ASTM E3300-21 PDF

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... SCOPE 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. ...