ASTM D4750-87(2001)
(Test Method)Standard Test Method for Determining Subsurface Liquid Levels in a Borehole or Monitoring Well (Observation Well) (Withdrawn 2010)
Standard Test Method for Determining Subsurface Liquid Levels in a Borehole or Monitoring Well (Observation Well) (Withdrawn 2010)
SIGNIFICANCE AND USE
In geotechnical, hydrologic, and waste-management investigations, it is frequently desirable, or required, to obtain information concerning the presence of ground water or other liquids and the depths to the ground-water table or other liquid surface. Such investigations typically include drilling of exploratory boreholes, performing aquifer tests, and possibly completion as a monitoring or observation well. The opportunity exists to record the level of liquid in such boreholes or wells, as the boreholes are being advanced and after their completion.
Conceptually, a stabilized borehole liquid level reflects the pressure of ground water or other liquid in the earth material exposed along the sides of the borehole or well. Under suitable conditions, the borehole liquid level and the ground-water, or other liquid, level will be the same, and the former can be used to determine the latter. However, when earth materials are not exposed to a borehole, such as material which is sealed off with casing or drilling mud, the borehole water levels may not accurately reflect the ground-water level. Consequently, the user is cautioned that the liquid level in a borehole does not necessarily bear a relationship to the ground-water level at the site.
The user is cautioned that there are many factors which can influence borehole liquid levels and the interpretation of borehole liquid-level measurements. These factors are not described or discussed in this test method. The interpretation and application of borehole liquid-level information should be done by a trained specialist.
Installation of piezometers should be considered where complex ground-water conditions prevail or where changes in intergranular stress, other than those associated with fluctuation in water level, have occurred or are anticipated.
SCOPE
1.1 This test method describes the procedures for measuring the level of liquid in a borehole or well and determining the stabilized level of liquid in a borehole.
1.2 The test method applies to boreholes (cased or uncased) and monitoring wells (observation wells) that are vertical or sufficiently vertical so a flexible measuring device can be lowered into the hole.
1.3 Borehole liquid-level measurements obtained using this test method will not necessarily correspond to the level of the liquid in the vicinity of the borehole unless sufficient time has been allowed for the level to reach equilibrium position.
1.4 This test method generally is not applicable for the determination of pore-pressure changes due to changes in stress conditions of the earth material.
1.5 This test method is not applicable for the concurrent determination of multiple liquid levels in a borehole.
1.6 The values stated in inch-pound units are to be regarded as the standard.
1.7 This standard does not purport to address all of the safety problems, 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.
WITHDRAWN RATIONALE
This test method describes the procedures for measuring the level of liquid in a borehole or well and determining the stabilized level of liquid in a borehole.
Formerly under the jurisdiction of Committee D18 on Soil and Rock, this test method was withdrawn in February 2010 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:D4750–87 (Reapproved 2001)
Standard Test Method for
Determining Subsurface Liquid Levels in a Borehole or
Monitoring Well (Observation Well)
This standard is issued under the fixed designation D4750; 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 Normally, a borehole is advanced using an auger, a drill, or
casing with or without drilling fluid.
1.1 This test method describes the procedures for measuring
3.1.2 earth material—soil, bedrock, or fill.
the level of liquid in a borehole or well and determining the
3.1.3 ground-water level—the level of the water table sur-
stabilized level of liquid in a borehole.
rounding a borehole or well. The ground-water level can be
1.2 The test method applies to boreholes (cased or uncased)
represented as an elevation or as a depth below the ground
and monitoring wells (observation wells) that are vertical or
surface.
sufficiently vertical so a flexible measuring device can be
3.1.4 liquid level—the level of liquid in a borehole or well
lowered into the hole.
at a particular time. The liquid level can be reported as an
1.3 Borehole liquid-level measurements obtained using this
elevation or as a depth below the top of the land surface. If the
test method will not necessarily correspond to the level of the
liquid is ground water it is known as water level.
liquid in the vicinity of the borehole unless sufficient time has
3.1.5 monitoring well (observation well)—a special well
been allowed for the level to reach equilibrium position.
drilled in a selected location for observing parameters such as
1.4 This test method generally is not applicable for the
liquid level or pressure changes or for collecting liquid
determination of pore-pressure changes due to changes in
samples. The well may be cased or uncased, but if cased the
stress conditions of the earth material.
casing should have openings to allow flow of borehole liquid
1.5 This test method is not applicable for the concurrent
into or out of the casing.
determination of multiple liquid levels in a borehole.
3.1.6 stabilized borehole liquid level—the borehole liquid
1.6 The values stated in inch-pound units are to be regarded
level which remains essentially constant with time, that is,
as the standard.
liquid does not flow into or out of the borehole.
1.7 This standard does not purport to address all of the
3.1.7 top of borehole—the surface of the ground surround-
safety problems, if any, associated with its use. It is the
ing the borehole.
responsibility of the user of this standard to establish appro-
3.1.8 water table (ground-water table)—the surface of a
priate safety and health practices and determine the applica-
ground-water body at which the water pressure equals atmo-
bility of regulatory limitations prior to use.
spheric pressure. Earth material below the ground-water table
2. Referenced Documents
is saturated with water.
3.2 Definitions:
2.1 ASTM Standards:
3.2.1 For definitions of other terms used in this test method,
D653 Terminology Relating to Soil, Rock, and Contained
see Terminology D653.
Fluids
4. Significance and Use
3. Terminology
4.1 In geotechnical, hydrologic, and waste-management
3.1 Definitions of Terms Specific to This Standard:
investigations, it is frequently desirable, or required, to obtain
3.1.1 borehole—aholeofcircularcross-sectionmadeinsoil
information concerning the presence of ground water or other
or rock to ascertain the nature of the subsurface materials.
liquids and the depths to the ground-water table or other liquid
surface. Such investigations typically include drilling of ex-
ploratory boreholes, performing aquifer tests, and possibly
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.21 on GroundWater and
completion as a monitoring or observation well. The opportu-
Vadose Zone Investigations.
nity exists to record the level of liquid in such boreholes or
Current edition approved Nov. 27, 1987. Published January 1988. DOI: 10.1520/
wells, as the boreholes are being advanced and after their
D4750-87R01.
Annual Book of ASTM Standards, Vol 04.08. completion.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4750–87 (2001)
4.2 Conceptually, a stabilized borehole liquid level reflects 6. Calibration and Standardization
the pressure of ground water or other liquid in the earth
6.1 Calibrate measuring apparatus in accordance with the
materialexposedalongthesidesoftheboreholeorwell.Under
manufacturers’ directions.
suitable conditions, the borehole liquid level and the ground-
water, or other liquid, level will be the same, and the former
7. Procedure
can be used to determine the latter. However, when earth
7.1 Liquid-level measurements are made relative to a refer-
materials are not exposed to a borehole, such as material which
ence point. Establish and identify a reference point at or near
is sealed off with casing or drilling mud, the borehole water
the top of the borehole or a well casing. Determine and record
levels may not accurately reflect the ground-water level.
the distance from the reference point to the top of the borehole
Consequently, the user is cautioned that the liquid level in a
(land surface). If the borehole liquid level is to be reported as
borehole does not necessarily bear a relationship to the
an elevation, determine the elevation of the reference point or
ground-water level at the site.
the top of borehole (land surface). Three alternative measure-
4.3 The user is cautioned that there are many factors which
ment procedures (A, B, and C) are described.
can influence borehole liquid levels and the interpretation of
NOTE 1—In general, ProcedureAallows for greater accuracy than B or
borehole liquid-level measurements. These factors are not
C, and B allows for greater accuracy than C; other procedures have a
described or discussed in this test method. The interpretation
variety of accuracies that must be determined from the referenced
and application of borehole liquid-level information should be
literature (2-5).
done by a trained specialist.
7.2 Procedure A—Measuring Tape:
4.4 Installation of piezometers should be considered where
7.2.1 Chalk the lower few feet of tape by drawing the tape
complex ground-water conditions prevail or where changes in
across a piece of colored carpenter’s chalk.
intergranular stress, other than those associated with fluctua-
7.2.2 Lower a weighted measuring tape slowly into the
tion in water level, have occurred or are anticipated.
borehole or well until the liquid surface is penetrated. Observe
and record the reading on the tape at the reference point.
5. Apparatus
Withdraw the tape from the borehole and observe the lower
5.1 Apparatus conforming to one of the following shall be end of the tape. The demarcation between the wetted and
unwetted portions of the chalked tape should be apparent.
used for measuring borehole liquid levels:
Observe and record the reading on the tape at that point. The
5.1.1 Weighted Measuring Tape—A measuring tape with a
difference between the two readings is the depth from the
weightattachedtotheend.Thetapeshallhavegraduationsthat
reference point to the liquid level.
can be read to the nearest 0.01 ft. The tape shall not stretch
more than 0.05% under normal use. Steel surveying tapes in
NOTE 2—Submergence of the weight and tape may temporarily cause a
lengths of 50, 100, 200, 300, and 500 ft (20, 30, 50 or 100 m)
liquid-level rise in wells or boreholes having very small diameters. This
and widths of ⁄4 in. (6 mm) are commonly used.Ablack metal effect can be significant if the well is in materials of very low hydraulic
conductivity.
tape is better than a chromium-plated tape. Tapes are mounted
NOTE 3—Under dry surface conditions, it may be desirable to pull the
on hand-cranked reels up to 500 ft (100 m) lengths. Mount a
tape from the well or borehole by hand, being careful not to allow it to
slender weight, made of lead, to the end of the tape to ensure
become kinked, and reading the liquid mark before rewinding the tape
plumbness and to permit some feel for obstructions.Attach the
onto the reel. In this way, the liquid mark on the chalked part of the tape
weight to the tape with wire strong enough to hold the weight
is rapidly brought to the surface before the wetted part of the tape dries.
but not as strong as the tape.This permits saving the tape in the
In cold regions, rapid withdrawal of the tape from the well is necessary
before the wet part freezes and becomes difficult to read.The tape must be
event the weight becomes lodged in the well or borehole. The
protected if rain is falling during measurements.
size of the weight shall be such that its displacement of water
NOTE 4—Insomepumpedwells,orincontaminatedwells,alayerofoil
causes less than a 0.05-ft (15-mm) rise in the borehole water
may float on the water. If the oil layer is only a foot or less thick, read the
level, or a correction shall be made for the displacement. If the
tape at the top of the oil mark and use this reading for the water-level
weight extends beyond the end of the tape, a length correction
measurement. The measurement will not be greatly in error because the
will be needed in measurement Procedure C (see 7.2.3).
level of the oil surface in this case will differ only slightly from the level
5.1.2 Electrical Measuring Device—A cable or tape with of the water surface that would be measured if no oil was present. If
several feet of oil are present in the well, or if it is necessary to know the
electrical wire encased, equipped with a weighted sensing tip
thickness of the oil layer, a water-detector paste for detecting water in oil
on one end and an electric meter at the other end. An electric
and gasoline storage tanks is available commercially. The paste is applied
circuit is completed when the tip contacts water; this is
to the lower end of the tape that is submerged in the well. It will show the
registered on the meter. The cable may be marked with
top of the oil as a wet line and the top of the water as a distinct color
graduations similar to a measuring tape (as described in 5.1.1).
change.
5.1.3 Other Measuring Devices—Anumber of other record-
7.2.3 As a standard of good practice, the observer should
ing and non-recording devices may be used. See Ref. (1) for
make two measurements. If two measu
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