ASTM_D_6634_-_D_6634M_-_14.pdf

Designation:D6634/D6634M14Standard Guide forSelection of Purging and Sampling Devices for GroundwaterMonitoring Wells1This standard is issued under the fixed designation D6634/D6634M;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 describes the characteristics and operatingprinciples of purging and sampling devices available for use ingroundwater monitoring wells and provides criteria for select-ing appropriate devices for specific applications.The selecteddevice(s)should be capable of purging the well and providingvalid representative samples of groundwater and includeddissolved constituents.The scope does not include proceduresfor purging or collecting samples from monitoring wells,sampling devices for non-aqueous phase liquids,diffusion-typesampling devices or sampling from devices other than moni-toring wells.1.2 This guide reviews many of the most commonly useddevices for purging and sampling groundwater monitoringwells.The practitioner should ensure that the purging andsampling methods used,whether or not they are addressed inthis guide,are adequate to satisfy the monitoring objectives ateach site.1.3 This guide offers an organized collection of informationor a series of options and does not recommend a specific courseof action.This guide cannot replace education or experienceand should be used in conjunction with professional judgment.Not all aspects of this guide may be applicable in all circum-stances.This ASTM guide is not intended to represent orreplace the standard of care by which the adequacy of a givenprofessional service must be judged,nor should this documentbe applied without consideration of the many unique aspects ofa project.The word“Standard”in the title of this documentmeans only that the document has been approved through theASTM consensus process.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.Dimensions provided are typical.1.5 This standard does not purport to address all of thesafety problems,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD5088 Practice for Decontamination of Field EquipmentUsed at Waste SitesD6452 Guide for Purging Methods for Wells Used forGroundwater Quality Investigations3.Terminology3.1 Definitions:For definitions of general terms used withinthis guide,refer to Terminology D653.4.Summary of Guide4.1 The primary objective of groundwater sampling pro-grams is to obtain samples that are representative of existinggroundwater conditions retaining the physical and chemicalproperties of the groundwater in a specific water-bearing zone.3Depending on the purging and sampling protocol,this mayrequire that the well is purged of stagnant water,or until1This 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.1,2014.Published February 2014.Originallyapproved in 2001.Last previous edition approved in 2006 as D6634 01(2006).DOI:10.1520/D6634_D6634M-14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3For example,the plasticizers in flexible PVC can contaminate samples withphthalate esters.The use of silicone rubber tubing,which contains no plasticizers,can obviate this problem;however,the potential for sample bias due to sorption/desorption exists with both materials(1).These pumps can be used with theintermediate vessel system described above,so that the sample contacts only theintake tubing and vessel avoiding contact with the pump mechanism tubing.Alternatively,using silicone rubber tubing at the pump head only can minimize thisproblem(2,3).*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 pre-determined purging criteria are met.Therefore,device(s)selected for use in groundwater sampling programs