ASTM D4050-96(2008)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D4050 − 96(Reapproved 2008)
Standard Test Method for
(Field Procedure) for Withdrawal and Injection Well Tests 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 D4750 Test Method for Determining Subsurface Liquid
Levels in a Borehole or Monitoring Well (Observation
1.1 This test method covers the field procedure for selecting
Well) (Withdrawn 2010)
well locations, controlling discharge or injection rates, and
measuringwaterlevelsusedtoanalyzethehydraulicproperties
3. Terminology
of an aquifer or aquifers and adjacent confining beds.
3.1 Definitions:
1.2 This test method is used in conjunction with an analyti-
3.1.1 aquifer, confined—an aquifer bounded above and be-
cal procedure such as Test Methods D4105 or D4106 to
low by confining beds and in which the static head is above the
determine aquifer properties.
top of the aquifer.
1.3 The appropriate field and analytical procedures are
3.1.2 confining bed—a hydrogeologic unit of less permeable
selected as described in Guide D4043.
material bounding one or more aquifers.
1.4 This standard does not purport to address all of the
3.1.3 control well—well by which the head and flow in the
safety concerns, if any, associated with its use. It is the
aquifer is changed, for example, by pumping, injection, or
responsibility of the user of this standard to establish appro-
change of head.
priate safety and health practices and determine the applica-
3.1.4 hydraulic conductivity (field aquifer tests)—the vol-
bility of regulatory limitations prior to use.
ume of water at the existing kinematic viscosity that will move
2. Referenced Documents
in a unit time under a unit hydraulic gradient through a unit
area measured at right angles to the direction of flow.
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained 3.1.5 observation well—a well open to all or part of an
Fluids aquifer.
D2488 Practice for Description and Identification of Soils
3.1.6 piezometer—a device used to measure hydraulic head
(Visual-Manual Procedure)
at a point in the subsurface.
D4043 Guide for Selection of Aquifer Test Method in
3.1.7 specific storage—the volume of water released from
Determining Hydraulic Properties by Well Techniques
or taken into storage per unit volume of the porous medium per
D4105 Test Method for (Analytical Procedure) for Deter-
unit change in head.
mining Transmissivity and Storage Coefficient of Non-
3.1.8 storage coeffıcient —the volume of water an aquifer
leaky Confined Aquifers by the Modified Theis Nonequi-
releases from or takes into storage per unit surface area of the
librium Method
aquifer per unit change in head. For a confined aquifer, the
D4106 Test Method for (Analytical Procedure) for Deter-
storagecoefficientisequaltotheproductofthespecificstorage
mining Transmissivity and Storage Coefficient of Non-
and aquifer thickness. For an unconfined aquifer, the storage
leaky Confined Aquifers by the Theis Nonequilibrium
coefficient is approximately equal to the specific yield.
Method
3.1.9 transmissivity—the volume of water at the existing
kinematic viscosity that will move in a unit time under a unit
This test method is under the jurisdiction ofASTM Committee D18 on Soil and
hydraulic gradient through a unit width of the aquifer.
Rock and is the direct responsibility of Subcommittee D18.21 on Groundwater and
Vadose Zone Investigations.
3.1.10 For definitions of other terms used in this test
Current edition approved Sept. 15, 2008. Published October 2008. Originally
method, see Terminology D653.
approved in 1991. Last previous edition approved in 2002 as D4050 – 96 (2002).
DOI: 10.1520/D4050-96R08.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
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D4050 − 96 (2008)
4. Summary of Test Method a discharge rate small enough such that the rate can be
maintained throughout the test without fully opening the gate
4.1 This test method describes the field practices in con-
valve. If neither method of control is practical, split the
ducting withdrawal and injection well tests. These methods
discharge and route part of the discharge back to the well
involve withdrawal of water from or injection of water to an
through a separate discharge line.
aquifer through a control well and measurement of the water-
level response in the aquifer. The analysis of the data from this
6.5 Many aquifer tests are made at “sites of opportunity,”
field practice is described in standards such as Test Methods
that is, using existing production wells as the control well and
D4105 and D4106.
using other existing wells for observation of water level. In
such cases the locations and screened intervals of the wells
5. Significance and Use
should be compatible with the requirements of the method of
test analysis.
5.1 Withdrawal and injection well test field procedures are
used with appropriate analytical procedures in appropriate
6.6 Water-Level Measurement Equipment—Manual mea-
hydrogeological sites to determine transmissivity and storage
surements can be made with a steel tape or electric tape as
coefficient of aquifers and hydraulic conductivity of confining
described in Test Method D4750, with a mechanical recorder
beds.
linked to a float, or combination of pressure transducer and
electronic data logger.
6. Apparatus
6.6.1 Mechanical Recorders—Mechanicalrecordersemploy
6.1 Various types of equipment can be used to withdraw or
a float in the well to produce a graphic record of water level
inject water into the control well, measure withdrawal and
changes. Early in the test, it may be difficult to distinguish
injection rates, and measure water levels. The test procedure
small increments of time on the recorder chart, therefore the
may be conducted with different types of equipment to achieve
recorder should be supplemented with additional early time
similar results. The objectives to be achieved by the use of the
measurements or by marking the trace of an automatic water-
equipment are given in this section and in Sections 7 and 8.
level recorder chart and recording the time by the mark. Check
the mechanical recorder periodically throughout the test using
6.2 Control Well—Discharge or injection well test methods
the steel tape.
require that water be withdrawn from or injected into a single
well. This well, known as the control well, must be drilled and 6.6.2 Pressure Transducers and Electronic Data
completed such that it transmits water to or from the aquifer Loggers—A combination of a pressure transducer and elec-
(usually the entire thickness of the aquifer) at rates such that a tronic data logger can provide rapid measurements of water-
level change, and can be programmed to sample at reduced
measurable water level change will occur at observation wells.
Thecontrolwellshouldbeasefficientaspossible,toreducethe frequency late in the test. Select the pressure transducer to
measure pressure changes equivalent to the range of expected
head loss between the aquifer and the well. Well development
should be as complete as possible to eliminate additional water level changes. Check the transducer in the field by
raising and lowering the transducer a measured distance in the
production of sand or silt and consequent changes in well
efficiency and pumping water levels during the test. The well. Also check the transducer readings periodically with a
steel tape.
cuttings from the control well should be described and re-
corded according to Practice D2488. The analytical method
selectedforanalysisofthedatamayspecifycertaindimensions 7. Conditioning
of the control well such as screen length and depth of screen
7.1 Pre-Test Procedures:
placement. Specific requirements for control wells may be
7.1.1 Selecting Aquifer-Test Method—Develop a conceptual
given in standards for specific analytical methods (see, for
model of the site hydrogeology and select the appropriate
example, Test Methods D4105 and D4106).
aquifer test method according to Guide D4043. Observe the
6.3 Observation Wells or Piezometers—Numbers of obser-
requirements of the selected test method with regard to
vation wells and their distance from the control well and their
specifications for the control well and observations wells.
screened interval may be dependent upon the test method to be
7.1.2 Field Reconnaissance—Make a field reconnaissance
employed. Refer to the analytical test method to be used for
of the site before conducting the test to include as much detail
specifications of observation wells (see, for example, Test
as possible on depth, continuity, extent, and preliminary
Methods D4105 and D4106).
estimates of the hydrologic properties of the aquifers and
6.4 Control Well Pump—A pump capable of withdrawal of confining beds. Note the location of existing wells and water-
a constant or predetermined variable rate of water from the holding or conveying structures that might interfere with the
control well. The pump and motor should be adequately sized test. The control should be equipped with a pipeline or
for the designed pumping rate and lift. The pump or motor conveyancestructureadequatetotransmitthewaterawayfrom
mustbeequippedwithacontrolmechanismtoadjustdischarge the test site, so that recharge is not induced near the site. Make
rate. In the case of diesel-, gasoline-, or natural-gas-fueled arrangements to ensure that nearby wells are turned off well
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