ASTM D5920/D5920M-20

Standard Practice for (Analytical Procedure) Tests of Anisotropic Unconfined Aquifers by Neuman Method

SIGNIFICANCE AND USE
5.1 Assumptions:  
5.1.1 The control well discharges at a constant rate, Q.  
5.1.2 The control well, observation wells, and piezometers are of infinitesimal diameter.  
5.1.3 The unconfined aquifer is homogeneous and really extensive.  
5.1.4 Discharge from the control well is derived initially from elastic storage in the aquifer, and later from gravity drainage from the water table.  
5.1.5 The geometry of the aquifer, control well, observation wells, and piezometers is shown in Fig. 2. The geometry of the test wells should be adjusted depending on the parameters of interest.
FIG. 2 Cross Section Through a Discharging Well Screened in Part of an Unconfined Aquifer  
5.2 Implications of Assumptions:  
5.2.1 Use of the Neuman (1) method assumes the control well is of infinitesimal diameter. The storage in the control well may adversely affect drawdown measurements obtained in the early part of the test. See 5.2.2 of Practice D4106 for assistance in determining the duration of the effects of well-bore storage on drawdown.  
5.2.2 If drawdown is large compared with the initial saturated thickness of the aquifer, the late-time drawdown may need to be adjusted for the effect of the reduction in saturated thickness. Section 5.2.3 of Practice D4106 provides guidance in correcting for the reduction in saturated thickness. According to Neuman  (1) such adjustments should be made only for late-time values.  
5.3 Practice D3740 provides evaluation factors for the activities in this practice.
Note 1: The quality of the result produced by this practice is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this practice are cautioned that compliance with Practice D3740 does not in itself ensure reliable results. Reliable results depend on many fact...
SCOPE
1.1 This practice covers an analytical procedure for determining the transmissivity, storage coefficient, specific yield, and horizontal-to-vertical hydraulic conductivity ratio of an unconfined aquifer. It is used to analyze the drawdown of water levels in piezometers and partially or fully penetrating observation wells during pumping from a control well at a constant rate.  
1.2 The analytical procedure given in this practice is used in conjunction with Guide D4043 and Test Method D4050.  
1.3 The valid use of the Neuman method is limited to determination of transmissivities for aquifers in hydrogeologic settings with reasonable correspondence to the assumptions of the theory.  
1.4 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. Reporting of test result in units other than SI shall not be regarded as nonconformance with this standard.  
1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.  
1.5.1 The procedures used to specify how data are collected/recorded or calculated in the standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering data.  
1.6 This practice offers a set of in...

General Information

• Status: Published
• Publication Date: 14-May-2020
• ICS: 07.060 - Geology. Meteorology. Hydrology
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.21 - Groundwater and Vadose Zone Investigations

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D5920/D5920M −20
Standard Practice for
(Analytical Procedure) Tests of Anisotropic Unconfined
1
Aquifers by Neuman Method
This standard is issued under the fixed designation D5920/D5920M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* of this standard to consider significant digits used in analysis
methods for engineering data.
1.1 This practice covers an analytical procedure for deter-
mining the transmissivity, storage coefficient, specific yield, 1.6 This practice offers a set of instructions for performing
and horizontal-to-vertical hydraulic conductivity ratio of an one or more specific operations. This document cannot replace
unconfinedaquifer.Itisusedtoanalyzethedrawdownofwater education or experience and should be used in conjunction
levels in piezometers and partially or fully penetrating obser- with professional judgment. Not all aspects of the practice may
vation wells during pumping from a control well at a constant be applicable in all circumstances. This ASTM standard is not
rate. intended to represent or replace the standard of care by which
the adequacy of a given professional service must be judged,
1.2 Theanalyticalproceduregiveninthispracticeisusedin
nor should this document be applied without the consideration
conjunction with Guide D4043 and Test Method D4050.
of a project’s many unique aspects. The word “Standard” in
1.3 The valid use of the Neuman method is limited to
the title of this document means only that the document has
determination of transmissivities for aquifers in hydrogeologic
been approved through the ASTM consensus process.
settings with reasonable correspondence to the assumptions of
1.7 This standard does not purport to address all of the
the theory.
safety concerns, if any, associated with its use. It is the
1.4 Units—The values stated in either SI units or inch-
responsibility of the user of this standard to establish appro-
pound units are to be regarded separately as standard. The
priate safety, health, and environmental practices and deter-
values stated in each system may not be exact equivalents;
mine the applicability of regulatory limitations prior to use.
therefore,eachsystemshallbeusedindependentlyoftheother.
1.8 This international standard was developed in accor-
Combining values from the two systems may result in noncon-
dance with internationally recognized principles on standard-
formance with the standard. Reporting of test result in units
ization established in the Decision on Principles for the
other than SI shall not be regarded as nonconformance with
Development of International Standards, Guides and Recom-
this standard.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.5 All observed and calculated values shall conform to the
guidelines for significant digits and rounding established in
2. Referenced Documents
Practice D6026.
2
1.5.1 Theproceduresusedtospecifyhowdataarecollected/ 2.1 ASTM Standards:
recorded or calculated in the standard are regarded as the
D653Terminology Relating to Soil, Rock, and Contained
industry standard. In addition, they are representative of the Fluids
significant digits that generally should be retained. The proce-
D3740Practice for Minimum Requirements for Agencies
dures used do not consider material variation, purpose for Engaged in Testing and/or Inspection of Soil and Rock as
obtaining the data, special purpose studies, or any consider-
Used in Engineering Design and Construction
ations for the user’s objectives; and it is common practice to D4043Guide for Selection of Aquifer Test Method in
increase or reduce significant digits of reported data to be
Determining Hydraulic Properties by Well Techniques
commensuratewiththeseconsiderations.Itisbeyondthescope D4050Test Method for (Field Procedure) for Withdrawal
and Injection Well Testing for Determining Hydraulic
Properties of Aquifer Systems
1
This practice is under the jurisdiction of ASTM Committee D18 on Soil and
Rock and is the direct responsibility of Subcommittee D18.21 on Groundwater and
2
Vadose Zone Investigations. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 15, 2020. Published May 2020. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1996. Last previous edition approved in 2014 as D5920-14. DOI: Standards volume information, re
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D5920 − 14 D5920/D5920M − 20
Standard Test Method (Analytical Procedure) Practice for
(Analytical Procedure) Tests of Anisotropic Unconfined
1
Aquifers by Neuman Method
This standard is issued under the fixed designation D5920;D5920/D5920M; the number immediately following the designation indicates
the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This test method covers an analytical procedure for determining the transmissivity, storage coefficient, specific yield, and
horizontal-to-vertical hydraulic conductivity ratio of an unconfined aquifer. It is used to analyze the drawdown of water levels in
piezometers and partially or fully penetrating observation wells during pumping from a control well at a constant rate.
1.2 The analytical procedure given in this test method is used in conjunction with Guide D4043 and Test Method D4050.
1.3 The valid use of the Neuman method is limited to determination of transmissivities for aquifers in hydrogeologic settings
with reasonable correspondence to the assumptions of the theory.
1.4 The values stated in SI units are to be regarded as standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in
Engineering Design and Construction
D4043 Guide for Selection of Aquifer Test Method in Determining Hydraulic Properties by Well Techniques
D4050 Test Method for (Field Procedure) for Withdrawal and Injection Well Testing for Determining Hydraulic Properties of
Aquifer Systems
D4105 Practice for (Analytical Procedure) for Determining Transmissivity and Storage Coefficient of Nonleaky Confined
Aquifers by the Modified Theis Nonequilibrium Method
D4106 Practice for (Analytical Procedure) for Determining Transmissivity and Storage Coefficient of Nonleaky Confined
Aquifers by the Theis Nonequilibrium Method
D6026 Practice for Using Significant Digits in Geotechnical Data
3. Terminology
3.1 Definitions—For definitions of general technical terms used within this guide, refer to Terminology D653.
3.2 Symbols and Dimensions:
3.2.1 b [L]—initial saturated thickness of the aquifer.
3.2.2 d [L]—vertical distance between top of screen in pumping well and initial position of the water table.
3.2.3 d [nd]—dimensionless d, equal to d/b.
D
3.2.4 J (x)—zero-order Bessel function of the first kind.
0
−1
3.2.5 K [LT ]—hydraulic conductivity in the plane of the aquifer, radially from the control well.
r
1
This test method practice is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.21 on Groundwater
and Vadose Zone Investigations.
Current edition approved June 1, 2014May 15, 2020. Published July 2014May 2020. Originally approved in 1996. Last previous edition approved in 20062014 as
D5920-96(2006)D5920, which was withdrawn February 2014 and reinstated in June 2014. DOI: 10.1520/D5920-14.-14. DOI: 10.1520/D5920_D5920M-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D5920/D5920M − 20
−1
3.2.6 K [LT ]—hydraulic conductivity normal to the plane of the aquifer.
Z
3.2.6.1 Discussion—
The use of the symbol K for the hydraulic conductivity is the predominant usage in groundwater literature by hydrogeologists,
whereas, the symbol k is commonly used for this term in soil and rock mechanics and soil science.
3.2.7 l [L]—vertical distance between bottom of screen in control well and initial position of water table.
3.2.8 l [nd]—dimensionless l, equal to l/b.
D
3 −1
3.2.9 Q [L T ]—discharge rate.
3.2.10 r [L]—radial d
...