1.1 本指南介绍了用于评估候选背景数据集的数据可视化、统计、法医化学和地球化学方法（包括案例研究）；这一评估导致了沉积物现场代表性背景数据集的开发。然后，可以将统计方法应用于代表性背景数据集，以制定背景阈值（BTV），该阈值是沉积物场地代表性沉积物背景浓度上限的测量值。此外，可以使用两个样本统计测试来比较具有代表性的背景数据集和沉积物现场数据集，以确定这两个数据集之间是否存在统计学上的显著差异（在特定的置信水平下）（例如，这两个数据集的中值或平均值显著不同）。 1.1.1 本指南旨在提供信息、补充和支持，但不取代地方、州、部落、联邦或国际机构制定的指南。 1.2 技术上可辩护的具有代表性的沉积物背景浓度对以下几个目的至关重要 ( 1. ) . 2. 其中包括沉积物现场划定、确定补救目标和清理水平、补救措施选择、评估代表性背景浓度带来的风险，以及制定适当的补救后监测计划。 1.3 指南中介绍了沉积物现场代表性沉积物背景浓度的总体框架 E3382 指导 E3240 提供了关于概念场地模型（CSM）开发如何适应受污染沉积物场地基于风险的纠正措施框架的一般性讨论，而指南 E3382 提供了在开发具有代表性的沉积物背景浓度时需要考虑的沉积物场地CSM要素的详细讨论。指导 E3344 描述了如何选择合适的背景参考区域，从中收集沉积物样本进行实验室分析。指导 E3164 描述了在现场获取沉积物样本的采样方法（无论是从沉积物现场还是背景参考区域），而指南 E3163 讨论了对沉积物样品中潜在的关注污染物（PCOCs）进行化学分析的适当实验室方法。指南中包含的相关内容 E3344 和 E3382 本文对其进行了总结，但应查阅个别指南以了解这些主题的更详细内容。 1.4 本指南侧重于开发代表性沉积物背景浓度的方法，用于根据各种监管计划执行的补救措施，包括《综合环境响应、赔偿和责任法案》（CERCLA）。 尽管本指南中引用的许多参考文献都是以CERCLA为导向的，但本指南适用于根据地方、州、部落、联邦和国际清理计划执行的补救措施。然而，该指南并没有描述每个司法管辖区的要求。应审查正在进行清理的监管实体的要求，以确认其合规性。 1.5 本指南适用于已收集沉积物数据且随时可用的受污染沉积物现场。此外，本指南假设已经进行了风险评估，从而确定了超过基于风险的阈值的关注污染物（COCs）。 1.5.1 此外，本指南假设已确定的基于风险的阈值足够低，足以对纠正措施的实施提出挑战，或者该场地受到不受控制的持续人为或自然来源的再污染，或者两者兼而有之。 在所有情况下，代表性沉积物背景浓度将有助于确定纠正补救措施的范围（当用作补救目标或清理水平时），评估代表性背景浓度带来的风险，并制定适当的补救后监测计划。 1.6 单位-- 以SI或CGS单位表示的数值应视为标准。本标准不包括其他计量单位。 1.7 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 4.1 预期用途: 4.1.1 本指南可供参与沉积物纠正行动计划的各方使用，包括监管机构、项目发起人、环境顾问、毒理学家、风险评估师、现场修复专业人员、环境承包商和其他利益相关者。 4.2 CSM的重要性: 4.2.1 应不断更新和完善CSM，以描述沉积物纠正措施项目的物理特性、化学成分和发生、生物特征和环境条件（指南 E1689 ). 4.3 参考材料: 4.3.1 本指南应与中列出的其他ASTM指南一起使用 2.1 （尤其是指南 E3344 和 E3382 ); 本指南还应与本指南末尾参考文献中的材料一起使用（包括 1. ). 利用这些参考材料将指导用户制定沉积物场地的代表性背景浓度。 4.4 灵活的现场具体实施: 4.4.1 本指南提供了一个系统但灵活的框架，以适应监管机构和用户根据项目目标、场地复杂性、独特场地特征、监管要求、新制定的指南、新发表的科学研究、监管标准的变化、科学知识和技术能力的进步、，以及不可预见的情况。 4.5 监管框架: 4.5.1 本指南适用于广泛的地方、州、部落、联邦或国际司法管辖区，每个司法管辖区都有自己独特的监管框架。因此，本指南并不提供与任何这些监管框架相关的要求或指导的详细讨论，也无意取代适用的法规和指导。 本指南的用户需要了解正在执行工作的司法管辖区的监管要求和指南。 4.6 系统的项目规划和范围界定过程: 4.6.1 在应用本指南时，用户应进行系统的项目规划和范围界定过程，以收集信息，帮助为特定项目做出特定地点、用户定义的决策，包括组建一支经验丰富的项目专业团队。这些从业者应具备适当的专业知识，以确定、规划和执行沉积物数据采集和分析程序。该团队可能包括但不限于项目发起人、环境顾问、毒理学家、现场修复专业人员、分析化学家、地球化学家和统计学家。 4.7 使用代表性背景设置边界: 4.7.1 沉积物的代表性背景浓度可用于描绘沉积物校正行动，通过区分与现场相关的影响和代表性背景密度来确定沉积物校正行动区域的边界。此应用程序需要为具有代表性的背景数据集开发BTV。 4.8 使用代表性背景建立清理级别: 4.8.1 沉积物的代表性背景浓度可用于确定用于沉积物纠正措施的清理水平。在基于风险的沉积物清理水平低于代表性背景浓度的情况下，通常使用背景浓度作为清理水平 ( 4. ) 。这确保了清理水平的可持续性。任何来自持续污染源的再污染最终将导致地表沉积物浓度大于风险- 基于净化水平，但即使在再污染之后，表面沉积物仍应满足基于代表性背景浓度的净化水平。 4.9 风险评估中代表性背景的使用: 4.9.1 代表性背景浓度可用于风险评估过程（包括人类和生态风险评估），以了解污染物的背景水平对人类健康和环境构成的风险，以及导致沉积物浓度超过代表性背景浓度的与现场相关的释放或活动（或两者兼有）带来的增量风险。相反，如果将沉积物从现有的COC浓度修复到较低的值（即代表性的背景浓度），则可以使用它们来估计各种污染物的风险降低。 4.10 补救后监测程序中代表性背景的使用: 4.10.1 补救后监测程序也可以使用具有代表性的背景沉积物浓度作为纠正措施目标，或者了解补救后浓度与非当前或历史现场释放或活动来源的比较情况。通常，为确保现场相关排放得到控制且不会再次污染纠正措施后的沉积物而采取的源控制措施必须基于对代表性背景的持续贡献的理解。在本次评估中，必须考虑与当前或历史现场相关发布或活动无关的持续来源（可能受到或不受来源控制行动的影响）。 4.11 其他注意事项: 4.11.1 本指南并不涵盖开发具有代表性的沉积物背景浓度的程序的所有组成部分。 4.11.2 本指南未详细介绍开发代表性背景浓度的总体过程（包括CSM考虑因素），但在指南中进行了更深入的讨论 E3382 . 4.11.3 本指南未详细介绍沉积物场地背景参考区域的选择，但在指南中进行了广泛描述 E3344 . 4.11.4 本指南不包括沉积物取样和实验室分析。指南 E3163 和 E3164 包含有关沉积物取样和实验室分析的广泛信息。 4.11.5 本指南未涵盖数据质量目标。中描述了数据质量目标 ( 5. ) . 4.11.6 本指南未涵盖背景研究设计注意事项，但在包括指南在内的其他参考文献中进行了描述 E3163 和 E3164 以及 ( 6. , 7. ) . 4.11.7 本指南中没有全面讨论地理空间分析的注意事项，但在中对环境评估进行了更深入的讨论 ( 8. ) ，侧重于与地理空间分析相关的质量保证问题。 4.11.8 在本指南中，只有COCs的浓度被认为在范围内。残余本底放射性超出范围。 4.12 本指南的结构和组成部分: 4.12.1 本指南的用户应在继续使用前审查本指南的总体结构和组成部分，包括: 部分 1. 范围 部分 2. 参考文件 部分 3. 术语 部分 4. 意义和用途 部分 5. 代表性背景浓度开发过程概述 部分 6. 候选背景数据集的开发 部分 7. 评估候选背景数据集以获得代表性背景数据集 部分 8. 数据可视化 部分 9 高非检测数据点的评估 部分 10 外部数据点的评估 部分 11 有机污染物的法医化学评价 部分 12 金属的地球化学评价 部分 13 从候选背景数据集开发代表性背景数据集的方法应用 部分 14 代表性背景浓度的发展 部分 15 使用统计双样本测试对沉积物位置和代表性背景数据集进行比较 部分 16 关键词 附录X1 有机和无机化学概述 附录X2 一个示例沉积物现场的说明性案例研究 附录X3 异常值测试总结和两个- 样本统计测试 工具书类

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 select an appropriate background reference area(s) from which to collect sediment samples for laboratory analysis. Guide E3164 describes the sampling methodologies to obtain sediment samples in the field (whether from the sediment site or background reference area[s]), while Guide E3163 discusses appropriate laboratory methodologies for the chemical analysis of potential contaminants of concern (PCOCs) in the sediment samples. Relevant content contained in Guides E3344 and E3382 is summarized herein, but the individual guides should be consulted for more detailed coverage of these topics. 1.4 This guide focuses on the approach for the development 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, tribal, 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 being performed should be reviewed to confirm compliance. 1.5 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 of concern (COCs) that exceed risk-based thresholds have been identified. 1.5.1 Furthermore, this guide presumes that the identified risk-based thresholds are low enough to pose corrective action implementation challenges, or the site is subject to recontamination from uncontrolled ongoing anthropogenic or natural sources, or both. In all cases, representative sediment background concentrations will be useful for determining the extent of corrective remedial actions (when used as remedial goals or cleanup levels), evaluating risks posed by representative background concentrations, and establishing appropriate post-remedial monitoring plans. 1.6 Units— The values stated in SI or CGS units are to be regarded as standard. No other units of measurement are included in this standard. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 This 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 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 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 Use of Representative Background to Set a Boundary: 4.7.1 Representative background concentrations for sediments can be used to delineate a sediment corrective action, establishing the boundary of the sediment corrective action area by distinguishing site-related impacts from representative background concentrations. This application requires the development of a BTV for the representative background data set. 4.8 Use of Representative Background to Establish Cleanup Levels: 4.8.1 Representative background concentrations for sediments can 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 ( 4 ) . 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 following recontamination. 4.9 Use of Representative Background in Risk Assessments: 4.9.1 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 or activities (or both) that result in sediment concentrations that exceed representative background concentrations. Conversely, they can be used to estimate the risk reduction for various contaminants, if sediment is remediated from existing COC concentrations to lower values (that is, representative background concentrations). 4.10 Use of Representative Background in Post-Remedy Monitoring Programs: 4.10.1 Post-remedy monitoring programs can also use representative background sediment concentrations either as a corrective action target or to understand how post-remedy concentrations compare to the sources not attributable to current or historical site releases or activities. Typically, source control actions taken to ensure that site-related releases are controlled and will not re-contaminate the post-corrective action sediments must be developed based on an understanding of ongoing contributions from representative background. Ongoing sources unrelated to current or historical site-related releases or activities (that may or may not be subject to source control actions) must be considered in this evaluation. 4.11 Other Considerations: 4.11.1 This guide does not cover all components of a program to develop representative sediment background concentrations. 4.11.2 The overarching process to develop representative background concentrations (including CSM considerations) is not covered in detail in this guide but is discussed in more depth in Guide E3382 . 4.11.3 The selection of a background reference area(s) for the sediment site is not covered in detail in this guide but is extensively described in Guide E3344 . 4.11.4 Sediment sampling and laboratory analyses are not covered in this guide. Guides E3163 and E3164 contain extensive information concerning sediment sampling and laboratory analyses. 4.11.5 Data quality objectives are not covered in this guide. Data quality objectives are described in ( 5 ) . 4.11.6 Background study design considerations are not covered in this guide but are described in other references, including Guides E3163 and E3164 , as well as ( 6 , 7 ) . 4.11.7 Geospatial analysis considerations are not thoroughly discussed in this guidance but are discussed in more depth relative to environmental evaluations in ( 8 ) , which focuses on quality assurance concerns relative to geospatial analyses. 4.11.8 In this guide, only the concentrations of COCs are considered to be in scope. Residual background radioactivity is out of scope. 4.12 Structure and Components of This Guide: 4.12.1 The user of this guide should review the overall structure and components of this guide before proceeding with use, including: Section 1 Scope Section 2 Referenced Documents Section 3 Terminology Section 4 Significance and Use Section 5 Overview of Representative Background Concentration Development Process Section 6 Development of Candidate Background Data Sets Section 7 Evaluation of Candidate Background Data Sets to Obtain Representative Background Data Sets Section 8 Data Visualization Section 9 Evaluation of High Nondetect Data Points Section 10 Evaluation of Outlying Data Points Section 11 Forensic Chemistry Evaluation of Organic Contaminants Section 12 Geochemical Evaluation of Metals Section 13 Methodology Application to Develop a Representative Background Data Set from a Candidate Background Data Set Section 14 Development of Representative Background Concentrations Section 15 Comparison of Sediment Site and Representative Background Data Sets Using Statistical Two-Sample Testing Section 16 Keywords Appendix X1 Organic and Inorganic Chemistry Overview Appendix X2 Illustrative Case Studies from One Example Sediment Site Appendix X3 Summaries for Outlier Testing and Two-Sample Statistical Testing References