1.1 This guide covers the selection of appropriate remedial actions at sites where a release of chemicals (for example, vapor-phase, dissolved-phase, or non-aqueous phase liquids (NAPL)) into the environment has occurred. This overall remedy selection process is illustrated in Fig. 1. The guide is intended to be applied within a risk-based corrective action (RBCA) framework.

1.2 The purpose of this guide is to facilitate the selection of acceptable remedial actions and to minimize bad decisions leading to the selection of remedial actions that do not satisfy both the risk-based remedial action objectives and the non-risk remedial action objectives.

1.3 This guide is intended to be applied at sites that require a remedial action to address unacceptable human heath or ecological risks, other regulatory requirements, and/or other unacceptable site conditions. Prior to use of this guide, a site assessment should be completed resulting in: (1) the establishment of remedial action objectives, (2) a determination that a remedial action is required to achieve the remedial action objectives, (3) an identification of site areas requiring a remedial action, and (4) a conceptual site model that reflects the results of the site assessment. The risk-based remedial action objectives are assumed to have been established using RBCA or another risk-based assessment method that results in the identification of appropriate remedial action objectives based on an evaluation of sources, exposure pathways, and potential receptors. Remedial action objectives may be established using Guide E1739, Guide E2081, and/or Guide E2205. In addition, applicable federal, state, and local regulations, statutes, and policies should be followed and should form the basis for determining risk-based and non-risk remedial action objectives. The remedial action objectives may include resource protection standards and the prevention of aesthetic or nuisance impacts in addition to protection of human health and the environment.

1.4 Each risk-based remedial action objective for an exposure pathway will typically include numeric remedial action levels for each chemical of concern (COC). Remedial action levels may also be developed for non-risk remedial action objectives such as resource protection standards. The non-risk remedial action levels may include thickness or mobility criteria for NAPL. The selected remedy must be effective and timely for each remedial action objective based on the consideration of the associated exposure pathway or resource protection standard.

1.5 To facilitate the selection of acceptable remedial actions, this guide establishes a process for remedy selection (Fig. 2) that involves:

1.6 This guide is intended for use in the selection of final remedial actions. This guide may also be used in the selection of interim measures provided that risk-based remedial action objectives and non-risk remedial action objectives are available for the evaluation of these interim measures.

1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.8 This guide is not intended to specifically address contractor health and safety issues. It is the responsibility of the user of this guide to ensure that Occupational Safety and Health Administration (OSHA) regulatory requirements are met, and appropriate industry practices are consulted for guidance.

1.9 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.

1.10 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.