ASTM E2993-23 PDF

SIGNIFICANCE AND USE 5.1 Several different factors should be taken into consideration when evaluating methane hazard, rather than, for example, use of a single concentration-based screening level as a de-facto hazard assessment level. Key variables are identified and briefly discussed in this section. Legal background information is provided in Appendix X3. The Bibliography includes references where more detailed information can be found on the effect of various parameters on gas concentrations. 5.2 Application—This guide is intended for use by those undertaking an assessment of hazards to people and property as a result of subsurface methane suspected to be present based on due diligence or other site evaluations (see 6.1.1). 5.2.1 This guide addresses shallow methane, including its presence in the vadose zone; at residential, commercial, and industrial sites with existing construction; or where development is proposed. 5.3 This guide provides a consistent, streamlined process for deciding on action and the urgency of action for the identified hazard. Advantages include: 5.3.1 Decisions are based on reducing the actual risk of adverse impacts to people and property. 5.3.2 Assessment is based on collecting only the information that is necessary to evaluate hazard. 5.3.3 Available resources are focused on those sites and conditions that pose the greatest risk to people and property at any time. 5.3.4 Response actions are chosen based on the existence of a hazard and are designed to mitigate the hazard and reduce risk to an acceptable level. 5.3.5 The urgency of initial response to an identified hazard is commensurate with its potential adverse impact to people and property. 5.4 Limitations—This guide does not address potential hazards from other gases and vapors that may also be present in the subsurface such as hydrogen sulfide, carbon dioxide, and/or volatile organic compounds (VOCs) that may co-occur with methane. If the presence of hydrogen sulfide or other... SCOPE 1.1 This guide provides a consistent basis for assessing methane in the vadose zone, evaluating hazard and risk, determining the appropriate response, and identifying the urgency of the response. 1.2 Purpose—This guide covers techniques for evaluating potential hazards associated with methane present in the vadose zone beneath or near existing or proposed buildings or other structures (for example, potential fires or explosions within the buildings or structures), when such hazards are suspected to be present based on due diligence or other site evaluations (see 6.1.1). Buildings in this context include normal below grade utilities associated with a building. 1.3 Objectives—This guide: (1) provides a practical and reasonable industry standard for evaluating, prioritizing, and addressing potential methane hazards based on mass flow and (2) provides a tool for screening out low-risk sites. 1.4 This guide offers a set of instructions for performing one or more specific operations. This guide cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This guide is not intended to represent or replace the standard of care by which the adequacy of a given professional service should be judged, nor should this guide be applied without consideration of a project's many unique aspects. The word “Standard” in the title means only that the guide has been approved through the ASTM International consensus process. 1.5 Not addressed by this guide are: 1.5.1 Requirements or guidance or both with respect to methane sampling or evaluation in federal, state, or local regulations. Users are cautioned that federal, state, and local guidance may impose specific requirements that differ from those of this guide; 1.5.2 Safety concerns, if any, associated with its use. It is the responsibility of the user of this sta...