ASTM_D_5299_-_99_2012e1.pdf

Designation:D529999(Reapproved 2012)1Standard Guide forDecommissioning of Groundwater Wells,Vadose ZoneMonitoring Devices,Boreholes,and Other Devices forEnvironmental Activities1This standard is issued under the fixed designation D5299;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTEEditorial changes were made throughout in February 2012.1.Scope1.1 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 vadose zone monitoring 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 a routinegeotechnical investigation indicates the presence of contamination at asite.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 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 and areused to monitor for hazardous chemicals in groundwater.Decommissioning of monitoring 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;nolonger required for monitoring;no longer capable of providingrepresentative samples or is providing unreliable samples;orrequired to be decommissioned;or to meet regulatory require-ments.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 water level tobelow the base of the well screen,or complete silting of a tail pipe.Theseconditions may indicate that a well is not functioning properly.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 or react chemically in a detrimental way withthe 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 Feb.15,2012.Published December 2012.Originallyapproved in 1992.Last previous edition approved in 2005 as D5299 99(2005).DOI:10.1520/D5299-99R12E01.Copyright ASTM Inte