4.1 This guide may be used in the investigation of underground storage tank systems for equipment problems in a wide variety of applications. Use of this guide is voluntary. It is intended to assist users who want to investigate equipment failures, malfunctions, and other potential causes of suspected releases.

4.2 The following groups of users may find the guide particularly helpful:

4.2.1 Storage tank system designers and manufacturers;

4.2.2 Storage tank installers, testers, and inspectors;

4.2.3 Storage tank maintenance contractors;

4.2.4 Storage tank removal contractors;

4.2.5 Federal, state, tribal or local regulators, including departments of health, departments of environmental protection, and fire departments;

4.2.6 Petroleum release remediation professionals;

4.2.7 Insurance adjusters;

4.2.8 Storage tank owners and operators;

4.2.9 Consultants, auditors, and compliance assistance personnel.

4.3 This guide is intended to assist in the development of protocols for determination of source and cause of a release and the investigation of a malfunction or failure of any component of a UST system and the implementation of said protocols. This guide outlines steps that may be necessary and include, but are not limited to initial evaluation of the UST system to determine if there has been a component failure preparation of samples of failed or compromised equipment for laboratory analysis; visual; and analytical evaluation of release indications; and documentation of the investigation. The guide provides a series of investigation options from which the user may design failure investigation protocols. The guide describes common investigation techniques in the order in which they might be employed in an investigation.

4.4 A user may elect to utilize this guide for a number of reasons, which include, but are not limited to:

4.4.1 To differentiate new releases from new discovery of old releases;

4.4.2 To establish malfunction and failure rates of various UST system components;

4.4.3 To determine expected life spans of various UST components;

4.4.4 To identify opportunities for improving the performance and reliability of storage tank equipment;

4.4.5 To focus inspection and maintenance efforts on those component of the UST system that are most prone to compromise, malfunction and failure;

4.4.6 To identify those components of the UST system that require more frequent maintenance;

4.4.7 To reduce equipment replacement costs;

4.4.8 To prevent petroleum releases;

4.4.9 To identify those conditions that may cause or contribute to equipment or component compromise, deterioration or other cause of malfunction or failure of the UST system;

4.4.10 To comply with environmental regulations that require the investigation of suspected releases and determine the source and cause of releases; and

4.4.11 To identify conditions that may cause or contribute to nonsudden releases that may not be detected by other leak detection methods.

4.5 This guide may be used to establish a framework that pulls together the common approaches to investigation. The framework will allow the user to establish an investigation protocol to meet the user’s specific requirements. Specific user requirements will vary depending upon the purposes of the data collection and the decisions that the investigation is intended to support. This guide does not provide methods to establish specific user investigation requirements nor does it establish minimum levels of documentation.

4.6 This guide will acquaint users with methods and tools that may be used in investigations of equipment problems associated with USTs. The user may include a subset of the methods described in this guide in their investigation. The user may consider a variety of factors in determining which combination of the methods to employ.

4.7 This guide is not intended to require the user to conduct a failure investigation.

4.8 This guide is focused on the identification, documentation, and preservation of compromised UST system equipment. It does not provide guidance on establishing root causes of compromise, malfunction or failure. The identification of root causes of compromise, malfunction or failure may require further expert analysis of the data and equipment collected during the failure investigation.

4.9 Determination of equipment failures and evidence of the source and cause of a release are often unavailable due to the loss of critical information necessary to pinpoint equipment failures and conduct an investigation. Adjustment, repair or removal of failed equipment before determining and documenting the cause of the failure may interfere with the failure investigation. Failures may be caused by compatibility issues, manufacturer defects, corrosion, degradation, improper installation, damage, age, misuse, use or other causes. This guide may be used to identify techniques and procedures applicable to maintenance personnel and equipment vendors that will allow an investigator to evaluate possible equipment failures before equipment is adjusted, repaired, replaced or destroyed.

4.10 This guide does not address all the safety measures that must be taken when removing and disassembling UST systems. Because most UST systems have contained flammable or combustible liquids special precautions should be taken to prevent fire, explosions and exposure to toxic vapors. API standard STD 2015 and RP 2016 address some of the safety considerations as do many of the procedures available from fire departments.

1.1 Overview—This guide is an organized collection of information and series of options for industry, regulators, consultants and the public, intended to assist with the development of investigation protocols for underground storage tank facilities in the United States. While the guide does not recommend a specific course of action, it establishes an investigation framework, and it provides a series of techniques that may be employed to: identify equipment problems; in some cases collect and preserve failed equipment for forensic evaluation or laboratory analysis; identify the source of a release; and document the investigation. The guide includes information on methods of investigation, documentation, collecting and preserving samples; chain of custody; storage; shipping; working with equipment manufacturers; and notification of regulators and listing laboratories. The goal in using the guide is to identify the appropriate level of investigation and to gather and preserve information, in an organized manner, which could be used in the future to improve system design or performance. While this guide may act as a starting point for users with limited experience in failure investigation, the user is encouraged to consult with failure analysis experts for specific investigation procedures that may be needed for certain equipment and the investigation should be conducted by a qualified professional. As users develop their specific investigation protocols, they may find that the investigations can be streamlined for certain types of facilities.

1.2 Limitations of This Guide: 

1.2.1 Given the variability of the different investigators that may wish to use this guide and the different types of facilities and failures that will be investigated, it is not possible to address all the relevant standards that might apply to a particular investigation. This guide uses generalized language and examples to guide the user. If it is not clear to the user how to apply standards to their specific circumstances, it is recommended that users seek assistance from qualified professionals.

1.2.2 This guide does not address safety issues associated with the investigation, taking samples and storing equipment. Users are cautioned to exercise proper care in handling equipment that was in contact with flammable and combustible liquids and vapors. Some of the activities described in this guide may be subject to OSHA (Occupational Safety and Health Administration) regulations or may only be conducted by individuals with appropriate HAZWOPER (Hazardous Waste Operations and Emergency Response) training certifications recognized by federal and state regulatory authorities, such as HAZWOPER training.

1.2.3 This guide does not address laboratory investigations of material properties and detailed failure analysis.

1.2.4 This guide does not cover underground storage tank systems storing liquefied petroleum gas (LPG).

1.2.5 This guide does not replace state-required closure assessments and investigations. Requirements vary from state to state and often include specific sampling requirements. The user should comply with the requirement of the authority having jurisdiction.

1.2.6 Prior to implementing the steps described in Section 5, users of this guide must determine if the authority having jurisdiction has any qualification requirements for the individual performing the investigation.

1.2.7 Investigations addressed by this guide may involve knowledge, skills, and abilities generally attributed to individuals certified as tank systems installers, inspectors, or removers, or those who are trained in soil and groundwater sampling protocols (for example, geologists, groundwater professionals, or engineers).

1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 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.