ASTM D6429-99(2006)
(Guide)Standard Guide for Selecting Surface Geophysical Methods
Standard Guide for Selecting Surface Geophysical Methods
SCOPE
1.1 This guide covers the selection of surface geophysical methods, as commonly applied to geologic, geotechnical, hydrologic, and environmental investigations (hereafter referred to as site characterization), as well as forensic and archaeological applications. This guide does not describe the specific procedures for conducting geophysical surveys. Individual guides are being developed for each surface geophysical method.
1.2 Surface geophysical methods yield direct and indirect measurements of the physical properties of soil and rock and pore fluids, as well as buried objects.
1.3 The geophysical methods presented in this guide are regularly used and have been proven effective for hydrologic, geologic, geotechnical, and hazardous waste site assessments.
1.4 This guide provides an overview of applications for which surface geophysical methods are appropriate. It does not address the details of the theory underlying specific methods, field procedures, or interpretation of the data. Numerous references are included for that purpose and are considered an essential part of this guide. It is recommended that the user of this guide be familiar with the references cited () and with Guides D 420, D 5730, D 5753, D 5777, and D 6285, as well as Practices D 5088, D 5608, D 6235, and Test Method G 57.
1.5 To obtain detailed information on specific geophysical methods, ASTM standards, other publications, and references cited in this guide, should be consulted.
1.6 The success of a geophysical survey is dependent upon many factors. One of the most important factors is the competence of the person(s) responsible for planning, carrying out the survey, and interpreting the data. An understanding of the method's theory, field procedures, and interpretation along with an understanding of the site geology, is necessary to successfully complete a survey. Personnel not having specialized training or experience should be cautious about using geophysical methods and should solicit assistance from qualified practitioners.
1.7 The values stated in SI units are to be regarded as the guide. The values given in parentheses are for information only.
1.8 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide 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 project's 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.
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.
General Information
Relations
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:D6429–99 (Reapproved 2006)
Standard Guide for
Selecting Surface Geophysical Methods
This standard is issued under the fixed designation D6429; 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 The values stated in SI units are to be regarded as the
guide. The values given in parentheses are for information
1.1 This guide covers the selection of surface geophysical
only.
methods, as commonly applied to geologic, geotechnical,
1.8 This guide offers an organized collection of information
hydrologic, and environmental investigations (hereafter re-
or a series of options and does not recommend a specific
ferred to as site characterization), as well as forensic and
course of action. This document cannot replace education or
archaeological applications. This guide does not describe the
experience and should be used in conjunction with professional
specific procedures for conducting geophysical surveys. Indi-
judgment. Not all aspects of this guide may be applicable in all
vidualguidesarebeingdevelopedforeachsurfacegeophysical
circumstances. This ASTM standard is not intended to repre-
method.
sent or replace the standard of care by which the adequacy of
1.2 Surface geophysical methods yield direct and indirect
a given professional service must be judged, nor should this
measurements of the physical properties of soil and rock and
document be applied without consideration of a project’s many
pore fluids, as well as buried objects.
unique aspects. The word “Standard” in the title of this
1.3 The geophysical methods presented in this guide are
document means only that the document has been approved
regularly used and have been proven effective for hydrologic,
through the ASTM consensus process.
geologic, geotechnical, and hazardous waste site assessments.
1.9 This standard does not purport to address all of the
1.4 This guide provides an overview of applications for
safety concerns, if any, associated with its use. It is the
which surface geophysical methods are appropriate. It does not
responsibility of the user of this standard to establish appro-
address the details of the theory underlying specific methods,
priate safety and health practices and determine the applica-
field procedures, or interpretation of the data. Numerous
bility of regulatory limitations prior to use.
references are included for that purpose and are considered an
essential part of this guide. It is recommended that the user of
2. Referenced Documents
thisguidebefamiliarwiththereferencescited(1-20) andwith
2.1 ASTM Standards:
Guides D420, D5730, D5753, D5777, and D6285, as well as
D420 Guide to Site Characterization for Engineering De-
Practices D5088, D5608, D6235, and Test Method G57.
sign and Construction Purposes
1.5 To obtain detailed information on specific geophysical
D653 Terminology Relating to Soil, Rock, and Contained
methods, ASTM standards, other publications, and references
Fluids
cited in this guide, should be consulted.
D4428/D4428M Test Methods for Crosshole Seismic Test-
1.6 The success of a geophysical survey is dependent upon
ing
many factors. One of the most important factors is the
D5088 Practice for Decontamination of Field Equipment
competence of the person(s) responsible for planning, carrying
Used at Waste Sites
out the survey, and interpreting the data. An understanding of
D5608 Practices for Decontamination of Field Equipment
the method’s theory, field procedures, and interpretation along
Used at Low Level Radioactive Waste Sites
with an understanding of the site geology, is necessary to
D5730 Guide for Site Characterization for Environmental
successfully complete a survey. Personnel not having special-
Purposes With Emphasis on Soil, Rock, the Vadose Zone
ized training or experience should be cautious about using
and Ground Water
geophysical methods and should solicit assistance from quali-
D5753 Guide for Planning and Conducting Borehole Geo-
fied practitioners.
physical Logging
D5777 Guide for Using the Seismic Refraction Method for
ThisguideisunderthejurisdictionofASTMCommitteeD18onSoilandRock
Subsurface Investigation
and is the direct responsibility of Subcommittee D18.01 on Surface and Subsurface
Characterization.
Current edition approved March 15, 2006. Published May 2006. Originally
approved in 1999. Last previous edition approved in 1999 as D6429–99. DOI:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D6429-99R06.
2 contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
The boldface numbers given in parentheses refer to a list of references at the
Standards volume information, refer to the standard’s Document Summary page on
end of this standard.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6429–99 (2006)
D6235 Practice for Expedited Site Characterization of Va- 5. Significance and Use
dose Zone and Ground Water Contamination at Hazardous
5.1 This guide applies to commonly used surface geophysi-
Waste Contaminated Sites
cal methods for those applications listed in Table 1. The rating
D6285 Guide for Locating Abandoned Wells
systemusedinTable1isbasedupontheabilityofeachmethod
G57 Test Method for Field Measurement of Soil Resistivity
to produce results under average field conditions when com-
Using the Wenner Four-Electrode Method
paredtoothermethodsappliedtothesameapplication.An“A”
rating implies a preferred method and a “B” rating implies an
3. Terminology
alternate method. There may be a single method or multiple
3.1 Definitions—Definitions shall be in accordance with the
methodsthatcanbeappliedwithequalsuccess.Theremayalso
terms and symbols given in Terminology D653. Also see Ref
be a method or methods that will be successful technically at a
(1) for specific geophysical terms and definitions.
lower cost. The final selection must be made considering site
specific conditions and project objectives; therefore, it is
4. Summary of Guide
critical to have an experienced professional make the final
4.1 This guide applies to surface geophysical techniques
decision as to the method(s) selected.
that are commonly used in site characterization, as well as
5.1.1 Benson (2) provides one of the earlier guides to the
forensic and archaeological applications.
application of geophysics to environmental problems.
4.2 The selection of preferred geophysical methods for a
5.1.2 Ward (3) is a three-volume compendium that deals
number of common applications is summarized inTable 1.The
with geophysical methods applied to geotechnical and envi-
table is followed by brief descriptions of each application.
ronmental problems.
4.3 A brief description of each geophysical method along
5.1.3 Olhoeft (4) provides an expert system for helping
with some of the field considerations and limitations also are
selectgeophysicalmethodstobeusedathazardouswastesites.
provided.
5.1.4 EPA (5) provides an excellent literature review of the
4.4 It is recommended that personnel consult appropriate
theory and use of geophysical methods for use at contaminated
references on each of the methods, applications, and their
sites.
interpretations. All geophysical measurements should be car-
5.2 An Introduction to Geophysical Measurements:
ried out by knowledgeable professionals who have experience
and training in theory and application of the method, and the 5.2.1 A primary factor affecting the accuracy of geotechni-
interpretation of the data resulting from the use of the specific cal or environmental site characterization efforts is the number
method. of sample points or borings. Insufficient spatial sampling to
A,B
TABLE 1 Selection of Geophysical Methods for Common Applications
Geophysical Methods
Seismic Electrical Electromagnetic
Ground
DC Frequency Time Pipe/Cable Metal
Applications
Refraction Reflection SP Penetrating Magnetics Gravity
Resistivity Domain Domain VLF (6.7) Locator Detectors
(6.1) (6.2) (6.4) Radar (6.11) (6.12)
(6.3) (6.5) (6.6) (6.8) (6.9)
(6.10)
Natural Geologic and Hydrologic
Conditions
Soil/unconsolidated layers A B A B A B A
Rock layers B A B B B
Depth to bedrock A A B B B B A B
Depth to water table A A B B B B A
Fractures and fault zones B B B A B A B B B
Voids and sinkholes B B B B B A A
Soil and rock properties A A B
Dam and lagoon leakage B A B B
Inorganic Contaminants
Landfill leachate A A A B B
Saltwater intrusion A A A B B
Soil salinity A A
Organic Contaminants
Light, nonaqueous phase liquids B B B B
C
Dissolved phase
Dense, nonaqueous phase
C
liquids
Manmade Buried Objects
Utilities BABA
Drums and USTs A A A A A
UXO ABA
Abandoned wells B B B A
Landfill and trench boundaries B B A B A
Forensics B A B B A B
Archaeological features B B B A A A B
A
“A” implies primary choice of method.
B
“B” implies secondary choice or alternate method.
C
Also see natural geologic and hydrologic conditions to characterize contaminant pathways.
D6429–99 (2006)
adequately characterize the conditions at a site can result if the improve the site characterization findings and provide fill-in
number of samples is too small. Interpolation between these data between other measurements.
sample points may be difficult and may lead to an inaccurate
5.5.2 The level of success of a geophysical survey is
site characterization. Benson (2) provides an assessment of the improved if the survey objectives are well defined. In some
probability of target detection using only borings.
cases, the objective may be refined as the survey uncovers new
or unknown data about the site conditions. The flexibility to
5.2.2 Surface and borehole geophysical measurements gen-
changeoraddtothetechnicalapproachshouldbebuiltintothe
erally can be made relatively quickly, are minimally intrusive,
program to account for changes in interpretation of site
and enable interpolation between known points of control.
conditions as a site investigation progresses.
Continuous data acquisition can be obtained with certain
geophysical methods at speeds up to several km/h. In some 5.6 Profiling and Sounding Measurements:
cases, total site coverage is economically possible. Because of 5.6.1 Profiling by stations or by continuous measurements
the greater sample density, the use of geophysical methods can
provides a means of assessing lateral changes in subsurface
be used to define background (ambient) conditions and detect conditions.
anomalous conditions resulting in a more accurate site charac-
5.6.2 Soundings provide a means of assessing depth and
terization than using borings alone.
thickness of geologic layers or other targets. Most surface
geophysical sounding measurements can resolve three and
5.2.3 Geophysical measurements provide a means of map-
ping lateral and vertical variations of one or more physical possibly four layers.
properties or monitoring temporal changes in conditions, or 5.7 Ease of Use and Interpretation of Data:
both.
5.7.1 The theory of applied geophysics is quantitative,
5.3 A contrast must be present for geophysical measure- however, in application, geophysical methods often yield
interpretations that are qualitative.
ments to be successful.
5.7.2 Some geophysical methods provide data from which a
5.3.1 Geophysical methods measure the physical, electrical,
preliminary interpretation can be made in the field, for ex-
or chemical properties of soil, rock, and pore fluids. To detect
ample, ground penetrating radar (GPR), frequency domain
an anomaly, a soil to rock contact, the presence of inorganic
electromagnetic profiling, direct current (DC) resistivity pro-
contaminants, or a buried drum, there must be a contrast in the
filing, magnetic profiling, and metal detector profiling. A map
property being measured, for example, the target to be detected
of GPR anomalies or a contour map of the EM (electromag-
or geologic feature to be defined must have properties signifi-
netic), resistivity, magnetic or metal detector data often can be
cantly different from “background” conditions.
created in the field.
5.3.2 For example, the interface between fresh water and
5.7.3 Some methods, (for example, time domain electro-
saltwater in an aquifer can be detected by the differences in
magnetics and DC resistivity soundings, seismic refraction,
electricalpropertiesoftheporefluids.Thecontactbetweensoil
seismic reflection, and gravity), require that the data be
and unweathered bedrock can be detected by the differences in
processed before any quantitative interpretation can be done.
acoustic velocity of the materials. In some cases, the differ-
5.7.4 Any preliminary interpretation of field data should be
ences in measured physical properties may be too small for
treated with caution. Such preliminary analysis should be
anomaly detection by geophysical methods.
confirmed by correlation with other information from known
5.3.3 Because physical properties of soil and rock vary
pointsofcontrol,suchasboringsoroutcrops.Suchpreliminary
widely, some by many orders of magnitude, one or more of
analysis is subject to change after data processing and is
these properties usually will correspond to a geologic discon-
performed mostly as a means of quality control (QC).
tinuity; therefore, boundaries determined by the geophysical
5.7.5 It is the interpretation and integration of all site data
methods will usually coincide with geological boundaries, and
that results in useful information for site characterization. The
a cross-section produced from the geophysical data may
conversion of raw data to useful information is a value-added
resemble a geological cross-section, although the two are not
process that experienced professionals achieve by careful
necessarily identical.
analysis. Such analysis must be conducted by a competent
5.4 Geophysical methods commonly are used for the fol-
professional to ensure that the interpretation is consistent with
lowing reasons:
geologic and hydrologic conditions.
5.4.1 Mapping natural hydrogeologic conditions;
5.8 Discussion of Applications:
5.4.2 Detecting and mapping contaminant plumes; and,
5.8.1 Natural Geologic and Hydrologic Conditions:
5.4.3 Locating and mapping buried objects.
5.8.1.1 Soil/Unconsolidated Layers—This application in-
5.5 Geophysical methods should be used in the following
cludes determining the depth to, thickness of, and areal extent
instances:
ofunconsolidatedlayers.Theselayersmaybediscontinuousor
5.5.1 Surface geophysical methods can and should be used include lenses of various materials.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.