4.1 Millions of oil and gas wells, water supply wells, and wells installed for environmental monitoring and remediation purposes, have been abandoned. The need to determine the locations of these abandoned wells is based on safety and threats to the environment. Improperly constructed or abandoned wells may pose a safety threat to humans and animals, may be sources of brines and other undesirable fluids coming to the surface, may be conduits for transport of contamination from the surface to the substrate, or may cross-contaminate water-bearing zones in the subsurface. All states do not require documentation of the abandonment of wells and may not have specific requirements for abandonment procedures.

1.1 This guide provides an approach to selecting and implementing a program to identify the locations of abandoned wells. This guide provides descriptions of methods to be used as starting points in the search for these locations. It is not intended to be a step-by-step procedure to conduct the search program.

1.2 The described methods are approaches that have been used at many sites in the past. Other methods may be appropriate. Typically, several approaches are used to obtain acceptable confirmation of well locations. This guide is not limited to specific wells. The method chosen should be appropriate for the size of the area being searched and the type of well being located. Some well types and construction materials may preclude their detection by any of the methods described.

1.3 This guide offers an organized collection of information or series of options and does not recommend a specific course of action. This guide cannot replace education and experience and should be used in conjunction with professional judgment.

1.4 This guide does not purport to address all aspects of exploration and site safety. It is the responsibility of the user of this guide to establish appropriate safety and health practices and determine the applicability of regulatory limitations before its use.

1.5 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document 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 services must be judged nor should this document be applied without consideration of a projects many unique aspects. The word Standard in the title of this document means only that the document has been approved through the ASTM consensus process.