ASTM E2531-06(2014)

Standard Guide for Development of Conceptual Site Models and Remediation Strategies for Light Nonaqueous-Phase Liquids Released to the Subsurface

SIGNIFICANCE AND USE
5.1 This guide will help users answer simple and fundamental questions about the LNAPL occurrence and behavior in the subsurface. It will help users to identify specific risk-based drivers and non-risk factors for action at a site and prioritize resources consistent with these drivers and factors.  
5.2 The site management decision process described in this guide includes several features that are only examples of standardized approaches to addressing the objectives of the particular activity. For example, Table 1 provides example indicators of the presence of LNAPL. Table 1 should be customized by the user with a modified list of LNAPL indicators as technically appropriate for the site or group of sites being addressed.  
5.3 This guide advocates use of simple analyses and available data for the LCSM in Tier 1 to make use of existing data and to interpret existing data potentially in new ways. The Tier 1 LCSM is designed to identify where additional data may be needed and where decisions can be made using existing data and bounding estimates.  
5.4 This guide expands the LCSM in Tier 2 and Tier 3 to a detailed, dynamic description that considers three-dimensional plume geometry, chemistry, and fluxes associated with the LNAPL that are both chemical- and location-specific.  
5.5 This guide fosters effective use of existing site data, while recognizing that information may be only indirectly related to the LNAPL body conditions. This guide also provides a framework for collecting additional data and defining the value of improving the LCSM for remedial decisions.  
5.6 By defining the key components of the LCSM, this guide helps identify the framework for understanding LNAPL occurrence and behavior at a site. This guide recommends that specific LNAPL site objectives be identified by the user and stakeholders and remediation metrics be based on the LNAPL site objectives. The LNAPL site objectives should be based on a variety of issues, including:  
5.6.1 Potenti...
SCOPE
1.1 This guide applies to sites with LNAPL present as residual, free, or mobile phases, and anywhere that LNAPL is a source for impacts in soil, ground water, and soil vapor. Use of this guide may show LNAPL to be present where it was previously unrecognized. Information about LNAPL phases and methods for evaluating its potential presence are included in 4.3, guide terminology is in Section 3, and technical glossaries are in Appendix X7 and Appendix X8. Fig. 1 is a flowchart that summarizes the procedures of this guide.  
1.2 This guide is intended to supplement the conceptual site model developed in the RBCA process (Guides E1739 and E2081) and in the conceptual site model standard (Guide E1689) by considering LNAPL conditions in sufficient detail to evaluate risks and remedial action options.  
1.3 Federal, state, and local regulatory policies and statutes should be followed and form the basis of determining the remedial objectives, whether risk-based or otherwise. Fig. 1 illustrates the interaction between this guide and other related guidance and references.  
1.4 Petroleum and other chemical LNAPLs are the primary focus of this guide. Certain technical aspects apply to dense NAPL (DNAPL), but this guide does not address the additional complexities of DNAPLs.  
1.5 The composite chemical and physical properties of an LNAPL are a function of the individual chemicals that make-up an LNAPL. The properties of the LNAPL and the subsurface conditions in which it may be present vary widely from site to site. The complexity and level of detail needed in the LCSM varies depending on the exposure pathways and risks and the scope and extent of the remedial actions that are needed. The LCSM follows a tiered development of sufficient detail for risk assessment and remedial action decisions to be made. Additional data collection or technical analysis is typically needed when fundamental questions about the LNAPL cannot be answ...

General Information

• Status: Historical
• Publication Date: 31-Oct-2014
• ICS: 13.080.05 - Examination of soils in general
• Technical Committee: E50 - Environmental Assessment, Risk Management and Corrective Action
• Drafting Committee: E50.04 - Corrective Action

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: E2531 − 06 (Reapproved 2014)
Standard Guide for
Development of Conceptual Site Models and Remediation
Strategies for Light Nonaqueous-Phase Liquids Released to
the Subsurface
This standard is issued under the fixed designation E2531; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This guide provides a framework for developing a light nonaqueous phase liquid (LNAPL)
conceptual site model (LCSM) and for using that LCSM in a corrective action decision framework.
LNAPLs are most commonly petroleum or petroleum products liquids. Historically, subsurface
LNAPL distribution has been conceptualized based on the thickness observed in monitoring wells.
However, these conceptualizations often result in an insufficient risk analysis and frequently lead to
poor remedial strategies. By using this guide, the user will be able to perform a more appropriate
assessment and develop an LCSM from which better remedial decisions can be made.
The design of this guide is a “tiered” approach, similar to the risk-based corrective action (RBCA)
process (Guides E1739 and E2081), where an increase in tiers results from an increase in the site
complexity and site-specific information required for the decision-making process.The RBCAguides
apply to LNAPL and to dissolved and vapor phases. This guide supplements the RBCA guides by
providing more information about identifying LNAPL, linking the LCSM to the RBCAprocess, and
describing how the presence of LNAPL impacts corrective action at sites.
In addition to developing the LCSM, the components of this guide will support the user in
identifying site objectives, determining risk-based drivers and non-risk factors, defining remediation
metrics, evaluating remedial strategies, and preparing a site for closure. If the processes in this guide
are adequately followed for sites with LNAPL, it is expected that more efficient, consistent,
economical, and environmentally protective decisions will be made.
1. Scope E1689)byconsideringLNAPLconditionsinsufficientdetailto
evaluate risks and remedial action options.
1.1 This guide applies to sites with LNAPL present as
residual, free, or mobile phases, and anywhere that LNAPL is
1.3 Federal, state, and local regulatory policies and statutes
a source for impacts in soil, ground water, and soil vapor. Use
should be followed and form the basis of determining the
of this guide may show LNAPL to be present where it was
remedial objectives, whether risk-based or otherwise. Fig.1
previously unrecognized. Information about LNAPL phases
illustrates the interaction between this guide and other related
and methods for evaluating its potential presence are included
guidance and references.
in 4.3, guide terminology is in Section 3, and technical
1.4 Petroleum and other chemical LNAPLs are the primary
glossaries are in Appendix X7 and Appendix X8. Fig.1 is a
focus of this guide. Certain technical aspects apply to dense
flowchart that summarizes the procedures of this guide.
NAPL(DNAPL),butthisguidedoesnotaddresstheadditional
1.2 Thisguideisintendedtosupplementtheconceptualsite
complexities of DNAPLs.
model developed in the RBCA process (Guides E1739 and
1.5 The composite chemical and physical properties of an
E2081) and in the conceptual site model standard (Guide
LNAPL are a function of the individual chemicals that
make-up an LNAPL. The properties of the LNAPL and the
subsurface conditions in which it may be present vary widely
ThisguideisunderthejurisdictionofASTMCommitteeE50onEnvironmental
Assessment, Risk Management and CorrectiveAction and is the direct responsibil-
from site to site. The complexity and level of detail needed in
ity of Subcommittee E50.04 on Corrective Action.
the LCSM varies depending on the exposure pathways and
Current edition approved Nov. 1, 2014. Published December 2014. Originally
ε1
risks and the scope and extent of the remedial actions that are
approved in 2006. Last previous edition approved in 2006 as E2531–06 . DOI:
10.1520/E2531-06R14. needed. The LCSM follows a tiered development of sufficient
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2531 − 06 (2014)
detail for risk assessment and remedial action decisions to be 1.14.2 Remedial actions taken should be protective of
made. Additional data collection or technical analysis is human health and the environment now and in the future.
typically needed when fundamental questions about the
1.14.3 Remedial actions should have a reasonable probabil-
LNAPL cannot be answered with existing information.
ity of meeting the LNAPL site objectives.
1.6 This guide does not develop new risk assessment 1.14.4 Remedial actions implemented should not result in
protocols.Itisintendedtobeusedinconjunctionwithexisting greater site risk than existed before taking actions.
risk-based corrective action guidance (for example, Guides
1.14.5 Applicable federal, state, and local regulations
E1739 and E2081) and regulatory agency requirements (for
should be followed (for example, waste management
example, USEPA 1989, 1991, 1992, 1996, 1997).
requirements, ground water designations, worker protection).
1.7 ThisguideassiststheuserindevelopinganLCSMupon
1.15 This guide is organized as follows:
which a decision framework is applied to assist the user in
1.15.1 Section 2 lists associated and pertinentASTM docu-
selecting remedial action options.
ments.
1.8 The goal of this guide is to provide sound technical
1.15.2 Section 3 defines terminology used in this guide.
underpinning to LNAPL corrective action using appropriately
1.15.3 Section 4 includes a summary of this guide.
scaled, site-specific knowledge of the physical and chemical
1.15.4 Section 5 provides the significance and use of this
processes controlling LNAPL and the associated plumes in
guide.
ground water and soil vapor.
1.15.5 Section 6 presents the components of the LCSM.
1.9 This guide provides flexibility and assists the user in
1.15.6 Section 7 offers step-by-step procedures.
developing general LNAPL site objectives based on the
1.15.7 Nonmandatory appendices are supplied for the fol-
LCSM. This guide recognizes LNAPL site objectives are
lowing additional information:
determined by regulatory, business, regional, social, and other
1.15.7.1 Appendix X1 provides additional LNAPLreading.
site-specific factors. Within the context of the Guide E2081
RBCA process, these factors are called the technical policy 1.15.7.2 Appendix X2 provides an overview of multiphase
decisions.
modeling.
1.15.7.3 Appendix X3 provides example screening level
1.10 Remediation metrics are defined based on the site
calculations pertaining to the LCSM.
objectives and are measurable attributes of a remedial action.
1.15.7.4 Appendix X4 provides information about data
Remediationmetricsmayincludeenvironmentalbenefits,such
collection techniques.
asfluxcontrol,riskreduction,orchemicallongevityreduction.
Remediation metrics may also include costs, such as installa-
1.15.7.5 Appendix X5 provides example remediation met-
tioncosts,energyuse,businessimpairments,wastegeneration,
rics.
waterdisposal,andothers.Remediationmetricsareusedinthe
1.15.7.6 Appendix X6 provides two simplified examples of
decision analysis for remedial options and in tracking the
the use of the LNAPL guide.
performance of implemented remedial action alternatives.
1.15.7.7 Appendix X7 and Appendix X8 are glossaries of
1.11 This guide does not provide procedures for selecting technical terminology relevant for LNAPL decision-making.
one type of remedial technology over another. Rather, it
1.15.8 A reference list is included at the end of the docu-
recommends that technology selection decisions be based on
ment.
the LCSM, sound professional judgment, and the LNAPL site
1.16 Theappendicesareprovidedforadditionalinformation
objectives. These facets are complex and interdisciplinary.
and are not included as mandatory sections of this guide.
Appropriateuserknowledge,skills,andjudgmentarerequired.
1.17 This standard does not purport to address all of the
1.12 This guide is not a detailed procedure for engineering
safety concerns, if any, associated with its use. It is the
analysisanddesignofremedialactionsystems.Itisintendedto
responsibility of the user of this standard to establish appro-
be used by qualified professionals to develop a remediation
priate safety and health practices and determine the applica-
strategythatisbasedonthescientificandtechnicalinformation
bility of regulatory limitations prior to use.
contained in the LCSM. The remediation strategy should be
1.18 This guide offers an organized collection of informa-
consistent with the site objectives. Supporting engineering
tion or a series of options and does not recommend a specific
analysis and design should be conducted in accordance with
course of action. This document cannot replace education or
relevant professional engineering standards, codes, and re-
experienceandshouldbeusedinconjunctionwithprofessional
quirements.
judgment. Not all aspects of this guide may be applicable in all
1.13 ASTM standards are not federal or state regulations;
circumstances. This ASTM standard is not intended to repre-
they are voluntary consensus standards.
sent or replace the standard of care by which the adequacy of
1.14 The following principles should be followed when
a given professional service must be judged, nor should this
using this guide:
document be applied without consideration of a project’s many
1.14.1 Data and information collected should be relevant to unique aspects. The word “Standard” in the title of this
and of sufficient quantity and quality to develop a technically- document means only that the document has been approved
sound LCSM. through the ASTM consensus process.
E2531 − 06 (2014)
2. Referenced Documents may be associated with a given LNAPL release and are a
2 concern because of potential risk or aesthetic issues.
2.1 ASTM Standards:
3.1.3.1 Discussion—Identification can be based on their
D653Terminology Relating to Soil, Rock, and Contained
historical and current use at a site, detected concentrations in
Fluids
environmental media and their mobility, toxicity, and persis-
D6235Practice for Expedited Site Characterization of Va-
tence in the environment. Because chemicals of concern may
dose Zone and Groundwater Contamination at Hazardous
be identified at many points in the corrective action process,
Waste Contaminated Sites
includingbeforeanydeterminationthattheyposeanunaccept-
D5717Guide for Design of Ground-Water Monitoring Sys-
able risk to human health or the environment, the term should
tems in Karst and Fractured-Rock Aquifers (Withdrawn
not automatically be construed to be associated with increased
2005)
or unacceptable risk.
E1689Guide for Developing Conceptual Site Models for
3.1.4 conceptual model, n—integration of site information
Contaminated Sites
E1739Guide for Risk-Based Corrective Action Applied at and interpretations generally including facets pertaining to the
physical,chemical,transport,andreceptorcharacteristicspres-
Petroleum Release Sites
ent at a specific site.
E1903Practice for Environmental Site Assessments: Phase
II Environmental Site Assessment Process 3.1.4.1 Discussion—Aconceptual model is used to describe
E1912Guide forAccelerated Site Characterization for Con- comprehensively the sources and chemicals of concern in
firmed or Suspected Petroleum Releases (Withdrawn environmental media and the associated risks for particular
2013) locations, both now and in the future, as appropriate, at a site.
E1943Guide for Remediation of Ground Water by Natural
3.1.5 corrective action, n—sequence of actions taken to
Attenuation at Petroleum Release Sites
address LNAPL releases, protect receptors, and meet other
E2081Guide for Risk-Based Corrective Action
environmental goals.
E2091Guide for Use of Activity and Use Limitations,
3.1.5.1 Discussion—Corrective actions may include site
Including Institutional and Engineering Controls
assessment and investigation, risk assessment, response
E2205Guide for Risk-Based Corrective Action for Protec-
actions,interimremedialaction,remedialaction,operationand
tion of Ecological Resources
maintenance of equipment, monitoring of progress, making
E2348Guide for Framework for a Consensus-based Envi-
no-further-action determinations, and termination of the reme-
ronmental Decision-making Process
dial action.
2.2 EPA Standard:
3.1.6 dense nonaqueous phase liquids (DNAPL),
EPAMethod 8021BAromatic and Halogenated Volatiles by
n—nonaqueousphaseliquidwithaspecificgravitygreaterthan
Gas Chromatography Using Photoionization and/or Elec-
one (for example, a chlorinated solvent, creosote, polychlori-
trolytic Conductivity Detectors
nated biphenyls).
3. Terminology 3.1.7 engineering controls, n—physical modifications to a
site or facility (for example, slurry walls, capping, and point-
3.1 Definitions—Definitions of terms specific to this stan-
of-use water treatment) to reduce or eliminate the potential for
dard are included in this section, with additional technical
exposure to LNAPLor chemicals of concern in environmental
terminology provided for reference in Appendix X7 and
media.
Appendix X8.
3.1.1 active remediation, n—actions taken to reduce or 3.1.8 entrapped LNAPL, n—residual LNAPLin the form of
control LNAPLsource flux or the concentrations of chemicals discontinuous blobs in the void space of a porous medium in a
of concern in dissolved- or vapor-phase plumes.Active reme- submerged portion of a smear zone resulting from the upward
diation could be implemented when the no-further-action and movement of the water table into an LNAPL body.
passive remediation courses of action are not appropriate. 3.1.8.1 Discussion—At a residual condition, however, a
transient fall of the water table can result in local area
3.1.2 attenuation, n—the reduction in concentrations of
redistribution of LNAPL that is no longer in a residual
chemicals of concern in the environment with distance and
condition.
time due to processes such as diffusion, dispersion, sorption,
chemical degradation, and biodegradation.
3.1.9 exposure pathway, n—course a chemical of concern
takes from the source area to a receptor or relevant ecological
3.1.3 chemicals of concern, n—specific chemicals that are
receptor and habitat.
identified for evaluation in the corrective action process that
3.1.9.1 Discussion—An exposure pathway describes the
mech
...

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.
´1
Designation: E2531 − 06 E2531 − 06 (Reapproved 2014)
Standard Guide for
Development of Conceptual Site Models and Remediation
Strategies for Light Nonaqueous-Phase Liquids Released to
the Subsurface
This standard is issued under the fixed designation E2531; 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—The LNAPL transmissivity metric in Table X5.1 was editorially corrected in July 2009.
INTRODUCTION
This guide provides a framework for developing a light nonaqueous phase liquid (LNAPL)
conceptual site model (LCSM) and for using that LCSM in a corrective action decision framework.
LNAPLs are most commonly petroleum or petroleum products liquids. Historically, subsurface
LNAPL distribution has been conceptualized based on the thickness observed in monitoring wells.
However, these conceptualizations often result in an insufficient risk analysis and frequently lead to
poor remedial strategies. By using this guide, the user will be able to perform a more appropriate
assessment and develop an LCSM from which better remedial decisions can be made.
The design of this guide is a “tiered” approach, similar to the risk-based corrective action (RBCA)
process (Guides E1739 and E2081), where an increase in tiers results from an increase in the site
complexity and site-specific information required for the decision-making process. The RBCA guides
apply to LNAPL and to dissolved and vapor phases. This guide supplements the RBCA guides by
providing more information about identifying LNAPL, linking the LCSM to the RBCA process, and
describing how the presence of LNAPL impacts corrective action at sites.
In addition to developing the LCSM, the components of this guide will support the user in
identifying site objectives, determining risk-based drivers and non-risk factors, defining remediation
metrics, evaluating remedial strategies, and preparing a site for closure. If the processes in this guide
are adequately followed for sites with LNAPL, it is expected that more efficient, consistent,
economical, and environmentally protective decisions will be made.
1. Scope
1.1 This guide applies to sites with LNAPL present as residual, free, or mobile phases, and anywhere that LNAPL is a source
for impacts in soil, ground water, and soil vapor. Use of this guide may show LNAPL to be present where it was previously
unrecognized. Information about LNAPL phases and methods for evaluating its potential presence are included in 4.3, guide
terminology is in Section 3, and technical glossaries are in Appendix X7 and Appendix X8. Fig. 1 is a flowchart that summarizes
the procedures of this guide.
1.2 This guide is intended to supplement the conceptual site model developed in the RBCA process (Guides E1739 and E2081)
and in the conceptual site model standard (Guide E1689) by considering LNAPL conditions in sufficient detail to evaluate risks
and remedial action options.
1.3 Federal, state, and local regulatory policies and statutes should be followed and form the basis of determining the remedial
objectives, whether risk-based or otherwise. Fig. 1 illustrates the interaction between this guide and other related guidance and
references.
1.4 Petroleum and other chemical LNAPLs are the primary focus of this guide. Certain technical aspects apply to dense NAPL
(DNAPL), but this guide does not address the additional complexities of DNAPLs.
This guide is under the jurisdiction of ASTM Committee E50 on Environmental Assessment, Risk Management and Corrective Action and is the direct responsibility
of Subcommittee E50.04 on Corrective Action.
Current edition approved Nov. 1, 2006Nov. 1, 2014. Published February 2007December 2014. Originally approved in 2006. Last previous edition approved in 2006 as
ε1
E2531–06 . DOI: 10.1520/E2531-06E01.10.1520/E2531-06R14.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2531 − 06 (2014)
1.5 The composite chemical and physical properties of an LNAPL are a function of the individual chemicals that make-up an
LNAPL. The properties of the LNAPL and the subsurface conditions in which it may be present vary widely from site to site. The
complexity and level of detail needed in the LCSM varies depending on the exposure pathways and risks and the scope and extent
of the remedial actions that are needed. The LCSM follows a tiered development of sufficient detail for risk assessment and
remedial action decisions to be made. Additional data collection or technical analysis is typically needed when fundamental
questions about the LNAPL cannot be answered with existing information.
1.6 This guide does not develop new risk assessment protocols. It is intended to be used in conjunction with existing risk-based
corrective action guidance (for example, Guides E1739 and E2081) and regulatory agency requirements (for example, USEPA
1989, 1991, 1992, 1996, 1997).
1.7 This guide assists the user in developing an LCSM upon which a decision framework is applied to assist the user in selecting
remedial action options.
1.8 The goal of this guide is to provide sound technical underpinning to LNAPL corrective action using appropriately scaled,
site-specific knowledge of the physical and chemical processes controlling LNAPL and the associated plumes in ground water and
soil vapor.
1.9 This guide provides flexibility and assists the user in developing general LNAPL site objectives based on the LCSM. This
guide recognizes LNAPL site objectives are determined by regulatory, business, regional, social, and other site-specific factors.
Within the context of the Guide E2081 RBCA process, these factors are called the technical policy decisions.
1.10 Remediation metrics are defined based on the site objectives and are measurable attributes of a remedial action.
Remediation metrics may include environmental benefits, such as flux control, risk reduction, or chemical longevity reduction.
Remediation metrics may also include costs, such as installation costs, energy use, business impairments, waste generation, water
disposal, and others. Remediation metrics are used in the decision analysis for remedial options and in tracking the performance
of implemented remedial action alternatives.
1.11 This guide does not provide procedures for selecting one type of remedial technology over another. Rather, it recommends
that technology selection decisions be based on the LCSM, sound professional judgment, and the LNAPL site objectives. These
facets are complex and interdisciplinary. Appropriate user knowledge, skills, and judgment are required.
1.12 This guide is not a detailed procedure for engineering analysis and design of remedial action systems. It is intended to be
used by qualified professionals to develop a remediation strategy that is based on the scientific and technical information contained
in the LCSM. The remediation strategy should be consistent with the site objectives. Supporting engineering analysis and design
should be conducted in accordance with relevant professional engineering standards, codes, and requirements.
1.13 ASTM standards are not federal or state regulations; they are voluntary consensus standards.
1.14 The following principles should be followed when using this guide:
1.14.1 Data and information collected should be relevant to and of sufficient quantity and quality to develop a technically-sound
LCSM.
1.14.2 Remedial actions taken should be protective of human health and the environment now and in the future.
1.14.3 Remedial actions should have a reasonable probability of meeting the LNAPL site objectives.
1.14.4 Remedial actions implemented should not result in greater site risk than existed before taking actions.
1.14.5 Applicable federal, state, and local regulations should be followed (for example, waste management requirements,
ground water designations, worker protection).
1.15 This guide is organized as follows:
1.15.1 Section 2 lists associated and pertinent ASTM documents.
1.15.2 Section 3 defines terminology used in this guide.
1.15.3 Section 4 includes a summary of this guide.
1.15.4 Section 5 provides the significance and use of this guide.
1.15.5 Section 6 presents the components of the LCSM.
1.15.6 Section 7 offers step-by-step procedures.
1.15.7 Nonmandatory appendices are supplied for the following additional information:
1.15.7.1 Appendix X1 provides additional LNAPL reading.
1.15.7.2 Appendix X2 provides an overview of multiphase modeling.
1.15.7.3 Appendix X3 provides example screening level calculations pertaining to the LCSM.
1.15.7.4 Appendix X4 provides information about data collection techniques.
1.15.7.5 Appendix X5 provides example remediation metrics.
1.15.7.6 Appendix X6 provides two simplified examples of the use of the LNAPL guide.
1.15.7.7 Appendix X7 and Appendix X8 are glossaries of technical terminology relevant for LNAPL decision-making.
1.15.8 A reference list is included at the end of the document.
1.16 The appendices are provided for additional information and are not included as mandatory sections of this guide.
E2531 − 06 (2014)
1.17 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.
1.18 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.
2. Referenced Documents
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D6235 Practice for Expedited Site Characterization of Vadose Zone and Groundwater Contamination at Hazardous Waste
Contaminated Sites
D5717 Guide for Design of Ground-Water Monitoring Systems in Karst and Fractured-Rock Aquifers (Withdrawn 2005)
E1689 Guide for Developing Conceptual Site Models for Contaminated Sites
E1739 Guide for Risk-Based Corrective Action Applied at Petroleum Release Sites
E1903 Practice for Environmental Site Assessments: Phase II Environmental Site Assessment Process
E1912 Guide for Accelerated Site Characterization for Confirmed or Suspected Petroleum Releases (Withdrawn 2013)
E1943 Guide for Remediation of Ground Water by Natural Attenuation at Petroleum Release Sites
E2081 Guide for Risk-Based Corrective Action
E2091 Guide for Use of Activity and Use Limitations, Including Institutional and Engineering Controls
E2205 Guide for Risk-Based Corrective Action for Protection of Ecological Resources
E2348 Guide for Framework for a Consensus-based Environmental Decision-making Process
2.2 EPA Standard:
EPA Method 8021B Aromatic and Halogenated Volatiles by Gas Chromatography Using Photoionization and/or Electrolytic
Conductivity Detectors
3. Terminology
3.1 Definitions—Definitions of terms specific to this standard are included in this section, with additional technical terminology
provided for reference in Appendix X7 and Appendix X8.
3.1.1 active remediation, n—actions taken to reduce or control LNAPL source flux or the concentrations of chemicals of concern
in dissolved- or vapor-phase plumes. Active remediation could be implemented when the no-further-action and passive remediation
courses of action are not appropriate.
3.1.2 attenuation, n—the reduction in concentrations of chemicals of concern in the environment with distance and time due to
processes such as diffusion, dispersion, sorption, chemical degradation, and biodegradation.
3.1.3 chemicals of concern, n—specific chemicals that are identified for evaluation in the corrective action process that may be
associated with a given LNAPL release and are a concern because of potential risk or aesthetic issues.
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.
The last approved version of this historical standard is referenced on www.astm.org.
Available from United States Environmental Protection Association (EPA), Ariel Rios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http://www.epa.gov.
3.1.3.1 Discussion—
Identification can be based on their historical and current use at a site, detected concentrations in environmental media and their
mobility, toxicity, and persistence in the environment. Because chemicals of concern may be identified at many points in the
corrective action process, including before any determination that they pose an unacceptable risk to human health or the
environment, the term should not automatically be construed to be associated with increased or unacceptable risk.
3.1.4 conceptual model, n—integration of site information and interpretations generally including facets pertaining to the
physical, chemical, transport, and receptor characteristics present at a specific site.
3.1.4.1 Discussion—
E2531 − 06 (2014)
A conceptual model is used to describe comprehensively the sources and chemicals of concern in environmental media and the
associated risks for particular locations, both now and in the future, as appropriate, at a site.
3.1.5 corrective action, n—sequence of actions taken to address LNAPL releases, protect receptors, and meet other
environmental goals.
3.1.5.1 Discussion—
Corrective actions may include site assessment and investigation, risk assessment, response actions, interim remedial action,
remedial action, operation and maintenance of equipment, monit
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