# DIMP Integrity Management for Gas Distribution: Report of Phase 1 Investigations (2005) - **operation:** document - **citation:** PHMSA Guidance, DIMP Integrity Management for Gas Distribution: Report of Phase 1 Investigations (2005) - **title:** DIMP Integrity Management for Gas Distribution: Report of Phase 1 Investigations (2005) - **source type:** guidance - **agency:** Pipeline and Hazardous Materials Safety Administration - **status:** guidance - **official:** true - **published on:** Not available - **effective on:** Not available - **summary:** DIMP Integrity Management for Gas Distribution: Report of Phase 1 Investigations (2005) Document integritymanagementforgasdistributionphase1investigations2005.pdf (1.19 MB) Four multi-stakeholder work/study groups were established to collect and analyze available information and to reach findings and conclusions to inform future work by the PHMSA relative to implementing integrity management principles for gas distri - **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-guidance-dimp-integrity-management-gas-distribution-report-of-phase-1-investigations-2005-e5463708.json - **markdown:** https://regulus.evalyn.ai/document/phmsa-guidance-dimp-integrity-management-gas-distribution-report-of-phase-1-investigations-2005-e5463708.md - **app url:** https://regulus.evalyn.ai/document/phmsa-guidance-dimp-integrity-management-gas-distribution-report-of-phase-1-investigations-2005-e5463708 - **source url:** https://www.phmsa.dot.gov/pipeline/gas-distribution-integrity-management/dimp-integrity-management-gas-distribution-report-of-phase-1-investigations-2005 **body:** DIMP Integrity Management for Gas Distribution: Report of Phase 1 Investigations (2005) Document integritymanagementforgasdistributionphase1investigations2005.pdf (1.19 MB) Four multi-stakeholder work/study groups were established to collect and analyze available information and to reach findings and conclusions to inform future work by the PHMSA relative to implementing integrity management principles for gas distribution pipelines. The groups have concluded that current pipeline safety regulations (49 CFR Part 192) do not now convey the concept of a risk-based distribution integrity management process and that it would be appropriate to modify the regulations to do so. Effective Date: Thursday, December 1, 2005 <<>> Integrity Management for Gas Distribution Report of Phase 1 Investigations December 2005 Prepared by joint work/study groups including representatives of: Stakeholder Public State Pipeline Safety Representatives Gas Distribution Pipeline Industry Pipeline and Hazardous Materials Safety Administration <<>> Integrity Management for Gas Distribution Pipelines Report of Phase 1 Investigations December 2005 Prepared by Joint Work/study Groups including Representatives of: Stakeholder Public Gas Distribution Pipeline Industry State Pipeline Safety Representatives Pipeline and Hazardous Materials Safety Administration <<>> i Table of Contents Executive Summary……………………………………………………………….1 1. Structure of this Report………………………………………………………...3 2. Introduction…………………………………………………………………….3 Background………………………………………………………………..3 American Gas Foundation Study………………………………………….4 Origins of Current Study…………………………………………………..5 Phase 1 Program Structure………………………………………………...6 Review by PHMSA Advisory Committees………………………………..8 3. Key Findings……………………………………………………………………8 National Focus of Integrity Management Efforts (Threats)……………….8 Regulatory Needs………………………………………………………….9 Guidance…………………………………………………………………..11 Preventing Excavation Damage…………………………………………..12 Excess Flow Valves………………………………………………………13 Data Reporting……………………………………………………………14 Performance Measures……………………………………………………15 4. Path Forward…………………………………………………………………..17 Regulatory Needs…………………………………………………………18 Guidance………………………………………………………………….18 Preventing Excavation Damage…………………………………………..19 Data Reporting……………………………………………………………20 Performance Measures……………………………………………………21 Research and Development……………………………………………….22 Scope………………………………………………………………………22 5. Conclusion……………………………………………………………………..23 Appendices A. Participants B. Complete list of Findings C. Complete list of Path Forward Actions D. Comments of International Association of Fire Chiefs E. Statement on Distribution Integrity Management Cost Recovery Attachments 1. Report of the Strategic Options Group 2. Report of the Risk Control Practices Group 3. Report of the Excavation Damage Prevention Group 4. Report of the Data Group <<>> ii Acronym List AGF – American Gas Foundation ASME – American Society of Mechanical Engineers ASTM – American Society of Testing and Materials BAA – Broad Agency Announcement DIMP – Distribution Integrity Management Program DOT – Department of Transportation EFV – Excess Flow Valve GPTC – Gas Piping Technology Committee IAFC – International Association of Fire Chiefs IG – Inspector General IM – Integrity Management IMP – Integrity Management Program LDC – Local Distribution Company LEAKS – Leak Management Program Consisting of: Locate, Evaluate, Act, Keep Records, and Self-Assess NAPSR – National Association of Pipeline Safety Representatives NARUC – National Association of Regulatory Utility Commissioners PHMSA – Pipeline and Hazardous Materials Safety Administration PIM – Pipeline Integrity Management (transmission) PSIA – Pipeline Safety Improvement Act of 2002 R&D – Research and Development SMYS – Specified Minimum Yield Strength <<>> Integrity Management for Distribution Pipelines 1 Phase 1 Investigations Executive Summary The Pipeline and Hazardous Materials Safety Administration (PHMSA) has implemented integrity management requirements for hazardous liquid and gas transmission pipelines. No similar requirements presently exist for gas distribution pipelines, but observers have suggested that they are needed. Four multi-stakeholder work/study groups were established to collect and analyze available information and to reach findings and conclusions to inform future work by the PHMSA relative to implementing integrity management principles for gas distribution pipelines. The groups have concluded that current pipeline safety regulations (49 CFR Part 192) do not now convey the concept of a risk-based distribution integrity management process and that it would be appropriate to modify the regulations to do so. The groups found that the most useful option for implementing distribution integrity management requirements is a high-level, flexible federal regulation, in conjunction with implementation guidance, a nation-wide education program expected to be conducted as part of implementing 3-digit dialing for One-Call programs, and continuing research and development. Differences between gas distribution pipeline operators, and the pipeline systems they operate, make it impractical simply to apply the integrity management requirements for transmission pipelines to distribution. The significant diversity among gas distribution pipeline operators also makes it impractical to establish prescriptive requirements that would be appropriate for all circumstances. Instead, the groups concluded that it would be appropriate to require that all distribution pipeline operators, regardless of size, implement an integrity management program including seven key elements, namely that each operator: 1. Develop and implement a written integrity management plan. 2. Know its infrastructure. 3. Identify threats, both existing and of potential future importance. 4. Assess and prioritize risks. 5. Identify and implement appropriate measures to mitigate risks. 6. Measure performance, monitor results, and evaluate the effectiveness of its programs, making changes where needed. 7. Periodically report a limited set of performance measures to its regulator. Since entire distribution systems would be covered by the distribution integrity management plan, there is no need to identify high consequence areas or identified sites as part of the plan as was required for transmission pipelines. The Executive Steering Group considers that it should be possible to develop and promulgate a regulation within about two years so that distribution operators can develop integrity management plans during 2008 and begin implementing those plans in about 2009. Guidance will be needed to assist operators in implementing the high-level regulatory provisions in their particular circumstances. Detailed guidance will be needed <<>> Integrity Management for Distribution Pipelines 2 Phase 1 Investigations for the smallest operators, who have limited resources for developing customized programs. The groups concluded that excavation damage poses the most significant single threat to distribution system integrity. Reducing this threat requires affecting the behavior of persons not subject to the jurisdiction of pipeline safety authorities (e.g., excavators working for other than pipeline facility owners/operators). Some states have implemented effective comprehensive damage prevention programs that have resulted in significant reductions in the frequency of damage from excavation. Effective programs include nine elements: 1. 2. Enhanced communication between operators and excavators Fostering support and partnership of all stakeholders in all phases (enforcement, system improvement, etc.) of the program 3. Operator’s use of performance measures for persons performing locating of pipelines and pipeline construction 4. Partnership in employee training 5. Partnership in public education 6. Enforcement agencies’ role as partner and facilitator to help resolve issues 7. Fair and consistent enforcement of the law 8. Use of technology to improve all parts of the process 9. Analysis of data to continually evaluate/improve program effectiveness Not all states have implemented such programs. Federal legislation is likely needed to support the development and implementation of such programs by all states. Work on this legislation can begin immediately. This represents the greatest single opportunity for distribution pipeline safety improvements. The groups concluded that excess flow valves (EFVs) can be a valuable incident mitigation option, but that a federal mandate for their installation would be inappropriate. (All groups agreed with this conclusion, although some individual members favored a mandate). Analysis of operational experience demonstrated that when properly specified and installed, the valves function as designed; they successfully terminate gas flow under accident conditions and only rarely malfunction to prevent flow when an accident has not occurred. A regulatory provision that would require that operators consider certain risk factors in deciding when to install EFVs would be appropriate. Guidance would be useful concerning the conditions under which EFVs are not feasible (e.g., low pressures, gas constituents inconsistent with valve operation) and concerning risk factors indicating when their installation might be appropriate. The groups also concluded that management of gas leaks is fundamental to successful management of distribution risk, and an effective leak management program is thus a vital risk control practice. Effective programs include the following elements: 1. Locate the leak, 2. Evaluate its severity, <<>> Integrity Management for Distribution Pipelines 3 Phase 1 Investigations 3. Act appropriately to mitigate the leak, 4. Keep records, and 5. Self-assess to determine if additional actions are necessary to keep the system safe. This effort concluded, as did the American Gas Foundation before it1, that distribution pipelines are safe. Incidents continue to occur, but their frequency has been reduced. There is room for improvement. Implementing integrity management, consistent with the findings and conclusions of the work/study groups, should help achieve additional improvement. 1. Structure of This Report This report covers the work of four work/study groups, as described in the next section. The main body of the report (Sections 2 through 5) describes the context in which this work was performed and the key overall findings and conclusions. The appendices present: • A: a list of participants, • B: the complete list of findings and conclusions from all four work/study groups, • C: the complete list of path forward actions suggested by the four groups, and • D: independent comments on excess flow valves from the International Association of Fire Chiefs and related organizations. The separate reports of each of the four work/study groups are included as attachments to this report. 2. Introduction Background The Department of Transportation’s (DOT) Pipeline and Hazardous Materials Safety Administration (PHMSA) published new rules requiring “integrity management” programs for hazardous liquid pipelines in 20002 and 20023 and for natural gas transmission pipelines in 2003.4 Under these rules, operators of hazardous liquid and gas transmission pipelines were required to identify the threats to their pipelines, analyze the risk posed by these threats, collect information about the physical condition of their pipelines, and take actions to address applicable threats and integrity concerns before pipeline accidents could occur. 1 American Gas Foundation, “Safety Performance and Integrity of the Natural Gas Distribution Infrastructure,” January, 2005. 2 65 FR 75378, December 1, 2000. 3 67 FR 2136, January 16, 2002. 4 68 FR 69778, December 15, 2003. <<>> Integrity Management for Distribution Pipelines 4 Phase 1 Investigations The initial implementation of these integrity management regulations has resulted in the identification and repair of many conditions that could potentially have resulted in pipeline accidents had they not been addressed. The early results of these programs led PHMSA to consider whether a similar regulatory approach would be appropriate for gas distribution pipelines. Distribution pipelines are different from other pipelines. Hazardous liquid and gas transmission pipelines traverse long distances (including many rural areas), are generally of large diameter (up to 48 inches), are comprised primarily of steel pipe, typically operate at relatively high stress levels, and have few branch connections. Failures of hazardous liquid pipelines can result in significant environmental contamination. Failures of gas transmission pipelines usually occur as a catastrophic rupture of the pipeline, caused by the high pressure of the contained gas. Distribution pipeline systems exist in restricted geographical areas that are predominantly urban/suburban, because the purpose of these pipelines is to deliver natural gas to end users – residential, commercial, industrial, institutional, and electric generation customers. Distribution pipelines are generally small in diameter (as small as 5/8 inch), and are constructed of several kinds of materials including a significant percentage of plastic pipe. Distribution pipelines also have frequent branch connections, since service lines, providing gas to individual customers, branch off of a common “main” pipeline, typically installed under the street. The dominant cause of distribution incidents is excavation damage with third party damage being the major contributor to these incidents. Other than as caused by excavation damage, distribution pipeline failures almost always involve leaks, rather than ruptures, because the internal gas pressure is much lower than for transmission pipelines. These differences mean that many of the tools and techniques used in integrity management programs for other types of pipelines are not appropriate or cannot be used for distribution pipelines. American Gas Foundation Study In considering whether and how integrity management principles could be applied to distribution pipelines, the first question that was addressed was whether performance supported the need for additional regulations. The American Gas Foundation (AGF) undertook a study5 in 2003-2004 to characterize the state of distribution pipeline safety. This study analyzed the safety performance of gas distribution pipeline systems from 1990 to 2002 as represented by the number of incidents reported to PHMSA by operators during that period.6 5 American Gas Foundation, “Safety Performance and Integrity of the Natural Gas Distribution Infrastructure,” January, 2005. 6 49 CFR 191.3 defines an incident as an event that involves a release of gas from a pipeline and (1) a death or (2) a personal injury necessitating in-patient hospitalization or (3) that results in estimated property damage of $50,000 or more. 49 CFR 191.9 requires operators of distribution pipelines to submit written reports of all incidents meeting these criteria. <<>> Integrity Management for Distribution Pipelines 5 Phase 1 Investigations The AGF study compared the number of incidents reported for gas transmission pipelines to those reported for distribution pipelines. Direct comparison of reported incident totals can be misleading, however, since there are many more miles of distribution pipelines than there are transmission pipelines (approximately 1.9 million miles of distribution pipeline compared to approximately 300,000 miles of transmission pipeline7). The AGF study allowed for comparison by “normalizing” the incident statistics for both types of pipelines by considering the number of incidents reported per 100,000 miles of in-service pipeline. The AGF study found that the total number of incidents reported per 100,000 miles was generally less for distribution pipelines than that reported for gas transmission pipelines over the same period. There was no statistically-significant trend (i.e., neither increase nor decrease) in the number of incidents per year for either type of pipeline. The AGF study also found that the number of incidents that resulted in death or injury (called “serious incidents” within the study) was approximately the same for both transmission and distribution pipelines over the study period. The study found a statistically significant downward trend in the number of serious incidents for both types of pipelines. The AGF study thus demonstrated that the safety performance of distribution pipelines is good, comparable to that of gas transmission pipelines. The study did not show, however, that the level of safety of distribution pipelines was so great as to preclude the need for a new regulatory approach. Origins of the Current Study In 2004, the Department of Transportation (DOT) Inspector General (IG) suggested that application of integrity management (IM) principles could help improve the safety of distribution pipelines. In testimony before Congress in July 20048, the IG noted that recently-issued rules had required that operators of hazardous liquid and gas transmission pipelines implement integrity management plans (IMP), but that no such requirement had been imposed on operators of distribution pipelines. The IG acknowledged that a reason why distribution pipeline operators had been excluded from the requirements applicable to operators of gas transmission pipelines was that smart pigs could not be used to inspect distribution pipeline systems. (Such inspections were a principal element of the IM requirements for transmission pipelines). The IG concluded, however, that there was no reason that other elements of IM could not be implemented for distribution pipelines. 7 2003 values reported on the Office of Pipeline Safety web site, http://ops.dot.gov/stats/GTANNUAL2.HTM. 8 “Progress and Challenges in Improving Pipeline Safety,” Statement of the Honorable Kenneth M. Mead, Inspector General, Department of Transportation, before the Committee on Energy and Commerce, Subcommittee on Energy and Air Quality, U. S. House of Representatives, July 20, 2004. <<>> Integrity Management for Distribution Pipelines 6 Phase 1 Investigations The IG’s testimony recommended that DOT should define an approach for requiring operators of distribution pipeline systems to implement some form of integrity management or enhanced safety program with elements similar to those required in hazardous liquid and gas transmission pipeline integrity management programs. The Appropriations Committee asked PHMSA “to report to the House and Senate Committees on Appropriations by May 1, 2005, detailing the extent to which integrity management plan [IMP] elements may be applied to the natural gas distribution pipeline industry in order to enhance distribution system safety.”9 PHMSA conducted a public meeting on December 16, 2004, in Washington, DC, to solicit comments from all stakeholders on ways in which distribution pipeline integrity might be improved through application of IM principles. Comments made during this meeting emphasized the differences between distribution pipeline systems and those for gas transmission. These differences make it impractical to apply the gas transmission IM requirements to distribution pipelines directly. Comments at the meeting also noted that there is significant diversity among operators of distribution pipeline systems and among the systems they operate, meaning that any new requirements addressing distribution pipeline operators needed to incorporate a high degree of flexibility. Following the public meeting, PHMSA embarked on a multi-phased effort intended to develop an approach that will address the three elements of the strategy described by the DOT Inspector General: • understand the infrastructure, • identify and characterize the threats, and • determine how best to manage the known risks (prevention, detection and mitigation). This effort was described in PHMSA’s report to Congress, submitted in response to the direction in the Appropriations Committee’s report.10 Phase 1 was described as working with a number of groups comprised of state pipeline safety regulators, pipeline operators, and representatives of the public to seek out additional information about the issues affecting distribution system integrity. This report documents the results of the Phase 1 investigations. Phase 1 Program Structure Most distribution pipelines in the United States are regulated by state pipeline safety agencies. It was important to involve state pipeline safety regulators and operators of distribution pipelines in the Phase 1 program, in order to tap their expertise and help assure that conclusions were practical. The Phase 1 effort was designed to involve representatives of state pipeline safety agencies, representatives of distribution pipeline 9 House of Representatives Report 108-792, November 20, 2004. 10 Office of Pipeline Safety, Pipeline and Hazardous Materials Safety Administration, Department of Transportation, “Assuring the Integrity of Gas Distribution Pipeline Systems: A Report to the Congress,” May 2005. <<>> Integrity Management for Distribution Pipelines 7 Phase 1 Investigations owners (both investor-owned and municipal agencies), and members of the interested public. Representatives of PHMSA also participated. Management oversight was provided by an Executive Steering Group, consisting of state regulatory commissioners, industry executive managers, and members of the public. Day-to-day coordination was by a Coordinating Group that included managers from state agencies and the industry trade associations (American Gas Association and American Public Gas Association). The principal investigations were conducted by four work/study groups: • Strategic Options Group – evaluating strategic approaches to implementing integrity management elements for distribution pipelines • Risk Control Practices Group – evaluating existing risk control practices, required and/or implemented voluntarily by operators, and the adequacy of existing regulations and guidance • Excavation Damage Prevention Group – evaluating means to reduce the frequency of damage from excavation near pipelines, which is the predominant cause of distribution pipeline incidents • Data Group – evaluating existing data on incidents and leaks to identify factors important in preventing distribution incidents and correlating information from surveys of the efficacy of excess flow valves as a risk mitigation tool The groups conducted their investigations in parallel, to allow this program to be completed promptly (work began in March 2005). Information was exchanged among the groups as needed. Each group prepared a report documenting its work, and these reports are included as attachments to this report. The responsibilities of each work/study group are described in more detail in the May, 2005, PHMSA Report to Congress and in the Action Plan that was included in that report. The findings and conclusions of each work/study group are presented in their individual reports (which are attached to this report). Inconsistencies or conflicts between the findings of individual groups were addressed by the Coordinating Group. The resulting key findings of the overall program are described in the sections of this report that follow. In the event conflicting statements exist between the work/study group reports and the main body, the information in the main body prevails. The work/study groups also identified, and documented in their reports, a number of actions that would be appropriate for future work as PHMSA and industry prepare to implement an integrity management approach for distribution pipelines. The key elements of this path forward are also described in this summary report. The members of the groups involved in Phase 1 provide this report to support actions by PHMSA and industry as they proceed with subsequent phases. This summary report has been prepared to make the findings and conclusions readily available for all stakeholders who will be involved in implementing integrity management principles for distribution pipelines. <<>> Integrity Management for Distribution Pipelines 8 Phase 1 Investigations Review by PHMSA Advisory Committees The status of this work was reviewed with the Technical Pipeline Safety Standards Committee and the Technical Hazardous Liquid Pipeline Safety Standards Committee, meeting in joint session, on December 13, 2005. The hazardous liquid pipeline committee was included in this review, because the findings regarding federal legislation to advance damage prevention programs will affect all types of pipelines. The committees supported the general concepts reflected by the product of this effort, recognizing that PHMSA would proceed with rulemaking based on these concepts. Members expressed concern about the imposition of a complex federal requirement on small pipeline operators, including master meter operators, and agreed that additional clear guidance will be needed to facilitate their compliance. 3. Key Findings Each work/study group reached a number of findings and conclusions about the areas covered by their investigations. A complete list of the group findings is presented in Appendix B to this report. Additional discussion, including further explanation by the groups regarding their findings and conclusions, can be found in the individual group reports, which stand alone but are attached to this report for the reader’s convenience. Each work/study group was asked to identify its “key” findings for purposes of this summary report. These key findings address a number of issues that will be important as further work is undertaken to enhance the integrity management approach for distribution pipelines. These issues are discussed here, along with the key findings that relate to each. This presentation is intended to allow the reader to gain an overview of the important issues. It must be emphasized that, although the work/study groups have identified these as their most important findings, all group findings have importance. Future work should consider all group findings and conclusions. National Focus of Integrity Management Efforts (Threats) The integrity management process begins with consideration of what is important to assure pipeline safety, that is, what are the threats to integrity? Understanding the threats is the first step in identifying the appropriate actions to assure integrity. The PHMSA collects data on threats affecting pipelines through incident reports. Operators must characterize each incident they report as being in one of eight categories. The categories are: Corrosion Material or Welds Natural Forces Equipment Excavation Operations Other Outside Force Damage Other <<>> Integrity Management for Distribution Pipelines 9 Phase 1 Investigations These threat categories are appropriate as a foundation for integrity management programs. They represent broad categories. Each can be further subdivided into specific threats. For example, corrosion can be internal or external corrosion. It can be general corrosion or localized pitting. Where appropriate, operators will need to evaluate their threats at this finer level of detail to identify and implement appropriate responsive actions. However, the general categories, matching the current data collection requirements, are appropriate categories for integrity threats on a national basis. The Data Group evaluated available historical data to identify trends. For distribution pipelines, excavation damage is the predominant cause of reported incidents. Corrosion is the major cause of leaks, but a small fraction of incidents result from corrosion. The Data Group reached a key finding concerning this review of available data: While a decreasing trend in the rate of reportable distribution incidents resulting in fatalities and injuries, including incidents caused by outside force damage, exists for the preceding 13-years, no statistically significant trend was identified for total reportable distribution incidents for that same period. While this conclusion is encouraging, it supports the need to explore new requirements for integrity management that will help reduce the occurrence rate of all incidents. Regulatory Needs The major question, then, is what kind of requirements would be most appropriate to implement an integrity management approach for distribution pipelines? This question was considered by the Risk Control Practices Group and the Strategic Options Group. It is important to recognize the wide diversity that exists among distribution pipeline operators. Some operators are very large, serving more than one million customers. Some operators are very small, such as master meter operators serving only a few customers. Many operators serve from 100 and 10,000 customers, and a sizable majority of these operators are municipal agencies. The pipeline systems that these operators manage are very diverse. Larger systems, in areas where gas service has been available for many years, can include thousands of miles of pipeline of various materials and ages. Systems in areas where gas service has only been available in recent years can be more uniform, consisting of one or a few types of pipe with similar fittings and connections installed using uniform procedures. The smallest systems, such as many master meter systems, may include a limited amount of pipeline, of one material, and all installed at the same time. The issues important to assuring the integrity of these diverse systems will vary. This diversity makes it difficult for any one prescriptive requirement to address all possible circumstances. It is important that any new requirements that are developed allow sufficient flexibility for the operators of distribution pipeline systems, and the state <<>> Integrity Management for Distribution Pipelines Phase 1 Investigations 10 regulators who oversee their operations, to customize their integrity management efforts to address their specific systems, threats, and issues. The Risk Control Practices Group examined existing federal regulations and the effect they are having, to determine if there were any gaps that would need to be filled by any new integrity management regulations. The group reached a key finding in this area: Current design, construction, installation, initial testing, corrosion control, and operation and maintenance regulations should be effective in providing for integrity of the distribution facilities that are being installed today. This conclusion assures us that current requirements are adequate to “build in” necessary safety for new distribution pipeline systems. New integrity management requirements, then, can focus on improving safety for existing systems and assuring that the built-in level of safety is maintained for new pipelines. The Strategic Options Group considered the form in which new requirements implementing integrity management would be most useful. The group reached two key findings in this area: The most useful option for implementing distribution integrity management requirements is a high-level, flexible federal regulation that excludes no operators, in conjunction with implementation guidance, a nation-wide education program expected to be conducted as part of implementing 3-digit dialing for one-call programs, and continuing research and development. A small number of elements are all that is needed to describe the basic structure of a high-level, flexible federal regulation addressing distribution integrity management. These elements are: • Development of an integrity management plan • Know your infrastructure • Identify threats (existing and potential) • Assess and prioritize risk • Identify and implement measures to mitigate risks • Measure performance, monitor results, and evaluate effectiveness • Report results Finally, the Risk Control Practices Group reached a key finding regarding the necessary scope of any new integrity management requirements. Since the entire distribution system will be covered by the proposed distribution integrity management program (DIMP) plan, there is no need to identify high consequence areas or identified sites as part of the DIMP plan. This means that integrity management requirements for distribution pipelines can be both simpler and more broadly applied than the requirements applicable to other pipelines. <<>> Integrity Management for Distribution Pipelines Phase 1 Investigations 11 For hazardous liquid and gas transmission pipelines, it was necessary to identify high consequence areas – those locations in which a pipeline accident could have the greatest effect. The focus of integrity management requirements for those pipelines was then on the identified areas. For distribution pipelines, high consequence areas need not be defined, and integrity management requirements will affect the entire pipeline system. Guidance Historically, guidance developed by a consensus process has been used by operators to assist them in implementing most regulatory requirements. The Gas Piping Technology Committee (GPTC) has developed and maintains a guideline addressing federal requirements applicable to distribution pipeline systems. The American Society of Mechanical Engineers (ASME) and the American Society of Testing and Materials (ASTM) have also developed consensus standards addressing specific technical issues within their areas of expertise that are important in implementing safety requirements. In addition, DOT, through the Transportation Safety Institute (TSI), maintains a small operator’s handbook that provides guidance for operators to help assure compliance with the regulations even for operators who lack the resources to develop compliance plans of their own. High-level, flexible requirements for integrity management will mean that operators will face many choices in deciding what actions to take. Such choices can be facilitated by providing additional guidance that will assist the operators and help to assure that integrity management activities are appropriate for particular circumstances. The Risk Control Practices Group reached two key findings in this area: The PHMSA plan for a “high level, risk-based, performance-oriented Federal regulation”11 that requires a specific distribution IMP is supported by the fact that (a) the elements necessary to implement a distribution IMP have been identified; (b) the threats have been identified; and (c) methods exist for operators to develop the elements. Operators may need additional guidance materials. The Gas Piping Technology Committee should develop guidance to assist operators in determining (a) which threat prioritization methods, (b) which risk control practices, and (c) which performance measures are most appropriate for their risk control program. These findings provide assurance that the foundation for distribution integrity management requirements is firm, and suggest areas in which additional guidance would be useful. Special attention will likely need to be given to the needs of the smallest operators, who lack the resources to develop integrity management plans on their own. 11 “Assuring the Integrity of Gas Distribution Pipeline Systems,” Report to the Congress, May 2005, Submitted by Office of Pipeline Safety, Pipeline and Hazardous Materials Safety Administration, U.S. Department of Transportation, p. 3. <<>> Integrity Management for Distribution Pipelines Phase 1 Investigations 12 Preventing Excavation Damage Excavation damage is the single most significant cause of incidents on distribution pipeline systems. Many, perhaps most, incidents that result from excavation damage occur immediately, at the time the damage is inflicted. Thus, reducing incidents caused by this threat requires that the threat itself be reduced, i.e., that damage be prevented in the first place. The significance of this threat led to the establishment of a work/study group dedicated specifically to considering ways in which excavation damage could be reduced. Reducing the frequency of excavation damage requires changes in behavior by persons who are not regulated by pipeline safety authorities, that is, contractors and others who perform excavation. Practical actions that operators can implement can have only limited effectiveness in reducing the frequency of damage events. It would be impractical to require that distribution pipeline operators monitor and restrict the activities of those conducting excavations near their pipelines. Instead, action is needed on a broader basis than simply additional regulation imposed on pipeline operators. The Excavation Damage Prevention Group reached four key findings in this area: Excavation damage poses by far the single greatest threat to distribution system safety, reliability and integrity; therefore excavation damage prevention presents the most significant opportunity for distribution pipeline safety improvements. States with comprehensive damage prevention programs that include effective enforcement have a substantially lower probability of excavation damage to pipeline facilities than states that do not. The lower probability of excavation damage translates to a substantially lower risk of serious incidents and consequences resulting from excavation damage to pipelines. A comprehensive damage prevention program requires nine important elements be present and functional for the program to be effective. All stakeholders must participate in the excavation damage prevention process. The elements are: 1. Enhanced communication between operators and excavators 2. Fostering support and partnership of all stakeholders in all phases (enforcement, system improvement, etc.) of the program 3. Operator’s use of performance measures for persons performing locating of pipelines and pipeline construction 4. Partnership in employee training 5. Partnership in public education 6. Enforcement agencies’ role as partner and facilitator to help resolve issues 7. 8. 9. Fair and consistent enforcement of the law Use of technology to improve all parts of the process Analysis of data to continually evaluate/improve program effectiveness <<>> Integrity Management for Distribution Pipelines Phase 1 Investigations 13 Federal Legislation is needed to support the development and implementation of damage prevention programs that include effective enforcement as a part of the state's pipeline safety program. This is consistent with the objectives of the state pipeline safety programs, which are to ensure the safety of the public by addressing threats to the distribution infrastructure. The legislation will not be effective unless it includes provisions for ongoing funding such as federal grants to support these efforts. This funding is intended to be in addition to, and independent of, existing federal funding of state pipeline safety programs12 . Addressing these findings will help establish a situation in which those responsible for excavation damage to pipelines will be required and motivated to modify behavior in a way that will reduce the frequency of such damage. As noted in the first key finding above, this represents the greatest single opportunity for distribution pipeline safety improvements. Excess Flow Valves Excess Flow Valves (EFV) are devices that can be installed in each service line and that may shut off gas flow if the line is severed downstream of the valve. These valves represent a measure that may mitigate the consequences of some incidents if they occur despite the preventive actions that may be taken to reduce the likelihood. - **truncated:** true - **body characters:** 583404