【国外标准】 Standard Guide for Developing Representative Background Concentrations at Sediment Sites — Framework Overview, Including Conceptual Site Model Considerations

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 scoping process to collect information to assist in making site-specific, user-defined decisions for a particular project, including assembling an experienced team of project professionals. These practitioners should have the appropriate expertise to scope, plan, and execute a sediment data acquisition and analysis program. This team may include, but is not limited to, project sponsors, environmental consultants, toxicologists, site remediation professionals, analytical chemists, geochemists, and statisticians.4.7 Other Considerations: 4.7.1 This guide does not provide a detailed description of all topics of a program to derive representative sediment background concentrations. It is meant to be used in conjunction with other guides (such as Guides E3163, E3164, E3240, E3242, and E3344) to do so.4.7.2 Sediment sampling and laboratory analyses are not covered in detail in this guide. Guides E3163 and E3164 contain extensive information concerning sediment sampling and laboratory analysis methodologies.4.7.3 Data quality objectives are not covered in this guide. Data quality objectives are described in (2).4.7.4 The selection of a background reference area(s) is not covered in detail in this guide but is extensively described in Guide E3344.4.7.5 Background study design considerations are not covered in detail in this guide, but are extensively described in other references, including Guide E3164 and (3).4.7.6 The use of data evaluation methodologies to obtain representative background data sets from candidate background data sets is not covered in detail in this guide but is discussed in more depth in Guide E3242.4.7.6.1 Identification and removal of high nondetect values from candidate background data sets are discussed in detail in Guide E3242.4.7.6.2 Identification and removal of outliers from candidate background data sets are discussed in detail in Practice E178, as well as Guide E3242.4.7.6.3 Geochemical methodologies used in evaluating candidate background data sets to obtain representative background data sets are discussed in detail in Guide E3242; their applications during reference-area selection are discussed in Guide E3344.4.7.6.4 Chemical forensics methodologies used in evaluating candidate background data sets to obtain representative background data sets are discussed in detail in Guide E3242; their applications during reference-area selection are discussed in Guide E3344.4.7.7 The use of statistical methods to calculate BTVs from representative background data sets and to compare such data sets to the site data sets are discussed in detail in Guide E3242.4.7.8 Geospatial analysis considerations are not thoroughly discussed in this guidance but are discussed in more depth relative to environmental evaluations in (4), which focuses on quality assurance concerns relative to geospatial analyses.4.7.9 In this guide, “sediment” (3.1.16) is defined as a matrix being found at the bottom of a water body. Upland soils of sedimentary origin are excluded from consideration as sediment in this guide.4.7.10 In this guide, only COC concentrations are considered. Residual background radioactivity is out of scope for this guide.4.8 Structure and Components of This Guide: The user of this guide should review the overall structure and components of this guide before proceeding with use, including:• Section 1 • Section 2 Referenced Documents• Section 3 Terminology• Section 4 • Section 5 Overview of Representative Background Concentrations• Section 6 Framework for Developing Representative Background Concentrations for Sediment Sites• Section 7 Conceptual Site Model Considerations When Developing Representative Background Concentrations for Sediment Sites• Section 8 Keywords• References  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 E3163, E3164, E3242, and E3344 is summarized herein, but the individual guides should be consulted for more detailed coverage of these topics.1.4 Representative sediment background 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 corrective actions performed under local, state, tribal, federal, and international corrective action programs. However, this guide does not provide a detailed description of the requirements or existing background guidance for each jurisdiction.1.5 This guide would optimally be applied at the start of any sediment corrective action program but can be initiated at other points in the program as well.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 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.