ASTM D4050-20

Standard Test Method for (Field Procedure) for Withdrawal and Injection Well Testing for Determining Hydraulic Properties of Aquifer Systems

SIGNIFICANCE AND USE
5.1 Withdrawal or injection well test field procedures are used with appropriate analytical procedures in appropriate hydrogeological sites to determine transmissivity and storage coefficient of aquifers and hydraulic conductivity of confining beds.  
5.2 Practice D3740 provides evaluation factors for the activities in this test method.
Note 2: The quality of the result produced by this standard 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 standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.  
5.3 This test method may be limited due to the correspondence between the field situation determined by this test method and the simplifying assumptions of the analytical Test Methods D4105/D4105M or D4106 and D4043.
SCOPE
1.1 This test method covers the field procedure for selecting well locations, controlling change (discharge or injection) rates, and measuring water levels used to analyze the hydraulic properties of an aquifer or aquifers and adjacent confining beds.  
1.2 This test method is used in conjunction with an analytical procedure such as Test Methods D4105/D4105M or D4106 to evaluate the data and determine aquifer properties.  
1.3 The appropriate field and analytical procedures are selected as described in Guide D4043.  
1.4 Limitations—The limitations of this test method are primarily related to the correspondence between the field situation determined by this test method and the simplifying assumptions of the analytical Test Methods D4105/D4105M or D4106 and D4043.  
1.5 Units—The values stated in SI units are to be regarded as standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.  
1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.  
1.6.1 The procedures used to specify how data are collected/recorded or calculated, in this 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 analytical methods for engineering design.  
1.7 This test method offers a set of instructions for performing one or more operations. This document cannot replace education or experience and should be used in conjunction with professional judgement. Not all aspects of this standard may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a projects many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.  
1.8 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.9 This international standard was developed in accordance with internationally recognized principles on standardization e...

General Information

• Status: Published
• Publication Date: 31-Dec-2019
• ICS: 13.060.10 - Water of natural resources
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.21 - Groundwater and Vadose Zone Investigations

Relations

• Replaces: ASTM D4050-14 - Standard Test Method for (Field Procedure) for Withdrawal and Injection Well Testing for Determining Hydraulic Properties of Aquifer Systems
• Effective Date: 01-Jan-2020
• Refers: ASTM D3740-23 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Nov-2023
• Refers: ASTM D3740-19 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Oct-2019
• Refers: ASTM D2488-17 - Standard Practice for Description and Identification of Soils (Visual-Manual Procedures)
• Effective Date: 15-Jul-2017
• Refers: ASTM D4043-17 - Standard Guide for Selection of Aquifer Test Method in Determining Hydraulic Properties by Well Techniques
• Effective Date: 01-Jan-2017
• Refers: ASTM D4044/D4044M-15 - Standard Test Method for (Field Procedure) for Instantaneous Change in Head (Slug) Tests for Determining Hydraulic Properties of Aquifers (Withdrawn 2024)
• Effective Date: 01-Sep-2015
• Refers: ASTM D4106-15 - Standard Test Method for (Analytical Procedure) for Determining Transmissivity and Storage Coefficient of Nonleaky Confined Aquifers by the Theis Nonequilibrium Method
• Effective Date: 15-Apr-2015
• Refers: ASTM D4105/D4105M-15e1 - Standard Test Method for (Analytical Procedure) for Determining Transmissivity and Storage Coefficient of Nonleaky Confined Aquifers by the Modified Theis Nonequilibrium Method
• Effective Date: 15-Apr-2015
• Refers: ASTM D653-14 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Aug-2014
• Refers: ASTM D3740-12a - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-May-2012
• Refers: ASTM D3740-12 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Mar-2012
• Refers: ASTM D653-11 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Sep-2011
• Refers: ASTM D3740-11 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Sep-2011
• Refers: ASTM D4043-96(2010)e1 - Standard Guide for Selection of Aquifer Test Method in Determining Hydraulic Properties by Well Techniques
• Effective Date: 01-Aug-2010
• Refers: ASTM D3740-10 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Mar-2010

Overview

ASTM D4050-20, Standard Test Method for (Field Procedure) for Withdrawal and Injection Well Testing for Determining Hydraulic Properties of Aquifer Systems, is a recognized method published by ASTM International. This standard outlines procedures for the field testing of aquifer systems using both withdrawal (pumping) and injection well techniques. The focus is on determining essential hydraulic properties of aquifers and confining beds, including transmissivity, storage coefficient, and hydraulic conductivity.

These properties are vital to understanding groundwater resources, predicting aquifer behavior under stress, managing water supplies, and ensuring environmental protection. The standard is intended to be used in conjunction with analytical methods such as ASTM D4105/D4105M, D4106, and with reference to Guide D4043 for selection of appropriate procedures.

Key Topics

• Field Procedure Guidance: Detailed instructions on selecting well locations, controlling water withdrawal or injection rates, and measuring water-level changes to produce reliable test data.
• Hydraulic Properties Assessment: Supports the determination of transmissivity and storage coefficient of aquifers, as well as hydraulic conductivity of confining beds.
• Test Planning and Execution:
  • Selection and assessment of control and observation wells or piezometers
  • Pre-test site reconnaissance and conceptual hydrogeological modeling
  • Calibration and use of pumps, data-loggers, sand measurement devices, and water-level recording instruments
  • Adherence to best practice in data collection, significant digits, and calibration
• Data Analysis and Reporting:
  • Structured approach for recording, analyzing, and presenting field data
  • Guidance on plotting drawdown, recovery, and discharge data for interpretation in compliance with referenced analytical standards
  • Emphasis on documentation of well construction, site maps, and calibration records
• Quality Assurance and Limitations: Highlights the influence of personnel competence, equipment suitability, and the importance of adhering to supporting standards such as ASTM D3740 for agency qualification.

Applications

ASTM D4050-20 is widely applied in the following contexts:

• Groundwater Resource Assessment: Accurately characterizing aquifer properties for well field development, water supply planning, and sustainable management.
• Environmental Monitoring and Remediation: Determining aquifer response for contaminated site investigations and remedial system design, including pump-and-treat or aquifer recharge projects.
• Regulatory Compliance: Ensuring methods align with regulatory requirements for water withdrawal, aquifer protection, and environmental impact assessment.
• Engineering and Construction Projects: Supporting the design and safety evaluation of infrastructure reliant on groundwater conditions, such as foundations, tunnels, and cut-off walls.
• Academic and Research Studies: Providing a reliable basis for aquifer testing methodology in scientific research.

By standardizing test methods for withdrawal and injection well testing, D4050-20 helps generate dependable data for groundwater modeling, resource management, and regulatory submissions.

Related Standards

Users should reference additional relevant standards to ensure comprehensive application and compliance:

• ASTM D4105/D4105M: Analytical procedure for transmissivity and storage coefficient in nonleaky confined aquifers
• ASTM D4106: Analytical procedure using Theis Nonequilibrium Method for confined aquifers
• ASTM D4043: Guide for selection of aquifer test method using well techniques
• ASTM D3740: Practice for evaluating agencies conducting soil and rock testing and inspection
• ASTM D6026: Guidance on significant digits in geotechnical data reporting
• ASTM D4044/D4044M: Field procedure for instantaneous change in head (slug) tests
• ASTM D653: Terminology relating to soil, rock, and contained fluids

Keywords: aquifer testing, hydraulic conductivity, transmissivity, storage coefficient, groundwater, injection well, withdrawal well, ASTM D4050, water level measurement, field procedure, aquifer properties, confining beds.

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: D4050 − 20
Standard Test Method for
(Field Procedure) for Withdrawal and Injection Well Testing
for Determining Hydraulic Properties of Aquifer Systems
This standard is issued under the fixed designation D4050; 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* 1.7 This test method offers a set of instructions for perform-
ing one or more operations. This document cannot replace
1.1 This test method covers the field procedure for selecting
educationorexperienceandshouldbeusedinconjunctionwith
well locations, controlling change (discharge or injection)
professionaljudgement.Notallaspectsofthisstandardmaybe
rates, and measuring water levels used to analyze the hydraulic
applicable in all circumstances. This ASTM standard is not
properties of an aquifer or aquifers and adjacent confining
intended to represent or replace the standard of care by which
beds.
the adequacy of a given professional service must be judged,
1.2 This test method is used in conjunction with an analyti-
nor should this document be applied without consideration of
cal procedure such as Test Methods D4105/D4105M or D4106
a projects many unique aspects. The word “Standard” in the
to evaluate the data and determine aquifer properties.
title of this document means only that the document has been
approved through the ASTM consensus process.
1.3 The appropriate field and analytical procedures are
selected as described in Guide D4043. 1.8 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.4 Limitations—The limitations of this test method are
responsibility of the user of this standard to establish appro-
primarily related to the correspondence between the field
priate safety, health, and environmental practices and deter-
situation determined by this test method and the simplifying
mine the applicability of regulatory limitations prior to use.
assumptions of the analyticalTest Methods D4105/D4105M or
1.9 This international standard was developed in accor-
D4106 and D4043.
dance with internationally recognized principles on standard-
1.5 Units—The values stated in SI units are to be regarded
ization established in the Decision on Principles for the
as standard. Reporting of test results in units other than SI shall
Development of International Standards, Guides and Recom-
not be regarded as nonconformance with this standard.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.6 All observed and calculated values shall conform to the
guidelines for significant digits and rounding established in
2. Referenced Documents
Practice D6026.
2.1 ASTM Standards:
1.6.1 Theproceduresusedtospecifyhowdataarecollected/
D653 Terminology Relating to Soil, Rock, and Contained
recorded or calculated, in this standard are regarded as the
Fluids
industry standard. In addition, they are representative of the
D2488 Practice for Description and Identification of Soils
significant digits that generally should be retained. The proce-
(Visual-Manual Procedures)
dures used do not consider material variation, purpose for
D3740 Practice for Minimum Requirements for Agencies
obtaining the data, special purpose studies, or any consider-
Engaged in Testing and/or Inspection of Soil and Rock as
ations for the user’s objectives; and it is common practice to
Used in Engineering Design and Construction
increase or reduce significant digits of reported data to be
D4043 Guide for Selection of Aquifer Test Method in
commensuratewiththeseconsiderations.Itisbeyondthescope
Determining Hydraulic Properties by Well Techniques
of this standard to consider significant digits used in analytical
D4044/D4044M Test Method for (Field Procedure) for In-
methods for engineering design.
stantaneous Change in Head (Slug) Tests for Determining
Hydraulic Properties of Aquifers
Thistestmethodisunder the jurisdiction ofASTM CommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.21 on Groundwater and
Vadose Zone Investigations. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Jan. 1, 2020. Published January 2020. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1991. Last previous edition approved in 2014 as D4050 – 14. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D4050-20. 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
D4050 − 20
D4105/D4105M Test Method for (Analytical Procedure) for evaluated to make sure that sufficient accuracy and sensitivity
Determining Transmissivity and Storage Coefficient of will be provided for the later evaluation of data by D4105/
Nonleaky Confined Aquifers by the Modified Theis Non- D4105M and D4106.
equilibrium Method
6.2 Control Well—Discharge or injection well test methods
D4106 Test Method for (Analytical Procedure) for Deter-
require that water be withdrawn from or injected into a single
mining Transmissivity and Storage Coefficient of Non-
well. This well, known as the control well, must be drilled and
leaky Confined Aquifers by the Theis Nonequilibrium
completed such that it transmits water to or from the aquifer
Method
(usually the entire thickness of the aquifer) at rates such that a
D6026 Practice for Using Significant Digits in Geotechnical
measurable water level change will occur at observation wells.
Data
The control well must be as efficient as possible, to reduce the
head loss between the aquifer and the well. Well development
3. Terminology
should be as complete as possible to eliminate additional
3.1 Definitions:
production of sand or silt and consequent changes in well
3.1.1 For definitions of common technical terms in this
efficiency and pumping water levels during the test. The
standard, refer to Terminology D653.
cuttingsfromthecontrolwell(ifavailable)shouldbedescribed
and recorded according to Practice D2488. The analytical
4. Summary of Test Method
method selected for analysis of the data may specify certain
dimensions of the control well such as screen length and depth
4.1 This test method describes the field practices in con-
of screen placement. Specific requirements for control wells
ducting aquifer performance tests by either withdrawal or
are given in standards for specific analytical methods (see, for
injection through a well point. These methods involve chang-
example, Test Methods D4105/D4105M and D4106).
ing the control well water level by either the withdrawal of
waterfromorinjectionofwatertoanaquiferandmeasurement
6.3 Observation Wells or Piezometers—Numbers of obser-
of the water-level response in the aquifer. The analysis of the
vation wells and their distance from the control well and their
data from this field practice is described in standards such as
screened interval may be dependent upon the test method to be
Test Methods D4105/D4105M and D4106.
employed. Refer to the analytical test method to be used for
specifications of observation wells (see, for example, Test
NOTE 1—The injection or withdrawal of water into an aquifer may be
regulated or require regulatory approvals. Withdrawal of contaminated Methods D4105/D4105M and D4106).
waters may require that the removed water be treated prior to discharge.
6.4 Control Well Pump—A pump capable of withdrawal or
injection of a constant or predetermined variable rate of water
5. Significance and Use
to or from the control well. The pump and motor must be
5.1 Withdrawal or injection well test field procedures are
adequately sized for the designed pumping rate and lift. The
used with appropriate analytical procedures in appropriate
pump or motor must be equipped with a control mechanism to
hydrogeological sites to determine transmissivity and storage
adjust discharge rate. In the case of diesel-, gasoline-, or
coefficient of aquifers and hydraulic conductivity of confining
natural-gas-fueled engines, throttle settings need to allow for
beds.
small adjustments in pumping rates. Pumps equipped with
5.2 Practice D3740 provides evaluation factors for the electric motors are usually controlled by adjusting back pres-
activities in this test method. sure on the pump through a gate valve in the discharge line.
Take care to select a discharge rate small enough such that the
NOTE 2—The quality of the result produced by this standard is
rate can be maintained throughout the test without fully
dependent on the competence of the personnel performing it, and the
openingthegatevalve.Ifneithermethodofcontrolispractical,
suitability of the equipment and facilities used. Agencies that meet the
criteria of Practice D3740 are generally considered capable of competent
split the discharge and route part of the discharge back to the
and objective testing/sampling/inspection/etc. Users of this standard are
well through a separate discharge line. If water is withdrawn,
cautioned that compliance with Practice D3740 does not in itself assure
the discharge should be at a distance sufficiently away from the
reliable results. Reliable results depend on many factors; Practice D3740
area to prevent recharging back into the aquifer being tested.
provides a means of evaluating some of those factors.
6.5 Many aquifer tests are made at “sites of opportunity,”
5.3 This test method may be limited due to the correspon-
that is, using existing production or monitoring wells as the
dence between the field situation determined by this test
control well and using other existing wells for observation of
method and the simplifying assumptions of the analytical Test
water level. In such cases, evaluate the locations and screened
Methods D4105/D4105M or D4106 and D4043.
intervalsofthewellsforcompatibilitywiththerequirementsof
the method of test analysis.
6. Apparatus
6.1 Various types of equipment can be used to withdraw or 6.6 Water-Level Measurement Equipment—Manual mea-
inject water into the control well, measure withdrawal and surements can be made with a steel tape or electric tape, with
injection rates, and measure water levels. The test procedure a mechanical recorder linked to a float, or combination of
may be conducted with different types of equipment to achieve pressure transducer and electronic data logger.The accuracy of
similar results. The objectives to be achieved by the use of the the water level measurement must be adequate to satisfy the
equipmentaregiveninthissectionandinSections7and8.The requirements of D4105/D4105M and D4106. Generally a
selection of equipment and measuring apparatus will be water level accuracy of 0.254 cm should be adequate.
D4050 − 20
6.6.1 Mechanical Recorders—Mechanicalrecordersemploy 7.1.3 Testing of Control Well—Conduct a short term pre-
a float in the well to produce a graphic record of water level liminary test of the control well to estimate hydraulic proper-
changes. Early in the test, it may be difficult to distinguish tiesoftheaquifer,estimatethedurationofthetestandestablish
small increments of time on the recorder chart, therefore the a pumping rate for the field procedure.
recorderreadingsshouldbesupplementedwithadditionalearly 7.1.4 Testing Observation Wells—Test the observation wells
time measurements or by marking the trace of an automatic or piezometers prior to the aquifer test to make sure that they
water-level recorder chart and recording the time by the mark. are hydraulically connected to the aquifer. Accomplish this by
Check the mechanical recorder periodically throughout the test adding or withdrawing a known volume of water (slug) and
using the steel tape. measure the water-level response in the well. The resultant
6.6.2 Pressure Transducers and Electronic Data response needs to be rapid enough to make sure that the water
Loggers—A combination of a pressure transducer and elec- levelinthepiezometerwillreflectthewaterlevelintheaquifer
tronic data logger can provide rapid measurements of water- duringthetest.Redeveloppiezometerswithunusuallysluggish
level change, and can be programmed to sample at a higher response.Informationonperformingaslugtestcanbefoundin
frequency early in the test and a reduced frequency late in the Test Method D4044/D4044M.
test. Select the pressure transducer to measure pressure 7.1.5 Measuring Pre-Testing Water-Level Trends—Measure
and record water levels in the observationwells prior tostart of
changes equivalent to the range of expected water level
changes. Check the transducer in the field by raising and pumping for a period long enough to establish the static
pre-test water level trend. This period is at least equal to t
...

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: D4050 − 14 D4050 − 20
Standard Test Method for
(Field Procedure) for Withdrawal and Injection Well Testing
for Determining Hydraulic Properties of Aquifer Systems
This standard is issued under the fixed designation D4050; 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 the field procedure for selecting well locations, controlling change (discharge or injection) rates,
and measuring water levels used to analyze the hydraulic properties of an aquifer or aquifers and adjacent confining beds.
1.2 This test method is used in conjunction with an analytical procedure such as Test Methods D4105D4105/D4105M or D4106
to evaluate the data and determine aquifer properties.
1.3 The appropriate field and analytical procedures are selected as described in Guide D4043.
1.4 Limitations—Limitations—TheThe limitations of this test method are primarily related to the correspondence between the
field situation determined by this test method and the simplifying assumptions of the analytical Test Methods D4105D4105/
D4105M or D4106D4106 and D4043D4043. .
1.5 Units—The values stated in SI units are to be regarded as standard. Reporting of test results in units other than SI shall not
be regarded as nonconformance with this standard.
1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice
D6026D6026. .
1.6.1 The procedures used to specify how data are collected/recorded or calculated, in this 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 analytical methods for engineering design.
1.7 This test method offers a set of instructions for performing one or more operations. This document cannot replace education
or experience and should be used in conjunction with professional judgement. Not all aspects of this standard may be applicable
in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of
a given professional service must be judged, nor should this document be applied without consideration of a projects many unique
aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM
consensus process.
1.8 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.9 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.
2. Referenced Documents
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained Fluids
This test method 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, 2014Jan. 1, 2020. Published July 2014January 2020. Originally approved in 1991. Last previous edition approved in 20082014 as
D4050 – 96 (2008).D4050 – 14. DOI: 10.1520/D4050-14.10.1520/D4050-20.
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
D4050 − 20
D2488 Practice for Description and Identification of Soils (Visual-Manual Procedures)
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
D4044D4044/D4044M Test Method for (Field Procedure) for Instantaneous Change in Head (Slug) Tests for Determining
Hydraulic Properties of Aquifers
D4105D4105/D4105M Test Method for (Analytical Procedure) for Determining Transmissivity and Storage Coefficient of
Nonleaky Confined Aquifers by the Modified Theis Nonequilibrium Method
D4106 Test Method 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—Definitions: For definitions of common technical terms in this test method, refer to Terminology D653.
3.1.1 For definitions of common technical terms in this standard, refer to Terminology D653.
4. Summary of Test Method
4.1 This test method describes the field practices in conducting aquifer performance tests by either withdrawal or injection
through a well point. These methods involve changing the control well water level by either the withdrawal of water from or
injection of water to an aquifer and measurement of the water-level response in the aquifer. The analysis of the data from this field
practice is described in standards such as Test Methods D4105D4105/D4105M and D4106.
NOTE 1—The injection or withdrawal of water into an aquifer may be regulated or require regulatory approvals. Withdrawal of contaminated waters
may require that the removed water be properly treated prior to discharge.
5. Significance and Use
5.1 Withdrawal or injection well test field procedures are used with appropriate analytical procedures in appropriate
hydrogeological sites to determine transmissivity and storage coefficient of aquifers and hydraulic conductivity of confining beds.
5.2 Practice D3740 provides evaluation factors for the activities in this test method.
NOTE 2—The quality of the result produced by this standard 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 standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable
results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
5.3 This test method may be limited due to the correspondence between the field situation determined by this test method and
the simplifying assumptions of the analytical Test Methods D4106D4105/D4105M or D4106D4106 and D4043D4043.
6. Apparatus
6.1 Various types of equipment can be used to withdraw or inject water into the control well, measure withdrawal and injection
rates, and measure water levels. The test procedure may be conducted with different types of equipment to achieve similar results.
The objectives to be achieved by the use of the equipment are given in this section and in Sections 7 and 8. The selection of
equipment and measuring apparatus will be evaluated to ensure make sure that sufficient accuracy and sensitivity will be provided
for the later evaluation of data by D4105D4105/D4105M and D4106D4106.
6.2 Control Well—Discharge or injection well test methods require that water be withdrawn from or injected into a single well.
This well, known as the control well, must be drilled and completed such that it transmits water to or from the aquifer (usually
the entire thickness of the aquifer) at rates such that a measurable water level change will occur at observation wells. The control
well shouldmust be as efficient as possible, to reduce the head loss between the aquifer and the well. Well development should be
as complete as possible to eliminate additional production of sand or silt and consequent changes in well efficiency and pumping
water levels during the test. The cuttings from the control well (if available) should be described and recorded according to Practice
D2488. The analytical method selected for analysis of the data may specify certain dimensions of the control well such as screen
length and depth of screen placement. Specific requirements for control wells may be are given in standards for specific analytical
methods (see, for example, Test Methods D4105D4105/D4105M and D4106).
6.3 Observation Wells or Piezometers—Numbers of observation wells and their distance from the control well and their
screened interval may be dependent upon the test method to be employed. Refer to the analytical test method to be used for
specifications of observation wells (see, for example, Test Methods D4105D4105/D4105M and D4106).
6.4 Control Well Pump—A pump capable of withdrawal or injection of a constant or predetermined variable rate of water to or
from the control well. The pump and motor shouldmust be adequately sized for the designed pumping rate and lift. The pump or
motor must be equipped with a control mechanism to adjust discharge rate. In the case of diesel-, gasoline-, or natural-gas-fueled
D4050 − 20
engines, throttle settings should need to allow for small adjustments in pumping rates. Pumps equipped with electric motors are
usually controlled by adjusting back pressure on the pump through a gate valve in the discharge line. Take care to select a discharge
rate small enough such that the rate can be maintained throughout the test without fully opening the gate valve. If neither method
of control is practical, split the discharge and route part of the discharge back to the well through a separate discharge line. If water
is withdrawn, the discharge should be at a distance sufficiently away from the area to prevent recharging back into the aquifer being
tested.
6.5 Many aquifer tests are made at “sites of opportunity,” that is, using existing production or monitoring wells as the control
well and using other existing wells for observation of water level. In such cases cases, evaluate the locations and screened intervals
of the wells should be compatible for compatibility with the requirements of the method of test analysis.
6.6 Water-Level Measurement Equipment—Manual measurements can be made with a steel tape or electric tape, with a
mechanical recorder linked to a float, or combination of pressure transducer and electronic data logger. The accuracy of the water
level measurement shouldmust be adequate to satisfy the requirements of D4105D4105/D4105M and D4106D4106. Generally a
water level accuracy of 0.254 cm should be adequate.
6.6.1 Mechanical Recorders—Mechanical recorders employ a float in the well to produce a graphic record of water level
changes. Early in the test, it may be difficult to distinguish small increments of time on the recorder chart, therefore the recorder
readings should be supplemented with additional early time measurements or by marking the trace of an automatic water-level
recorder chart and recording the time by the mark. Check the mechanical recorder periodically throughout the test using the steel
tape.
6.6.2 Pressure Transducers and Electronic Data Loggers—A combination of a pressure transducer and electronic data logger
can provide rapid measurements of water-level change, and can be programmed to sample at a higher frequency early in the test
and a reduced frequency late in the test. Select the pressure transducer to measure pressure changes equivalent to the range of
expected water level changes. Check the transducer in the field by raising and lowering the transducer a measured distance in the
well. Also check the transducer readings periodically with a steel tape.
NOTE 3—Pressure transducers have ratings that are depth specific and should be selected to measure the expected range of water levels.
6.6.3 Equipment used for measuring flows and water levels shouldmust have calibration records, or be calibrated for the test.
6.7 Sand Content Measurement Device—Apparatus to measure the sand content in discharged water. Cone Types (for example,
Imhoff) can be used for higher concentrations of sand in the discharge water and centrifugal sand separators (for example, Rossum)
can be used for lower levels and are commercially available and commonly used.
6.8 Barometric Pressure—Barometric pressures should be determined and routinely logged, Determine the barometric pressures
and routinely log the data, particularly if the test is of a long duration, such as over several days between the initial and finalend
readings.
7. Conditioning
7.1 Pre-Test Procedures:
7.1.1 Selecting Aquifer-Test Method—Develop a conceptual model of the site hydrogeology and select the appropriate aquifer
test method according to Guide D4043. Observe the requirements of the selected test method with regard to specifications for the
control well and observations wells.
7.1.2 Field Reconnaissance—
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