1.1''Purpose'''The purpose of this guide is to provide practical guidance and a useful process for conducting a vapor encroachment screen (VES) on a property parcel involved in a real estate transaction in the United States of America with respect to chemicals of concern (COC) that may migrate as vapors into the vadose zone of a property as a result of contaminated soil and/or groundwater on or near the property. This guide may be used in conjunction with E1527 but does not alter or in any way define the scope of that practice. In addition, performance of this guide is not a requirement of and does not constitute, expand, or in any way define '''all appropriate inquiry''' as defined and approved by the U.S. Environmental Protection Agency (EPA) under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the regulations there under, including 40 CFR Sec. 312.11.

1.2''Objectives'''Objectives guiding the development of this guide are: (1) to synthesize and put into writing a practical guide for conducting a VES on a property involved in a real estate transaction and (2) to provide that the process to screen for a VEC is practical and reasonable.

1.3''Considerations Outside the Scope'''The use of this guide is strictly limited to the scope set forth in this section. Section 11 of this guide identifies, for informational purposes, certain tasks (not an all-inclusive list) that may be conducted on a property that are beyond the scope of this guide but that may warrant consideration by parties to a real estate transaction. Whether to include an investigation of any such conditions in the environmental professional's scope of services should be evaluated by the user and should be agreed upon between the user and environmental professional as additional services beyond the scope of this guide before initiation of a Phase I ESA conducted in conjunction with a VES or initiation of an independent VES.

1.4''Units'''The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5''Organization of this Guide'''This guide has eleven sections and nine appendices. The appendices are included for informational purposes and are not part of the procedures prescribed in this guide.

1.6''This guide 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.

1.7''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 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 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 consensus process.

1.8''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.