Preventing leaks from underground storage tanks is of paramount importance in this decade as environmental resources are seriously threatened by the release of toxic substances and costs of reparation are exorbitant. Inspecting underground storage tanks is one action that helps prevent and correct potential tank failures that could result in such release. The study identifies and characterizes the types of internal practices (current, emerging, and outmoded) to conduct internal inspections of underground storage tanks. EPA sponsored this survey of state-of-the-art internal inspection methods as an initial compilation of this important information, for dissemination to the regulated community. The document addresses those methods pertaining to tanks; description of the inspections performed on ancillary equipment (pipes, vents, etc.) of UST systems is not within the scope of the report. The report is the result of an effort to examine the various tools and techniques used for conducting internal inspections. The study documents the significant factors evaluated during an inspection. It examines the application of each inspection method by identifying the objectives of the technique, its procedural steps, the necessary equipment and instrumentation, the considerations for use in the field.

Shipping list no.: 91-0158-P. No longer available for sale by the Supt. of Docs. "January 1991." Includes bibliographical references. "EPA/600/2-90/061." "Funded ... under contract no. 68-03-3409 to CDM Federal Programs Corporation"--Title page verso.