of Groundwater Wells,Vadose ZoneMonitoring Devices,Boreholes,and Other Devices forEnvironmental Activities1This standard is issued under the fixed designation D5299/D5299M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This guide covers procedures that are specifically re-lated to permanent decommissioning(closure)of the followingas applied to environmental activities.It is intended for usewhere solid or hazardous materials or wastes are found,orwhere conditions occur requiring the need for decommission-ing.The following devices are considered in this guide:1.1.1 A borehole used for geoenvironmental purposes(seeNote 1),1.1.2 Monitoring wells,1.1.3 Observation wells,1.1.4 Injection wells(see Note 2),1.1.5 Piezometers,1.1.6 Wells used for the extraction of contaminatedgroundwater,the removal of floating or submerged materialsother than water such as gasoline or tetrachloroethylene,orother devices used for the extraction of soil gas,1.1.7 A borehole used to construct a monitoring well,and1.1.8 Any other well or boring that houses a vadose zonemonitoring device.1.2 Temporary decommissioning of the above is not cov-ered in this guide.NOTE1This guide may be used to decommission boreholes where nocontamination is observed at a site(see Practice D420 for details);however,the primary use of the guide is to decommission boreholes andwells where solid or hazardous waste have been identified.Methodsidentified in this guide can also be used in other situations such as thedecommissioning of water supply wells and boreholes where watercontaminated with nonhazardous pollutants(such as nitrates or sulfates)are present.This guide should be consulted in the event that routinegeotechnical studies indicate the presence of contamination at a site.Consult and follow national,state,or local regulations as they may controlrequired decommissioning procedures.NOTE2The term“well”is used in this guide to denote monitoringwells,piezometers,or other devices constructed in a manner similar to awell.Some of the devices listed such as injection and extraction wells canbe decommissioned using this guide for information but are not specifi-cally covered in detail in the text.NOTE3Details on the decommissioning of multiple-screened wellsare not provided in this guide due to the many methods used to constructthese types of wells and the numerous types of commercially availablemultiple-screened well systems.However,in some instances,the methodspresented in this guide may be used with few changes.An example of howthis guide may be used is the complete removal of the multiple-screenedwells by overdrilling.1.3 Most monitoring wells and piezometers are intendedprimarily for water quality sampling,water level observation,or soil gas sampling,or combination thereof,to determinequality.Many wells are relatively small in diameter typically2.5 to 20 cm 1 to 8 inches and are used to monitor forhazardous chemicals in groundwater.Decommissioning ofmonitoring wells is necessary to:1.3.1 Eliminate the possibility that the well is used forpurposes other than intended,1.3.2 Prevent migration of contaminants into an aquifer orbetween aquifers,1.3.3 Prevent migration of contaminants in the vadose zone,1.3.4 Reduce the potential for vertical or horizontal migra-tion of fluids in the well or adjacent to the well,and1.3.5 Remove the well from active use when the well is nolonger capable of rehabilitation or has failed structurally;is nolonger needed for monitoring;is no longer capable of provid-ing representative samples or is providing unreliable samples;is required to be decommissioned;or to meet regulatoryrequirements.NOTE4The determination of whether a well is providing a represen-tative water quality sample is not defined in this guide.Examples of whena representative water quality sample may not be collected include thebiological or chemical clogging of well screens,a drop in the water levelto below the base of the well screen,or complete silting of the screen.These conditions may indicate that a well is not functioning correctly.1.4 This guide is intended to provide information for effec-tive permanent closure of wells so that the physical structure ofthe well does not provide a means of hydraulic communicationbetween aquifers,with above surfaces or react chemically in adetrimental way with the environment.1.5 The intent of this guide is to provide procedures thatwhen followed result in a reasonable level of confidence in the1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.21 on Groundwater andVadose Zone Investigations.Current edition approved Nov.15,2018.Published Nov