ASTM_D_5521_-_D_5521M_-_13.pdf

Designation:D5521/D5521M13Standard Guide forDevelopment of Groundwater Monitoring Wells in GranularAquifers1This standard is issued under the fixed designation D5521/D5521M;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 the development of screened wellsinstalled for the purpose of obtaining representative ground-water information and water quality samples from granularaquifers,though the methods described herein could also beapplied to wells used for other purposes.Other well-development methods that are used exclusively in open-borehole bedrock wells are not described in this guide.1.2 The applications and limitations of the methods de-scribed in this guide are based on the assumption that theprimary objective of the monitoring wells to which themethods are applied is to obtain representative water qualitysamples from aquifers.Screened monitoring wells developedusing the methods described in this guide should yield rela-tively sediment-free samples from granular aquifer materials,ranging from gravels to silty sands.While many monitoringwells are considered“small-diameter”wells(that is,less than10 cm 4 in.inside diameter),some of the techniquesdescribed in this guide will be more easily applied to large-diameter wells(that is,10 cm 4 in.or greater insidediameter).1.3 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.1.4 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 and health practices and determine the applica-bility of regulatory limitations prior to use.1.5 This guide offers an organized collection of informationor a series of options and does not recommend a specificcourse of action.This document cannot replace education orexperience and should be used in conjunction with professionaljudgment.Not all aspects of this guide may be applicable in allcircumstances.This ASTM standard is not intended to repre-sent or replace the standard of care by which the adequacy ofa given professional service must be judged,nor should thisdocument be applied without consideration of a projects manyunique aspects.The word“Standard”in the title of thisdocument means only that the document has been approvedthrough the ASTM consensus process.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 SitesD5092 Practice for Design and Installation of GroundwaterMonitoring Wells3.Terminology3.1 Definitions:3.1.1 For definitions of common terminology terms usedwithin this guide,refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 air entrapmenttrapping of air or other gas in porespaces of the formation or filter pack during development withcompressed air.3.2.2 air lift pumpa device consisting of two pipes,withone(the air line)inside the other(the eductor pipe),used towithdraw water from a well.The lower ends of the pipes aresubmerged,and compressed air is delivered through the innerpipe to form a mixture of air and water.This mixture rises inthe outer pipe to the surface because the specific gravity of thismixture is less than that of the water column.1This 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 Aug.1,2013.Published September 2013.Originallyapproved in 1994.Last previous edition approved in 2005 as D5521 05.DOI:10.1520/D5521_D5521M-13.2For 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 States1 3.2.3 air linea small vertical air pipe used in air-liftpumping.It usually extends from the ground surface to near thesubmerged lower end of the eductor pipe.The length of the airline below the static water level is used in calculating the airpressure required to start air-lift pumping.3.2.4 annular seal