ASTM_D_4105_-_D_4105M_-_20.pdf

Designation:D4105/D4105M20Standard Practice for(Analytical Procedure)for Determining Transmissivity andStorage Coefficient of Nonleaky Confined Aquifers by theModified Theis Nonequilibrium Method1This standard is issued under the fixed designation D4105/D4105M;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 practice covers an analytical procedure for deter-mining transmissivity and storage coefficient of a nonleakyconfined aquifer under conditions of radial flow to a fullypenetrating well of constant flux.This practice is a shortcutprocedure used to apply the Theis nonequilibrium method.TheTheis method is described in Practice D4106.1.2 This practice,along with others,is used in conjunctionwith the field procedure given in Test Method D4050.1.3 LimitationsThe limitations of this practice are primar-ily related to the correspondence between the field situationand the simplifying assumptions of this practice(see 5.1).Furthermore,application is valid only for values of u less than0.01(u is defined in Eq 2,in 8.6).1.4 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.4.1 The procedures used to specify how data are collected/recorded or calculated,in this standard are regarded as theindustry standard.In addition,they are representative of thesignificant digits that generally should be retained.The proce-dures used do not consider material variation,purpose forobtaining the data,special purpose studies,or any consider-ations for the users objectives;and it is common practice toincrease or reduce significant digits of reported data to becommensurate with these considerations.It is beyond the scopeof this standard to consider significant digits used in analyticalmethods for engineering design.1.5 UnitsThe values stated in either SI Units or inch-pound units are to be regarded separately as standard.Thevalues in each system may not be exact equivalents;thereforeeach system shall be used independently of the other.Combin-ing values from the two systems may result in non-conformance with the standard.Reporting of results in unitsother than SI shall not be regarded as nonconformance withthis practice.1.6 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 the 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 the considerationof a projects many unique aspects.The word“Standard”inthe title of this document means only that the document hasbeen approved through the ASTM consensus process.1.7 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.1.8 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 ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4043 Guide for Selection of Aquifer Test Method inDetermining Hydraulic Properties by Well Techniques1This practice is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.21 on Groundwater andVadose Zone Investigations.Current edition approved May 15,2020.Published June 2020.Originallyapproved in 1991.Last previous edition approved in 2015 as D4105 15.DOI:10.1520/D4105_D4105M-20.2For 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 t