1.1 本指南讨论了可用于评估非水相液体（NAPL）在沉积物中的移动潜力（即孔隙尺度迁移或NAPL体尺度迁移）的方法。沉积物中的NAPL运动评估与旱地土壤中的NAPL运动评估显著不同。因此，评估旱地土壤中NAPL运动的框架对沉积物的适用性有限。特别是，由于高地NAPL概念性场地模型可能不适用于许多沉积物场地，本指南提供了一个框架来评估NAPL在沉积物中是移动的（在孔隙尺度）还是迁移的（在NAPL体尺度）。 1.2 由于以下几个原因，NAPL在沉积物中移动的可能性评估很重要，包括（但不限于）对潜在受体的风险评估、潜在补救行动的必要性和潜在补救策略。例如，如果NAPL正在迁移，敏感受体可能会受到影响，这将影响为沉积物现场区域选择的任何补救措施的选择和时机。 如果NAPL不可移动或迁移，则可能不需要采取补救措施。 1.3 本指南适用于通过各种筛选方法在沉积物中识别出NAPL的沉积物现场，并且需要进行NAPL运动评估（指南 E3248 ). 1.4 石油碳氢化合物、煤焦油和其他焦油NAPL（包括燃料、油和杂酚油）是本指南的主要重点。这些形式的污染通常与炼油厂、石油配送码头、人工煤气厂（MGP）和各种大型工业场地的历史操作有关。 1.5 尽管本指南的某些技术方面适用于其他NAPL（例如，稠NAPL[DNAPL]，如氯化烃溶剂），但本指南并未完全解决这些DNAPL的额外复杂性。 1.6 本指南的目的是提供一个可靠的技术基础，以确定现场的NAPL在孔隙尺度上是可移动的还是不可移动的，如果是可移动的，则在NAPL体尺度上是稳定的还是迁移的。 沉积物中NAPL移动的可能性是开发概念现场模型（CSM）以及决定现场应选择何种补救方案以减少对人类健康和生态受体的潜在风险的关键组成部分。 1.7 本指南可用于帮助开发或完善沉积物现场的CSM。通常需要稳健的CSM来优化现场未来的潜在工作，其中可能包括现场的各种风险管理和补救策略，以及任何补救措施实施后的后续监测。 1.8 本指南考虑了NAPL在源自三大类潜在NAPL侵位机制的沉积物中的流动性（指南 E3248 ). 1.8.1 NAPL通过平流（流经土壤孔隙网络）从高地迁移到相邻水体下方沉积物的孔隙网络是NAPL侵位机制的一类。这通常发生在粗粒中- 沉积物中的颗粒地层。 1.8.2 轻NAPL（LNAPL）直接排放到水道中，在那里被机械能分解形成LNAPL珠，这是另一种NAPL侵位机制。当地表水中的悬浮颗粒粘附在LNAPL颗粒上时，会形成油颗粒聚集体（OPA）。一旦足够的颗粒粘附到LNAPL珠上，并且OPA变得足够致密，它就会通过水柱沉降到合格的沉积物表面，在那里形成原位沉积的NAPL（IDN），并可能被未来的沉积所掩埋。 1.8.3 NAPL侵位机制的第三类是DNAPL流（即，DNAPL直接排入水道），然后通过水柱沉降，并直接沉积到合格的沉积物表面，在那里它可能被未来的沉积所掩埋。 1.9 沸腾促进了NAPL通过气泡从沉积物传输到水柱 不是 在本指南的范围内。 本指南涵盖了沸腾和相关NAPL/污染物传输的评估 E3300 . 由于侵蚀力（例如，螺旋桨清洗）导致的NAPL运输 不是 在本指南的范围内。 1.10 本指南（参见第节 5. )提出了一个整体框架，以评估现场的NAPL在孔隙尺度上是移动的还是不移动的，以及在NAPL体尺度上是迁移的还是稳定的。它提供了解决NAPL运动评估问题的方法和方法的指导。 1.11 本指南（参见第节 6. )讨论各种实验室测试数据的使用( 附录X1 )，计算方法和其他方法，从技术上评估现场不同位置沉积物中的NAPL在孔隙尺度上是移动的还是不移动的，在NAPL体尺度上是稳定的还是迁移的。这种评估可以使用分层和证据权重（WOE）框架进行。例如，NAPL可能在站点的一个部分移动或迁移，但在站点的其他部分不移动。 目前没有行业标准的分层和WOE框架来评估沉积物中的NAPL是移动的还是迁移的，但中给出了此类框架的示例 附录X2 . 案例研究演示了中展示的示例分层和WOE框架的应用 附录X2 显示在 附录X3 . 1.12 本指南（参见第节 7. )讨论了适用的实验室离心测试方法，这些方法用于在适用的测试条件下评估NAPL在孔隙尺度上的流动性或不流动性（另请参见 附录X4 ). 附录X5 讨论了用于离心试验的沉积物样品的实验室制备。 1.13 本指南（参见第节 8. )讨论了适用的实验室水驱测试方法，这些方法用于在适用的测试条件下评估NAPL在孔隙尺度上的流动性或不流动性。本节讨论了刚性壁和柔性壁渗透计测试（另请参见 附录X6 ). 附录X5 讨论了用于水驱测试的沉积物样品的实验室制备。 1.14 本指南（参见第节 9 )讨论了可深入了解现场孔隙尺度NAPL迁移率和NAPL体尺度迁移的计算方法。为了进行其中一些计算，需要NAPL特性数据，例如密度、粘度和NAPL-水界面张力（参见 附录X1 ). 计算方法包括NAPL密度与水力梯度计算；孔隙进入压力计算；临界NAPL层厚度计算；和NAPL孔隙速度计算（另请参见 附录X7 和 附录X8 ). 1.15 本指南（参见第节 10 )介绍了其他有助于评估孔隙尺度NAPL流动性和NAPL体尺度迁移的现场观察方法。这些方法包括NAPL饱和度的垂直剖面（包括NAPL区上方未受影响沉积物厚度的等厚线图）； 以及在沉积物中安装监测井。 1.16 单位- 以国际单位制或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。 1.17 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。 1.18 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 疏水性有机液体（例如，石油碳氢化合物、煤焦油）可能作为NAPL长期存在于环境中。 不存在标准化的指南和测试方法来评估沉积物中的NAPL运动（孔隙尺度流动性和NAPL体尺度迁移）。文献检索导致可用和适用的研究数量有限。目前的研究重点是特定地点的沉积物NAPL运动评估方法。 4.2 ASTM国际组织（指南）等组织目前已有标准化指南和测试方法，用于评估丘陵地区NAPL的流动性和迁移 E2531 和 E2856 )，州际技术和监管委员会 ( 2. ) 和美国石油学会 ( 3. , 4. ) . 高地现场常用的方法可能适用于也可能不适用于任何给定的沉积物现场。本指南提供了各种方法对特定沉积物条件的适用性的观点。 4.3 本指南描述了在沉积物NAPL运动评估中有用的各种方法，如实验室测试方法、计算方法和现场观察解释。 然后，该指南提供了评估这些方法生成的数据的框架，以确定在原位条件下在沉积物中观察到的NAPL是否表现出任何形式的移动。 4.4 高地地点的重要暴露途径通常不适用于沉积物地点。美国环境保护局指出，“现场表面沉积物生物活性层中的污染物通常会导致暴露。” ( 5. ) . 在水生环境中，底栖生物生活在表层沉积物中，以维持对上覆含氧水的访问。这些底栖生物是食物链的基础。如果地下沉积物中的NAPL没有迁移，NAPL将不会移动到表面沉积物中，并导致暴露于底栖生物。稳定且仅存在于地下沉积物中的NAPL可能不会对人类或生态受体构成风险，因为如果上覆沉积物仍然存在（即未被疏浚或侵蚀），则没有完整的暴露途径。 由于没有完整的暴露途径，在任何补救过程中可能不需要去除地下沉积物中的NAPL。因此，了解NAPL在沉积物中的移动潜力是管理受污染沉积物场地的关键因素。要为受NAPL影响的沉积物制定有效的补救方案，并对沉积物现场进行长期管理，需要了解NAPL运动。 4.5 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: 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. NAPL移动性和迁移评估框架 部分 6. 分层和加权证据NAPL运动评估方法 部分 7. 离心试验方法 部分 8. 水驱试验方法 部分 9 NAPL潜在垂直运动的计算方法 部分 10 现场观察方法 部分 11 关键词 附录X1 NAPL运动评估中常用的实验室分析方法（非强制性） 附录X2 评估NAPL移动的分层和WOE方法示例（非强制性） 附录X3 案例研究（非强制性） 附录X4 NAPL移动性测试中离心机测试技术的附加信息（非强制性） 附录X5 沉积物岩心的实验室处理和制备（非强制性） 附录X6 NAPL流动性测试中水驱测试方法的补充信息（非强制性） 附录X7 NAPL净垂直梯度计算方法（非强制性） 附录X8 NAPL有效导水率估算方法（非强制性） 工具书类 4.6 本指南中描述的活动应由熟悉NAPL影响的沉积物现场表征技术和沉积物修复科学技术以及沉积物NAPL流动性和迁移评估协议和方法的人员进行。 4.7 本指南可供参与沉积物项目的各方使用，包括监管机构、项目发起人、环境顾问、毒理学专家、风险评估师、现场修复专业人员、环境承包商、分析测试实验室、数据验证人、数据审查人和用户，以及其他利益相关者，其中可能包括但不限于业主、买方、，开发商、贷款人、保险公司、政府机构、社区成员和团体。 4.8 本指南无意取代或取代联邦、州、地方或国际监管要求。相反，本指南可用于补充和支持此类要求。采取的任何补救措施应符合实施纠正措施的监管实体的监管标准。 4.9 本指南提供了一个基于总体特征和元素的框架，这些特征和元素应由用户根据特定沉积场地的特定条件、监管背景和计划目标进行定制。 本指南不应单独用作规定性检查表。 4.10 沉积物中NAPL运动的评估是一门不断发展的科学。本指南提供了一个系统而灵活的框架，以适应监管机构和用户基于项目目标、场地复杂性、独特场地特征、规划和监管要求、新制定的指南、新发布的科学研究、替代科学方法和程序的使用、监管标准的变化而采取的各种方法，科学知识和技术能力的进步、多证据线（LOE）方法和不可预见的情况。 4.11 本指南的使用支持多种LOE方法，使用分层或WOE评估框架，评估沉积物中的NAPL运动。 4.12 本指南的使用与指导用户获取适当数据的基于沉积物风险的纠正措施（RBCA）过程一致； 获取和评估额外数据；并完善目标、目的、受体、暴露途径和CSM。随着沉积物RBCA过程的进行，在过程的每个步骤中得出的数据和结论有助于关注后续评估。这一综合过程为受NAPL影响的沉积物提供了高效、经济的决策和及时、适当的响应行动。

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 is to provide a sound technical basis to determine if NAPL at the site is mobile or immobile at the pore scale, and if mobile, whether it is stable or migrating at the NAPL body scale. The potential for NAPL movement in the sediment is a key component in the development of the conceptual site model (CSM) and in deciding what remedial options should potentially be chosen for the site to reduce potential risks to human health and ecological receptors. 1.7 This guide can be used to help develop, or refine, a CSM for the sediment site. A robust CSM is typically needed to optimize potential future work efforts at the site, which may include various risk management and remedial strategies for the site, as well as subsequent monitoring after any remedy implementation. 1.8 This guide considers the mobility of NAPL in sediments that originated from three broad categories of potential NAPL emplacement mechanisms (Guide E3248 ). 1.8.1 Migration of NAPL by advection (flow through the soil pore network) from an upland site into the pore network of sediments beneath an adjacent water body is one category of NAPL emplacement mechanism. This most commonly occurs within coarse-grained strata in the sediment. 1.8.2 Direct discharge of light NAPL (LNAPL) into a waterway, where it is broken down by mechanical energy to form LNAPL beads, is another category of NAPL emplacement mechanism. Oil-particle aggregates (OPAs) are formed when suspended particulates in surface water adhere to LNAPL beads. Once enough particulates have adhered to an LNAPL bead and the OPA becomes dense enough, it settles through the water column onto a competent sediment surface, where it forms an in situ deposited NAPL (IDN) and may be buried by future sedimentation. 1.8.3 The third category of NAPL emplacement mechanism is DNAPL flow (that is, direct discharge of DNAPL into a waterway), followed by settling through the water column and deposition directly onto a competent sediment surface, where it may be buried by future sedimentation. 1.9 Ebullition-facilitated transport of NAPL from the sediment to the water column by gas bubbles is not within the scope of this guide. The evaluation of ebullition and associated NAPL/contaminant transport is covered in Guide E3300 . Transport of NAPL due to erosional forces (for example, propeller wash) is not within the scope of this guide. 1.10 This guide (see Section 5 ) presents an overall framework to evaluate if NAPL at the site is mobile or immobile at the pore scale, and migrating or stable at the NAPL body scale. It provides guidance on approaches and methodologies that address questions regarding NAPL movement evaluation. 1.11 This guide (see Section 6 ) discusses the use of data from various laboratory tests ( Appendix X1 ), calculation methodologies, and other methodologies to technically evaluate if NAPL in sediment at various locations in the site is mobile or immobile at the pore scale, and stable or migrating at the NAPL body scale. This evaluation can be performed using tiered and weight of evidence (WOE) frameworks. For example, it may be possible that NAPL is mobile or migrating in one part of the site, but is immobile in other parts of the site. There are currently no industry standard tiered and WOE frameworks to evaluate if NAPL in sediment is mobile or migrating, but illustrative examples of such frameworks are presented in Appendix X2 . Case studies demonstrating the application of the example tiered and WOE frameworks exhibited in Appendix X2 are presented in Appendix X3 . 1.12 This guide (see Section 7 ) discusses applicable laboratory centrifuge testing methodologies that are used to evaluate NAPL mobility or immobility at the pore scale under the applicable test conditions (also see Appendix X4 ). Appendix X5 discusses the laboratory preparation of sediment samples used in centrifuge testing. 1.13 This guide (see Section 8 ) discusses applicable laboratory water drive testing methodologies that are used to evaluate NAPL mobility or immobility at the pore scale under the applicable test conditions. This section discusses both rigid wall and flexible wall permeameter testing (also see Appendix X6 ). Appendix X5 discusses the laboratory preparation of sediment samples used in water drive testing. 1.14 This guide (see Section 9 ) discusses calculation methodologies that provide insight into pore-scale NAPL mobility and NAPL body-scale migration at the site. To perform some of these calculations, NAPL property data such as density, viscosity, and NAPL–water interfacial tension are needed (see Appendix X1 ). The calculation methodologies include NAPL density versus hydraulic gradient calculations; pore entry pressure calculations; critical NAPL layer thickness calculations; and NAPL pore velocity calculations (also see Appendix X7 and Appendix X8 ). 1.15 This guide (see Section 10 ) presents other field observation approaches that are useful in evaluating pore-scale NAPL mobility and NAPL body-scale migration. These methodologies include vertical profiles of NAPL saturation (including isopach mapping of the thickness of unimpacted sediment above the NAPL zone); and installation of monitoring wells in sediment. 1.16 Units— The values stated in SI or CGS units are to be regarded as the standard. No other units of measurement are included in this standard. 1.17 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.18 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 sediment likely does not pose a risk to human or ecological receptors, because there is no completed pathway to exposure if the overlying sediment remains in place (that is, it is not dredged or eroded). With no completed exposure pathway, removal of the NAPL in the subsurface sediment may not be needed during any remedy. Therefore, understanding the potential for movement of NAPL in sediments is a key factor in the management of contaminated sediment sites. Knowledge of NAPL movement is required for developing effective remedial options for NAPL impacted sediments and for long-term management of sediment sites. 4.5 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 NAPL Mobility and Migration Evaluation Framework Section 6 Tiered and Weight of Evidence NAPL Movement Evaluation Approaches Section 7 Centrifuge Test Methods Section 8 Water Drive Test Methods Section 9 Calculation Methods for Potential Vertical Movement of NAPL Section 10 Field Observation Methodologies Section 11 Keywords Appendix X1 Laboratory Analysis Methods Commonly Used in NAPL Movement Evaluations (non-mandatory) Appendix X2 Illustrative Examples of Tiered and WOE Approaches to Evaluate NAPL Movement (non-mandatory) Appendix X3 Case Studies (non-mandatory) Appendix X4 Additional Information on Centrifuge Testing Technology in NAPL Mobility Testing (non-mandatory) Appendix X5 Laboratory Handling and Preparation of Sediment Cores (non-mandatory) Appendix X6 Additional Information on Water Drive Test Methods in NAPL Mobility Testing (non-mandatory) Appendix X7 NAPL Net Vertical Gradient Calculation Method (non-mandatory) Appendix X8 NAPL Effective Hydraulic Conductivity Estimation Methods (non-mandatory) References 4.6 Activities described in this guide should be conducted by persons familiar with NAPL-impacted sediment site characterization techniques and sediment remediation science and technology, as well as sediment NAPL mobility and migration assessment protocols and methodologies. 4.7 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. 4.8 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. Any remedial actions taken should meet the regulatory standards for the regulatory entity under which the corrective action is being performed. 4.9 This guide provides a framework based on overarching features and elements that should be customized by the user, based on site-specific conditions, regulatory context, and program objectives for a particular sediment site. This guide should not be used alone as a prescriptive checklist. 4.10 Assessment of NAPL movement in sediments is an evolving science. This guide provides a systematic, yet flexible, framework to accommodate variations in approaches by regulatory agencies and users, 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 knowledge and technical capability, multiple line of evidence (LOE) approaches, and unforeseen circumstances. 4.11 Use of this guide supports multiple LOE approaches, using tiered or WOE evaluation frameworks, for the evaluation of NAPL movement in sediments. 4.12 Use of this guide is consistent with the sediment risk-based corrective action (RBCA) process that guides the user to obtain the appropriate data; acquire and evaluate additional data; and refine goals, objectives, receptors, exposure pathways, and the CSM. As the sediment RBCA process proceeds, data and conclusions reached at each step of the process help focus subsequent evaluation. This integrative process results in efficient, cost-effective decision-making and timely, appropriate response actions for NAPL-impacted sediments.