ASTM_D_6771_-_21.pdf

Designation:D677121Standard Practice forLow-Flow Purging and Sampling Used for GroundwaterMonitoring1This standard is issued under the fixed designation D6771;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.1.Scope*1.1 This practice describes the method of low-flow purgingand sampling used to collect groundwater samples from wellsto assess groundwater quality.1.2 The purpose of this procedure is to collect groundwatersamples that represent a flow-weighted average of solute andcolloid concentrations transported through the formation nearthe well screen under ambient conditions.Samples collectedusing this method can be analyzed for groundwater contami-nants and/or naturally occurring analytes.1.3 This practice is generally not suitable for use in wellswith very low-yields and cannot be conducted using grabsampling or inertial lift devices.This practice is not suitable foruse in wells with non-aqueous phase liquids.1.4 UnitsThe values stated in SI units are to be regardedas standard.The values given in parentheses are approximatemathematical conversions to inch-pound units that are pro-vided for information only and are not considered standard.1.5 This practice offers a set of instructions for performingone or more specific operations.This document cannot replaceeducation or experience and should be used in conjunctionwith professional judgment.Not all aspects of this practice maybe applicable in all circumstances.This ASTM standard is notintended to represent or replace the standard of care by whichthe adequacy of a given professional service must be judged,nor should this document be applied without consideration ofa projects many unique aspects.The word“standard”in thetitle means only that the document has been approved throughthe ASTM consensus process.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD5088 Practice for Decontamination of Field EquipmentUsed at Waste SitesD5092/D5092M Practice for Design and Installation ofGroundwater Monitoring WellsD5521/D5521M Guide for Development of GroundwaterMonitoring Wells in Granular AquifersD5608 Practices for Decontamination of Sampling and NonSample Contacting Equipment Used at Low Level Radio-active Waste SitesD5903 Guide for Planning and Preparing for a GroundwaterSampling EventD5978/D5978M Guide for Maintenance and Rehabilitationof Groundwater Monitoring WellsD6089 Guide for Documenting a Groundwater SamplingEventD6452 Guide for Purging Methods for Wells Used forGround Water Quality InvestigationsD6517 Guide for Field Preservation of Ground WaterSamplesD6564/D6564M Guide for Field Filtration of GroundwaterSamplesD6634/D6634M Guide for Selection of Purging and Sam-pling Devices for Groundwater Monitoring WellsD6725/D6725M Practice for Direct Push Installation ofPrepacked Screen Monitoring Wells in UnconsolidatedAquifers1These test methods are under the jurisdiction ofASTM Committee D18 on Soiland Rock and are the direct responsibility of Subcommittee D18.21 on Groundwaterand Vadose Zone Investigations.Current edition approved Nov.1,2021.Published November 2021.Originallyapproved in 2002.Last previous edition approved in 2018 as D6771 18.DOI:10.1520/D6771-21.2For 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.*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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1D6911 Guide for Packaging and Shipping EnvironmentalSamples for Laboratory AnalysisD7069 Guide for Field Quality Assurance in a GroundwaterSampling EventD7929 Guide for Selection of Passive Techniques fo