ASTM D7663-12(2018)e1
(Practice)Standard Practice for Active Soil Gas Sampling in the Vadose Zone for Vapor Intrusion Evaluations
Standard Practice for Active Soil Gas Sampling in the Vadose Zone for Vapor Intrusion Evaluations
SIGNIFICANCE AND USE
5.1 Soil-gas sampling results can be dependent on numerous factors both within and outside the control of the sampling personnel. Key variables are identified and briefly discussed below. Please see the documents listed in the Bibliography for more detailed information on the effect of various variables.
5.2 Application—The techniques described in this standard practice are suitable for collecting samples for subsequent analysis for VOCs by US EPA Method TO-15, US EPA Method TO-17, Test Method D5466, Practice D6196, ISO 16017-1, or other VOC methods (for example, US EPA Methods TO-3 and TO-12). In general, off-site analysis is employed when data are needed for input to a human health risk assessment and low- or sub-ppbv analytical sensitivity is required. On-site analysis typically has lesser analytical sensitivity and tends to be employed for screening level studies. The techniques also may prove useful for analytical categories other than VOCs, such as methane, ammonia, mercury, or hydrogen sulfide (See Test Method D5504).
5.3 Limitations:
5.3.1 This method only addresses collection of gas-phase species. Less volatile compounds, such as SVOCs, may be present in the environment both in the gas phase and sorbed onto particulate matter, as well as in liquid phase. In soil gas, the gas-phase fraction is the primary concern. In other potential sampling locations (for example, ambient or indoor air), however, sampling for the particulate phase fraction may also be of interest.
5.3.2 The data produced using this method should be representative of the soil gas concentrations in the geological materials in the immediate vicinity of the sample probe or well at the time of sample collection (that is, they represent a point-in-time and point-in-space measurement). The degree to which these data are representative of any larger areas or different times depends on numerous site-specific factors.
5.4 Effect of Purging of Dead Space—If a soil gas probe is to be sa...
SCOPE
1.1 Purpose—This practice covers standardized techniques for actively collecting soil gas samples from the vadose zone beneath or near dwellings and other buildings.
1.2 Objectives—Objectives guiding the development of this practice are: (1) to synthesize and put in writing good commercial and customary practice for active soil gas sampling, (2) to provide an industry standard for soil gas sampling performed in support of vapor intrusion evaluations that is practical and reasonable.
1.3 This practice allows a variety of techniques to be used for collecting soil gas samples because different techniques may offer certain advantages for specific applications. Three techniques are presented: sampling at discrete depths, sampling over a small screened interval, and sampling using permanent vapor monitoring wells.
1.4 Some of the recommendations require knowledge of pressure differential and tracer gas concentration measurements.
1.5 The values stated in SI units shall be regarded as standard. Other units are shown for information only.
1.6 This practice does not address requirements of any local, regional, state, provincial, or national regulations or guidance, or both, with respect to soil gas sampling. Users are cautioned that local, regional, state, provincial, or national guidance may impose specific requirements that differ from those of this practice.
1.7 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.
1.8 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applic...
General Information
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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.
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Designation: D7663 − 12 (Reapproved 2018)
Standard Practice for
Active Soil Gas Sampling in the Vadose Zone for Vapor
Intrusion Evaluations
This standard is issued under the fixed designation D7663; 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.
ε NOTE—Reapproved with editorial change in February 2018.
1. Scope 1.8 This practice offers a set of instructions for performing
one or more specific operations. This document cannot replace
1.1 Purpose—This practice covers standardized techniques
educationorexperienceandshouldbeusedinconjunctionwith
for actively collecting soil gas samples from the vadose zone
professional judgment. Not all aspects of this practice may be
beneath or near dwellings and other buildings.
applicable in all circumstances. This ASTM practice is not
1.2 Objectives—Objectives guiding the development of this
intended to represent or replace the standard of care by which
practice are: (1) to synthesize and put in writing good com-
the adequacy of a given professional service must be judged,
mercialandcustomarypracticeforactivesoilgassampling,(2)
nor should this document be applied without consideration of
toprovideanindustrystandardforsoilgassamplingperformed
a project’s many unique aspects. The word “Standard” in the
in support of vapor intrusion evaluations that is practical and
title means only that the document has been approved through
reasonable.
the ASTM consensus process.
1.3 This practice allows a variety of techniques to be used
1.9 This international standard was developed in accor-
for collecting soil gas samples because different techniques
dance with internationally recognized principles on standard-
may offer certain advantages for specific applications. Three
ization established in the Decision on Principles for the
techniquesarepresented:samplingatdiscretedepths,sampling
Development of International Standards, Guides and Recom-
over a small screened interval, and sampling using permanent
mendations issued by the World Trade Organization Technical
vapor monitoring wells.
Barriers to Trade (TBT) Committee.
1.4 Some of the recommendations require knowledge of
2. Referenced Documents
pressure differential and tracer gas concentration measure-
ments.
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained
1.5 The values stated in SI units shall be regarded as
Fluids
standard. Other units are shown for information only.
D854 Test Methods for Specific Gravity of Soil Solids by
1.6 Thispracticedoesnotaddressrequirementsofanylocal,
Water Pycnometer
regional, state, provincial, or national regulations or guidance,
D1356 Terminology Relating to Sampling and Analysis of
or both, with respect to soil gas sampling. Users are cautioned
Atmospheres
that local, regional, state, provincial, or national guidance may
D1946 Practice for Analysis of Reformed Gas by Gas
impose specific requirements that differ from those of this
Chromatography
practice.
D2216 Test Methods for Laboratory Determination ofWater
1.7 This standard does not purport to address all of the
(Moisture) Content of Soil and Rock by Mass
safety concerns, if any, associated with its use. It is the
D2487 Practice for Classification of Soils for Engineering
responsibility of the user of this standard to establish appro-
Purposes (Unified Soil Classification System)
priate safety, health, and environmental practices and deter-
D3404 Guide for Measuring Matric Potential in Vadose
mine the applicability of regulatory limitations prior to use.
Zone Using Tensiometers
D4696 Guide for Pore-Liquid Sampling from the Vadose
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
Vadose Zone Investigations. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 15, 2018. Published July 2018. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2011. Last previous edition approved in 2011 as D7663–11. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D7663-12R18E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D7663 − 12 (2018)
Zone (Withdrawn 2017) 3.3.6 blank sample, n—a sample that is intended to contain
D4700 Guide for Soil Sampling from the Vadose Zone none of the analytes of interest and which is subjected to the
D5088 Practice for Decontamination of Field Equipment usual analytical or measurement process to establish a zero
Used at Waste Sites baseline or background value; blank samples are named
D5092 Practice for Design and Installation of Groundwater according to their type and use (for example, field blank, trip
Monitoring Wells blank, equipment blank, reagent blank).
D5314 Guide for Soil Gas Monitoring in the Vadose Zone
3.3.7 contaminant, n—substances not normally found in an
(Withdrawn 2015)
environment at the observed concentration.
D5466 Test Method for Determination of Volatile Organic
3.3.8 dead volume, n—the total air-filled internal volume of
Compounds in Atmospheres (Canister Sampling Method-
the sampling system.
ology)
3.3.9 duplicate samples, n—two samples taken from and
D5504 TestMethodforDeterminationofSulfurCompounds
representative of the same population and carried through all
in Natural Gas and Gaseous Fuels by Gas Chromatogra-
steps of the sampling and analytical procedures in an identical
phy and Chemiluminescence
manner.
D6196 Practice for Choosing Sorbents, Sampling Param-
eters and Thermal Desorption Analytical Conditions for
3.3.10 effective porosity, n—the amount of interconnected
Monitoring Volatile Organic Chemicals in Air
voidspace(withinintergranularpores,fractures,openings,and
D6725 Practice for Direct Push Installation of Prepacked
the like) available for fluid movement: generally less than total
Screen Monitoring Wells in Unconsolidated Aquifers
porosity.
E741 Test Method for Determining Air Change in a Single
3.3.11 equipment blank, n—a sample of the gas which is
Zone by Means of a Tracer Gas Dilution
used to purge the sampling equipment between uses; sampling
E2024 Test Methods for Atmospheric Leaks Using a Ther-
equipmentblanksareusedtocheckthecleanlinessofsampling
mal Conductivity Leak Detector
devices and the thoroughness of the cleaning procedure.
F1815 Test Methods for Saturated Hydraulic Conductivity,
3.3.12 field blank, n—unused media carried to the sampling
Water Retention, Porosity, and Bulk Density of Athletic
site, exposed to sampling conditions (for example, connected
Field Rootzones
tothesamplinglines)andreturnedtothelaboratoryandtreated
3. Terminology
as an environmental sample; field blanks are used to check for
analytical artifacts or background contaminants or both intro-
3.1 This section provides definitions and descriptions of
duced by sampling and analytical procedures.
terms used in or related to this practice.Alist of acronyms and
a list of symbols also are included. The terms are an integral
3.3.13 fracture, n—a break in the mechanical continuity of
part of this practice and are critical to an understanding of the
a body of rock or soil caused by stress exceeding the strength
practice and its use.
of the rock or soil. Includes joints and faults.
3.2 Definitions:
3.3.14 free product, n—organic contaminants in the liquid
3.2.1 For definitions of common technical terms in this (“free” or non-aqueous) phase.
standard, refer to Terminology D653.
3.3.15 ground water, n—thepartofthesubsurfacewaterthat
3.3 Definitions of Terms Specific to This Standard: is in the saturated zone.
3.3.1 active sampling, n—a means of collecting a gas-phase
3.3.16 liquid phase, n—contaminant residing as a liquid in
substance that employs a mechanical device such as a pump or
vadose zone pore space, often referred to as “free product.”
vacuum assisted critical orifice to draw air into or through a
3.3.17 moisture content, n—the amount of water lost from a
sampling device.
soil upon drying to a constant weight, expressed as the weight
3.3.2 adsorption, n—a physical process in which molecules
per unit weight of dry soil or as the volume of water per unit
or gas, of dissolved substances, or of liquids adhere in an
bulk volume of the soil.
extremely thin layer to the surfaces of solid bodies with which
3.3.18 passive sampling, n—a means of collecting an air-
they are in contact.
borne substance that depends on gaseous diffusion, gravity, or
3.3.3 ambient air, n—any unconfined portion of the atmo-
other unassisted means to bring the sample to the collection
sphere; open air.
surface of sorbent.
3.3.4 attenuation factor (α), n—ratio of indoor air concen-
3.3.19 partitioning, n—the act or process of distributing a
tration to soil-gas concentration for a given compound.
chemical among different phases or compartments.
3.3.5 background level, n—the concentration of a substance
3.3.20 perched aquifer, n—a lens of saturated soil above the
that is typically found in ambient air (for example, due to
mainwatertablethatformsontopofanisolatedgeologiclayer
industrial or automobile emissions), indoor air (for example,
of low permeability.
from building materials or indoor activities) or the natural
3.3.21 permeability, n—the ease with which a porous me-
geology of an area.
dium can transmit a fluid under a potential gradient.
3.3.22 preferential pathway, n—a migration route for
The last approved version of this historical standard is referenced on
www.astm.org. chemicals of concern that has less constraint on gas transport
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D7663 − 12 (2018)
thanthesurroundingsoil;preferentialpathwaysmaybenatural 3.3.38 water table, n—the top of the saturated zone in an
(for example, vertically fractured bedrock where the fractures unconfined aquifer.
areinterconnected)orman-made(forexample,utilityconduits,
3.4 Acronyms and Abbreviations:
sewers, dry wells).
3.4.1 BLS—Below Land Surface (also known as below
3.3.23 porosity, n—the volume fraction of a rock or uncon- ground surface [bgs])
solidated sediment not occupied by solid material but usually
3.4.2 HDPE—High density polyethylene tubing
occupied by liquids, vapor, or air, or combinations thereof.
3.4.3 OD—Outer Diameter
Porosity is the void volume of soil divided by the total volume
3.4.4 PEEK—Polyetheretherketone
of soil.
3.4.5 PTFE—Polytetrafluoroethylene
3.3.24 purge volume, n—the amount of air removed from
thesamplingsystempriortothestartofsamplecollection.This
3.4.6 ppbv—part-per-billion on a volume basis
is usually referred to in number of dead volumes.
3.4.7 PRT—post-run tubing
3.3.25 reagent blank, n—sample of one or more reagents
3.4.8 QC—Quality Control
used in a given analysis.
3.4.9 SVOC—Semi-Volatile Organic Compound
3.3.26 saturated zone, n—the zone in which all of the voids
3.4.10 TO—Toxic Organic
in the rock or soil are filled with water at a pressure that is
3.4.11 USEPA—United States Environmental Protection
greater than atmospheric; the water table is the top of the
Agency
saturated zone in an unconfined aquifer.
3.4.12 VOC—Volatile Organic Compound
3.3.27 semi-volatile organic compound (SVOC), n—organic
compounds with boiling points typically in the range 240-260 3.5 Symbols
to 380-400 °C with polar compounds in the higher range. 3.5.1 Variables (typical units)
3.5.1.1 C = concentration (ppbv, µg/m,%)
3.3.28 soil gas, n—vadose zone atmosphere. Soil gas is the
3.5.1.2 C = detection limit concentration (µg/m )
DL
air existing in void spaces in the soil between the groundwater
3.5.1.3 d = diameter (cm)
table and the ground surface.
3.5.1.4 L = length (cm)
3.3.29 soil moisture, n—the water contained in the pore
3.5.1.5 M = mass (µg)
spaces in the vadose zone.
3.5.1.6 n = number of data points
3.3.30 sorbent sampling, n—the collection of an air sample
3.5.1.7 Q = flow rate (cm /min)
viaremovalofchemicalsfromagasbypassingthegasthrough
3.5.1.8 t = time (min)
or allowing it to come in contact with a sorptive medium; the
3.5.1.9 V = volume (cm )
chemicals are subsequently desorbed for analysis.
3.5.1.10 X = molecular weight of compound X (g/mol)
MW
3.5.1.11 α=attenuationcoefficientorfactor(dimensionless)
3.3.31 sub-slab vapor sampling, n—the collection of vapor
3.5.1.12 ∆P = change in pressure (Pa)
from the zone just beneath the lowest floor slab of a building.
3.5.1.13 τ = residence time (min)
3.3.32 tracer, n—a material that can be easily identified and
3.6 Superscripts
determined even at very low concentrations and that may be
3.6.1 — = mean value
added to other substances to enable their movements to be
followed or their presence to be detected.
3.7 Subscripts
3.7.1 i = pertaining to compound, time, or location i
3.3.33 tracer gas, n—a gas used with a detection device to
determinetherateofairinterchangewithinaspace,orbetween
4. Summary of Practice
spaces.
3.3.34 trip blank, n—clean, unused sampling media that is 4.1 This practice describes the active collection of soil gas
samples from soil pore spaces in the vadose zone or in fill
carried to the sampling site and transported to the laboratory
for analysis without having been exposed to sampling proce- material directly under building slabs to determine the concen-
tration of volatile organic compounds (VOCs). Three tech-
dures.
niques are presented: (1) sampling at discrete depths, (2)
3.3.35 vadose zone, n—hydrogeological region extending
sampling over a small screened interval, or (3) sampling using
from the soil surface to the top of the principal water table.
permanent vapor monitoring wells with one or more screened
Perched ground water may exist within this zone.
intervals. For sampling at a given depth, options include (i) a
3.3.36 vapor intrusion, n—the migration of a volatile
short stainless steel probe installed in a small diameter hole
chemical(s) from subsurface soil or water into an overlying or
drilled through building slab, (ii) disposable drive tips and
nearby building.
post-run tubing (PRT), or (iii) installation of sampling points
3.3.37 volatile organic compound (VOC), n—organic com- using tubing placed into a borehole and sealed in place with
poundswithboilingpointstypicallyrangingfromalowerlimit clay or other packing material. Several different combinations
between 50 °C and 100 °C, a
...
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