1.1 本指南介绍了导致（或影响）沸腾促进的非水相液体（NAPL）/污染物传输的过程、量化传输的方法、样品定时的考虑因素、采样程序以及在将年度沸腾促进的NAPL/污染物负载外推到现场或部分现场时使用结果。本指南的目的不是解决出现沸腾促进NAPL/污染物运输的现场补救、沸腾运输机制后污染物的归宿和运输、气泡内污染物浓度的测量、沸腾相关的人类健康和生态风险、NAPL平流、，或确定泥线以下的沸腾深度。此外，在本指南涵盖的有气体生成和沉积物NAPL污染有限的区域，可以进行无NAPL/污染物的气体运输。 应在预计沉积物封顶的现场评估沸腾。 1.2 本指南的用户应了解适用于存在或怀疑发生NAPL的沉积物现场的适当监管要求。用户应咨询适用的监管机构要求，以确定适当的技术决策标准，并在必要时寻求监管部门的批准。 1.3 ASTM标准指南不是法规；它们是共识标准指南，可自愿遵循，以支持适用的监管要求。本指南可与其他为沉积物项目制定的ASTM指南结合使用。该指南补充了根据国际、联邦、州和地方环境计划进行的表征和补救工作，但它并没有取代监管机构的要求。 1.4 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户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。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）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》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 沸腾在沉积物中普遍存在，当存在相关的NAPL/污染物运输时，沸腾主要是一个重大问题，导致对人类、生态受体或两者的暴露风险。当封顶被选为现场补救措施的一部分时，沸腾也可能是一个问题。 4.2 了解沸腾促进的NAPL/污染物在沉积物中迁移的潜力是构成整体概念现场模型（CSM）的一个重要元素，该模型是以下内容的基础: (1) 评估人类和生态受体是否（以及如何）暴露于NAPL/污染物，以及 (2) 评估补救方案。此外，由于缺乏标准化的术语和表征协议，证明沸腾促进沉积物中NAPL/污染物向监管机构和其他利益相关者运输的潜力（和程度）历来受到阻碍。沸腾的复杂性促进了NAPL/污染物在沉积物中的迁移，以及缺乏商定的现场数据分析和解释方法，导致了沉积物现场纠正措施决策的不确定性。这有时会导致对补救结果的误解。沸腾- 由于各种物理、地球化学和生物差异，沉积物中NAPL/污染物的促进传输机制不同于沉积物或高地环境中的平流传输机制，因此需要本指南。 4.3 本指南旨在作为一份独立文件，以考虑沸腾和沸腾促进NAPL/污染物运输的独特条件，并补充用于在受污染沉积物现场开发CSM的其他指南（指南 E1689 , E1739 , E2081年 , E2531 和 E3248 ). 本指南将帮助用户了解沉积物环境的独特和基本特征，这些特征会影响沸腾促进NAPL/污染物运输的发生。了解影响沸腾促进NAPL/污染物在沉积物柱内迁移的现场特征将有助于确定调查这些条件所需的具体数据要求，这将进一步完善CSM，并为补救决策提供良好基础。 4.4 沸腾促进的NAPL/污染物传输是本指南中讨论的主要传输机制。 4.4.1 除了沸腾促进NAPL/污染物运输外，孔隙水平流也可能促进NAPL/污染物运输；然而，这一过程超出了本指南的范围。指南中讨论了沉积物中NAPL的平流输送 E3248 . 4.4.2 与侵蚀引起的NAPL/污染物传输相关的过程（例如，螺旋桨清洗）不在本指南的范围内。 4.5 本指南确定了技术可靠和全面的CSM所需的相关信息，以支持对沸腾促进的NAPL/沉积物中污染物迁移的调查或补救。它描述了导致（或影响）沸腾促进的NAPL/污染物传输的条件，量化沸腾促进的NAPL/污染物通量率的方法，现场测量的注意事项，以及在外推NAPL/污染物通量率时使用现场结果。 技术上可靠和全面的CSM将导致对沸腾促进的NAPL/沉积物中污染物传输进行更有效和一致的调查，以支持补救决策。本指南也有助于单独评估现场的沸腾（例如，作为沉积物帽设计的输入）。 4.6 许多物质（例如氯化溶剂、石油产品和杂酚油）以不混溶液体（称为NAPL）的形式进入地下，该液体可能与水分离流动。NAPL可能含有污染物，如多环芳烃（PAHs）。 4.6.1 水体表面的光泽可能来自沸腾以外的来源，例如自然/生物光泽、平流NAPL/污染物输送、排水口（例如市政和工业）或船舶泄漏。识别除沸腾以外的光泽来源不在本指南的范围内。 4.7 本指南假设已开发CSM，其中包括沉积物中NAPL/污染物的性质和程度。该CSM将包括对以下内容的理解: (1) 水文环境， (2) 沉积物和水体的物理和化学特征， (3) NAPL/污染物的物理和化学特性， (4) NAPL/污染物侵位机制， (5) NAPL/污染区的物理范围，以及 (6) 人类和生态暴露于沉积物中NAPL/污染物或通过NAPL/污染物释放到上覆地表水的可能性。本指南不介绍收集这些信息的方法和手段。 4.8 本指南假设用户已经开发了一个概念模型，该模型为开发概念模型（CM）提供了一个框架，该概念模型是整个概念模型的一个组成部分，用于解决沸腾促进的NAPL/污染物传输问题。本指南将帮助用户了解导致（或影响）沸腾的物理和化学条件以及侵位机制- 促进NAPL/污染物传输，并帮助优先选择和执行收集现场数据和解释结果的方法，以支持现场CSM的开发。 4.8.1 沸腾促进NAPL/污染物传输CM的元素描述了环境的物理和化学特性、水力条件、NAPL/污染物的来源以及NAPL/污染物区的性质和范围。构型管理是一个动态的、不断发展的模型，随着新数据的收集和评估，或由于自然或工程过程导致的现场物理条件变化，该模型将随着时间而变化。构型管理的目标是充分详细地描述NAPL/污染物的性质、分布和设置，以便能够充分解决有关当前和潜在未来风险、寿命和补救措施适应性的问题。 4.8.2 沸腾的要素- 促进NAPL/污染物运输CM可能包括但不限于: 4.8.2.1 影响天然气产量的因素: (1) 存在能够矿化的微生物群 (2) 不稳定OM的存在 (3) 有利于甲烷生成的地球化学条件 (4) 沉积物温度 4.8.2.2 影响气泡成核、气泡生长和通过沉淀柱迁移的因素: (1) 成核位点的可用性 (2) 沉积物特性（例如，抗拉强度、粒度、孔隙度、体积密度、内聚力和不均匀性） (3) 孔隙水性质（例如，气体浓度、盐度、pH值和地球化学） (4) 环境设置（例如，静水压力、大气压力和地下水渗流） 4.8.2.3 NAPL/污染区的存在和范围，包括识别其与活跃沸腾区的位置。 4.8.2.4 沸腾- 促进NAPL/污染物传输速率，包括空间和时间变异性: (1) 筛选级别评估 (2) 定量评估 4.9 在继续使用之前，本指南的用户应查看本指南的整体结构和组件，包括: 4.9.1 部分 1. :范围； 4.9.2 部分 2. :参考文件； 4.9.3 部分 3. :术语； 4.9.4 部分 4. :意义和用途； 4.9.5 部分 5. :概念场地模型开发过程中的基本原理和注意事项 4.9.6 部分 6. :气体沸腾和沸腾通量测量的初始筛选； 4.9.7 部分 7. :气体沸腾测量； 4.9.8 部分 8. :沸腾促进NAPL/污染物运输的量化； 4.9.9 部分 9 :NAPL/污染物通量测量中的现场注意事项； 4.9.10 部分 10 :关键字； 4.9.11 附录X1 :沉积物中生物气体产生的有机物降解和微生物学； 4.9.12 附录X2 :使用放射性同位素分析识别碳源； 4.9.13 附录X3 :生物气体的台架试验；和 4.9.14 参考资料。 4.10 本指南概述了在水生沉积物环境中影响沸腾促进NAPL/污染物迁移的独特特征。本指南的目的不是为沉积物现场调查、风险评估、监测或补救行动提供具体指导。 4.10.1 本指南可供沉积物现场相关各方使用，包括监管机构、项目发起人、环境顾问、现场修复专业人员、环境承包商、分析测试实验室、数据审查员和用户以及其他利益相关者。 4.10.2 本指南并不取代聘请合格人员评估沸腾促进的NAPL/沉积物中污染物运输的需要。开发CSM所需的活动应由熟悉NAPL/污染物的人员进行- 受影响的沉积物现场表征技术、沉积物中NAPL/污染物的物理和化学特性、归宿和运输过程、修复技术和沉积物评估协议。本指南的用户应考虑组建一个由经验丰富、具有适当专业知识的项目专业人员组成的团队，以确定范围、规划和执行适当的数据采集活动。

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. 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 Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== 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. Understanding the site characteristics that influence ebullition-facilitated NAPL/contaminant transport within the sediment column will aid in identifying specific data requirements necessary to investigate these conditions, which will enable further refinement of the CSM and provide a sound basis for remedy decisions. 4.4 Ebullition-facilitated NAPL/contaminant transport is the primary transport mechanism that is addressed within this guide. 4.4.1 In addition to ebullition-facilitated NAPL/contaminant transport, porewater advection may also facilitate NAPL/contaminant transport; however, this process is beyond the scope of this guide. Advective transport of NAPL in sediments is addressed in Guide E3248 . 4.4.2 Processes associated with NAPL/contaminant transport due to erosion (for example, propeller wash) are not within the scope of this guide. 4.5 This guide identifies the relevant information necessary for a technically reliable and comprehensive CSM in support of the investigation or remediation of ebullition-facilitated NAPL/contaminant transport in sediments. It describes the conditions that lead to (or influence) ebullition-facilitated NAPL/contaminant transport, methods for quantifying the ebullition-facilitated NAPL/contaminant flux rate, considerations for field measurements, and use of field results in extrapolating the NAPL/contaminant flux rate. A technically reliable and comprehensive CSM will result in a more efficient and consistent investigation of ebullition-facilitated NAPL/contaminant transport in sediments to support remedy decisions. This guide may also be beneficial for evaluating ebullition alone at sites (for example, as input into sediment cap design). 4.6 Many materials (for example, chlorinated solvents, petroleum products, and creosote) enter the subsurface as an immiscible liquid, known as NAPL, which may flow as a separate phase from water. NAPL can contain contaminants, such as polycyclic aromatic hydrocarbons (PAHs). 4.6.1 Sheens may be observed on the surface of the water body from sources other than ebullition, such as natural/biogenic sheens, advective NAPL/contaminant transport, outfalls (for example, municipal and industrial), or vessel leaks. Identifying sources of sheens other than ebullition is not within the scope of this guide. 4.7 This guide assumes that a CSM has been developed that includes the nature and extent of NAPL/contaminants in sediment. This CSM would include an understanding of (1) the hydrological setting, (2) the physical and chemical characteristics of the sediment and water body, (3) the physical and chemical characteristics of the NAPL/contaminants, (4) mechanism(s) of NAPL/contaminant emplacement, (5) the physical extent of the NAPL/contaminant zone, and (6) the potential for human and ecological exposures to NAPL/contaminants in sediment, or via NAPL/contaminant release to overlying surface water. The means and methods for collecting this information are not addressed in this guide. 4.8 This guide assumes that the user has developed a CSM that provides a framework for developing a conceptual model (CM) that is a component of the overall CSM, which addresses ebullition-facilitated NAPL/contaminant transport. This guide will help users understand the physical and chemical conditions and emplacement mechanisms that lead to (or influence) ebullition-facilitated NAPL/contaminant transport, as well as aid in prioritizing and executing methods for gathering field data and interpreting results to support the development of a CSM for the site. 4.8.1 The elements of the ebullition-facilitated NAPL/contaminant transport CM describe the physical and chemical properties of the environment, the hydraulic conditions, the source of the NAPL/contaminants, and the nature and extent of the NAPL/contaminant zone. The CM is a dynamic, evolving model that will change through time as new data are collected and evaluated or as physical conditions of the site change due to natural or engineered processes. The goal of the CM is to describe the nature, distribution, and setting of the NAPL/contaminants in sufficient detail, so that questions regarding current and potential future risks, longevity, and amenability to remedial action can be adequately addressed. 4.8.2 The elements for the ebullition-facilitated NAPL/contaminant transport CM may include, but are not limited to: 4.8.2.1 Factors affecting the rate of gas production: (1) Presence of microbial consortia capable of OM mineralization (2) Presence of labile OM (3) Geochemical conditions conducive to methanogenesis (4) Sediment temperature 4.8.2.2 Factors affecting the nucleation of gas bubbles, bubble growth and migration through the sediment column: (1) Availability of nucleation sites (2) Sediment properties (for example, tensile strength, grain size, porosity, bulk density, cohesion, and heterogeneity) (3) Porewater properties (for example, gas concentrations, salinity, pH, and geochemistry) (4) Environmental setting (for example, hydrostatic pressure, atmospheric pressure, and groundwater seepage) 4.8.2.3 Presence and extent of the NAPL/contaminant zone, including identification of where it is collocated with active ebullition zones. 4.8.2.4 Ebullition-facilitated NAPL/contaminant transport rates, including spatial and temporal variability: (1) Screening-level evaluations (2) Quantitative evaluations 4.9 The user of this guide should review the overall structure and components of this guide before proceeding with use, including: 4.9.1 Section 1 : Scope; 4.9.2 Section 2 : Referenced Documents; 4.9.3 Section 3 : Terminology; 4.9.4 Section 4 : Significance and Use; 4.9.5 Section 5 : Fundamentals and Considerations During Development of a Conceptual Site Model 4.9.6 Section 6 : Initial Screening for Gas Ebullition and Ebullition Flux Measurement; 4.9.7 Section 7 : Gas Ebullition Measurement; 4.9.8 Section 8 : Quantification of Ebullition-Facilitated Transport of NAPL/Contaminants; 4.9.9 Section 9 : Field Considerations in the Measurement of NAPL/Contaminant Fluxes; 4.9.10 Section 10 : Keywords; 4.9.11 Appendix X1 : Organic Matter Degradation and Microbiology of Biogenic Gas Production in Sediments; 4.9.12 Appendix X2 : Carbon Source Identification Using Radioisotope Analysis; 4.9.13 Appendix X3 : Bench Scale Testing for Biogenic Gas; and 4.9.14 References. 4.10 This guide provides an overview of the unique characteristics influencing ebullition-facilitated NAPL/contaminant transport in aquatic sediment environments. This guide is not intended to provide specific guidance on sediment site investigation, risk assessment, monitoring, or remedial action. 4.10.1 This guide may be used by various parties involved in a sediment site, including regulatory agencies, project sponsors, environmental consultants, site remediation professionals, environmental contractors, analytical testing laboratories, data reviewers and users, and other stakeholders. 4.10.2 This guide does not replace the need for engaging competent persons to evaluate ebullition-facilitated NAPL/contaminant transport in sediments. Activities necessary to develop a CSM should be conducted by persons familiar with NAPL/contaminant-impacted sediment site characterization techniques, physical and chemical properties of NAPL/contaminants in sediments, fate and transport processes, remediation technologies, and sediment evaluation protocols. The users of this guide should consider assembling a team of experienced project professionals with appropriate expertise to scope, plan, and execute appropriate data acquisition activities.