E50.04 - Corrective Action

SIGNIFICANCE AND USE
4.1 Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a family of more than 4700 synthetic organic chemicals. PFAS can withstand high temperatures and survive highly corrosive environments. They are used in the manufacture of coatings, surface treatments, and specialty chemicals in cookware, carpets, food packaging, clothing, cosmetics, and other common consumer products. PFAS also have many industrial applications and are an active ingredient in certain types of fire-fighting foams (aqueous film-forming foams, or AFFF). PFAS coatings resist oil, grease, and water. PFAS are persistent compounds. Therefore, PFAS should be considered for purposes of managing investigation-derived waste where PFAS is known or suspected to be present in environmental media.  
4.1.1 PFAS are emerging contaminants for which environmental regulations and guidance are dynamic and are being developed simultaneously at federal, state, local, and international levels as more is learned about their characteristics, environmental fate, and management/treatment. Therefore, site-specific rules, regulations, and guidance should be evaluated for options and restrictions on management of PFAS  investigation-derived waste. For example, the Massachusetts Department of Environmental Protection has determined that PFAS wastes are “hazardous materials” subject to the Massachusetts Oil and Hazardous Material Release Prevention and Response Act (M.G.L. Chapter 21E) and the Massachusetts Contingency Plan. Other states and jurisdictions may have or will develop and implement similar determinations that affect the on-site management, storage, and labeling and off-site transportation requirements for PFAS  investigation-derived waste.  
4.1.2 Given the characteristics and persistence of PFAS compounds, PFAS  investigation-derived waste presents special handling and treatment/disposal considerations. EPA recently issued Interim Guidance on the Destruction and Disposal of Perfluoralkyl and Polyfluoralky...
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1.1 Existing guidance on the management of investigation-derived waste is focused upon cuttings, purge water, personal protective equipment, and other miscellaneous solid waste generated at property that may be impacted by the release of hazardous materials and hazardous substances. These hazardous substances include, but are not limited to, heavy metals, petroleum, petroleum byproducts, solvents, polycyclic aromatic hydrocarbons, organic and inorganic corrosives, radioactive material, and explosives. Guidance on the management of investigation derived waste generated at sites that may be impacted by releases of perfluoroalkyl and polyfluoroalkyl substances (PFAS) is limited. This standard guide addresses this deficiency  
1.2 This guide describes best practices for managing investigation-derived waste associated with PFAS that are consistent with federal and state policies and regulations at the date of issuance. The user is advised to determine if new regulations or rules have been promulgated by the state, federal, or tribal regulatory agency having jurisdiction over the property.  
1.3 This guide describes considerations to prevent the unintended and unauthorized disposal of liquid investigation-derived waste that may contain PFAS into wastewater treatment plants or systems that are not permitted to receive these waste streams.  
1.4 This guide describes considerations to prevent the unintended and unauthorized disposal of solid investigation-derived waste that may contain PFAS into landfills or other solid waste disposal facilities that are not permitted to receive these waste streams.  
1.5 This guide describes several stormwater pollution prevention best management practices applicable to investigation-derived waste.  
1.6 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,...

SIGNIFICANCE AND USE
4.1 This guide provides an overview of analytical methods, techniques, and procedures that may be used in determination of PFAS in environmental media.  
4.2 This guide provides considerations relevant to the selection and application of PFAS analytical methods, techniques, and procedures, including the limitations of published analytical methods and the potential benefits and challenges of non-standard analytical approaches.  
4.3 This guide presents comparisons of published analytical methods and approaches, including tabular comparison of target analyte lists and method features, to aid users in the selection and application of analytical methods and techniques for project-specific applications.  
4.4 This guide describes qualitative techniques available to determine total PFAS, including explanation of terms, discussion of preparation and analytical techniques and limitations, conceptual overview schematic, and summary comparison table.  
4.5 This guide provides current information on research trends in PFAS determination techniques applied to environmental media.  
4.6 This guide provides an integrated framework that results in efficient, cost-effective decision-making for timely, appropriate response actions for PFAS-impacted environmental media.  
4.7 This guide is not intended to replace or supersede federal, state, local, or international regulatory requirements. Instead, this guide may be used to complement and support such requirements.  
4.8 This guide may be used by various parties involved in response actions for PFAS-impacted environmental media, including regulatory agencies, project sponsors, environmental consultants and contractors, site remediation professionals, analytical testing laboratories, data reviewers, data users, academic institutions, research institutes, and other stakeholders.  
4.9 The users of this guide should consider assembling a team of experienced professionals with appropriate expertise to scope, plan, and execute PFA...
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1.1 This guide discusses the selection and application of analytical methods and techniques used to identify and quantitate per- and polyfluoroalkyl substances (PFAS) in environmental media. This guide provides a flexible, defensible framework applicable to a wide range of environmental programs. It is structured to support a tiered approach with analytical methods, procedures, and techniques of increasing complexity as the user proceeds through the evaluation process. This guide addresses key decision criteria and best practices to aid users in achieving project objectives. There are numerous technical decisions that must be made in the selection and application of analytical methods and techniques used during environmental data acquisition programs. It is not the intent of this guide to define appropriate technical decisions, but rather to provide technical support within existing decision frameworks.  
1.2 This guide informs practitioners on the considerations relevant to the selection and application of analytical methods and techniques for the quantitative and qualitative determination of PFAS in a variety of environmental sample media. This guide encourages user-led collaboration with stakeholders, including analytical laboratories, data evaluation practitioners, and regulators, in the selection and application of analytical methods and techniques used to support project-specific decision criteria and objectives as applied within a particular environmental regulatory program. This guide recognizes the complexity and diversity of environmental programs and project objectives and provides technical guidance for a range of project applications.  
1.3 This guide is intended to complement, not replace, existing regulatory requirements or guidance. ASTM International (ASTM) guides are not regulations; they are consensus-based standards that may be followed as needed.  
1.4 This guide recognizes that PFAS can be catego...

SIGNIFICANCE AND USE
4.1 Intended Use:  
4.1.1 This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, and other stakeholders.  
4.2 Importance of the CSM:  
4.2.1 The CSM should be continuously updated and refined to describe the physical properties, chemical composition and occurrence, biologic features, and environmental conditions of the sediment corrective action project (Guide E1689).  
4.3 Reference Material:  
4.3.1 This guide should be used in conjunction with other ASTM guides listed in 2.1 (especially Guides E3344 and E3382); this guide should also be used in conjunction with the material in the References at the end of this guide (including 1). Utilizing these reference materials will direct the user in developing representative background concentrations for a sediment site.  
4.4 Flexible Site-Specific Implementation:  
4.4.1 This guide provides a systematic, but flexible, framework to accommodate variations in approaches by regulatory agencies and by the user based on project objectives, site complexity, unique site features, regulatory requirements, newly developed guidance, newly published scientific research, changes in regulatory criteria, advances in scientific knowledge and technical capability, and unforeseen circumstances.  
4.5 Regulatory Frameworks:  
4.5.1 This guide is intended to be applicable to a broad range of local, state, tribal, federal, or international jurisdictions, each with its own unique regulatory framework. As such, this guide does not provide a detailed discussion of the requirements or guidance associated with any of these regulatory frameworks, nor is it intended to supplant applicable regulations and guidance. The user of this guide will need to be aware of the regulatory requirements and guidance in the jurisdiction where the work...
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1.1 This guide describes data visualization, statistical, forensic chemistry and geochemical methodologies (including case studies) used in the evaluation of candidate background data sets; this evaluation leads to the development of representative background data sets for the sediment site. Statistical methodologies can then be applied to the representative background data sets to develop background threshold values (BTVs) that are measures of the upper limit of representative sediment background concentrations for the sediment site. In addition, representative background data sets and sediment site data sets can be compared using two-sample statistical tests to determine if there are statistically significant differences (at a specified confidence level) between the two data sets (such as, the median or mean values of the two data sets are significantly different).  
1.1.1 This guide is intended to inform, complement, and support, but not supersede the guidelines established by local, state, tribal, federal, or international agencies.  
1.2 Technically defensible representative sediment background concentrations are critical for several purposes (1).2 These include sediment site delineation, establishing remedial goals and cleanup levels, remedy selection, assessment of risks posed by representative background concentrations, and establishing appropriate post-remedial monitoring plans.  
1.3 The overarching framework for the development of representative sediment background concentrations at sediment sites is presented in Guide E3382. Guide E3240 provides a general discussion of how conceptual site model (CSM) development fits into the risk-based corrective action framework for contaminated sediment sites, while Guide E3382 provides a detailed discussion of the elements of a sediment site CSM that need to be considered when developing representative sediment background concentrations. Guide E3344 describes how to se...

SIGNIFICANCE AND USE
4.1 Intended Use-This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, and other stakeholders.  
4.2 Importance of the CSM-The CSM should be continuously updated and refined to describe the physical properties, chemical composition and occurrence, biologic features, and environmental conditions of the sediment corrective action project (Guide E1689).  
4.3 Reference Material-This guide should be used in conjunction with other ASTM guides listed in 2.1 (especially Guides E3242 and E3382); this guide should also be used in conjunction with the material in the References at the end of this guide (including 3). Utilizing these reference materials will direct the user in developing representative sediment background concentrations.  
4.4 Flexible Site-Specific Implementation-This guide provides a systematic but flexible framework to accommodate variations in approaches by regulatory agencies and by the user based on project objectives, site complexity, unique site features, regulatory requirements, newly developed guidance, newly published scientific research, changes in regulatory criteria, advances in scientific knowledge and technical capability, and unforeseen circumstances.  
4.5 Regulatory Frameworks-This guide is intended to be applicable at a broad range of local, state, tribal, federal (such as CERCLA), or international jurisdictions, each with its own unique regulatory framework. As such, this guide does not provide a detailed discussion of the requirements or guidance associated with any of these regulatory frameworks, nor is it intended to supplant applicable regulations and guidance. The user of this guide will need to be aware of the regulatory requirements and guidance in the jurisdiction where the work is being performed.  
4.6 Systematic Project Plan...
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1.1 This guide focuses on the selection of sediment background reference areas from aquatic environments for the purpose of developing representative sediment background concentrations. These concentrations are typically used in contaminated sediment corrective actions performed under various regulatory programs, including the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Although many of the references cited in this guide are CERCLA-oriented, the guide is applicable to remedial actions performed under local, state, tribal, federal, and international cleanup programs. However, this guide does not describe the requirements for each jurisdiction.  
1.1.1 The sediment background reference areas chosen using this guide will need to be approved by the regulatory agency having jurisdiction (or they should take no exception to the areas chosen), especially if the representative background sediment concentrations will potentially be used to develop sediment remedial criteria.  
1.2 This guide provides a framework to select appropriate sediment background reference areas for the collection of sediment data in the development of representative sediment background concentrations. It is intended to inform, complement, and support, but not supersede, local, state, tribal, federal, or international guidelines.  
1.2.1 This guide is designed to apply to contaminated sediment sites where sediment data have been collected and are readily available. Additionally, it assumes that risk assessments have been performed, so that the potential contaminants of concern (PCOCs) that exceed risk-based thresholds have been identified. This guide can be applied at multiple points within the project life cycle (such as site assessment and remedial design).  
1.2.2 Furthermore, this guide presumes that the identified risk-based thresholds are low enough to pose corrective action implementation challenges or that th...

SIGNIFICANCE AND USE
4.1 PFAS are widely used in commercial and industrial applications worldwide (see Fig. 1). PFAS are of concern due to their documented persistence and their studied impacts on human health and the environmental. While there is no comprehensive source of information on the many individual PFAS substances and their functions in different applications, a range of resources are available to the practitioner. This guide provides information to assist the practitioner in navigating these challenges during the initial screening and site characterization process.
FIG. 1 Activity/Industry that may be Sources of PFAS Use and Release
Source: AEI Consultants  
4.2 The user should note that PFAS regulatory management framework at the federal and state level are evolving quickly. Therefore, consultation with legal and technical representatives with knowledge of federal, state, and local PFAS regulations is advised prior to use of this guide. Environmental audit policies or privileges may be applicable to some of the steps described in this guide (see EPA, 2000).  
4.3 Multi-step Risk Management Framework:  
4.3.1 The actions described in this guide are intended to provide a multi-step risk management framework to confirm, with reasonable certainty, that PFAS may have been used at a federally-owned, publicly-owned, or privately-owned property. This standard provides guidance on how to focus limited resources on using a multi-step process, illustrated in Fig. 2, to identify property potentially impacted by on-site or off-site uses and releases of PFAS. Section 4.5 describes the use and occurrence of PFAS. Section 4.6 describes activities at government and federal installations where PFAS use is expected. Section 4.7 broadly outlines the industry sectors where the use of PFAS has been documented (Glüge, 2020 (2), Gaines, 2022 (3)).
FIG. 2 Initial Site Screening and Characterization Flow Diagram  
4.4 PFAs History and Use:  
4.4.1 In the 1940s, industrial processes to co...
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1.1 Per- and polyfluoroalkyl substances (PFAS) are a group of over 7,000 manmade compounds consisting of polymeric chains of carbon bonded to fluorine atoms, usually with a polar functional group at the head. This guide recognizes that PFAS can be categorized as polymeric or nonpolymeric, collectively amounting to more than 4,700 Chemical Abstracts Service (CAS)-registered substances. Environmental concerns pertaining to PFAS are centered primarily on the perfluoroalkyl acids (PFAA), a subclass of per-and polyfluoroalkyl substances, which display extreme persistence and chain-length dependent bioaccumulation and adverse effects in biota.  
1.2 The regulatory framework for PFAS continues to evolve, both domestically and internationally. The United States Environmental Protection Agency (EPA) is proceeding with a wide-ranging set of PFAS regulatory actions (EPA, 2021). While the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) does not currently recognize PFAS as hazardous substances, the statute does require actions to protect public health and the environment from contaminants and pollutants released to the environment. Other federal regulatory programs, such as the Safe Drinking Water Act are being used to address drinking water supplies adversely impacted by releases of PFAS. The Clean Water Act’s National Pollutant Discharge Elimination System (NPDES) permitting program is tool that both federal and state regulators are using to regulate the inflows of PFAS-impacted wastewaters at both publicly-owned treatment works (POTW) and federally-owned wastewater treatment plants and the concentration of PFAS in permitted effluent. EPA continues to add additional per-and polyfluoroalkyl substances to the list of substances reportable under the federal Toxic Release Inventory (TRI) reporting program. International efforts to address per-and polyfluoroalkyl substances include Australia’s PFAS Nation...

SIGNIFICANCE AND USE
4.1 Intended Users:  
4.1.1 This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, and other stakeholders.  
4.2 Reference Material:  
4.2.1 This guide should be used in conjunction with other ASTM guides listed in 2.1 (especially Guides E3163, E3240, E3242, E3344 and E3382), as well as the material in the References section.  
4.3 Flexible Site-Specific Implementation:  
4.3.1 This guide provides a systematic but flexible framework to accommodate variations in approaches by regulatory agencies and by the user based on project objectives, site complexity, unique site features, regulatory requirements, newly developed guidance, newly published scientific research, changes in regulatory criteria, advances in scientific knowledge and technical capability, and unforeseen circumstances.
4.3.1.1 This guide provides a monitoring plan development, execution and analysis framework based on over-arching features and elements that should be customized by the user based on site-specific conditions, regulatory context, and sediment corrective action objectives.
4.3.1.2 Implementation of the guide is site-specific. The user may choose to customize the implementation of the guide for a particular site, especially smaller, less complex sites.
4.3.1.3 This guide should not be used alone as a prescriptive checklist.  
4.3.2 The users of this guide are encouraged to update and refine (when needed) the conceptual site model, Project Work Plans and Project Reports used to describe the physical properties, chemical composition and occurrence, biologic features, and environmental conditions of the sediment corrective action project.  
4.4 Regulatory Frameworks:  
4.4.1 This guide is intended to be applicable to a broad range of local, state, tribal, federal, or internation...
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1.1 This guide pertains to corrective action monitoring before (baseline monitoring), during (remedy implementation monitoring) and after (post-remedy monitoring) sediment remedial activities. It does not address monitoring performed during remedial investigations, pre-remedial risk assessments, and pre-design investigations.  
1.2 Sediment monitoring programs (baseline, remedy implementation and post-remedy) are typically used in contaminated sediment corrective actions performed under various regulatory programs, including the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Although many of the references cited in this guide are CERCLA-oriented, the guide is applicable to corrective actions performed under local, state, tribal, federal, and international corrective action programs. However, this guide does not provide a detailed description of the monitoring program requirements or existing guidance for each jurisdiction. This guide is intended to inform, complement, and support but not supersede the guidelines established by local, state, tribal, federal, or international agencies.  
1.3 This guide provides a framework, which includes widely accepted considerations and best practices for monitoring sediment remedy efficacy.  
1.4 This guide is related to several other guides. Guide E3240 provides an overview of the sediment risk-based corrective action (RBCA) process, including the role of risk assessment and representative background. Guide E3163 discusses appropriate laboratory methodologies to use for the chemical analysis of potential contaminants of concern (PCOCs) in various media (such as, sediment, porewater, surface water and biota tissue) taken during sediment monitoring programs; it also discusses biological testing and community assessment. Guide E3382 describes the overall framework to determine representative background concentrations (including Conceptual Site Model [C...

SIGNIFICANCE AND USE
4.1 Intended Use:  
4.1.1 This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, and other stakeholders.  
4.2 Updates to CSM:  
4.2.1 The CSM should be updated as needed and refined to describe the physical properties, chemical composition and occurrence, biological features, and environmental conditions of the sediment corrective action project (Guide E1689).  
4.3 Reference Material:  
4.3.1 This guide should be used in conjunction with other ASTM guides listed in 2.1 (especially Guides E3163, E3164, E3240, E3242, and E3344), as well as the material in the References section (including (1)).  
4.4 Flexible Site-Specific Implementation:  
4.4.1 This guide provides a systematic but flexible framework to accommodate variations in approaches by regulatory agencies and by the user based on project objectives, site complexity, unique site features, regulatory requirements, newly developed guidance, newly published scientific research, changes in regulatory criteria, advances in scientific knowledge and technical capability, and unforeseen circumstances.  
4.5 Regulatory Frameworks:  
4.5.1 This guide is intended to be applicable to a broad range of local, state, tribal, federal, or international jurisdictions, each with its own unique regulatory framework. As such, this guide does not provide a detailed discussion of the requirements or guidance associated with any of these regulatory frameworks, nor is it intended to supplant applicable regulations and guidance. The user of this guide will need to be aware of the regulatory requirements and guidance in the jurisdiction where the work is being performed.  
4.6 Systematic Project Planning and Scoping Process:  
4.6.1 When applying this guide, the user should undertake a systematic project planning and sco...
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1.1 This guide provides an overarching framework for the development of representative sediment background concentrations at contaminated sediment sites. It is intended to inform, complement, and support but not supersede the guidelines established by local, state, tribal, federal, or international agencies.  
1.2 Technically defensible representative sediment background concentrations are critical for several purposes (Guide E3242) (1)2. These include sediment site delineation, establishing remedial goals, remedy selection, assessment of risks posed by representative background concentrations, and establishing appropriate post-remedial monitoring plans.  
1.3 As part of the overall framework presented in this guide, Guide E3240 provides a general discussion of how Conceptual Site Model (CSM) development fits into the risk-based corrective action framework for contaminated sediment sites. However, not all elements of a sediment CSM need to be considered when developing representative sediment background concentrations; those that do are discussed in detail in Section 7 of this guide.  
1.3.1 As additional data are collected and analyzed, the CSM should be updated as needed.  
1.3.2 This guide is related to several other guides. Guide E3344 describes how to select an appropriate background reference area(s). Guide E3164 covers the sampling methodologies used in the field to obtain sediment samples (whether from the sediment site or background reference area[s]), and Guide E3163 discusses appropriate laboratory methodologies to use for the chemical analysis of potential contaminants of concern (PCOCs) in sediment samples. Guide E3242 describes how to evaluate candidate background data to obtain representative background data sets (including statistical, geochemical, and forensic considerations) and then how to use them to calculate representative sediment background concentrations. Relevant content contained in Guides ...

SIGNIFICANCE AND USE
4.1 Guidance on management of NAPL sites and a large body of research effort contributing to their development (for example, ITRC 2018 (1); CRC CARE 2018 (2); CL:AIRE 2019 (3) and CRC CARE 2020 (4)) point to the significance of natural attenuation and NSZD in the evolution of NAPL source and the resulting distributions of COCs in soil, groundwater and vapor.  
4.2 Examples of reported ranges in estimated natural attenuation rates are 300 – 7700 gallons of NAPL/acre/year (Garg et al. 2017 (5)); and 0.4 – 280 metric tons of NAPL/year (CRC CARE 2020 (4)).  
4.3 The intent of this guide is to provide a standardized approach for the estimation of natural attenuation rates for NAPL in the subsurface. The rates can be used for establishing a baseline metric for those involved in the remedial decision-making process. There is a need for a systematic approach and refinement in data collection and interpretation for quantifying the spatially and temporally variable rates. Providing quality assurance in estimation of this metric will enable the assessment of relatively more engineered remedies as compared to natural remedies or MNA (Fig. 1), as well as estimation of the remediation timeframe. This comparison, when performed through a standardized approach, can lead to actionable metrics for transition to sustainable remedies through well-defined and transparent criteria. In the context of a spectrum of remediation options in terms of engineered and natural remedies (Fig. 1), the transition is from a relatively more engineered (or active remediation) to a relatively more nature-based remedy. When considered in the remedial decision-making process, estimates of natural attenuation rates can be used:  
4.3.1 Before active remediation (as baseline to assess whether active remediation is needed);  
4.3.2 During active remediation (as performance/optimization metric); and  
4.3.3 At the end of active remediation (support transition to MNA or site closure).  
4.4 Since natural ...
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1.1 This is a guide for determining the appropriate method or combination of methods for the estimation of natural attenuation or depletion rates at sites with non-aqueous phase liquid (NAPL) contamination in the subsurface. This guide builds on a number of existing guidance documents worldwide and incorporates the advances in methods for estimating the natural attenuation rates.  
1.2 The guide is focused on hydrocarbon chemicals of concern (COCs) that include petroleum hydrocarbons derived from crude oil (for example, motor fuels, jet oils, lubricants, petroleum solvents, and used oils) and other hydrocarbon NAPLs (for example, creosote and coal tars). While much of what is discussed may be relevant to other organic chemicals, the applicability of the standard to other NAPLs, like chlorinated solvents or polychlorinated biphenyls (PCBs), is not included in this guide.  
1.3 This guide is intended to evaluate the role of NAPL natural attenuation towards reaching the remedial objectives and/or performance goals at a specific site; and the selection of an appropriate remedy, including remediation through monitoring of natural or enhanced attenuation, or the remedy transition to natural mechanisms. While the evaluation can support some aspects of site characterization, the development of the conceptual site model and risk assessment, it is not intended to replace risk assessment and mitigation, such as addressing potential impact to human health or environment, or need for source control.  
1.4 Estimation of NAPL natural attenuation rates in the subsurface relies on indirect measurements of environmental indicators and their variation in time and space. Available methods described in this standard are based on evaluation of biogeochemical reactions and physical transport processes combined with data analysis to infer and quantify the natural attenuation rates for NAPL present in the vadose and/or saturated zones.  
1.5...

SIGNIFICANCE AND USE
4.1 The Eco-RBCA process presented in this guide is a streamlined decision-making process for implementing corrective action protective of ecological resources at chemical release sites in a consistent manner. Eco-RBCA provides a framework for sites not covered under regulatory programs, for sites under regulatory programs that lack guidance, or for sites under programs with guidance that lack detail. Eco-RBCA may also provide a useful framework to help merge an approach when multiple regulatory programs apply.  
4.2 Ecological risk assessment is a science-based process that can be used to provide insight for risk management decision-making. Numerous federal and state programs have guidance for conducting ERA. Available regulatory approaches to ERA were reviewed in preparation for the development of this Eco-RBCA guide. Eco-RBCA was designed to be adaptable to the use of a variety of methods for considering risks to relevant ecological receptors and habitats. Some attributes of the standard are:  
4.2.1 Use of a tiered approach, including process flow charts to identify critical steps and facilitate the development of an overview of the entire process;  
4.2.2 Identification, development, and use of TPDs from Step 1 and throughout the entire Eco-RBCA process;  
4.2.3 Indications of the value and timing of stakeholder involvement, recognizing that some regulations require coordination with federal, state, tribal, and natural-resource trustees, and other stakeholders;  
4.2.4 Identification of situations under which an ERA may or may not be necessary; and  
4.2.5 Identification of decision points where ERA results are used for risk management decision making.  
4.3 Activities described in this guide should involve persons with the appropriate skills and expertise. The user may rely on individuals expert in remediation science and technology, ecology/biology, ecotoxicology, ERA practices, and site characterization techniques.  
4.4 This guide and supporting app...
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1.1 This is a guide to risk-based corrective action for the protection of ecological resources and supplements the RBCA process (Guide E2081). The primary objective of the Eco-RBCA process is to provide a flexible framework for a tiered approach to ERA and risk management decision making at chemical release sites. To this end, available guidance documents from various federal and state agencies were reviewed and their common attributes incorporated into this guide, where possible. The Eco-RBCA process complements existing technical and regulatory ecological risk guidance (see 4.2). In particular, it is intended to be compatible with the USEPA programmatic guidelines for ERA  (1)2, guidance for the Superfund program (2), and other USEPA (3) risk assessment and corrective-action programs. Eco-RBCA might also be used in conjunction with corrective action strategies that include human health issues (for example, Guide E2081).  
1.2 Chemical release sites vary greatly in terms of complexity, physical and chemical characteristics, and the risk that they might pose to ecological resources. The Eco-RBCA process, as described in Guide E2081, recognizes this variability and incorporates a tiered approach that integrates site assessment, response actions, and remedial actions with ERA. The process begins with relatively simple analyses in Tier 1 and, if necessary, proceeds to more detailed evaluations in Tier 2 or Tier 3. The process of gathering and evaluating data is conducted in such a manner that only those data that are necessary for a given tier's decision making are collected at each tier. Hence, this can facilitate effective use of resources and reduce initial data requirements.  
1.3 Eco-RBCA is intended to provide a framework for sites not covered under regulatory programs and for sites under regulatory programs that lack specific guidance. Eco-RBCA may also provide a useful framework to help merge several possible appr...

SIGNIFICANCE AND USE
4.1 Contaminated sites subject to remediation are growing in complexity and associated remediation costs, presenting a challenge for managers of contaminated sites. The need to properly monitor, evaluate, and report remediation processes (including physical, chemical, and biological) characterizing site conditions and contaminant mass and attenuation is critical for the evaluation and selection of effective remediation strategies. Assessment and characterization of biological processes associated with contaminant attenuation is supported and improved by the accurate and consistent use of molecular biological tools (MBTs) including data acquisition, interpretation, and reporting.  
4.2 The development of this guide through ASTM International is designed to meet the needs of managers of contaminated sites within the United States and elsewhere. The variety of available MBTs and the complexity with which they are currently being applied are not addressed in existing ASTM International Standards. The principal users of this guide should be industry project managers, regulators, consultants, analytical laboratories, and community stakeholders.
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1.1 This guide provides a framework for the application of molecular biological tools (MBTs) to assess and characterize in-situ biological processes to improve contaminated soil and groundwater management. While the focus of this guide is on in-situ biological processes, some concepts of how to apply MBTs can also be applied to ex-situ bioremediation approaches (for example, biopiles, bioreactors) to support design, operation, and troubleshooting. The intent of this guide is to develop a consistent way in which MBTs are applied at contaminated sites, not to develop expertise. Technical experts need to be engaged whenscoping, planning, executing, and interpreting data for MBTs. Lastly, there is a brief description of isotopic techniques within section 5.2; however, the scope and focus of this guide is the use of nucleic acid-based MBTs to assess biological processes at contaminated sites.  
1.2 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.  
1.3 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.

SIGNIFICANCE AND USE
4.1 Hydrophobic organic liquids (for example, petroleum hydrocarbons, coal tars) may exist in the environment for long periods of time as NAPLs. Standardized guidance and test methods do not exist to assess NAPL movement (both pore-scale mobility and NAPL body-scale migration) in sediment. Literature searches have resulted in a limited body of available and applicable research. Current research has focused on site-specific sediment NAPL movement evaluation approaches.  
4.2 Standardized guidance and test methods currently exist for assessing NAPL mobility and migration at upland sites, from organizations such as ASTM International (Guides E2531 and E2856), Interstate Technology and Regulatory Council (2), and the American Petroleum Institute (3, 4). Approaches commonly used in upland sites may or may not be applicable for any given sediment site. This guide provides perspectives on the applicability of various methodologies for specific sediment conditions.  
4.3 This guide describes various methodologies that are useful in sediment NAPL movement evaluation, such as laboratory test methods, calculation approaches, and field observation interpretation. The guide then provides frameworks to evaluate the data generated from these methodologies to determine if the NAPL observed in the sediments under in situ conditions exhibits movement of any kind.  
4.4 Important exposure pathways in upland sites are usually not applicable to sediment sites. The U.S. Environmental Protection Agency notes, “Contaminants in the biologically active layer of the surface sediment at a site often drive exposure” (5). In aquatic environments, benthic organisms live in the surface sediment to maintain access to oxygenated overlying water. These benthic organisms are at the base of the food chain. If NAPL in subsurface sediment is not migrating, the NAPL will not move into the surface sediment and result in exposure to benthic organisms. NAPL that is stable and only present in subsurface se...
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1.1 This guide discusses methodologies that can be applied to evaluate the potential for the movement (that is, pore-scale mobility or NAPL body-scale migration) of non-aqueous phase liquid (NAPL) in sediments. NAPL movement assessment in sediments is significantly different than in upland soils. As such, the frameworks for evaluating NAPL movement in upland soils have limited applicability for sediments. In particular, because upland NAPL conceptual site models may not be applicable to many sediment sites, this guide provides a framework to evaluate whether NAPL is mobile (at the pore scale) or migrating (at the NAPL body scale) in sediments.  
1.2 Assessment of the potential for NAPL to move in sediment is important for several reasons, including (but not limited to) evaluation of risk to potential receptors, the need for potential remedial action, and potential remedial strategies. For example, if the NAPL is migrating, sensitive receptors may be impacted and this will influence the choice and timing of any remedy selected for an area of the sediment site. If the NAPL is not mobile or migrating, then remedial actions may not be warranted.  
1.3 This guide is applicable at sediment sites where NAPL has been identified in the sediment by various screening methods and the need for a NAPL movement evaluation is warranted (Guide E3248).  
1.4 Petroleum hydrocarbon, coal tar, and other tar NAPLs (including fuels, oils, and creosote) are the primary focus of this guide. These forms of contamination are commonly related to historical operations at refineries, petroleum distribution terminals, manufactured gas plants (MGPs), and various large industrial sites.  
1.5 Although certain technical aspects of this guide apply to other NAPLs (for example, dense NAPLs [DNAPLs] such as chlorinated hydrocarbon solvents), this guide does not completely address the additional complexities of those DNAPLs.  
1.6 The goal of this guide...

SIGNIFICANCE AND USE
4.1 The risk-based corrective action (RBCA) process presented in this guide is a consistent, streamlined decision process for selecting corrective actions at chemical release sites.  
4.2 Risk assessment is a developing science. The scientific approach used to develop the RBSL and SSTL may vary by regulatory agency and by user due to regulatory requirements, guidance and use of alternative scientifically-based methods.  
4.3 Activities described in this guide should be conducted by persons familiar with current site characterization techniques, remedial action science and technology, current human health risk and exposure assessment methodologies, toxicology, and current ecological evaluation methodologies.  
4.4 In order to properly apply the RBCA process, the user should AVOID the following:  
4.4.1 Prescribing Tier 1 RBSL or RESC as remedial action standards for all sites rather than screening levels,  
4.4.2 Limiting use of the RBCA process to Tier 1 evaluation only and not continuing with Tier 2 or Tier 3 analyses for sites where further tier evaluation is appropriate,  
4.4.3 Placing arbitrary time constraints on the corrective action process; for example, requiring that Tiers 1, 2, and 3 be completed within time periods that do not reflect the actual urgency of and risks posed by the site,  
4.4.4 Using the RBCA process only when active remedial action is not technically feasible, rather than as a process that is applicable during all phases of corrective action,  
4.4.5 Conducting active remedial action to achieve only technology-based remedial limits (for example, asymptotic levels) prior to determining applicable corrective action goals,  
4.4.6 Using predictive modeling that is not supported by available data or knowledge of site conditions,  
4.4.7 Limiting remedial action options to a single class of remedial actions for all sites (for example Guide E1943),  
4.4.8 Using unjustified or inappropriate exposure factors,  
4.4.9 Using unjustifie...
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1.1 This is a guide for conducting risk-based corrective action (RBCA) at chemical release sites based on protecting human health and the environment. The RBCA is a consistent decision-making process for the assessment and response to chemical releases. Chemical release sites vary greatly in terms of complexity, physical and chemical characteristics, and in the risk that they may pose to human health and the environment. The RBCA process recognizes this diversity by using a tiered approach that integrates site assessment and response actions with human health and ecological risk assessment to determine the need for remedial action and to tailor corrective action activities to site-specific conditions and risks. The evaluations and methods used in the RBCA process begin with simple analyses in Tier 1 and move to more complex evaluations in either Tier 2 or Tier 3, as applicable. The process of gathering and evaluating data is conducted in a scaled fashion. Consequently, only the data that are necessary for a particular tier's decision-making are collected at that tier.  
1.2 This guide describes an approach for risk-based corrective action. It is intended to help direct and streamline the corrective action process and to complement but not to supersede federal, state and local regulations. It can be employed at sites where corrective action is being conducted including sites where there may not be a regulatory framework for corrective action, or where the user wishes to conduct corrective action such as sites in voluntary cleanup programs or under Brownfields initiatives. In addition, it can also be used as a unifying framework when several different agency programs affect the site. Furthermore, the user should be aware of the federal, state and local corrective action programs that are applicable for the site and, regardless of the program, federal, state and local agency approvals may be required to implement the proce...

SIGNIFICANCE AND USE
5.1 This guide is significant in that it addresses the data and information options of each component of the ecological risk assessment process, for both a screening and complex ERA. It outlines the data and information options while recognizing that an ecological risk assessment may be focused to achieve a particular stated goal. This guide is not intended to represent the views of the U.S. Environmental Protection Agency (USEPA), or any other regulatory agency, on data collection for ecological risk assessment.  
5.2 This guide is to be used by managers, scientists, and technical staff of contractors, industry, government agencies, and universities responsible for conducting ecological risk assessments at contaminated sites. It is to be used to guide data collection phases of the ecological risk assessment. It will assist in the development of the conceptual site model (see Guide E1689) and the identification of potential assessment and measurement endpoints (see Guide E1848 and US EPA’s Generic Ecological Assessment Endpoints, 2016 (5)). While it was written to assist in planning an ERA, the list also may be used in the review of a completed ERA.
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1.1 An ecological-risk assessment (ERA) is a process for organizing and analyzing data, information, assumptions, and uncertainties to evaluate the likelihood that adverse ecological effects might occur or are occurring as a result of a stressor. This guide is intended to assist remedial project teams, specifically ecological risk assessors, in identifying data and information options that may be used to perform a screening or complex ecological risk assessment (ERA) at a contaminated site.
Note 1: While the intent of ERA is to evaluate risk (that is, the probability of adverse effects occurring in ecological receptors), there are no measures, statistics, or metrics that calculate or express risk explicitly. However, various metrics or indices, a common example being the hazard quotient, are used to inform risk assessments.  
1.2 The identification of data and information options for human health risk assessment is outside the scope of this guide.  
1.3 This guide is intended to provide a list for identifying data and information options and does not recommend a specific course of action for ERA activities.  
1.4 This guide addresses data and information options for the ecological risk assessment, not verification or long-term monitoring studies.  
1.5 This guide lists many of the common data and information options for ERA, but there may be others relevant for any particular site.  
1.6 This guide considers one component of an ERA, that is, identification of data and information options. Other ASTM guides have been developed, for example, Guides E1689 and E1848, and are being developed to cover other components of the risk assessment process.  
1.7 This guide does not provide information on how to perform any of the analytical procedures used to perform a risk assessment once data collection options are defined.  
1.8 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.

SIGNIFICANCE AND USE
4.1 NAPLs (for example, chlorinated solvents, petroleum products, and creosote) can be emplaced in sediments through a variety of mechanisms (Guide E3248). Dense non-aqueous phase liquids (DNAPLs) are more dense than water, whereas light non-aqueous phase liquids (LNAPLs) are less dense than water.  
4.2 Standardized guidance and test methods currently exist for assessing NAPL mobility at upland sites, from organizations such as ASTM (Guides E2531 and E2856), Interstate Technology & Regulatory Council (1)3 and the American Petroleum Institute (2, 3).  
4.3 Guide E3248 provides guidance regarding when a NAPL movement evaluation is warranted. After confirming that NAPL is present and evaluating nature and extent as appropriate, the next step in any NAPL movement evaluation is to evaluate if NAPL is mobile or immobile at the pore scale—this is done using tiered or weight of evidence (WOE) approaches. This guide provides a structured process to select samples to submit to the laboratory for NAPL mobility testing that is part of a NAPL movement evaluation.  
4.4 This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, and other stakeholders.  
4.5 This guide should be used in conjunction with other reference material (refer to Section 2 and References) that direct the user in developing and implementing sediment assessment programs.  
4.6 This guide is related to Guide E3163, concerning sediment analytical techniques used during sediment programs. This relates to Guide E3248, which discusses generic models for the emplacement and advection of NAPL in sediments. It is related to Guide E3268, which describes sample collection, field screening and sample handling considerations in NAPL movement evaluations. And this is related to Guide E3282, which describes evaluation met...
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1.1 This guide is designed for general application at a wide range of sediment sites where non-aqueous phase liquid (NAPL) is present or suspected to be present in the sediment. This guide describes a process to use field screening methods, specifically visual observations, and the results of shake tests, to categorize the relative amount of NAPL present in a sample. This categorization can then be utilized to select co-located sediment samples for laboratory testing to determine if the NAPL in the sample interval is mobile or immobile at the pore scale, or any other chemical or physical testing.  
1.1.1 There is no current industry standard methodology to select sediment samples for laboratory NAPL mobility testing; the use of different methodologies is possible. This guide focuses on a selection process that uses visual observations and shake tests. This process has the advantage of being simple to use and, if applied in a disciplined manner, has been demonstrated to provide good results in the field.  
1.2 This guide is intended to inform, complement, and support characterization and remedial efforts performed under international, federal, state, and local environmental programs but not supersede local, state, federal, or international regulations. The users of this guide should review existing information and data available for a sediment site to determine applicable regulatory agency requirements and the most appropriate entry point into and use of this guide.  
1.3 ASTM International (ASTM) standard guides are not regulations; they are consensus standard guides that may be followed voluntarily to support applicable regulatory requirements. This guide may be used in conjunction with other ASTM guides developed for assessing sediment sites.  
1.4 This guide does not address methods and means of sample collection (Guide E3163).  
1.5 Units—The values stated in SI or CGS units are to be regarded as the standard. N...

SIGNIFICANCE AND USE
4.1 Ebullition is ubiquitous in sediment and is primarily a significant concern when there is associated NAPL/contaminant transport, resulting in exposure risk to humans, ecological receptors, or both. Ebullition may also be a concern when capping has been chosen as part of a site remedy.  
4.2 Understanding the potential for ebullition-facilitated NAPL/contaminant transport in sediment is an important element of an overall conceptual site model (CSM) that forms a basis for (1) evaluating if (and how) human and ecological receptors may be exposed to NAPL/contaminants, and (2) assessing remedial alternatives. In addition, demonstrating the potential for (and extent of) ebullition-facilitated transport of NAPL/contaminants in sediments to regulators and other stakeholders has been historically hampered by the lack of standardized terminology and characterization protocols. The complexity of ebullition-facilitated NAPL/contaminant transport in sediment, and the lack of agreed upon methods for analysis and interpretation of site data, has led to uncertainty in corrective action decision-making at sediment sites. This has sometimes resulted in misleading expectations about remedial outcomes. The ebullition-facilitated transport mechanisms for NAPL/contaminants in sediments are different from advective transport mechanisms in sediment or in upland environments, due to a variety of physical, geochemical, and biological differences, thus necessitating this guide.  
4.3 This guide is intended to serve as a stand-alone document to consider conditions that are unique to ebullition and ebullition-facilitated NAPL/contaminant transport, as well as to complement other guides used for CSM development at contaminated sediment sites (Guides E1689, E1739, E2081, E2531, and E3248). This guide will aid users in understanding the unique and fundamental characteristics of sediment environments that influence the occurrence of ebullition-facilitated NAPL/contaminant transport. Understan...
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1.1 This guide addresses the processes that lead to (or influence) ebullition-facilitated nonaqueous phase liquid (NAPL)/contaminant transport, methods for quantifying that transport, considerations for sample timing, sampling procedures, and use of results in extrapolating an annual ebullition-facilitated NAPL/contaminant load to a site, or a portion of a site. This guide is not intended to address remediation of sites where ebullition-facilitated transport of NAPL/contaminants is occurring, fate and transport of contaminants subsequent to the ebullition transport mechanism, the measurement of contaminant concentrations within the gas bubbles, ebullition-associated human health and ecological risk, NAPL advection, or determining the depth of ebullition below the mudline. Additionally, gas transport without NAPL/contaminants is possible in areas with gas generation and limited NAPL contamination of the sediment, which is covered in this guide. Ebullition should be evaluated at sites where sediment capping is anticipated.  
1.2 The users of this guide should be aware of the appropriate regulatory requirements that apply to sediment sites where NAPL is present or suspected to occur. The user should consult applicable regulatory agency requirements to identify appropriate technical decision criteria and seek regulatory approvals, as necessary.  
1.3 ASTM standard guides are not regulations; they are consensus standard guides that may be followed voluntarily to support applicable regulatory requirements. This guide may be used in conjunction with other ASTM guides developed for sediment programs. The guide supplements characterization and remedial efforts performed under international, federal, state, and local environmental programs, but it does not replace regulatory agency requirements.  
1.4 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.  ...

SIGNIFICANCE AND USE
4.1 Many contaminants, including chlorinated solvents and petroleum products, enter the subsurface in the form of an immiscible liquid, known as a NAPL. Understanding the potential emplacement and transport mechanism for NAPL in sediment is an important element of an overall conceptual site model (CSM) that forms a basis for (1) investigating the nature and extent of NAPL, (2) evaluating if (and how) human and ecological receptors may be exposed to NAPL, and (3) assessing remedial alternatives. In addition, demonstrating the potential movement of NAPL in sediments is hampered by the lack of standardized terminology and characterization protocols, thus necessitating this guide.  
4.1.1 Understanding the presence and movement of NAPL in sediments is complicated by the lack of standardized protocols for characterizing NAPL movement in the diverse range of sediment environments. Literature searches have indicated that there is a limited body of available, applicable research. Current research has focused on site-specific sediment NAPL mobility assessment approaches, but application of common methods or decision-making processes identified across sites were limited.  
4.1.2 The movement (or lack of movement) of NAPL in sediments is a key factor in developing protective remedial options for NAPL-impacted sediments and for the long-term management of sediment sites. Typical exposure pathways that are addressed through risk management decisions at upland sites are usually not applicable to sediment sites. Rather, “contaminants in the biologically active layer of the surface sediment at a site often drive exposure” (1)5, because in aquatic environments, benthic organisms live in the surface sediment to maintain access to oxygenated overlying water. NAPL that is present in subsurface sediment below the biologically active layer that is not migrating and has an overlying sediment that is expected to remain in place (that is, is not dredged or eroded) does not pose a risk to ...
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1.1 This guide provides considerations to inform sample collection, field screening, and sample handling of sediments impacted with non-aqueous phase liquid (NAPL) to assist in data collection for the evaluation of NAPL movement in sediment. The conditions affecting NAPL emplacement and movement in sediments are significantly different than in upland soils. As such, the framework for the assessment of NAPL movement in upland soils has been determined to have limited applicability for sediments.  
1.2 This guide is applicable to sediment sites where the presence or suspected presence of NAPL has been identified. Sediments are the subject media considered in this guide, not surface water or groundwater.  
1.3 The goal of this guide is to provide a technical framework for sample collection, field screening, and sample handling activities used to evaluate NAPL conditions, in particular NAPL movement (that is, mobility at the pore scale and migration at the NAPL body scale) in sediments, which can be used to inform the development and selection of remedial options and post-remedial monitoring activities.  
1.4 This guide discusses sample collection procedures, including direct methods (that is, core and grab samples) and indirect methods (that is, DART®2, laser-induced florescence, and porewater samplers) for assessing NAPL presence or absence in sediment.  
1.5 This guide discusses field characterization procedures for assessment of NAPL-impacted sediments including visual screening, stratification assessment, shake test, ultraviolet (UV) light test, NAPL FLUTe™3, and headspace vapor monitoring.  
1.6 This guide discusses considerations to obtain samples representative of in situ conditions. This includes methods used to evaluate sediment integrity, sample retrieval from the sediment bed, core identification, sample storage onboard the vessel, sample retrieval from the coring device, sufficient sample recovery, core cut...

SIGNIFICANCE AND USE
4.1 Application:  
4.1.1 LNAPL transmissivity is an accurate metric for understanding LNAPL recovery, is directly proportional to LNAPL recoverability and tracking remediation progress towards residual LNAPL saturation.  
4.1.2 LNAPL transmissivity can be used to estimate the rate of recovery for a given drawdown from various technologies.  
4.1.3 LNAPL transmissivity is not an intrinsic aquifer property but rather a summary metric based on the aquifer properties, LNAPL physical properties, and the magnitude of LNAPL saturation over a given interval of aquifer.  
4.1.4 LNAPL transmissivity will vary over time with changing conditions such as, seasonal fluctuations in water table, changing hydrogeologic conditions and with variability in LNAPL impacts (that is, interval that LNAPL flows over in the formation and LNAPL pore space saturation) within the formation.  
4.1.5 Any observed temporal or spatial variability in values derived from consistent data collection and analysis methods of LNAPL transmissivity is not erroneous, rather is indicative of the actual variability in subsurface conditions related to the parameters encompassed by LNAPL transmissivity (that is, fluid pore space saturation, soil permeability, fluid density, fluid viscosity, and the interval that LNAPL flows over in the formation).  
4.1.6 LNAPL transmissivity is a more accurate metric for evaluating recoverability and mobile LNAPL than gauged LNAPL thickness. Gauged LNAPL thickness does not account for soil permeability, magnitude of LNAPL saturation above residual saturation, or physical fluid properties of LNAPL (that is, density, interfacial tension, and viscosity).  
4.1.7 The accurate calculation of LNAPL transmissivity requires certain aspects of the LNAPL Conceptual Site Model (LCSM) to be completely understood and defined in order to calculate LNAPL drawdown correctly. The methodologies for development of the LCSM are provided in Guide E2531. The general conceptual site model aspe...
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1.1 This guide provides field data collection and calculation methodologies for the estimation of light non-aqueous phase liquid (LNAPL) transmissivity in unconsolidated porous sediments. The methodologies presented herein may, or may not be, applicable to other hydrogeologic regimes (for example, karst, fracture flow). LNAPL transmissivity represents the volume of LNAPL (L3) through a unit width (L) of aquifer per unit time (t) per unit drawdown (L) with units of (L2/T). LNAPL transmissivity is a directly proportional metric for LNAPL recoverability whereas other metrics such as apparent LNAPL thickness gauged in wells do not exhibit a consistent relationship to recoverability. The recoverability for a given gauged LNAPL thickness in a well will vary between different soil types, LNAPL types or hydrogeologic conditions. LNAPL transmissivity accounts for those parameters and conditions. LNAPL transmissivity values can be used in the following five ways: (1) Estimate LNAPL recovery rate for multiple technologies; (2) Identify trends in recoverability via mapping; (3) Applied as a leading (startup) indicator for recovery; (4) Applied as a lagging (shutdown) indicator for LNAPL recovery; and (5) Applied as a robust calibration metric for multi-phase models (Hawthorne and Kirkman, 2011 (1)2 and ITRC ((2)). The methodologies for LNAPL transmissivity estimation provided in this document include short-term aquifer testing methods (LNAPL baildown/slug testing and manual LNAPL skimming testing), and long-term methods (that is, LNAPL recovery system performance analysis, and LNAPL tracer testing). The magnitude of transmissivity of any fluid in the subsurface is controlled by the same variables (that is, fluid pore space saturation, soil permeability, fluid density, fluid viscosity, the interval that LNAPL flows over in the formation and the gravitational acceleration constant). A direct mathematical relationship exists between th...

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...
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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...

SIGNIFICANCE AND USE
4.1 This guide is intended for use within a RBCA process or other risk-based framework for protection of human health and the environment that is based on an evaluation of sources, exposure pathways, and receptors.  
4.2 This guide is intended to identify the factors that should be considered in the selection and implementation of an appropriate remedial action to address COCs present in environmental media at the site at concentrations above the remedial action levels. The specific process used to select the remedial action will vary widely from site to site. However, in all cases, the selected remedial action should be both a protective remedial action (that is, achieves the risk-based remedial action objectives) and an acceptable remedial action (that is, satisfies the non-risk remedial action objectives).
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1.1 This guide covers the selection of appropriate remedial actions at sites where a release of chemicals (for example, vapor-phase, dissolved-phase, or non-aqueous phase liquids (NAPL)) into the environment has occurred. This overall remedy selection process is illustrated in Fig. 1. The guide is intended to be applied within a risk-based corrective action (RBCA) framework.
FIG. 1 Remedy Selection Process  
1.2 The purpose of this guide is to facilitate the selection of acceptable remedial actions and to minimize bad decisions leading to the selection of remedial actions that do not satisfy both the risk-based remedial action objectives and the non-risk remedial action objectives.  
1.3 This guide is intended to be applied at sites that require a remedial action to address unacceptable human heath or ecological risks, other regulatory requirements, and/or other unacceptable site conditions. Prior to use of this guide, a site assessment should be completed resulting in: (1) the establishment of remedial action objectives, (2) a determination that a remedial action is required to achieve the remedial action objectives, (3) an identification of site areas requiring a remedial action, and (4) a conceptual site model that reflects the results of the site assessment. The risk-based remedial action objectives are assumed to have been established using RBCA or another risk-based assessment method that results in the identification of appropriate remedial action objectives based on an evaluation of sources, exposure pathways, and potential receptors. Remedial action objectives may be established using Guide E1739, Guide E2081, and/or Guide E2205. In addition, applicable federal, state, and local regulations, statutes, and policies should be followed and should form the basis for determining risk-based and non-risk remedial action objectives. The remedial action objectives may include resource protection standards and the prevention of aesthetic or nuisance impacts in addition to protection of human health and the environment.  
1.4 Each risk-based remedial action objective for an exposure pathway will typically include numeric remedial action levels for each chemical of concern (COC). Remedial action levels may also be developed for non-risk remedial action objectives such as resource protection standards. The non-risk remedial action levels may include thickness or mobility criteria for NAPL. The selected remedy must be effective and timely for each remedial action objective based on the consideration of the associated exposure pathway or resource protection standard.  
1.5 To facilitate the selection of acceptable remedial actions, this guide establishes a process for remedy selection (Fig. 2) that involves:
FIG. 2 Remedy Selection Flowchart  
FIG. 2 Remedy Selection Flowchart (continued)  
1.5.1 Development of risk-based remedial action objectives that includes identification of complete exposure pathways and numeric remedial action levels (Section 5).  
1.5.2 Development of non-risk remedial action objectives based on resource protection and other non-risk considerations...

ABSTRACT
This guide deals with an approach to identification, selection, and use of ecological endpoints (both assessment and measurement endpoints) that are susceptible to the direct and indirect effects of both chemical and non-chemical stressors and agents associated with wastes and contaminated media at specific sites under current and future land uses. It does not address assessment and measurement endpoints for non-site specific studies (for example, chemical specific or regional risk assessments) or measurements in abiotic media (soil, water, or air). Conditions of the site and risk assessment that should be considered in identifying and selecting assessment and measurement endpoints include stressor characteristics, ecosystem types, spatial scale, temporal scale, ecological organization, and functionality/values. The following subsections present a partial listing of representative measurement endpoints: measurement endpoints representing ecosystem assessment endpoints, measurement endpoints representing community assessment endpoints, measurement endpoints representing population assessment endpoints, and measurement endpoints representing individual organism assessment endpoints. Other general considerations, desirable characteristics of assessment and measurement endpoints, candidate site-related ecological receptors, candidate assessment endpoints, specific steps in identifying, selecting and using assessment and measurement endpoints, addressing uncertainties in the identification and selection of assessment and measurement endpoints, documenting the selection of assessment and measurement endpoints.
SIGNIFICANCE AND USE
4.1 This guide assumes that a decision has been made that an ecological risk assessment is required for a contaminated site. In some cases, this decision could be made before any site data are collected. See Fig. 1.
FIG. 1 Conceptual Relationships between Assessment Endpoints, Measurement Endpoints and Lines of Evidence (Source: Federal Contaminated Sites Action Plan (FCSAP) Ecological Risk Assessment Guidance, Government of Canada, March 2012)  
4.2 The selection of assessment endpoints (defined as ecological values to be protected) and measurement endpoints (ecological characteristics related to the assessment endpoints) is a critical step in conducting an ecological risk assessment. Endpoint selection identifies those effects which are ecologically significant and not merely those that are adverse, thus providing a more rational and defensible basis for making risk and remedial decisions.  
4.3 This guide provides an approach for identifying, selecting and using assessment and measurement endpoints in an ecological risk assessment for a contaminated site. This guide has been developed because there is no universal, simple measure of ecological health analogous to measures used in human health risk assessment. Assessment and measurement endpoints have to be identified and selected from a variety of individual circumstances on a stressor-, ecosystem- and scale-specific basis. It is important to recognize that a diverse set of ecological endpoints could be required for a specific site. EPA/100/F15/005 Generic Ecological Assessment Endpoints (GEAEs) For Ecological Risk Assessment: Second Edition With Generic Ecosystem Services Endpoints Added. July 2016)  
4.4 This guide is intended to be used primarily by a biologist, ecologist, ecotoxicologist, or a team of environmental scientists during problem formulation and work plan development prior to initiating data collection activities at a contaminated site (3-8, 10).  
4.5 Ecological risk assessment is usually an...
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1.1 This guide covers an approach to identification, selection, and use of ecological endpoints (both assessment and measurement endpoints) (1-8)2 that are susceptible to the direct and indirect effects of both chemical and non-chemical stressors or agents associated with wastes and contaminated media at spe...

SIGNIFICANCE AND USE
4.1 Flexibility—Users may desire to incorporate sustainable aspects within the scalable framework throughout any or all phases of the cleanup, or any size of site.  
4.1.1 For simplicity the term cleanup is used in the guide when referring to any of the cleanup phases, for example site assessment, remedy selection, remedy design and implementation, remedy optimization, operation, maintenance and monitoring, and closure.  
4.1.2 Implementation of the guide is site-specific. The user may choose to customize the implementation of the guide for particular types of sites, for example, UST sites, dry cleaner sites, or particular phases of cleanup. Customization may be particularly relevant for groups of small, non-complex sites.  
4.2 Considerations—The information provided in this guide provides a framework to evaluate sustainable aspects in the context of site cleanup. The guide helps users identify factors and activities they may want to consider in cleanup projects, while protecting human health and the environment.  
4.3 Sustainable Performance Criterion—Based on the sustainable objectives identified for the site, users should implement one or more best management practices that substantially benefit each of the sustainable aspects (environmental, social and economic), see Section 6 for details. The user should demonstrate these benefits through publicly available documentation. Substantial benefits must be over and above those achieved by existing regulatory requirements, unless a regulatory agency adopts this guide for cleanup sites. In that case the regulatory agency will determine what constitutes substantial benefits under its own regulations.  
4.4 Transparency Goal—The user should document the activities and evaluations performed while using this guide. The documentation is needed to demonstrate the sustainable benefits through public disclosure and transparency. See Section 8 for more information.  
4.5 Stakeholder Involvement—The user should engage sta...
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1.1 This guide presents a framework that allows and encourages the user to address sustainable aspects (environmental, economic and social) within cleanup projects. The user may implement this guide to integrate sustainable objectives into cleanup while working within applicable regulatory criteria.  
1.2 The guide provides an overarching, consistent, transparent and scalable framework that helps the user identify and incorporate sustainable best management practices (BMPs) into site cleanup (which includes assessment and remediation), and enables the user to perform measurement of BMPs during the cleanup process. See Appendix X1 for example BMPs.  
1.3 The guide is intended to encourage incremental steps to incorporate sustainable elements into cleanup projects. The user chooses whether to pursue BMP implementation alone (Section 6) or to also measure the benefits of the implemented BMPs (Sections 6 and 7). The user also chooses the phases of the cleanup to which they apply the guide.  
1.4 The guide should be implemented within the existing site assessment and remediation process. The approach described in this guide should be used with other existing technical tools and policy to encourage the consideration of a more holistic approach with a broader range of cleanup options and activities than traditionally employed (NICOLE 2012(1))2.  
1.5 BMPs implemented under this guide should address all three aspects of sustainability: environmental, economic and social, while assuring that human health and safety as well as ecological risks are addressed. The goal of implementing BMPs is to take actions to address the sustainable objectives identified for the site.  
1.6 3.1.17 defines sustainable objectives; 3.1.15.1 defines sustainable aspects; 5.3 provides detail about core elements; and Section 6 describes a process to identify, evaluate, select, and implement BMPs.  
1.7 While the guide specifically applies to the cl...

SIGNIFICANCE AND USE
4.1 Intended Application of Guide—This guide is intended for use at properties that are presently developed or proposed for development for residential, commercial, or industrial purposes but which contain chemical-affected soil, groundwater, air, or other environmental media, which may pose an unacceptable risk to human health. This guide can be used as a tool for planning and implementation of property reuse or redevelopment activities at former commercial/industrial facilities, “brownfield” properties, or properties containing naturally occurring, chemical-affected environmental media so as to effectively manage potential human exposures to COCs which might otherwise limit productive use of the property.  
4.2 Situations Where This Guide May Be Applied—An engineering control may be needed as part of the development plan when: (1) COCs are present in soil, groundwater, or other environmental media at concentrations posing unacceptable risk(s) to human health per applicable regulatory criteria or a risk-based evaluation; (2) a potentially complete exposure pathway for COCs is likely to exist in the absence of an engineering control or other response measure, and (3) installation and maintenance of the engineering control is determined to be an applicable and cost-effective response action relative to other options. A property should not be excluded from development or redevelopment solely on the basis of chemical-affected media, in general, and chemical-affected groundwater, in particular. If no affected environmental media are identified as having COC concentrations in excess of applicable regulatory standards or risk-based criteria, then engineering controls or other response measures are not required.  
4.3 Assumptions for Use of This Guide—For use of this guide, it is assumed that (1) an environmental site assessment has been completed to characterize chemical-affected environmental media, (2) exposures to COCs posing an unacceptable risk to the health of cur...
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1.1 This guide presents general considerations for application of engineering controls to facilitate continued use or redevelopment of properties containing chemical-affected soil, groundwater, or other environmental media, due either to chemical releases or naturally-occurring conditions. This guide is not meant to be prescriptive but rather to present considerations for evaluating technologies capable of addressing potential human exposures associated with chemical-affected environmental media.  
1.2 Table 1 lists the considerations that should be taken into account when developing an engineering control in accordance with this guide.  
1.3 This guide is intended for use by real estate developers, civil/structural designers, environmental regulators, industrial parties, environmental consultants, and other persons concerned with residential, commercial, or industrial development of real properties where chemical-affected environmental media are present. The design process should involve the individuals and firms working on various aspects of the specifications for construction, operation, and maintenance. If the site is located on public property, then public participation should be considered during the design process.  
1.4 This guide is directed toward properties where chemical-affected environmental media, associated with either human-influenced activities or naturally-occurring conditions, will remain in place and where active or passive engineering controls will be used to reduce or eliminate exposures that may otherwise pose an unacceptable risk to property users.  
1.5 This guide identifies the exposure concerns associated with chemical-affected properties that may affect the property development plan, both in the construction phase and during the proposed use of the property; defines performance standards for control of applicable exposure pathways; and, for each exposure pathway, provides examples of eng...

SIGNIFICANCE AND USE
5.1 The information gained through the site investigation is used to characterize the physical, biological, and chemical systems existing at a site. The processes that determine contaminant releases, contaminant migration, and environmental receptor exposure to contaminants are described and integrated in a conceptual site model.  
5.2 Development of this model is critical for determining potential exposure routes (for example, ingestion and inhalation) and for suggesting possible effects of the contaminants on human health and the environment. Uncertainties associated with the conceptual site model need to be identified clearly so that efforts can be taken to reduce these uncertainties to acceptable levels. Early versions of the model, which are usually based on limited or incomplete information, will identify and emphasize the uncertainties that should be addressed.  
5.3 The conceptual site model is used to integrate all site information and to determine whether information including data are missing (data gaps) and whether additional information needs to be collected at the site. The model is used furthermore to facilitate the selection of remedial alternatives and to evaluate the effectiveness of remedial actions in reducing the exposure of environmental receptors to contaminants.  
5.4 This guide is not meant to replace regulatory requirements for conducting environmental site characterizations at contaminated (including radiologically contaminated) sites. It should supplement existing guidance and promote a uniform approach to developing conceptual site models.  
5.5 This guide is meant to be used by all those involved in developing conceptual site models. This should ideally include representatives from all phases of the investigative and remedial process, for example, preliminary assessment, remedial investigation, baseline human health and ecological risk assessments, and feasibility study. The conceptual site model should be used to enable experts fro...
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1.1 This guide is intended to assist in the development of conceptual site models to be used for the following: (1) integration of technical information from various sources, (2) support the selection of sample locations for establishing background concentrations of substances, (3) identify data needs and guide data collection activities, and (4) evaluate the risk to human health and the environment posed by a contaminated site. This guide generally describes the major components of conceptual site models, provides an outline for developing models, and presents an example of the parts of a model. This guide does not provide a detailed description of a site-specific conceptual site model because conditions at contaminated sites can vary greatly from one site to another.  
1.2 The values stated in either inch-pound or SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.3 This guide is intended to apply to any contaminated site.  
1.4 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.  
1.5 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.

SIGNIFICANCE AND USE
4.1 Understanding the potential emplacement and transport mechanism for NAPL in sediment is an important element of an overall conceptual site model (CSM) that forms a basis for (1) investigating the nature and extent of NAPL, (2) evaluating if (and how) human and ecological receptors may be exposed to NAPL, and (3) assessing remedial alternatives. In addition, demonstrating the potential movement of NAPL in sediments to regulators and other stakeholders has been historically hampered by the lack of standardized terminology and characterization protocols. The complexity of NAPL movement in sediment, and the lack of agreed upon methods for analysis and interpretation of site data, has led to uncertainty in corrective action decision-making. This has sometimes resulted in misleading expectations about remedial outcomes. The emplacement and transport mechanisms for NAPL in sediments are different from those in upland environments, due to a variety of physical, geochemical, and biological differences between sediment and upland environments, thus necessitating this guide.  
4.2 This guide is intended to supplement the CSM developed according to the principles outlined in the contaminated sites conceptual site model Guide E1689, the standard guide for developing a CSM for Light Non-Aqueous Phase Liquid (LNAPL) sites Guide E2531, and the Risk-Based Corrective Action (RBCA) Guides E1739 and E2081, by considering conditions for NAPL emplacement and movement (that is, advection) that are unique to a sediment environment. This guide will aid users in understanding the unique and fundamental characteristics of sediment environments that influence the occurrence and behavior of NAPL in sediments. Understanding the sources of NAPL encountered in sediment, the mechanisms for NAPL to become emplaced in sediments, and the site characteristics that influence the advective movement of NAPL within the sediment column will aid in identifying specific data requirements necessary to inv...
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1.1 This guide is designed for general application to a wide range of sediment sites where non-aqueous phase liquid (NAPL) is present or suspected to be present. This guide describes multiple emplacement mechanisms that can result in NAPL presence within the sediment stratigraphic profile and how the characteristics of the sediment, aquatic environment, and NAPL properties influence NAPL movement within sediments. This guide provides example conceptual models for NAPL emplacement in sediments in order to establish a common framework that can be used to assess conditions influencing NAPL movement by means of advection.  
1.2 This guide supplements methodologies for characterization and remedial efforts performed under international, federal, state and local environmental programs, but does not replace regulatory agency requirements. The users of this guide should review existing information and data available for a sediment site to determine applicable regulatory agency requirements and the most appropriate entry point into and use of this guide.  
1.3 ASTM standard guides are not regulations; they are consensus standard guides that may be followed voluntarily to support applicable regulatory requirements. This guide may be used in conjunction with other ASTM guides developed for assessing sediment sites.  
1.4 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.  
1.5 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.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Develo...

SIGNIFICANCE AND USE
4.1 This guide provides a consistent and transparent decision-making process for selecting risk-based corrective actions at sediment sites (that is, a Sediment-RBCA). Sediment-RBCA shares the same process as other RBCAs described in E1739, E2081, and E2205/E2205M but with explicit consideration of the constraints on how the available sediment assessment techniques impact decision making. Several factors exist that distinguish sediment sites from upland sites and warrant unique consideration, including background, potential for recontamination, sediment stability, sediment processes, lack of control on exposure and transport, exposure pathways and receptors, and unique site characteristics such as public lands, lack of site control on use and access. The diversity of available assessment techniques for a sediment site is considerably larger than for other media. Guidance on the technical tools themselves are described in other ASTM guides and regulatory guidance manuals.  
4.2 Sediment-RBCA incorporates the same paradigm of planning and scoping, problem formulation, exposure and effects assessments, risk characterization, and uncertainty analysis that is common to ecological and human health risk assessment guidance documents. Irrespective of terminology, both Sediment-RBCA and risk assessment share the same science-based process and share the same goal of informing risk management decisions. The specific approach used to develop risk-based human health and ecological criteria and risk-based management plans may vary from site to site based on jurisdictional requirements, site complexity, TPDs, and best professional judgment regarding the appropriate use of different assessment techniques. Some attributes of Sediment-RBCA are:  
4.2.1 Description of a tiered approach, including process flow charts, to identify critical steps and provide an overview of the entire RBCA process;  
4.2.2 Identification, development, and use of TPDs throughout the Sediment-RBCA process...
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1.1 Sediment-RBCA is based on protecting human health and the environment. The guide supplements the RBCA (Guide E2081) and Eco-RBCA (Guide E2205/E2205M) processes and provides a decision-making process for the management of contaminated sediment. Contaminated sediment sites vary greatly in terms of setting, usage, spatial and temporal complexity, and physical and chemical characteristics; and, therefore, they also vary greatly in terms of the risk that they may pose to human health and the environment. The Sediment-RBCA recognizes this diversity by using a tiered approach for gathering and evaluating data to determine the need for additional evaluation or risk management tailored to site-specific conditions and risks.  
1.2 This guide is intended to help direct and streamline the corrective action process and to complement (but not supersede) jurisdiction-specific guidance and regulations. It can be employed where jurisdiction-specific guidance is absent or insufficiently detailed; it can also assist to unify guidance when overlapping jurisdictions apply. It is compatible with a variety of programmatic guidelines for risk assessment and guidance from US Environmental Protection Agency (USEPA), Environment Canada, European, US states, that share the underlying risk assessment approach. In all applications, regulatory agencies should be consulted, as appropriate. Sediment-RBCA is not intended to apply to current permitted releases or permit applications.  
1.3 There are numerous TPDs related to the Sediment-RBCA process. Common examples are defining DQOs, identifying relevant receptors, defining toxicity values for risk evaluation, determining target risk levels, specifying the appropriate statistics and sample sizes, determining exposure assumptions, determining when and how to account for cumulative risks and additive effects among chemical(s) of concern, addressing resource protection, along with remedial action cons...

SIGNIFICANCE AND USE
4.1 This guide should be used to support existing decision frameworks for the selection and application of analytical procedures to sediment programs.  
4.2 Activities described in this guide should be conducted by persons familiar with current sediment site characterization and remediation techniques, sediment remediation science and technology, toxicology concepts, risk and exposure assessment methodologies, and ecological evaluation protocols.  
4.3 This guide may be used by various parties involved in sediment programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, analytical testing laboratories, data validators, data reviewers and users, and other stakeholders, which may include, but are not limited to, owners, buyers, developers, lenders, insurers, government agencies, and community members and groups.  
4.4 This guide is not intended to replace or supersede federal, state, local or international regulatory requirements. Instead this guide may be used to complement and support such requirements.  
4.5 This guide provides a decision framework based on over-arching features and elements that should be customized by the user based on site-specific conditions, regulatory context, and sediment program objectives for a particular site. This guide should not be used alone as a prescriptive checklist.  
4.6 The selection and application of analytical methods and test procedures for sediment programs is an evolving science. This guide provides a systematic but flexible decision framework to accommodate variations in approaches by regulatory agency and by user based on project objectives, site complexity, unique site features, programmatic and regulatory requirements, newly developed guidance, newly published scientific research, use of alternative scientifically-based methods and procedures, changes in regulatory criteria, advances in scientific...
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1.1 This is a guide for the selection and application of a range of analytical methods and testing procedures that may be used during sediment programs, including physical properties testing, chemical analytical methods, passive sampling procedures, bioassays and toxicity testing, environmental forensics methods and procedures, and methods development procedures for sediment programs.  
1.2 Sediment programs vary greatly in terms of environmental complexity, physical, chemical and biological characteristics, human health and ecological risk concerns, and geographic and regulatory context. This guide provides information for the selection and application of analytical methods and testing protocols applicable to a wide range of sediment programs.  
1.3 This guide describes widely accepted considerations and best practices used in the selection and application of analytical procedures used during sediment programs. This guide supports and complements existing regulations and technical guidance.  
1.4 This guide is designed for general application to a wide range of sediment programs performed under international, federal, state and local environmental programs. This guide describes the selection and application of analytical methods and test procedures, not the requirements for specific regulatory jurisdictions. This guide compliments but does not replace regulatory agency requirements.  
1.5 This guide may be used for a wide range of sediment programs, including programs with overlapping regulatory jurisdictions, programs without a clearly established regulatory framework, voluntary programs, Brownfield programs, and international programs. The users of this guide should be aware of the appropriate regulatory requirements that apply to sediment programs. The user should consult applicable regulatory agency requirements to identify appropriate technical decision criteria and seek regulatory approvals, as necessary, prio...

SIGNIFICANCE AND USE
4.1 Purpose—This guide provides a process for identifying, prioritizing, selecting, implementing, documenting, and reporting activities to reduce the environmental footprint of a cleanup as defined by the following core elements.  
4.1.1 Minimize Total Energy Use and Maximize Use of Renewable Energy—Reducing total energy use while also identifying means to increase the use of renewable energies throughout the cleanup. Possible methods may include reducing energy use, using energy efficient equipment, using on-site renewable resources (for example, wind, solar), and purchasing commercial energy from renewable resources.  
4.1.2 Minimize Air Pollutants and Greenhouse Gas Emissions—Reducing total air emissions, including emissions of air pollutants and greenhouse gases, throughout the cleanup. Possible methods may include minimizing the generation and transport of airborne contaminants and dust, using efficient emitting equipment (for example, vehicles and heavy equipment), using advanced emission controls, and using cleaner fuels or hybrid technologies.  
4.1.3 Minimize Water Use and Impacts to Water Resources—Minimizing the use of water and impacts to water resources throughout the cleanup. Possible methods may include conserving water use in cleanup processes, using water efficient products, capturing and reclaiming water for reuse, revegetating with water efficient plants, and employing traditional BMPs for storm water, erosion, and sedimentation control.  
4.1.4 Reduce, Reuse, and Recycle Materials and Waste—Minimizing the use of virgin materials and generation of waste throughout the cleanup as well as maximizing the use of recycled materials. Possible methods may include using recycled and locally generated materials, reusing waste materials (for example, concrete made with coal combustion products), diverting construction and demolition debris from disposal by recycling recovered resources, and using rapidly renewable materials or certified wood products.  ...
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1.1 Cleaning up sites improves environmental and public health conditions and as such can be viewed as “green.” However, cleanup activities use energy, water, and natural resources. The process of cleanup therefore creates its own environmental footprint. This guide describes a process for evaluating and implementing activities to reduce the environmental footprint of a cleanup project in the United States while working within the applicable regulatory framework and satisfying all applicable legal requirements.  
1.2 This guide may also be used as a process for sites that are not located in the United States; however, the specific legal references are not applicable.  
1.3 This guide describes a process for identifying, evaluating, and incorporating best management practices (BMPs) and, when deemed appropriate, for integrating a quantitative evaluation into a cleanup to reduce its environmental footprint.  
1.4 This guide is designed to be implemented in conjunction with any cleanup framework and should be used with other technical tools, guidance, policy, laws, and regulations to integrate greener cleanup practices, processes, and technologies into cleanup projects.  
1.5 This guide provides a process for evaluating and implementing activities to reduce the environmental footprint of a cleanup and is not designed to instruct users on how to clean up contaminated sites.  
1.6 ASTM also has a guide on Integrating Sustainable Objectives into Cleanup (E2876). That guide provides a broad framework for integrating elements of environmental, economic, and social aspects into cleanups. This guide may provide assistance with implementing E2876 and other sustainable remediation guidance, such as Holland, et al. (2011)(1).  
1.7 This guide specifically applies to the cleanup, not the redevelopment, of a site. However, the reasonably anticipated use of a site, if known, may influence the cleanup goals and scope.  
1.8 This g...

SIGNIFICANCE AND USE
4.1 The approach presented in this guide is a practical and streamlined process for determining the appropriateness of remediation by natural attenuation and implementing remediation by natural attenuation at a given petroleum release site. This information can be used to evaluate remediation by natural attenuation along with other remedial options for each site.  
4.2 In general, remediation by natural attenuation may be used in the following instances:  
4.2.1 As the sole remedial action at sites where immediate threats to human health, safety and the environment do not exist or have been mitigated, and constituents of concern are unlikely to impact a receptor;  
4.2.2 As a subsequent phase of remediation after another remedial action has sufficiently reduced concentrations/mass in the source area so that plume impacts on receptors are unlikely; or  
4.2.3 As a part of a multi-component remediation plan.  
4.3 This guide is intended to be used by environmental consultants, industry, and state and federal regulators involved in response actions at petroleum release sites. Activities described in this guide should be performed by a person appropriately trained to conduct the corrective action process.  
4.4 The implementation of remediation by natural attenuation requires that the user exercise the same care and professional judgement as with any other remedial alternative by:  
4.4.1 Ensuring that site characterization activities focus on collecting information required to evaluate and implement remediation by natural attenuation;  
4.4.2 Evaluating information to understand natural attenuation processes present at the site;  
4.4.3 Determining whether remediation by natural attenuation is the most appropriate and cost-effective remedial alternative with a reasonable probability of achieving remedial goals; and  
4.4.4 Monitoring remedial progress.  
4.5 Application and implementation of remediation by natural attenuation is intended to be compatible wit...
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1.1 This is a guide for determining the appropriateness of remediation by natural attenuation and implementing remediation by natural attenuation at a given petroleum release site, either as a stand alone remedial action or in combination with other remedial actions.  
1.2 Natural attenuation is a potential remediation alternative for containment and reduction of the mass and concentration of petroleum hydrocarbons in the environment to protect human health and the environment. Remediation by natural attenuation depends upon natural processes such as biodegradation, dispersion, dilution, volatilization, hydrolysis, and sorption to attenuate petroleum constituents of concern to achieve remedial goals.
Note 1: Remedial goals must be established through another process as determined by the appropriate regulatory agency.  
1.3 In general, remediation by natural attenuation should not be considered a presumptive remedy. A determination of whether remediation by natural attenuation is appropriate for an individual petroleum release site, relative to site-specific remedial goals, requires site characterization, assessment of potential risks, evaluation of the need for source area control, and evaluation of potential effectiveness similar to other remedial action technologies. Application and implementation of remediation by natural attenuation requires demonstration of remedial progress and attainment of remedial goals by use of converging lines of evidence obtained through monitoring and evaluation of resulting data. When properly applied to a site, remediation by natural attenuation is a process for risk management and achieving remedial goals. Monitoring should be conducted until it has been demonstrated that natural attenuation will continue and eventually meet remedial goals.  
1.3.1 The primary line of evidence for remediation by natural attenuation is provided by observed reductions in plume geometry and observed re...

SIGNIFICANCE AND USE
4.1 PFAS are widely used in commercial and industrial applications worldwide (see Fig. 1). PFAS are of concern due to their documented persistence and their studied impacts on human health and the environmental. While there is no comprehensive source of information on the many individual PFAS substances and their functions in different applications, a range of resources are available to the practitioner. This guide provides information to assist the practitioner in navigating these challenges during the initial screening and site characterization process.
FIG. 1 Activity/Industry that may be Sources of PFAS Use and Release
Source: AEI Consultants  
4.2 The user should note that PFAS regulatory management framework at the federal and state level are evolving quickly. Therefore, consultation with legal and technical representatives with knowledge of federal, state, and local PFAS regulations is advised prior to use of this guide. Environmental audit policies or privileges may be applicable to some of the steps described in this guide (see EPA, 2000).  
4.3 Multi-step Risk Management Framework:  
4.3.1 The actions described in this guide are intended to provide a multi-step risk management framework to confirm, with reasonable certainty, that PFAS may have been used at a federally-owned, publicly-owned, or privately-owned property. This standard provides guidance on how to focus limited resources on using a multi-step process, illustrated in Fig. 2, to identify property potentially impacted by on-site or off-site uses and releases of PFAS. Section 4.5 describes the use and occurrence of PFAS. Section 4.6 describes activities at government and federal installations where PFAS use is expected. Section 4.7 broadly outlines the industry sectors where the use of PFAS has been documented (Glüge, 2020 (2), Gaines, 2022 (3)).
FIG. 2 Initial Site Screening and Characterization Flow Diagram  
4.4 PFAs History and Use:  
4.4.1 In the 1940s, industrial processes to co...
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1.1 Per- and polyfluoroalkyl substances (PFAS) are a group of over 7,000 manmade compounds consisting of polymeric chains of carbon bonded to fluorine atoms, usually with a polar functional group at the head. This guide recognizes that PFAS can be categorized as polymeric or nonpolymeric, collectively amounting to more than 4,700 Chemical Abstracts Service (CAS)-registered substances. Environmental concerns pertaining to PFAS are centered primarily on the perfluoroalkyl acids (PFAA), a subclass of per-and polyfluoroalkyl substances, which display extreme persistence and chain-length dependent bioaccumulation and adverse effects in biota.  
1.2 The regulatory framework for PFAS continues to evolve, both domestically and internationally. The United States Environmental Protection Agency (EPA) is proceeding with a wide-ranging set of PFAS regulatory actions (EPA, 2021). While the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) does not currently recognize PFAS as hazardous substances, the statute does require actions to protect public health and the environment from contaminants and pollutants released to the environment. Other federal regulatory programs, such as the Safe Drinking Water Act are being used to address drinking water supplies adversely impacted by releases of PFAS. The Clean Water Act’s National Pollutant Discharge Elimination System (NPDES) permitting program is tool that both federal and state regulators are using to regulate the inflows of PFAS-impacted wastewaters at both publicly-owned treatment works (POTW) and federally-owned wastewater treatment plants and the concentration of PFAS in permitted effluent. EPA continues to add additional per-and polyfluoroalkyl substances to the list of substances reportable under the federal Toxic Release Inventory (TRI) reporting program. International efforts to address per-and polyfluoroalkyl substances include Australia’s PFAS Nation...

SIGNIFICANCE AND USE
4.1 Intended Use—This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, and other stakeholders.  
4.2 Importance of the CSM—The CSM should be continuously updated and refined to describe the physical properties, chemical composition and occurrence, biologic features, and environmental conditions of the sediment corrective action project (Guide E1689).  
4.3 Reference Material—This guide should be used in conjunction with other ASTM guides listed in 2.1 (especially Guide E3242); this guide should also be used in conjunction with the material in the References at the end of this guide (including 3). Utilizing these reference materials will direct the user in deriving representative sediment background concentrations.  
4.4 Flexible Site-Specific Implementation—This guide provides a systematic but flexible framework to accommodate variations in approaches by regulatory agencies and by the user based on project objectives, site complexity, unique site features, regulatory requirements, newly developed guidance, newly published scientific research, changes in regulatory criteria, advances in scientific knowledge and technical capability, and unforeseen circumstances.  
4.5 Regulatory Frameworks—This guide is intended to be applicable at a broad range of local, state, tribal, federal (such as CERCLA), or international jurisdictions, each with its own unique regulatory framework. As such, this guide does not provide a detailed discussion of the requirements or guidance associated with any of these regulatory frameworks, nor is it intended to supplant applicable regulations and guidance. The user of this guide will need to be aware of the regulatory requirements and guidance in the jurisdiction where the work is being performed.  
4.6 Systematic Project Planning and Scop...
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1.1 This guide focuses on the selection of sediment background reference areas from aquatic environments for the purpose of determining representative sediment background concentrations. These concentrations are typically used in contaminated sediment corrective actions performed under various regulatory programs, including the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Although many of the references cited in this guide are CERCLA oriented, the guide is applicable to remedial actions performed under local, state, tribal, federal, and international cleanup programs. However, this guide does not describe the requirements for each jurisdiction.  
1.1.1 The sediment background reference areas chosen using this guide will need to be approved by the regulatory agency having jurisdiction (or they should take no exception to the areas chosen), especially if the representative background sediment concentrations will potentially be used to develop sediment remedial criteria.  
1.2 This guide provides a framework to select appropriate sediment background reference areas for collection of sediment data in the determination of representative sediment background concentrations. It is intended to inform, complement, and support, but not supersede, local, state, tribal, federal, or international guidelines.  
1.2.1 This guide is designed to apply to contaminated sediment sites where sediment data have been collected and are readily available. Additionally, it assumes that risk assessments have been performed, so that the potential contaminants of concern (PCOCs) that exceed risk-based thresholds have been identified. This guide can be applied at multiple points within the project life cycle (such as site assessment and remedial design).  
1.2.2 Furthermore, this guide presumes that the identified risk-based thresholds are low enough to pose corrective action implementation challenges or that the...

SIGNIFICANCE AND USE
4.1 This guide provides an overview of analytical methods, techniques, and procedures that may be used in determination of PFAS in environmental media.  
4.2 This guide provides considerations relevant to the selection and application of PFAS analytical methods, techniques, and procedures, including the limitations of published analytical methods and the potential benefits and challenges of non-standard analytical approaches.  
4.3 This guide presents comparisons of published analytical methods and approaches, including tabular comparison of target analyte lists and method features, to aid users in the selection and application of analytical methods and techniques for project-specific applications.  
4.4 This guide describes qualitative techniques available to determine total PFAS, including explanation of terms, discussion of techniques, conceptual overview schematic, and summary comparison table.  
4.5 This guide provides current information on research trends in PFAS determination techniques applied to environmental media.  
4.6 This guide provides an integrated framework that results in efficient, cost-effective decision-making for timely, appropriate response actions for PFAS-impacted environmental media.  
4.7 This guide is not intended to replace or supersede federal, state, local, or international regulatory requirements. Instead, this guide may be used to complement and support such requirements.  
4.8 This guide may be used by various parties involved in response actions for PFAS-impacted environmental media, including regulatory agencies, project sponsors, environmental consultants and contractors, site remediation professionals, analytical testing laboratories, data reviewers, data users, academic institutions, research institutes, and other stakeholders.  
4.9 The users of this guide should consider assembling a team of experienced professionals with appropriate expertise to scope, plan, and execute PFAS environmental data acquisition activities...
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1.1 This guide discusses the selection and application of analytical methods and techniques used to identify and quantitate per- and polyfluoroalkyl substances (PFAS) in environmental media. This guide provides a flexible, defensible framework applicable to a wide range of environment programs. It is structured to support a tiered approach with analytical methods, procedures, and techniques of increasing complexity as the user proceeds through the evaluation process. This guide addresses key decision criteria and best practices to aid users in achieving project objectives. There are numerous technical decisions that must be made in the selection and application of analytical methods and techniques used during environmental data acquisition programs. It is not the intent of this guide to define appropriate technical decisions, but rather to provide technical support within existing decision frameworks.  
1.2 This guide informs practitioners on the considerations relevant to the selection and application of analytical methods and techniques for the quantitative and qualitative determination of PFAS in a variety of environmental sample media. This guide encourages user-led collaboration with stakeholders, including analytical laboratories, data evaluation practitioners, and regulators, in the selection and application of analytical methods and techniques used to support project-specific decision criteria and objectives as applied within a particular environmental regulatory program. This guide recognizes the complexity and diversity of environmental programs and project objectives and provides technical support for a range of project applications.  
1.3 This guide is intended to complement, not replace, existing regulatory requirements or guidance. ASTM International (ASTM) guides are not regulations; they are consensus-based standards that may be followed as needed.  
1.4 This guide recognizes that PFAS can be categoriz...

SIGNIFICANCE AND USE
4.1 This guide provides an overview of analytical methods, techniques, and procedures that may be used in determination of PFAS in environmental media.  
4.2 This guide provides considerations relevant to the selection and application of PFAS analytical methods, techniques, and procedures, including the limitations of published analytical methods and the potential benefits and challenges of non-standard analytical approaches.  
4.3 This guide presents comparisons of published analytical methods and approaches, including tabular comparison of target analyte lists and method features, to aid users in the selection and application of analytical methods and techniques for project-specific applications.  
4.4 This guide describes qualitative techniques available to determine total PFAS, including explanation of terms, discussion of techniques, conceptual overview schematic, and summary comparison table.  
4.5 This guide provides current information on research trends in PFAS determination techniques applied to environmental media.  
4.6 This guide provides an integrated framework that results in efficient, cost-effective decision-making for timely, appropriate response actions for PFAS-impacted environmental media.  
4.7 This guide is not intended to replace or supersede federal, state, local, or international regulatory requirements. Instead, this guide may be used to complement and support such requirements.  
4.8 This guide may be used by various parties involved in response actions for PFAS-impacted environmental media, including regulatory agencies, project sponsors, environmental consultants and contractors, site remediation professionals, analytical testing laboratories, data reviewers, data users, academic institutions, research institutes, and other stakeholders.  
4.9 The users of this guide should consider assembling a team of experienced professionals with appropriate expertise to scope, plan, and execute PFAS environmental data acquisition activities...
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1.1 This guide discusses the selection and application of analytical methods and techniques used to identify and determine per- and polyfluoroalkyl substances (PFAS) in environmental media. This guide provides a flexible, defensible framework applicable to a wide range of environment programs. It is structured to support a tiered approach with analytical methods, procedures, and techniques of increasing complexity as the user proceeds through the evaluation process. This guide addresses key decision criteria and best practices to aid users in achieving project objectives. There are numerous technical decisions that must be made in the selection and application of analytical methods and techniques used during environmental data acquisition programs. It is not the intent of this guide to define appropriate technical decisions, but rather to provide technical support within existing decision frameworks.  
1.2 This guide informs practitioners on the considerations relevant to the selection and application of analytical methods and techniques for the quantitative and qualitative determination of per- and polyfluoroalkyl substances (PFAS) in a variety of environmental sample media. This guide encourages user-led collaboration with stakeholders, including analytical laboratories, data evaluation practitioners, and regulators, in the selection and application of analytical methods and techniques used to support project-specific decision criteria and objectives as applied within a particular environmental regulatory program. This guide recognizes the complexity and diversity of environmental programs and project objectives and provides technical support for a range of project applications.  
1.3 This guide is intended to complement, not replace, existing regulatory requirements or guidance. ASTM International (ASTM) guides are not regulations; they are consensus-based standards that may be followed as needed.  
1.4 This guide ...

SIGNIFICANCE AND USE
4.1 Hydrophobic organic liquids (for example, petroleum hydrocarbons, coal tars) may exist in the environment for long periods of time as NAPLs. Standardized guidance and test methods do not exist to assess NAPL movement (both pore-scale mobility and NAPL body-scale migration) in sediment. Literature searches have resulted in a limited body of available and applicable research. Current research has focused on site-specific sediment NAPL movement evaluation approaches.  
4.2 Standardized guidance and test methods currently exist for assessing NAPL mobility and migration at upland sites, from organizations such as ASTM International (Guides E2531 and E2856), Interstate Technology and Regulatory Council (2), and the American Petroleum Institute (3, 4). Approaches commonly used in upland sites may or may not be applicable for any given sediment site. This guide provides perspectives on the applicability of various methodologies for specific sediment conditions.  
4.3 This guide describes various methodologies that are useful in sediment NAPL movement evaluation, such as laboratory test methods, calculation approaches, and field observation interpretation. The guide then provides frameworks to evaluate the data generated from these methodologies to determine if the NAPL observed in the sediments under in situ conditions exhibits movement of any kind.  
4.4 Important exposure pathways in upland sites are usually not applicable to sediment sites. The U.S. Environmental Protection Agency notes, “Contaminants in the biologically active layer of the surface sediment at a site often drive exposure” (5). In aquatic environments, benthic organisms live in the surface sediment to maintain access to oxygenated overlying water. These benthic organisms are at the base of the food chain. If NAPL in subsurface sediment is not migrating, the NAPL will not move into the surface sediment and result in exposure to benthic organisms. NAPL that is stable and only present in subsurface se...
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1.1 This guide discusses methodologies that can be applied to evaluate the potential for the movement (that is, pore-scale mobility or NAPL body-scale migration) of non-aqueous phase liquid (NAPL) in sediments. NAPL movement assessment in sediments is significantly different than in upland soils. As such, the frameworks for evaluating NAPL movement in upland soils have limited applicability for sediments. In particular, because upland NAPL conceptual site models may not be applicable to many sediment sites, this guide provides a framework to evaluate whether NAPL is mobile (at the pore scale) or migrating (at the NAPL body scale) in sediments.  
1.2 Assessment of the potential for NAPL to move in sediment is important for several reasons, including (but not limited to) evaluation of risk to potential receptors, the need for potential remedial action, and potential remedial strategies. For example, if the NAPL is migrating, sensitive receptors may be impacted and this will influence the choice and timing of any remedy selected for an area of the sediment site. If the NAPL is not mobile or migrating, then remedial actions may not be warranted.  
1.3 This guide is applicable at sediment sites where NAPL has been identified in the sediment by various screening methods and the need for a NAPL movement evaluation is warranted (Guide E3248).  
1.4 Petroleum hydrocarbon, coal tar, and other tar NAPLs (including fuels, oils, and creosote) are the primary focus of this guide. These forms of contamination are commonly related to historical operations at refineries, petroleum distribution terminals, manufactured gas plants (MGPs), and various large industrial sites.  
1.5 Although certain technical aspects of this guide apply to other NAPLs (for example, dense NAPLs [DNAPLs] such as chlorinated hydrocarbon solvents), this guide does not completely address the additional complexities of those DNAPLs.  
1.6 The goal of this guide...

SIGNIFICANCE AND USE
4.1 Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a family of more than 4700 synthetic organic chemicals. PFAS can withstand high temperatures and survive highly corrosive environments. They are used in the manufacture of coatings, surface treatments, and specialty chemicals in cookware, carpets, food packaging, clothing, cosmetics, and other common consumer products. PFAS also have many industrial applications and are an active ingredient in certain types of fire-fighting foams (aqueous film-forming foams, or AFFF). PFAS coatings resist oil, grease, and water. PFAS are persistent compounds. Therefore, PFAS should be considered for purposes of managing investigation-derived waste where PFAS is known or suspected to be present in environmental media.  
4.1.1 PFAS are emerging contaminants for which environmental regulations and guidance are dynamic and are being developed simultaneously at federal, state, local, and international levels as more is learned about their characteristics, environmental fate, and management/treatment. Therefore, site-specific rules, regulations, and guidance should be evaluated for options and restrictions on management of PFAS  investigation-derived waste. For example, the Massachusetts Department of Environmental Protection has determined that PFAS wastes are “hazardous materials” subject to the Massachusetts Oil and Hazardous Material Release Prevention and Response Act (M.G.L. Chapter 21E) and the Massachusetts Contingency Plan. Other states and jurisdictions may have or will develop and implement similar determinations that affect the on-site management, storage, and labeling and off-site transportation requirements for PFAS  investigation-derived waste.  
4.1.2 Given the characteristics and persistence of PFAS compounds, PFAS  investigation-derived waste presents special handling and treatment/disposal considerations. EPA recently issued Interim Guidance on the Destruction and Disposal of Perfluoralkyl and Polyfluoralky...
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1.1 Existing guidance on the management of investigation-derived waste is focused upon cuttings, purge water, personal protective equipment, and other miscellaneous solid waste generated at property that may be impacted by the release of hazardous materials and hazardous substances. These hazardous substances include, but are not limited to, heavy metals, petroleum, petroleum byproducts, solvents, polycyclic aromatic hydrocarbons, organic and inorganic corrosives, radioactive material, and explosives. Guidance on the management of investigation derived waste generated at sites that may be impacted by releases of perfluoroalkyl and polyfluoroalkyl substances (PFAS) is limited. This standard guide addresses this deficiency  
1.2 This guide describes best practices for managing investigation-derived waste associated with PFAS that are consistent with federal and state policies and regulations at the date of issuance. The user is advised to determine if new regulations or rules have been promulgated by the state, federal, or tribal regulatory agency having jurisdiction over the property.  
1.3 This guide describes considerations to prevent the unintended and unauthorized disposal of liquid investigation-derived waste that may contain PFAS into wastewater treatment plants or systems that are not permitted to receive these waste streams.  
1.4 This guide describes considerations to prevent the unintended and unauthorized disposal of solid investigation-derived waste that may contain PFAS into landfills or other solid waste disposal facilities that are not permitted to receive these waste streams.  
1.5 This guide describes several stormwater pollution prevention best management practices applicable to investigation-derived waste.  
1.6 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,...

SIGNIFICANCE AND USE
4.1 Hydrophobic organic liquids (for example, petroleum hydrocarbons, coal tars) may exist in the environment for long periods of time as NAPLs. Standardized guidance and test methods do not exist to assess NAPL movement (both pore-scale mobility and NAPL body-scale migration) in sediment. Literature searches have resulted in a limited body of available and applicable research. Current research has focused on site-specific sediment NAPL movement evaluation approaches.  
4.2 Standardized guidance and test methods currently exist for assessing NAPL mobility and migration at upland sites, from organizations such as ASTM International (Guides E2531 and E2856), Interstate Technology and Regulatory Council (2), and the American Petroleum Institute (3, 4). Approaches commonly used in upland sites may or may not be applicable for any given sediment site. This guide provides perspectives on the applicability of various methodologies for specific sediment conditions.  
4.3 This guide describes various methodologies that are useful in sediment NAPL movement evaluation, such as laboratory test methods, calculation approaches, and field observation analysis. The guide then provides frameworks to evaluate the data generated from these methodologies to determine if the NAPL observed in the sediments under in situ conditions exhibits movement of any kind.  
4.4 Important exposure pathways in upland sites are usually not applicable to sediment sites. The U.S. Environmental Protection Agency notes, “Contaminants in the biologically active layer of the surface sediment at a site often drive exposure” (5). In aquatic environments, benthic organisms live in the surface sediment to maintain access to oxygenated overlying water. These benthic organisms are at the base of the food chain. If NAPL in subsurface sediment is not migrating, the NAPL will not move into the surface sediment and result in exposure to benthic organisms. NAPL that is stable and only present in subsurface sediment...
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1.1 This guide discusses methodologies that can be applied to evaluate the potential for the movement (that is, pore-scale mobility or NAPL body-scale migration) of non-aqueous phase liquid (NAPL) in sediments. NAPL movement assessment in sediments is significantly different than in upland soils. As such, the frameworks for evaluating NAPL movement in upland soils have limited applicability for sediments. In particular, because upland NAPL conceptual site models may not be applicable to many sediment sites, this guide provides a framework to evaluate whether NAPL is mobile (at the pore scale) or migrating (at the NAPL body scale) in sediments.  
1.2 Assessment of the potential for NAPL to move in sediment is important for several reasons, including (but not limited to) evaluation of risk to potential receptors, the need for potential remedial action, and potential remedial strategies. For example, if the NAPL is migrating, sensitive receptors may be impacted and this will influence the choice and timing of any remedy selected for an area of the sediment site. If the NAPL is not mobile or migrating, then remedial actions may not be warranted.  
1.3 This guide is applicable at sediment sites where NAPL has been identified in the sediment by various screening methods and the need for a NAPL movement evaluation is warranted (Guide E3248).  
1.4 Petroleum hydrocarbon, coal tar, and other tar NAPLs (including fuels, oils, and creosote) are the primary focus of this guide. These forms of contamination are commonly related to historical operations at refineries, petroleum distribution terminals, manufactured gas plants (MGPs), and various large industrial sites.  
1.5 Although certain technical aspects of this guide apply to other NAPLs (for example, dense NAPLs [DNAPLs] such as chlorinated hydrocarbon solvents), this guide does not completely address the additional complexities of those DNAPLs.  
1.6 The goal of this guide...

SIGNIFICANCE AND USE
4.1 NAPLs (for example, chlorinated solvents, petroleum products, and creosote) can be emplaced in sediments through a variety of mechanisms (Guide E3248). Dense non-aqueous phase liquids (DNAPLs) are more dense than water, whereas light non-aqueous phase liquids (LNAPLs) are less dense than water.  
4.2 Standardized guidance and test methods currently exist for assessing NAPL mobility at upland sites, from organizations such as ASTM (Guides E2531 and E2856), Interstate Technology & Regulatory Council (1)3 and the American Petroleum Institute (2, 3).  
4.3 Guide E3248 provides guidance regarding when a NAPL movement evaluation is warranted. After confirming that NAPL is present and evaluating nature and extent as appropriate, the next step in any NAPL movement evaluation is to evaluate if NAPL is mobile or immobile at the pore scale—this is done using tiered or weight of evidence (WOE) approaches. This guide provides a structured process to select samples to submit to the laboratory for NAPL mobility testing that is part of a NAPL movement evaluation.  
4.4 This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, and other stakeholders.  
4.5 This guide should be used in conjunction with other reference material (refer to Section 2 and References) that direct the user in developing and implementing sediment assessment programs.  
4.6 This guide is related to Guide E3163, concerning sediment analytical techniques used during sediment programs. It is related to Guide E3248, which discusses generic models for the emplacement and advection of NAPL in sediments.  
4.7 This guide does not replace the need for engaging competent persons to evaluate NAPL emplacement and movement in sediments. Activities necessary to develop a conceptual site model should be conducted by p...
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1.1 This guide is designed for general application at a wide range of sediment sites where non-aqueous phase liquid (NAPL) is present or suspected to be present in the sediment. This guide describes a process to use field screening methods, specifically visual observations, and the results of shake tests, to categorize the relative amount of NAPL present in a sample. This categorization can then be utilized to select co-located sediment samples for laboratory testing to determine if the NAPL in the sample interval is mobile or immobile at the pore scale, or any other chemical or physical testing.  
1.1.1 There is no current industry standard methodology to select sediment samples for laboratory NAPL mobility testing; the use of different methodologies is possible. This guide focuses on a selection process that uses visual observations and shake tests. This process has the advantage of being simple to use and, if applied in a disciplined manner, has been demonstrated to provide good results in the field.  
1.2 This guide is intended to inform, complement, and support characterization and remedial efforts performed under international, federal, state, and local environmental programs but not supersede local, state, federal, or international regulations. The users of this guide should review existing information and data available for a sediment site to determine applicable regulatory agency requirements and the most appropriate entry point into and use of this guide.  
1.3 ASTM International (ASTM) standard guides are not regulations; they are consensus standard guides that may be followed voluntarily to support applicable regulatory requirements. This guide may be used in conjunction with other ASTM guides developed for assessing sediment sites.  
1.4 This guide does not address methods and means of sample collection (Guide E3163).  
1.5 Units—The values stated in SI or CGS units are to be regarded as the standard. N...

SIGNIFICANCE AND USE
4.1 Many contaminants, including chlorinated solvents and petroleum products, enter the subsurface in the form of an immiscible liquid, known as a NAPL. Understanding the potential emplacement and transport mechanism for NAPL in sediment is an important element of an overall conceptual site model (CSM) that forms a basis for (1) investigating the nature and extent of NAPL, (2) evaluating if (and how) human and ecological receptors may be exposed to NAPL, and (3) assessing remedial alternatives. In addition, demonstrating the potential movement of NAPL in sediments is hampered by the lack of standardized terminology and characterization protocols, thus necessitating this guide.  
4.1.1 Understanding the presence and movement of NAPL in sediments is complicated by the lack of standardized protocols for characterizing NAPL movement in the diverse range of sediment environments. Literature searches have indicated that there is a limited body of available, applicable research. Current research has focused on site-specific sediment NAPL mobility assessment approaches, but application of common methods or decision-making processes identified across sites were limited.  
4.1.2 The movement (or lack of movement) of NAPL in sediments is a key factor in developing protective remedial options for NAPL-impacted sediments and for the long-term management of sediment sites. Typical exposure pathways that are addressed through risk management decisions at upland sites are usually not applicable to sediment sites. Rather, “contaminants in the biologically active layer of the surface sediment at a site often drive exposure” (1)5, because in aquatic environments, benthic organisms live in the surface sediment to maintain access to oxygenated overlying water. NAPL that is present in subsurface sediment below the biologically active layer that is not migrating and has an overlying sediment that is expected to remain in place (that is, is not dredged or eroded) does not pose a risk to ...
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1.1 This guide provides considerations to inform sample collection, field screening, and sample handling of sediments impacted with non-aqueous phase liquid (NAPL) to assist in data collection for the evaluation of NAPL movement in sediment. The conditions affecting NAPL emplacement and movement in sediments are significantly different than in upland soils. As such, the framework for the assessment of NAPL movement in upland soils has been determined to have limited applicability for sediments.  
1.2 This guide is applicable to sediment sites where the presence or suspected presence of NAPL has been identified.  
1.3 The goal of this guide is to provide a technical framework for sample collection, field screening, and sample handling activities used to evaluate NAPL conditions, in particular NAPL movement (that is, mobility at the pore scale and migration at the NAPL body scale) in sediments, which can be used to inform the development and selection of remedial options and post-remedial monitoring activities.  
1.4 This guide discusses sample collection procedures, including direct methods (that is, core and grab samples) and indirect methods (that is, DART®2, laser-induced florescence, and porewater samplers) for assessing NAPL presence or absence in sediment.  
1.5 This guide discusses field characterization procedures for assessment of NAPL-impacted sediments including visual screening, stratification assessment, shake test, ultraviolet (UV) light test, NAPL FLUTe™3, and headspace vapor monitoring.  
1.6 This guide discusses considerations to obtain samples representative of in situ conditions. This includes methods used to evaluate sediment integrity, sample retrieval from the sediment bed, core identification, sample storage onboard the vessel, sample retrieval from the coring device, sufficient sample recovery, core cutting techniques, sample removal from the core, and sample freezing/cooling considerations.  ...

SIGNIFICANCE AND USE
4.1 Intended Use: This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, and other stakeholders.  
4.2 Related ASTM Standards: This guide is related to Guide E3164, which addresses corrective action monitoring before, during, and after sediment remediation activities; as well as Guide E3163, concerning sediment analytical techniques used during sediment programs.  
4.3 Use of Representative Background to Set a Boundary: Representative background concentrations for sediments can be used to delineate a sediment corrective action, establishing the boundary of the sediment corrective action by distinguishing site-related impacts from representative background concentrations.  
4.4 Use of Representative Background to Establish Cleanup Levels: Representative background concentrations for sediments can also be used to establish cleanup levels for use in sediment corrective actions. In cases where risk-based sediment cleanup levels are below representative background concentrations, background concentrations are typically used as the cleanup level. This ensures that the cleanup levels are sustainable. Any recontamination from ongoing sources will eventually result in surface sediment concentrations greater than the risk-based cleanup level, but the surface sediment should still meet a cleanup level based on representative background concentrations, even after recontamination.  
4.5 Use of Representative Background in Risk Assessments: Representative background concentrations can be used in the risk assessment process (including human and ecological risk assessments) to understand risks posed by background levels of contaminants to human health and the environment, and the incremental risks posed by site-related releases and/or activities that result in sediment concentrat...
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1.1 This guide focuses on the approach for determination of representative sediment background concentrations used for remedial actions performed under various regulatory programs, including the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Although many of the references cited in this guide are CERCLA oriented, the guide is applicable to remedial actions performed under local, state, federal, and international cleanup programs. However, the guide does not describe requirements for each jurisdiction. The requirements for the regulatory entity under which the cleanup is performed should be reviewed to confirm compliance.  
1.2 This guide provides a framework, including specific statistical and geochemical considerations, as well as case studies, demonstrating the approach to determine representative sediment background concentrations. This guide is intended to inform, complement, and support, but not supersede, local, state, federal, or international regulations.  
1.2.1 This guide does not address methods and means of data collection (Guide E3163, Guide E3164.)  
1.2.2 This guide is designed to apply to contaminated sediment sites where sediment data have been collected and are readily available. Additionally, this guide assumes that risk assessments have been performed, so that the contaminants/chemicals of interest that exceed risk-based thresholds have been identified.  
1.2.3 Furthermore, this guide presumes that risk-based thresholds identified are low enough to pose corrective action implementation challenges, and/or the site is subject to recontamination from ongoing anthropogenic and/or natural sources that are not controlled. In both cases, representative sediment background concentrations will be useful for determining the extent of corrective remedial actions (when used as remedial goals), evaluating risks posed by representative background concentrations, and establishing...

SIGNIFICANCE AND USE
Note 1: This standard should be used in conjunction with other reference material to guide the user in developing and implementing sediment corrective action monitoring programs.  
4.1 Activities described in this guide should be conducted by persons familiar with current sediment site characterization and remediation techniques.  
4.2 This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, analytical testing laboratories, data validators, data reviewers and users, and other stakeholders, which may include, but are not limited to, owners, buyers, developers, lenders, insurers, government agencies, and community members and groups.  
4.3 This guide is not intended to supplant applicable regulations. Instead this guide may be used to complement and support such regulatory requirements.  
4.4 This guide provides a decision framework based on over-arching features and elements that should be customized by the user based on site-specific conditions, regulatory context, and sediment corrective action objectives. This guide should not be used alone as a prescriptive checklist.  
4.5 This guide provides a systematic, but flexible decision framework to accommodate variations in approaches by regulatory agency and by the user based on project objectives, site complexity, unique site features, regulatory requirements, newly developed guidance, newly published scientific research, changes in regulatory criteria, advances in scientific knowledge and technical capability, and unforeseen circumstances.  
4.6 Implementation of the guide is site-specific. The user may choose to customize the implementation of the guide for particular types of sites, especially smaller, less complex sites.  
4.7 When applying this guide, the user should undertake a systematic project planning and...
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1.1 This guide pertains to corrective action monitoring before, during and after sediment remediation activities. It does not address monitoring performed during remedial investigations, risk assessments performed before the corrective action, and pre-design investigations. This standard primarily focuses on the approach for remedial actions performed under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Thus, many of the references cited are CERCLA oriented. The standard is also applicable to remedial actions performed under state, federal and international cleanup programs, but the standard does not describe requirements for each jurisdiction. The requirements for the regulatory entity under which the cleanup is performed should be reviewed to confirm they are met.  
1.2 This guide provides a framework, which includes widely accepted considerations and best practices for monitoring sediment remedy effectiveness. The monitoring sediment standard guide is intended to complement and support the selection of monitoring techniques, not supersede local, state, federal or international community regulations.  
1.3 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.  
1.4 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.

SIGNIFICANCE AND USE
4.1 Purpose—This guide provides a process for identifying, prioritizing, selecting, implementing, documenting, and reporting activities to reduce the environmental footprint of a cleanup as defined by the following core elements.  
4.1.1 Minimize Total Energy Use and Maximize Use of Renewable Energy—Reducing total energy use while also identifying means to increase the use of renewable energies throughout the cleanup. Possible methods may include reducing energy use, using energy efficient equipment, using on-site renewable resources (for example, wind, solar), and purchasing commercial energy from renewable resources.  
4.1.2 Minimize Air Pollutants and Greenhouse Gas Emissions—Reducing total air emissions, including emissions of air pollutants and greenhouse gases, throughout the cleanup. Possible methods may include minimizing the generation and transport of airborne contaminants and dust, using efficient emitting equipment (for example, vehicles and heavy equipment), using advanced emission controls, and using cleaner fuels or hybrid technologies.  
4.1.3 Minimize Water Use and Impacts to Water Resources—Minimizing the use of water and impacts to water resources throughout the cleanup. Possible methods may include conserving water use in cleanup processes, using water efficient products, capturing and reclaiming water for reuse, revegetating with water efficient plants, and employing traditional BMPs for storm water, erosion, and sedimentation control.  
4.1.4 Reduce, Reuse, and Recycle Materials and Waste—Minimizing the use of virgin materials and generation of waste throughout the cleanup as well as maximizing the use of recycled materials. Possible methods may include using recycled and locally generated materials, reusing waste materials (for example, concrete made with coal combustion products), diverting construction and demolition debris from disposal by recycling recovered resources, and using rapidly renewable materials or certified wood products.  ...
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1.1 Cleaning up sites improves environmental and public health conditions and as such can be viewed as “green.” However, cleanup activities use energy, water, and natural resources. The process of cleanup therefore creates its own environmental footprint. This guide describes a process for evaluating and implementing activities to reduce the environmental footprint of a cleanup project in the United States while working within the applicable regulatory framework and satisfying all applicable legal requirements.  
1.2 This guide may also be used as a process for sites that are not located in the United States; however, the specific legal references are not applicable.  
1.3 This guide describes a process for identifying, evaluating, and incorporating best management practices (BMPs) and, when deemed appropriate, for integrating a quantitative evaluation into a cleanup to reduce its environmental footprint.  
1.4 This guide is designed to be implemented in conjunction with any cleanup framework and should be used with other technical tools, guidance, policy, laws, and regulations to integrate greener cleanup practices, processes, and technologies into cleanup projects.  
1.5 This guide provides a process for evaluating and implementing activities to reduce the environmental footprint of a cleanup and is not designed to instruct users on how to clean up contaminated sites.  
1.6 ASTM also has a guide on Integrating Sustainable Objectives into Cleanup (E2876). That guide provides a broad framework for integrating elements of environmental, economic, and social aspects into cleanups. This guide may provide assistance with implementing E2876 and other sustainable remediation guidance, such as Holland, et al. (2011)(1).  
1.7 This guide specifically applies to the cleanup, not the redevelopment, of a site. However, the reasonably anticipated use of a site, if known, may influence the cleanup goals and scope.  
1.8 This g...

SIGNIFICANCE AND USE
4.1 Intended Application of Guide—This guide is intended for use at properties that are presently developed or proposed for development for residential, commercial, or industrial purposes but which contain chemical-affected soil, groundwater, air, or other environmental media, which may pose an unacceptable risk to human health. This guide can be used as a tool for planning and implementation of property reuse or redevelopment activities at former commercial/industrial facilities, “brownfield” properties, or properties containing naturally occurring, chemical-affected environmental media so as to effectively manage potential human exposures to COCs which might otherwise limit productive use of the property.  
4.2 Situations Where This Guide May Be Applied—An engineering control may be needed as part of the development plan when: (1) COCs are present in soil, groundwater, or other environmental media at concentrations posing unacceptable risk(s) to human health per applicable regulatory criteria or a risk-based evaluation; (2) a potentially complete exposure pathway for COCs is likely to exist in the absence of an engineering control or other response measure, and (3) installation and maintenance of the engineering control is determined to be an applicable and cost-effective response action relative to other options. A property should not be excluded from development or redevelopment solely on the basis of chemical-affected media, in general, and chemical-affected groundwater, in particular. If no affected environmental media are identified as having COC concentrations in excess of applicable regulatory standards or risk-based criteria, then engineering controls or other response measures are not required.  
4.3 Assumptions for Use of This Guide—For use of this guide, it is assumed that (1) an environmental site assessment has been completed to characterize chemical-affected environmental media, (2) exposures to COCs posing an unacceptable risk to the health of cur...
SCOPE
1.1 This guide presents general considerations for application of engineering controls to facilitate continued use or redevelopment of properties containing chemical-affected soil, groundwater, or other environmental media, due either to chemical releases or naturally-occurring conditions. This guide is not meant to be prescriptive but rather to present considerations for evaluating technologies capable of addressing potential human exposures associated with chemical-affected environmental media.  
1.2 Table 1 lists the considerations that should be taken into account when developing an engineering control in accordance with this guide. (A) Table presents design issues to be considered to demonstrate that the design of an engineering control for chemical-affected property has been developed in accordance with this guide. Consideration of the issues should be documented in accordance with the identified regulatory framework for the site.(B) References indicate sections of this guide.  
1.3 This guide is intended for use by real estate developers, civil/structural designers, environmental regulators, industrial parties, environmental consultants, and other persons concerned with residential, commercial, or industrial development of real properties where chemical-affected environmental media are present. The design process should involve the individuals and firms working on various aspects of the specifications for construction, operation, and maintenance. If the site is located on public property, then public participation should be considered during the design process.  
1.4 This guide is directed toward properties where chemical-affected environmental media, associated with either human-influenced activities or naturally-occurring conditions, will remain in place and where active or passive engineering controls will be used to reduce or eliminate exposures that may otherwise pose an unacceptable risk to property user...

SIGNIFICANCE AND USE
4.1 The risk-based corrective action (RBCA) process presented in this guide is a consistent, streamlined decision process for selecting corrective actions at chemical release sites.  
4.2 Risk assessment is a developing science. The scientific approach used to develop the RBSL and SSTL may vary by regulatory agency and by user due to regulatory requirements, guidance and use of alternative scientifically-based methods.  
4.3 Activities described in this guide should be conducted by persons familiar with current site characterization techniques, remedial action science and technology, current human health risk and exposure assessment methodologies, toxicology, and current ecological evaluation methodologies.  
4.4 In order to properly apply the RBCA process, the user should AVOID the following:  
4.4.1 Prescribing Tier 1 RBSL or RESC as remedial action standards for all sites rather than screening levels,  
4.4.2 Limiting use of the RBCA process to Tier 1 evaluation only and not continuing with Tier 2 or Tier 3 analyses for sites where further tier evaluation is appropriate,  
4.4.3 Placing arbitrary time constraints on the corrective action process; for example, requiring that Tiers 1, 2, and 3 be completed within time periods that do not reflect the actual urgency of and risks posed by the site,  
4.4.4 Using the RBCA process only when active remedial action is not technically feasible, rather than as a process that is applicable during all phases of corrective action,  
4.4.5 Conducting active remedial action to achieve only technology-based remedial limits (for example, asymptotic levels) prior to determining applicable corrective action goals,  
4.4.6 Using predictive modeling that is not supported by available data or knowledge of site conditions,  
4.4.7 Limiting remedial action options to a single class of remedial actions for all sites,  
4.4.8 Using unjustified or inappropriate exposure factors,  
4.4.9 Using unjustified or inappropriate toxicit...
SCOPE
1.1 This is a guide for conducting risk-based corrective action (RBCA) at chemical release sites based on protecting human health and the environment. The RBCA is a consistent decision-making process for the assessment and response to chemical releases. Chemical release sites vary greatly in terms of complexity, physical and chemical characteristics, and in the risk that they may pose to human health and the environment. The RBCA process recognizes this diversity by using a tiered approach that integrates site assessment and response actions with human health and ecological risk assessment to determine the need for remedial action and to tailor corrective action activities to site-specific conditions and risks. The evaluations and methods used in the RBCA process begin with simple analyses in Tier 1 and move to more complex evaluations in either Tier 2 or Tier 3, as applicable. The process of gathering and evaluating data is conducted in a scaled fashion. Consequently, only the data that are necessary for a particular tier's decision-making are collected at that tier.  
1.2 This guide describes an approach for risk-based corrective action. It is intended to help direct and streamline the corrective action process and to complement but not to supersede federal, state and local regulations. It can be employed at sites where corrective action is being conducted including sites where there may not be a regulatory framework for corrective action, or where the user wishes to conduct corrective action such as sites in voluntary cleanup programs or under Brownfields initiatives. In addition, it can also be used as a unifying framework when several different agency programs affect the site. Furthermore, the user should be aware of the federal, state and local corrective action programs that are applicable for the site and, regardless of the program, federal, state and local agency approvals may be required to implement the proce...

SIGNIFICANCE AND USE
4.1 This guide is intended for use within a RBCA process or other risk-based framework for protection of human health and the environment that is based on an evaluation of sources, exposure pathways, and receptors.  
4.2 This guide is intended to identify the factors that should be considered in the selection and implementation of an appropriate remedial action to address COCs present in environmental media at the site at concentrations above the remedial action levels. The specific process used to select the remedial action will vary widely from site to site. However, in all cases, the selected remedial action should be both a protective remedial action (that is, achieves the risk-based remedial action objectives) and an acceptable remedial action (that is, satisfies the non-risk remedial action objectives).
SCOPE
1.1 This guide covers the selection of appropriate remedial actions at sites where a release of chemicals (for example, vapor-phase, dissolved-phase, or non-aqueous phase liquids (NAPL)) into the environment has occurred. This overall remedy selection process is illustrated in Fig. 1. The guide is intended to be applied within a risk-based corrective action (RBCA) framework.  
1.5.1 Development of risk-based remedial action objectives that includes identification of complete exposure pathways and numeric remedial action levels (Section 5).  
1.5.2 Development of non-risk remedial action objectives based on resource protection and other non-risk considerations. Resource protection objectives typically include numeric remedial action levels while other non-risk criteria are typically non-numeric and may include: remediation timeframe, implementability, cost effectiveness, regulatory compliance, property use requirements, liability control, and community concern (Section 5).  
1.5.3 Evaluation of protectiveness to identify protective remedial actions that will be effective and timely for each risk-based remedial action objective for the site (Section 6).  
1.5.4 Evaluation of the retained remedies using the non-risk remedial action objectives to identify acceptable remedial actions that satisfy the minimum level for each non-risk criterion (Section 7).  
1.5.5 Remedial action selection to select the acceptable remedial action to be implemented at the site (Section 8).  
1.5.6 Remedy design and implementation to ensure that the selected remedy is effectively implemented at the site and satisfies the remedial action objectives (Section 9).  
1.6 This guide is intended for use in the selection of final remedial actions. This guide may also be used in the selection of interim measures provided that risk-based remedial action objectives and non-risk remedial action objectives are available for the evaluation of these interim measures.  
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.8 This guide is not intended to specifically address contractor health and safety issues. It is the responsibility of the user of this guide to ensure that Occupational Safety and Health Administration (OSHA) regulatory requirements are met,and appropriate industry practices are consulted for guidance.  
1.9 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.

SIGNIFICANCE AND USE
4.1 The Eco-RBCA process presented in this guide is a streamlined decision-making process for implementing corrective action protective of ecological resources at chemical release sites in a consistent manner. Eco-RBCA provides a framework for sites not covered under regulatory programs, for sites under regulatory programs that lack guidance, or for sites under programs with guidance that lack detail. Eco-RBCA may also provide a useful framework to help merge an approach when multiple regulatory programs apply.  
4.2 Ecological risk assessment is a science-based process that can be used to provide insight for risk management decision-making. Numerous federal and state programs have guidance for conducting ERA. Available regulatory approaches to ERA were reviewed in preparation for the development of this Eco-RBCA guide. Eco-RBCA was designed to be adaptable to the use of a variety of methods for considering risks to relevant ecological receptors and habitats. Some attributes of the standard are:  
4.2.1 Use of a tiered approach, including process flow charts to identify critical steps and facilitate the development of an overview of the entire process;  
4.2.2 Identification, development, and use of TPDs from Step 1 and throughout the entire Eco-RBCA process;  
4.2.3 Indications of the value and timing of stakeholder involvement, recognizing that some regulations require coordination with federal, state, tribal, and natural-resource trustees, and other stakeholders;  
4.2.4 Identification of situations under which an ERA may or may not be necessary; and  
4.2.5 Identification of decision points where ERA results are used for risk management decision making.  
4.3 Activities described in this guide should involve persons with the appropriate skills and expertise. The user may rely on individuals expert in remediation science and technology, ecology/biology, ecotoxicology, ERA practices, and site characterization techniques.  
4.4 This guide and supporting app...
SCOPE
1.1 This is a guide to risk-based corrective action for the protection of ecological resources and supplements the RBCA process (Guide E2081). The primary objective of the Eco-RBCA process is to provide a flexible framework for a tiered approach to ERA and risk management decision making at chemical release sites. To this end, available guidance documents from various federal and state agencies were reviewed and their common attributes incorporated into this guide, where possible. The Eco-RBCA process complements existing technical and regulatory ecological risk guidance (see 4.2). In particular, it is intended to be compatible with the USEPA programmatic guidelines for ERA  (1)2, guidance for the Superfund program (2), and other USEPA (3) risk assessment and corrective-action programs. Eco-RBCA might also be used in conjunction with corrective action strategies that include human health issues (for example, Guide E2081).  
1.2 Chemical release sites vary greatly in terms of complexity, physical and chemical characteristics, and the risk that they might pose to ecological resources. The Eco-RBCA process, as described in Guide E2081, recognizes this variability and incorporates a tiered approach that integrates site assessment, response actions, and remedial actions with ERA. The process begins with relatively simple analyses in Tier 1 and, if necessary, proceeds to more detailed evaluations in Tier 2 or Tier 3. The process of gathering and evaluating data is conducted in such a manner that only those data that are necessary for a given tier's decision making are collected at each tier. Hence, this can facilitate effective use of resources and reduce initial data requirements.  
1.3 Eco-RBCA is intended to provide a framework for sites not covered under regulatory programs and for sites under regulatory programs that lack specific guidance. Eco-RBCA may also provide a useful framework to help merge several possible appr...

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...
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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...

SIGNIFICANCE AND USE
4.1 Purpose—This guide provides a process for evaluating implementing, documenting, and reporting activities to reduce the environmental footprint of a cleanup as defined by the following core elements.  
4.1.1 Minimize Total Energy Use and Maximize Use of Renewable Energy—Reducing total energy use while also identifying means to increase the use of renewable energies throughout the cleanup. Possible methods may include reducing energy use, use of energy efficient equipment, use of onsite renewable resources (for example, wind, solar), and purchase of commercial energy from renewable resources.  
4.1.2 Minimize Air Pollutants and Greenhouse Gas Emissions—Reducing total air emissions, including emissions of air pollutants and greenhouse gases, throughout the cleanup. Possible methods may include minimizing the generation and transport of airborne contaminants and dust, efficient use of emitting equipment (for example, vehicles and heavy equipment), use of advanced emission controls, and use of cleaner fuels or hybrid technologies.  
4.1.3 Minimize Water Use and Impacts to Water Resources—Minimizing the use of water and impacts to water resources throughout the cleanup. Possible methods may include conserving water use in cleanup processes, use of water efficient products, water capture and reclamation for reuse, water efficient revegetation, and employing traditional BMPs for storm water, erosion, and sedimentation control.  
4.1.4 Reduce, Reuse, and Recycle Materials and Waste—Minimizing the use of virgin materials and generation of waste throughout the cleanup as well as maximizing the use of recycled materials. Possible methods may include using recycled and locally generated materials, reusing waste materials (for example, concrete made with coal combustion products), diverting construction and demolition debris from disposal by recycling recovered resources, and using rapidly renewable materials or certified wood products.  
4.1.5 Protect Land and Ecosystem...
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1.1 Cleaning up sites improves environmental and public health conditions and as such can be viewed as “green.” However, cleanup activities use energy, water, and natural resources. The process of cleanup therefore creates its own environmental footprint. This guide describes a process for evaluating and implementing activities to reduce the environmental footprint of a cleanup project in the United States while working within the applicable regulatory framework and satisfying all applicable legal requirements.  
1.2 This guide may also be used as a framework for sites that are not located in the United States; however, the specific legal references are not applicable.  
1.3 This guide describes a process for identifying, evaluating, and incorporating best management practices (BMPs) and, when deemed appropriate, for integrating a quantitative evaluation into a cleanup to reduce its environmental footprint.  
1.4 This guide is designed to be implemented in conjunction with any cleanup process and should be used with other technical tools, guidance, policy, laws, and regulations to integrate greener cleanup practices, processes, and technologies into cleanup projects.  
1.5 This guide provides a process for evaluating and implementing activities to reduce the environmental footprint of a cleanup and is not designed to instruct users on how to clean up contaminated sites.  
1.6 ASTM also has a guide on Integrating Sustainable Objectives into Cleanups (E2876). That guide provides a broad framework for integrating elements of environmental, economic, and social aspects into cleanups. This guide may provide assistance with implementing E2876 and other sustainable remediation guidance, such as Holland, et al. (2011)(1).  
1.7 This guide specifically applies to the cleanup, not the redevelopment, of a site. However, the reasonably anticipated use of a site, if known, may influence the cleanup goals and scope.  
1.8 This ...

SIGNIFICANCE AND USE
4.1 Purpose—This guide provides a process for evaluating implementing, documenting, and reporting activities to reduce the environmental footprint of a cleanup as defined by the following core elements.  
4.1.1 Minimize Total Energy Use and Maximize Use of Renewable Energy—Reducing total energy use while also identifying means to increase the use of renewable energies throughout the cleanup. Possible methods may include reducing energy use, use of energy efficient equipment, use of onsite renewable resources (for example, wind, solar), and purchase of commercial energy from renewable resources.  
4.1.2 Minimize Air Pollutants and Greenhouse Gas Emissions—Reducing total air emissions, including emissions of air pollutants and greenhouse gases, throughout the cleanup. Possible methods may include minimizing the generation and transport of airborne contaminants and dust, efficient use of emitting equipment (for example, vehicles and heavy equipment), use of advanced emission controls, and use of cleaner fuels or hybrid technologies.  
4.1.3 Minimize Water Use and Impacts to Water Resources—Minimizing the use of water and impacts to water resources throughout the cleanup. Possible methods may include conserving water use in cleanup processes, use of water efficient products, water capture and reclamation for reuse, water efficient revegetation, and employing traditional BMPs for storm water, erosion, and sedimentation control.  
4.1.4 Reduce, Reuse, and Recycle Materials and Waste—Minimizing the use of virgin materials and generation of waste throughout the cleanup as well as maximizing the use of recycled materials. Possible methods may include using recycled and locally generated materials, reusing waste materials (for example, concrete made with coal combustion products), diverting construction and demolition debris from disposal by recycling recovered resources, and using rapidly renewable materials or certified wood products.  
4.1.5 Protect Land and Ecosystem...
SCOPE
1.1 Cleaning up sites improves environmental and public health conditions and as such can be viewed as “green.” However, cleanup activities use energy, water, and natural resources. The process of cleanup therefore creates its own environmental footprint. This guide describes a process for evaluating and implementing activities to reduce the environmental footprint of a cleanup project in the United States while working within the applicable regulatory framework and satisfying all applicable legal requirements.  
1.2 This guide may also be used as a framework for sites that are not located in the United States; however, the specific legal references are not applicable.  
1.3 This guide describes a process for identifying, evaluating, and incorporating best management practices (BMPs) and, when deemed appropriate, for integrating a quantitative evaluation into a cleanup to reduce its environmental footprint.  
1.4 This guide is designed to be implemented in conjunction with any cleanup process and should be used with other technical tools, guidance, policy, laws, and regulations to integrate greener cleanup practices, processes, and technologies into cleanup projects.  
1.5 This guide provides a process for evaluating and implementing activities to reduce the environmental footprint of a cleanup and is not designed to instruct users on how to clean up contaminated sites.  
1.6 ASTM also has a guide on Integrating Sustainable Objectives into Cleanups (E2876). That guide provides a broad framework for integrating elements of environmental, economic, and social aspects into cleanups. This guide may provide assistance with implementing E2876 and other sustainable remediation guidance, such as Holland, et al. (2011)(1).  
1.7 This guide specifically applies to the cleanup, not the redevelopment, of a site. However, the reasonably anticipated use of a site, if known, may influence the cleanup goals and scope.  
1.8 This ...

SIGNIFICANCE AND USE
4.1 Flexibility—Users may desire to incorporate sustainable aspects within the scalable framework throughout any or all phases of the cleanup, or any size of site.  
4.1.1 For simplicity the term cleanup is used in the guide when referring to any of the cleanup phases, for example site assessment, remedy selection, remedy design and implementation, remedy optimization, operation, maintenance and monitoring, and closure.  
4.1.2 Implementation of the guide is site-specific. The user may choose to customize the implementation of the guide for particular types of sites, for example, UST sites, dry cleaner sites, or particular phases of cleanup. Customization may be particularly relevant for groups of small, non-complex sites.  
4.2 Considerations—The information provided in this guide provides a framework to evaluate sustainable aspects in the context of site cleanup. The guide helps users identify factors and activities they may want to consider in cleanup projects, while protecting human health and the environment.  
4.3 Sustainable Performance Criterion—Based on the sustainable objectives identified for the site, users should implement one or more best management practices that substantially benefit each of the sustainable aspects (environmental, social and economic), see Section 6 for details. The user should demonstrate these benefits through publicly available documentation. Substantial benefits must be over and above those achieved by existing regulatory requirements, unless a regulatory agency adopts this guide for cleanup sites. In that case the regulatory agency will determine what constitutes substantial benefits under its own regulations.  
4.4 Transparency Goal—The user should document the activities and evaluations performed while using this guide. The documentation is needed to demonstrate the sustainable benefits through public disclosure and transparency. See Section 8 for more information.  
4.5 Stakeholder Involvement—The user should engage sta...
SCOPE
1.1 This guide presents a framework that allows and encourages the user to address sustainable aspects (environmental, economic and social) within cleanup projects. The user may implement this guide to integrate sustainable objectives into cleanup while working within applicable regulatory criteria.  
1.2 The guide provides an overarching, consistent, transparent and scalable framework that helps the user identify and incorporate sustainable best management practices (BMPs) into site cleanup (which includes assessment and remediation), and enables the user to perform measurement of BMPs during the cleanup process. See Appendix X1 for example BMPs.  
1.3 The guide is intended to encourage incremental steps to incorporate sustainable elements into cleanup projects. The user chooses whether to pursue BMP implementation alone (Section 6) or to also measure the benefits of the implemented BMPs (Sections 6 and 7). The user also chooses the phases of the cleanup to which they apply the guide.  
1.4 The guide should be implemented within the existing site assessment and remediation process. The approach described in this guide should be used with other existing technical tools and policy to encourage the consideration of a more holistic approach with a broader range of cleanup options and activities than traditionally employed (NICOLE 2012(1))2.  
1.5 BMPs implemented under this guide should address all three aspects of sustainability: environmental, economic and social, while assuring that human health and safety as well as ecological risks are addressed. The goal of implementing BMPs is to take actions to address the sustainable objectives identified for the site.  
1.6 3.1.17 defines sustainable objectives; 3.1.15.1 defines sustainable aspects; 5.3 provides detail about core elements; and Section 6 describes a process to identify, evaluate, select, and implement BMPs.  
1.7 While the guide specifically applies to the cl...

SIGNIFICANCE AND USE
4.1 Application:
4.1.1 LNAPL transmissivity is an accurate metric for understanding LNAPL recovery, is directly proportional to LNAPL recoverability and tracking remediation progress towards residual LNAPL saturation.  
4.1.2 LNAPL transmissivity can be used to estimate the rate of recovery for a given drawdown from various technologies.  
4.1.3 LNAPL transmissivity is not an intrinsic aquifer property but rather a summary metric based on the aquifer properties, LNAPL physical properties, and the magnitude of LNAPL saturation over a given interval of aquifer.  
4.1.4 LNAPL transmissivity will vary over time with changing conditions such as, seasonal fluctuations in water table, changing hydrogeologic conditions and with variability in LNAPL impacts (that is, interval that LNAPL flows over in the formation and LNAPL pore space saturation) within the formation.  
4.1.5 Any observed temporal or spatial variability in values derived from consistent data collection and analysis methods of LNAPL transmissivity is not erroneous, rather is indicative of the actual variability in subsurface conditions related to the parameters encompassed by LNAPL transmissivity (that is, fluid pore space saturation, soil permeability, fluid density, fluid viscosity, and the interval that LNAPL flows over in the formation).  
4.1.6 LNAPL transmissivity is a more accurate metric for evaluating recoverability and mobile LNAPL than gauged LNAPL thickness. Gauged LNAPL thickness does not account for soil permeability, magnitude of LNAPL saturation above residual saturation, or physical fluid properties of LNAPL (that is, density, interfacial tension, and viscosity).  
4.1.7 The accurate calculation of LNAPL transmissivity requires certain aspects of the LNAPL Conceptual Site Model (LCSM) to be completely understood and defined in order to calculate LNAPL drawdown correctly. The methodologies for development of the LCSM are provided in Guide E2531. The general conceptual site model as...
SCOPE
1.1 This guide provides field data collection and calculation methodologies for the estimation of light non-aqueous phase liquid (LNAPL) transmissivity in unconsolidated porous sediments. The methodologies presented herein may, or may not be, applicable to other hydrogeologic regimes (for example, karst, fracture flow). LNAPL transmissivity represents the volume of LNAPL (L3) through a unit width (L) of aquifer per unit time (t) per unit drawdown (L) with units of (L2/T). LNAPL transmissivity is a directly proportional metric for LNAPL recoverability whereas other metrics such as apparent LNAPL thickness gauged in wells do not exhibit a consistent relationship to recoverability. The recoverability for a given gauged LNAPL thickness in a well will vary between different soil types, LNAPL types or hydrogeologic conditions. LNAPL transmissivity accounts for those parameters and conditions. LNAPL transmissivity values can be used in the following five ways: (1) Estimate LNAPL recovery rate for multiple technologies; (2) Identify trends in recoverability via mapping; (3) Applied as a leading (startup) indicator for recovery; (4) Applied as a lagging (shutdown) indicator for LNAPL recovery; and (5) Applied as a robust calibration metric for multi-phase models (Hawthorne and Kirkman, 2011 (1)2 and ITRC ((2)). The methodologies for LNAPL transmissivity estimation provided in this document include short-term aquifer testing methods (LNAPL baildown/slug testing and manual LNAPL skimming testing), and long-term methods (that is, LNAPL recovery system performance analysis, and LNAPL tracer testing). The magnitude of transmissivity of any fluid in the subsurface is controlled by the same variables (that is, fluid pore space saturation, soil permeability, fluid density, fluid viscosity, the interval that LNAPL flows over in the formation and the gravitational acceleration constant). A direct mathematical relationship exists between th...

SIGNIFICANCE AND USE
4.1 Application:
4.1.1 LNAPL transmissivity is an accurate metric for understanding LNAPL recovery, is directly proportional to LNAPL recoverability and tracking remediation progress towards residual LNAPL saturation.  
4.1.2 LNAPL transmissivity can be used to estimate the rate of recovery for a given drawdown from various technologies.  
4.1.3 LNAPL transmissivity is not an intrinsic aquifer property but rather a summary metric based on the aquifer properties, LNAPL physical properties, and the magnitude of LNAPL saturation over a given interval of aquifer.  
4.1.4 LNAPL transmissivity will vary over time with changing conditions such as, seasonal fluctuations in water table, changing hydrogeologic conditions and with variability in LNAPL impacts (that is, interval that LNAPL flows over in the formation and LNAPL pore space saturation) within the formation.  
4.1.5 Any observed temporal or spatial variability in values derived from consistent data collection and analysis methods of LNAPL transmissivity is not erroneous, rather is indicative of the actual variability in subsurface conditions related to the parameters encompassed by LNAPL transmissivity (that is, fluid pore space saturation, soil permeability, fluid density, fluid viscosity, and the interval that LNAPL flows over in the formation).  
4.1.6 LNAPL transmissivity is a more accurate metric for evaluating recoverability and mobile LNAPL than gauged LNAPL thickness. Gauged LNAPL thickness does not account for soil permeability, magnitude of LNAPL saturation above residual saturation, or physical fluid properties of LNAPL (that is, density, interfacial tension, and viscosity).  
4.1.7 The accurate calculation of LNAPL transmissivity requires certain aspects of the LNAPL Conceptual Site Model (LCSM) to be completely understood and defined in order to calculate LNAPL drawdown correctly. The methodologies for development of the LCSM are provided in Guide E2531. The general conceptual site model as...
SCOPE
1.1 This guide provides field data collection and calculation methodologies for the estimation of light non-aqueous phase liquid (LNAPL) transmissivity in unconsolidated porous sediments. The methodologies presented herein may, or may not be, applicable to other hydrogeologic regimes (for example, karst, fracture flow). LNAPL transmissivity represents the volume of LNAPL (L3) through a unit width (L) of aquifer per unit time (t) per unit drawdown (L) with units of (L2/T). LNAPL transmissivity is a directly proportional metric for LNAPL recoverability whereas other metrics such as apparent LNAPL thickness gauged in wells do not exhibit a consistent relationship to recoverability. The recoverability for a given gauged LNAPL thickness in a well will vary between different soil types, LNAPL types or hydrogeologic conditions. LNAPL transmissivity accounts for those parameters and conditions. LNAPL transmissivity values can be used in the following five ways: (1) Estimate LNAPL recovery rate for multiple technologies; (2) Identify trends in recoverability via mapping; (3) Applied as a leading (startup) indicator for recovery; (4) Applied as a lagging (shutdown) indicator for LNAPL recovery; and (5) Applied as a robust calibration metric for multi-phase models (Hawthorne and Kirkman, 2011 (1)2 and ITRC ((2)). The methodologies for LNAPL transmissivity estimation provided in this document include short-term aquifer testing methods (LNAPL baildown/slug testing and manual LNAPL skimming testing), and long-term methods (that is, LNAPL recovery system performance analysis, and LNAPL tracer testing). The magnitude of transmissivity of any fluid in the subsurface is controlled by the same variables (that is, fluid pore space saturation, soil permeability, fluid density, fluid viscosity, the interval that LNAPL flows over in the formation and the gravitational acceleration constant). A direct mathematical relationship exists between th...