1.1 Purpose—The purpose of this practice is to define good commercial and customary practice in the United States of America for conducting a vapor intrusion assessment (VIA) on a property parcel involved in a real estate transaction with respect to chemicals of concern (COC) that may migrate as vapors into existing or planned structures on a property due to contaminated soil and groundwater on the property or within close proximity to the property. This practice may be used as a voluntary supplement to Practice E 1527 and does not alter or in any way define the scope of that practice. In addition, performance of this standard is not a requirement of and does not constitute, expand, or in any way define “all appropriate inquiry” as defined or approved by U.S. EPA under CERCLA and the regulations thereunder, including 40 CFR Sec. 312.11.

1.1.1 Vapor Intrusion Condition (VIC)—In defining a standard of good commercial and customary practice for conducting a VIA on a parcel of property, the goal of the process established by this practice is to identify whether or not a vapor intrusion condition (VIC) exists or is likely to exist on the property. The term VIC means the presence or likely presence of any COC in the indoor air environment of existing or planned structures on a property caused by the release of vapor from contaminated soil or groundwater either on the property or within close proximity to the property, at a concentration that presents or may present an unacceptable health risk to occupants. The term is not intended to include de minimis conditions that do not normally represent an unacceptable health risk to occupants and that generally would not be the subject of an enforcement action if brought to the attention of appropriate governmental agencies. A condition determined to be de minimis does not represent a VIC.

1.1.2 Other Federal, State, and Local Environmental Laws—This practice does not address requirements of any federal, state, or local laws with respect to vapor intrusion. Users are cautioned that federal, state, and local laws, regulations or policy may impose VIA obligations that are beyond the scope of this practice (refer to Appendix X5 and Appendix X9). Users should also be aware that there are likely to be other legal obligations, for example, disclosure, with regard to COC discovered on the property that are not addressed in this practice and that may pose risks of civil or criminal liability, or both.

1.1.3 Documentation—The scope of this practice includes investigation and reporting requirements. Sufficient documentation of all sources, records, and resources used in the inquiry required by this practice shall be provided in the report (refer to Section 12).

1.2 Objectives—Objectives guiding the development of this practice are: (1) to synthesize and put into writing good commercial and customary practice for conducting a VIA on a property involved in a real estate transaction, (2) to supplement a Phase I environmental site assessment (ESA) conducted in accordance with Practice E 1527, (3) to ensure that the process for assessing vapor intrusion is practical and reasonable, and (4) to provide an industry standard for a VIA on a property involved in a real estate transaction.

1.3 Considerations Beyond Scope—The use of this practice is strictly limited to the scope set forth in this section. Section 13 of this practice identifies, for informational purposes, certain tasks (not an all-inclusive list) which may be conducted on a property that are beyond the scope of this practice but which may warrant consideration by parties to a real estate transaction. The need to include an investigation of any such conditions in the environmental professional's scope of services should be evaluated based upon, among other factors, the nature of the property and the reasons for performing the site assessment (for example, a more comprehensive evaluation of business environmental risk) and should be agreed upon between the user and environmental professional as additional services beyond the scope of this practice prior to initiation of the Phase I ESA or initiation of an independent VIA.

1.4 Organization of This Practice—This practice has thirteen sections and nine appendices. The appendices are included for informational purposes and are not part of the procedures prescribed in this practice.

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 and health practices and determine the applicability of regulatory limitations prior to use.

1.6 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word “Standard” in the title means only that the document has been approved through the ASTM consensus process.