ASTM_D_5920_-_14.pdf

Designation:D592014Standard Test Method(Analytical Procedure)forTests of Anisotropic Unconfined Aquifers by NeumanMethod1This standard is issued under the fixed designation D5920;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 test method covers an analytical procedure fordetermining the transmissivity,storage coefficient,specificyield,and horizontal-to-vertical hydraulic conductivity ratio ofan unconfined aquifer.It is used to analyze the drawdown ofwater levels in piezometers and partially or fully penetratingobservation wells during pumping from a control well at aconstant rate.1.2 The analytical procedure given in this test method isused in conjunction with Guide D4043 and Test MethodD4050.1.3 The valid use of the Neuman method is limited todetermination of transmissivities for aquifers in hydrogeologicsettings with reasonable correspondence to the assumptions ofthe theory.1.4 The values stated in SI units are to be regarded asstandard.1.5 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.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 TechniquesD4050 Test Method for(Field Procedure)for Withdrawaland Injection Well Tests for Determining Hydraulic Prop-erties of Aquifer SystemsD4105 Test Method for(Analytical Procedure)for Deter-mining Transmissivity and Storage Coefficient of Non-leaky Confined Aquifers by the Modified Theis Nonequi-librium MethodD4106 Test Method for(Analytical Procedure)for Deter-mining Transmissivity and Storage Coefficient of Non-leaky Confined Aquifers by the Theis NonequilibriumMethodD6026 Practice for Using Significant Digits in GeotechnicalData3.Terminology3.1 DefinitionsFor definitions of general technical termsused within this guide,refer to Terminology D653.3.2 Symbols and Dimensions:3.2.1 b Linitial saturated thickness of the aquifer.3.2.2 d Lvertical distance between top of screen inpumping well and initial position of the water table.3.2.3 dDnddimensionless d,equal to d/b.3.2.4 J0(x)zero-order Bessel function of the first kind.3.2.5 KrLT1hydraulic conductivity in the plane of theaquifer,radially from the control well.3.2.6 KZLT1hydraulic conductivity normal to the planeof the aquifer.3.2.6.1 DiscussionThe use of the symbol K for the hy-draulic conductivity is the predominant usage in groundwaterliterature by hydrogeologists,whereas,the symbol k is com-monly used for this term in soil and rock mechanics and soilscience.3.2.7 l Lvertical distance between bottom of screen incontrol well and initial position of water table.3.2.8 lDnddimensionless l,equal to l/b.3.2.9 Q L3T1discharge rate.3.2.10 r Lradial distance from control well.3.2.11 s Ldrawdown.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.21 on Groundwater andVadose Zone Investigations.Current edition approved June 1,2014.Published July 2014.Originally approvedin 1996.Last previous edition approved in 2006 as D5920-96(2006),which waswithdrawn February 2014 and reinstated in June 2014.DOI:10.1520/D5920-14.2For 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.*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 3.2.12 scLcorrected drawdown.3.2.13 sDnddimensionless drawdown,equal to 4Ts/Q.3.2.14 swtLdrawdown of the water table.3.2.15 S ndstorage coefficient,equal to Ssb.3.2.16 SsL1specific storage.3.2.17 Syndspecific yield.3.2.18 t Ttime since pumping started.3.2.19 trTtime since recovery started.3.2.20 tsnddimensionless time with respect to Ss,equalto Tt/Sr2.3.2.21 tynddimensionless time with respect to Sy,equalto Tt/Syr2.3.2.22 tTtime,t,corresponding to intersection of ahorizontal line through the intermediate data with an inclinedline through late data on semilogarithmic paper.3.2.23 tynddimensionless time,ty,corresponding to theintersection of a horizontal line through intermediate data withan inclined line through late data in Fig.1.3.2.24(t/r2)eTt/r2corresponding to