{"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":null,"effective_on":null,"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)\n\nDocument\n\n integritymanagementforgasdistributionphase1investigations2005.pdf (1.19 MB)\n\n        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.\n\n          Effective Date: Thursday, December 1, 2005\n\n<<<PAGE 1>>>\n\nIntegrity\nManagement for Gas\nDistribution\nReport of\nPhase 1\nInvestigations\nDecember 2005\nPrepared by joint work/study groups including representatives of:\nStakeholder Public\nState Pipeline Safety Representatives\nGas Distribution Pipeline Industry\nPipeline and Hazardous Materials Safety Administration\n\n<<<PAGE 2>>>\n\nIntegrity Management for Gas Distribution Pipelines\nReport of Phase 1 Investigations\nDecember 2005\nPrepared by Joint Work/study Groups including Representatives of:\nStakeholder Public\nGas Distribution Pipeline Industry\nState Pipeline Safety Representatives\nPipeline and Hazardous Materials Safety Administration\n\n<<<PAGE 3>>>\n\ni\nTable of Contents\nExecutive Summary……………………………………………………………….1\n1. Structure of this Report………………………………………………………...3\n2. Introduction…………………………………………………………………….3\nBackground………………………………………………………………..3\nAmerican Gas Foundation Study………………………………………….4\nOrigins of Current Study…………………………………………………..5\nPhase 1 Program Structure………………………………………………...6\nReview by PHMSA Advisory Committees………………………………..8\n3. Key Findings……………………………………………………………………8\nNational Focus of Integrity Management Efforts (Threats)……………….8\nRegulatory Needs………………………………………………………….9\nGuidance…………………………………………………………………..11\nPreventing Excavation Damage…………………………………………..12\nExcess Flow Valves………………………………………………………13\nData Reporting……………………………………………………………14\nPerformance Measures……………………………………………………15\n4. Path Forward…………………………………………………………………..17\nRegulatory Needs…………………………………………………………18\nGuidance………………………………………………………………….18\nPreventing Excavation Damage…………………………………………..19\nData Reporting……………………………………………………………20\nPerformance Measures……………………………………………………21\nResearch and Development……………………………………………….22\nScope………………………………………………………………………22\n5. Conclusion……………………………………………………………………..23\nAppendices\nA. Participants\nB. Complete list of Findings\nC. Complete list of Path Forward Actions\nD. Comments of International Association of Fire Chiefs\nE. Statement on Distribution Integrity Management Cost Recovery\nAttachments\n1. Report of the Strategic Options Group\n2. Report of the Risk Control Practices Group\n3. Report of the Excavation Damage Prevention Group\n4. Report of the Data Group\n\n<<<PAGE 4>>>\n\nii\nAcronym List\nAGF – American Gas Foundation\nASME – American Society of Mechanical Engineers\nASTM – American Society of Testing and Materials\nBAA – Broad Agency Announcement\nDIMP – Distribution Integrity Management Program\nDOT – Department of Transportation\nEFV – Excess Flow Valve\nGPTC – Gas Piping Technology Committee\nIAFC – International Association of Fire Chiefs\nIG – Inspector General\nIM – Integrity Management\nIMP – Integrity Management Program\nLDC – Local Distribution Company\nLEAKS – Leak Management Program Consisting of: Locate, Evaluate, Act, Keep\nRecords, and Self-Assess\nNAPSR – National Association of Pipeline Safety Representatives\nNARUC – National Association of Regulatory Utility Commissioners\nPHMSA – Pipeline and Hazardous Materials Safety Administration\nPIM – Pipeline Integrity Management (transmission)\nPSIA – Pipeline Safety Improvement Act of 2002\nR&D – Research and Development\nSMYS – Specified Minimum Yield Strength\n\n<<<PAGE 5>>>\n\nIntegrity Management for Distribution Pipelines 1\nPhase 1 Investigations\nExecutive Summary\nThe Pipeline and Hazardous Materials Safety Administration (PHMSA) has implemented\nintegrity management requirements for hazardous liquid and gas transmission pipelines.\nNo similar requirements presently exist for gas distribution pipelines, but observers have\nsuggested that they are needed. Four multi-stakeholder work/study groups were\nestablished to collect and analyze available information and to reach findings and\nconclusions to inform future work by the PHMSA relative to implementing integrity\nmanagement principles for gas distribution pipelines. The groups have concluded that\ncurrent pipeline safety regulations (49 CFR Part 192) do not now convey the concept of a\nrisk-based distribution integrity management process and that it would be appropriate to\nmodify the regulations to do so.\nThe groups found that the most useful option for implementing distribution integrity\nmanagement requirements is a high-level, flexible federal regulation, in conjunction with\nimplementation guidance, a nation-wide education program expected to be conducted as\npart of implementing 3-digit dialing for One-Call programs, and continuing research and\ndevelopment.\nDifferences between gas distribution pipeline operators, and the pipeline systems they\noperate, make it impractical simply to apply the integrity management requirements for\ntransmission pipelines to distribution. The significant diversity among gas distribution\npipeline operators also makes it impractical to establish prescriptive requirements that\nwould be appropriate for all circumstances. Instead, the groups concluded that it would\nbe appropriate to require that all distribution pipeline operators, regardless of size,\nimplement an integrity management program including seven key elements, namely that\neach operator:\n1. Develop and implement a written integrity management plan.\n2. Know its infrastructure.\n3. Identify threats, both existing and of potential future importance.\n4. Assess and prioritize risks.\n5. Identify and implement appropriate measures to mitigate risks.\n6. Measure performance, monitor results, and evaluate the effectiveness of its\nprograms, making changes where needed.\n7. Periodically report a limited set of performance measures to its regulator.\nSince entire distribution systems would be covered by the distribution integrity\nmanagement plan, there is no need to identify high consequence areas or identified sites\nas part of the plan as was required for transmission pipelines.\nThe Executive Steering Group considers that it should be possible to develop and\npromulgate a regulation within about two years so that distribution operators can develop\nintegrity management plans during 2008 and begin implementing those plans in about\n2009. Guidance will be needed to assist operators in implementing the high-level\nregulatory provisions in their particular circumstances. Detailed guidance will be needed\n\n<<<PAGE 6>>>\n\nIntegrity Management for Distribution Pipelines 2\nPhase 1 Investigations\nfor the smallest operators, who have limited resources for developing customized\nprograms.\nThe groups concluded that excavation damage poses the most significant single threat to\ndistribution system integrity. Reducing this threat requires affecting the behavior of\npersons not subject to the jurisdiction of pipeline safety authorities (e.g., excavators\nworking for other than pipeline facility owners/operators). Some states have\nimplemented effective comprehensive damage prevention programs that have resulted in\nsignificant reductions in the frequency of damage from excavation. Effective programs\ninclude nine elements:\n1. 2. Enhanced communication between operators and excavators\nFostering support and partnership of all stakeholders in all phases\n(enforcement, system improvement, etc.) of the program\n3. Operator’s use of performance measures for persons performing locating of\npipelines and pipeline construction\n4. Partnership in employee training\n5. Partnership in public education\n6. Enforcement agencies’ role as partner and facilitator to help resolve issues\n7. Fair and consistent enforcement of the law\n8. Use of technology to improve all parts of the process\n9. Analysis of data to continually evaluate/improve program effectiveness\nNot all states have implemented such programs. Federal legislation is likely needed to\nsupport the development and implementation of such programs by all states. Work on\nthis legislation can begin immediately. This represents the greatest single opportunity for\ndistribution pipeline safety improvements.\nThe groups concluded that excess flow valves (EFVs) can be a valuable incident\nmitigation option, but that a federal mandate for their installation would be inappropriate.\n(All groups agreed with this conclusion, although some individual members favored a\nmandate). Analysis of operational experience demonstrated that when properly specified\nand installed, the valves function as designed; they successfully terminate gas flow under\naccident conditions and only rarely malfunction to prevent flow when an accident has not\noccurred. A regulatory provision that would require that operators consider certain risk\nfactors in deciding when to install EFVs would be appropriate. Guidance would be\nuseful concerning the conditions under which EFVs are not feasible (e.g., low pressures,\ngas constituents inconsistent with valve operation) and concerning risk factors indicating\nwhen their installation might be appropriate.\nThe groups also concluded that management of gas leaks is fundamental to successful\nmanagement of distribution risk, and an effective leak management program is thus a\nvital risk control practice. Effective programs include the following elements:\n1. Locate the leak,\n2. Evaluate its severity,\n\n<<<PAGE 7>>>\n\nIntegrity Management for Distribution Pipelines 3\nPhase 1 Investigations\n3. Act appropriately to mitigate the leak,\n4. Keep records, and\n5. Self-assess to determine if additional actions are necessary to keep the system\nsafe.\nThis effort concluded, as did the American Gas Foundation before it1, that distribution\npipelines are safe. Incidents continue to occur, but their frequency has been reduced.\nThere is room for improvement. Implementing integrity management, consistent with the\nfindings and conclusions of the work/study groups, should help achieve additional\nimprovement.\n1. Structure of This Report\nThis report covers the work of four work/study groups, as described in the next section.\nThe main body of the report (Sections 2 through 5) describes the context in which this\nwork was performed and the key overall findings and conclusions. The appendices\npresent:\n• A: a list of participants,\n• B: the complete list of findings and conclusions from all four work/study groups,\n• C: the complete list of path forward actions suggested by the four groups, and\n• D: independent comments on excess flow valves from the International\nAssociation of Fire Chiefs and related organizations.\nThe separate reports of each of the four work/study groups are included as attachments to\nthis report.\n2. Introduction\nBackground\nThe Department of Transportation’s (DOT) Pipeline and Hazardous Materials Safety\nAdministration (PHMSA) published new rules requiring “integrity management”\nprograms for hazardous liquid pipelines in 20002 and 20023 and for natural gas\ntransmission pipelines in 2003.4 Under these rules, operators of hazardous liquid and gas\ntransmission pipelines were required to identify the threats to their pipelines, analyze the\nrisk posed by these threats, collect information about the physical condition of their\npipelines, and take actions to address applicable threats and integrity concerns before\npipeline accidents could occur.\n1 American Gas Foundation, “Safety Performance and Integrity of the Natural Gas Distribution\nInfrastructure,” January, 2005.\n2 65 FR 75378, December 1, 2000.\n3 67 FR 2136, January 16, 2002.\n4 68 FR 69778, December 15, 2003.\n\n<<<PAGE 8>>>\n\nIntegrity Management for Distribution Pipelines 4\nPhase 1 Investigations\nThe initial implementation of these integrity management regulations has resulted in the\nidentification and repair of many conditions that could potentially have resulted in\npipeline accidents had they not been addressed. The early results of these programs led\nPHMSA to consider whether a similar regulatory approach would be appropriate for gas\ndistribution pipelines.\nDistribution pipelines are different from other pipelines. Hazardous liquid and gas\ntransmission pipelines traverse long distances (including many rural areas), are generally\nof large diameter (up to 48 inches), are comprised primarily of steel pipe, typically\noperate at relatively high stress levels, and have few branch connections. Failures of\nhazardous liquid pipelines can result in significant environmental contamination.\nFailures of gas transmission pipelines usually occur as a catastrophic rupture of the\npipeline, caused by the high pressure of the contained gas.\nDistribution pipeline systems exist in restricted geographical areas that are predominantly\nurban/suburban, because the purpose of these pipelines is to deliver natural gas to end\nusers – residential, commercial, industrial, institutional, and electric generation\ncustomers. Distribution pipelines are generally small in diameter (as small as 5/8 inch),\nand are constructed of several kinds of materials including a significant percentage of\nplastic pipe. Distribution pipelines also have frequent branch connections, since service\nlines, providing gas to individual customers, branch off of a common “main” pipeline,\ntypically installed under the street. The dominant cause of distribution incidents is\nexcavation damage with third party damage being the major contributor to these\nincidents. Other than as caused by excavation damage, distribution pipeline failures\nalmost always involve leaks, rather than ruptures, because the internal gas pressure is\nmuch lower than for transmission pipelines. These differences mean that many of the\ntools and techniques used in integrity management programs for other types of pipelines\nare not appropriate or cannot be used for distribution pipelines.\nAmerican Gas Foundation Study\nIn considering whether and how integrity management principles could be applied to\ndistribution pipelines, the first question that was addressed was whether performance\nsupported the need for additional regulations. The American Gas Foundation (AGF)\nundertook a study5 in 2003-2004 to characterize the state of distribution pipeline safety.\nThis study analyzed the safety performance of gas distribution pipeline systems from\n1990 to 2002 as represented by the number of incidents reported to PHMSA by operators\nduring that period.6\n5 American Gas Foundation, “Safety Performance and Integrity of the Natural Gas Distribution\nInfrastructure,” January, 2005.\n6 49 CFR 191.3 defines an incident as an event that involves a release of gas from a pipeline and (1) a death\nor (2) a personal injury necessitating in-patient hospitalization or (3) that results in estimated property\ndamage of $50,000 or more. 49 CFR 191.9 requires operators of distribution pipelines to submit written\nreports of all incidents meeting these criteria.\n\n<<<PAGE 9>>>\n\nIntegrity Management for Distribution Pipelines 5\nPhase 1 Investigations\nThe AGF study compared the number of incidents reported for gas transmission pipelines\nto those reported for distribution pipelines. Direct comparison of reported incident totals\ncan be misleading, however, since there are many more miles of distribution pipelines\nthan there are transmission pipelines (approximately 1.9 million miles of distribution\npipeline compared to approximately 300,000 miles of transmission pipeline7). The AGF\nstudy allowed for comparison by “normalizing” the incident statistics for both types of\npipelines by considering the number of incidents reported per 100,000 miles of in-service\npipeline.\nThe AGF study found that the total number of incidents reported per 100,000 miles was\ngenerally less for distribution pipelines than that reported for gas transmission pipelines\nover the same period. There was no statistically-significant trend (i.e., neither increase\nnor decrease) in the number of incidents per year for either type of pipeline.\nThe AGF study also found that the number of incidents that resulted in death or injury\n(called “serious incidents” within the study) was approximately the same for both\ntransmission and distribution pipelines over the study period. The study found a\nstatistically significant downward trend in the number of serious incidents for both types\nof pipelines.\nThe AGF study thus demonstrated that the safety performance of distribution pipelines is\ngood, comparable to that of gas transmission pipelines. The study did not show,\nhowever, that the level of safety of distribution pipelines was so great as to preclude the\nneed for a new regulatory approach.\nOrigins of the Current Study\nIn 2004, the Department of Transportation (DOT) Inspector General (IG) suggested that\napplication of integrity management (IM) principles could help improve the safety of\ndistribution pipelines. In testimony before Congress in July 20048, the IG noted that\nrecently-issued rules had required that operators of hazardous liquid and gas transmission\npipelines implement integrity management plans (IMP), but that no such requirement had\nbeen imposed on operators of distribution pipelines. The IG acknowledged that a reason\nwhy distribution pipeline operators had been excluded from the requirements applicable\nto operators of gas transmission pipelines was that smart pigs could not be used to inspect\ndistribution pipeline systems. (Such inspections were a principal element of the IM\nrequirements for transmission pipelines). The IG concluded, however, that there was no\nreason that other elements of IM could not be implemented for distribution pipelines.\n7 2003 values reported on the Office of Pipeline Safety web site,\nhttp://ops.dot.gov/stats/GTANNUAL2.HTM.\n8 “Progress and Challenges in Improving Pipeline Safety,” Statement of the Honorable Kenneth M. Mead,\nInspector General, Department of Transportation, before the Committee on Energy and Commerce,\nSubcommittee on Energy and Air Quality, U. S. House of Representatives, July 20, 2004.\n\n<<<PAGE 10>>>\n\nIntegrity Management for Distribution Pipelines 6\nPhase 1 Investigations\nThe IG’s testimony recommended that DOT should define an approach for requiring\noperators of distribution pipeline systems to implement some form of integrity\nmanagement or enhanced safety program with elements similar to those required in\nhazardous liquid and gas transmission pipeline integrity management programs. The\nAppropriations Committee asked PHMSA “to report to the House and Senate\nCommittees on Appropriations by May 1, 2005, detailing the extent to which integrity\nmanagement plan [IMP] elements may be applied to the natural gas distribution pipeline\nindustry in order to enhance distribution system safety.”9\nPHMSA conducted a public meeting on December 16, 2004, in Washington, DC, to\nsolicit comments from all stakeholders on ways in which distribution pipeline integrity\nmight be improved through application of IM principles. Comments made during this\nmeeting emphasized the differences between distribution pipeline systems and those for\ngas transmission. These differences make it impractical to apply the gas transmission IM\nrequirements to distribution pipelines directly. Comments at the meeting also noted that\nthere is significant diversity among operators of distribution pipeline systems and among\nthe systems they operate, meaning that any new requirements addressing distribution\npipeline operators needed to incorporate a high degree of flexibility.\nFollowing the public meeting, PHMSA embarked on a multi-phased effort intended to\ndevelop an approach that will address the three elements of the strategy described by the\nDOT Inspector General:\n• understand the infrastructure,\n• identify and characterize the threats, and\n• determine how best to manage the known risks (prevention, detection and\nmitigation).\nThis effort was described in PHMSA’s report to Congress, submitted in response to the\ndirection in the Appropriations Committee’s report.10 Phase 1 was described as working\nwith a number of groups comprised of state pipeline safety regulators, pipeline operators,\nand representatives of the public to seek out additional information about the issues\naffecting distribution system integrity. This report documents the results of the Phase 1\ninvestigations.\nPhase 1 Program Structure\nMost distribution pipelines in the United States are regulated by state pipeline safety\nagencies. It was important to involve state pipeline safety regulators and operators of\ndistribution pipelines in the Phase 1 program, in order to tap their expertise and help\nassure that conclusions were practical. The Phase 1 effort was designed to involve\nrepresentatives of state pipeline safety agencies, representatives of distribution pipeline\n9 House of Representatives Report 108-792, November 20, 2004.\n10 Office of Pipeline Safety, Pipeline and Hazardous Materials Safety Administration, Department of\nTransportation, “Assuring the Integrity of Gas Distribution Pipeline Systems: A Report to the Congress,”\nMay 2005.\n\n<<<PAGE 11>>>\n\nIntegrity Management for Distribution Pipelines 7\nPhase 1 Investigations\nowners (both investor-owned and municipal agencies), and members of the interested\npublic. Representatives of PHMSA also participated.\nManagement oversight was provided by an Executive Steering Group, consisting of state\nregulatory commissioners, industry executive managers, and members of the public.\nDay-to-day coordination was by a Coordinating Group that included managers from state\nagencies and the industry trade associations (American Gas Association and American\nPublic Gas Association). The principal investigations were conducted by four\nwork/study groups:\n• Strategic Options Group – evaluating strategic approaches to implementing\nintegrity management elements for distribution pipelines\n• Risk Control Practices Group – evaluating existing risk control practices, required\nand/or implemented voluntarily by operators, and the adequacy of existing\nregulations and guidance\n• Excavation Damage Prevention Group – evaluating means to reduce the\nfrequency of damage from excavation near pipelines, which is the predominant\ncause of distribution pipeline incidents\n• Data Group – evaluating existing data on incidents and leaks to identify factors\nimportant in preventing distribution incidents and correlating information from\nsurveys of the efficacy of excess flow valves as a risk mitigation tool\nThe groups conducted their investigations in parallel, to allow this program to be\ncompleted promptly (work began in March 2005). Information was exchanged among\nthe groups as needed. Each group prepared a report documenting its work, and these\nreports are included as attachments to this report. The responsibilities of each work/study\ngroup are described in more detail in the May, 2005, PHMSA Report to Congress and in\nthe Action Plan that was included in that report.\nThe findings and conclusions of each work/study group are presented in their individual\nreports (which are attached to this report). Inconsistencies or conflicts between the\nfindings of individual groups were addressed by the Coordinating Group. The resulting\nkey findings of the overall program are described in the sections of this report that follow.\nIn the event conflicting statements exist between the work/study group reports and the\nmain body, the information in the main body prevails. The work/study groups also\nidentified, and documented in their reports, a number of actions that would be appropriate\nfor future work as PHMSA and industry prepare to implement an integrity management\napproach for distribution pipelines. The key elements of this path forward are also\ndescribed in this summary report.\nThe members of the groups involved in Phase 1 provide this report to support actions by\nPHMSA and industry as they proceed with subsequent phases. This summary report has\nbeen prepared to make the findings and conclusions readily available for all stakeholders\nwho will be involved in implementing integrity management principles for distribution\npipelines.\n\n<<<PAGE 12>>>\n\nIntegrity Management for Distribution Pipelines 8\nPhase 1 Investigations\nReview by PHMSA Advisory Committees\nThe status of this work was reviewed with the Technical Pipeline Safety Standards\nCommittee and the Technical Hazardous Liquid Pipeline Safety Standards Committee,\nmeeting in joint session, on December 13, 2005. The hazardous liquid pipeline\ncommittee was included in this review, because the findings regarding federal legislation\nto advance damage prevention programs will affect all types of pipelines.\nThe committees supported the general concepts reflected by the product of this effort,\nrecognizing that PHMSA would proceed with rulemaking based on these concepts.\nMembers expressed concern about the imposition of a complex federal requirement on\nsmall pipeline operators, including master meter operators, and agreed that additional\nclear guidance will be needed to facilitate their compliance.\n3. Key Findings\nEach work/study group reached a number of findings and conclusions about the areas\ncovered by their investigations. A complete list of the group findings is presented in\nAppendix B to this report. Additional discussion, including further explanation by the\ngroups regarding their findings and conclusions, can be found in the individual group\nreports, which stand alone but are attached to this report for the reader’s convenience.\nEach work/study group was asked to identify its “key” findings for purposes of this\nsummary report. These key findings address a number of issues that will be important as\nfurther work is undertaken to enhance the integrity management approach for distribution\npipelines. These issues are discussed here, along with the key findings that relate to each.\nThis presentation is intended to allow the reader to gain an overview of the important\nissues. It must be emphasized that, although the work/study groups have identified these\nas their most important findings, all group findings have importance. Future work should\nconsider all group findings and conclusions.\nNational Focus of Integrity Management Efforts (Threats)\nThe integrity management process begins with consideration of what is important to\nassure pipeline safety, that is, what are the threats to integrity? Understanding the threats\nis the first step in identifying the appropriate actions to assure integrity. The PHMSA\ncollects data on threats affecting pipelines through incident reports. Operators must\ncharacterize each incident they report as being in one of eight categories. The categories\nare:\nCorrosion Material or Welds\nNatural Forces Equipment\nExcavation Operations\nOther Outside Force Damage Other\n\n<<<PAGE 13>>>\n\nIntegrity Management for Distribution Pipelines 9\nPhase 1 Investigations\nThese threat categories are appropriate as a foundation for integrity management\nprograms. They represent broad categories. Each can be further subdivided into specific\nthreats. For example, corrosion can be internal or external corrosion. It can be general\ncorrosion or localized pitting. Where appropriate, operators will need to evaluate their\nthreats at this finer level of detail to identify and implement appropriate responsive\nactions. However, the general categories, matching the current data collection\nrequirements, are appropriate categories for integrity threats on a national basis.\nThe Data Group evaluated available historical data to identify trends. For distribution\npipelines, excavation damage is the predominant cause of reported incidents. Corrosion\nis the major cause of leaks, but a small fraction of incidents result from corrosion. The\nData Group reached a key finding concerning this review of available data:\nWhile a decreasing trend in the rate of reportable distribution incidents resulting\nin fatalities and injuries, including incidents caused by outside force damage,\nexists for the preceding 13-years, no statistically significant trend was identified\nfor total reportable distribution incidents for that same period.\nWhile this conclusion is encouraging, it supports the need to explore new requirements\nfor integrity management that will help reduce the occurrence rate of all incidents.\nRegulatory Needs\nThe major question, then, is what kind of requirements would be most appropriate to\nimplement an integrity management approach for distribution pipelines? This question\nwas considered by the Risk Control Practices Group and the Strategic Options Group.\nIt is important to recognize the wide diversity that exists among distribution pipeline\noperators. Some operators are very large, serving more than one million customers.\nSome operators are very small, such as master meter operators serving only a few\ncustomers. Many operators serve from 100 and 10,000 customers, and a sizable majority\nof these operators are municipal agencies.\nThe pipeline systems that these operators manage are very diverse. Larger systems, in\nareas where gas service has been available for many years, can include thousands of\nmiles of pipeline of various materials and ages. Systems in areas where gas service has\nonly been available in recent years can be more uniform, consisting of one or a few types\nof pipe with similar fittings and connections installed using uniform procedures. The\nsmallest systems, such as many master meter systems, may include a limited amount of\npipeline, of one material, and all installed at the same time. The issues important to\nassuring the integrity of these diverse systems will vary.\nThis diversity makes it difficult for any one prescriptive requirement to address all\npossible circumstances. It is important that any new requirements that are developed\nallow sufficient flexibility for the operators of distribution pipeline systems, and the state\n\n<<<PAGE 14>>>\n\nIntegrity Management for Distribution Pipelines Phase 1 Investigations\n10\nregulators who oversee their operations, to customize their integrity management efforts\nto address their specific systems, threats, and issues.\nThe Risk Control Practices Group examined existing federal regulations and the effect\nthey are having, to determine if there were any gaps that would need to be filled by any\nnew integrity management regulations. The group reached a key finding in this area:\nCurrent design, construction, installation, initial testing, corrosion control, and\noperation and maintenance regulations should be effective in providing for\nintegrity of the distribution facilities that are being installed today.\nThis conclusion assures us that current requirements are adequate to “build in” necessary\nsafety for new distribution pipeline systems. New integrity management requirements,\nthen, can focus on improving safety for existing systems and assuring that the built-in\nlevel of safety is maintained for new pipelines.\nThe Strategic Options Group considered the form in which new requirements\nimplementing integrity management would be most useful. The group reached two key\nfindings in this area:\nThe most useful option for implementing distribution integrity management\nrequirements is a high-level, flexible federal regulation that excludes no\noperators, in conjunction with implementation guidance, a nation-wide education\nprogram expected to be conducted as part of implementing 3-digit dialing for\none-call programs, and continuing research and development.\nA small number of elements are all that is needed to describe the basic structure\nof a high-level, flexible federal regulation addressing distribution integrity\nmanagement. These elements are:\n• Development of an integrity management plan\n• Know your infrastructure\n• Identify threats (existing and potential)\n• Assess and prioritize risk\n• Identify and implement measures to mitigate risks\n• Measure performance, monitor results, and evaluate effectiveness\n• Report results\nFinally, the Risk Control Practices Group reached a key finding regarding the necessary\nscope of any new integrity management requirements.\nSince the entire distribution system will be covered by the proposed distribution\nintegrity management program (DIMP) plan, there is no need to identify high\nconsequence areas or identified sites as part of the DIMP plan.\nThis means that integrity management requirements for distribution pipelines can be both\nsimpler and more broadly applied than the requirements applicable to other pipelines.\n\n<<<PAGE 15>>>\n\nIntegrity Management for Distribution Pipelines Phase 1 Investigations\n11\nFor hazardous liquid and gas transmission pipelines, it was necessary to identify high\nconsequence areas – those locations in which a pipeline accident could have the greatest\neffect. The focus of integrity management requirements for those pipelines was then on\nthe identified areas. For distribution pipelines, high consequence areas need not be\ndefined, and integrity management requirements will affect the entire pipeline system.\nGuidance\nHistorically, guidance developed by a consensus process has been used by operators to\nassist them in implementing most regulatory requirements. The Gas Piping Technology\nCommittee (GPTC) has developed and maintains a guideline addressing federal\nrequirements applicable to distribution pipeline systems. The American Society of\nMechanical Engineers (ASME) and the American Society of Testing and Materials\n(ASTM) have also developed consensus standards addressing specific technical issues\nwithin their areas of expertise that are important in implementing safety requirements. In\naddition, DOT, through the Transportation Safety Institute (TSI), maintains a small\noperator’s handbook that provides guidance for operators to help assure compliance with\nthe regulations even for operators who lack the resources to develop compliance plans of\ntheir own.\nHigh-level, flexible requirements for integrity management will mean that operators will\nface many choices in deciding what actions to take. Such choices can be facilitated by\nproviding additional guidance that will assist the operators and help to assure that\nintegrity management activities are appropriate for particular circumstances.\nThe Risk Control Practices Group reached two key findings in this area:\nThe PHMSA plan for a “high level, risk-based, performance-oriented Federal\nregulation”11 that requires a specific distribution IMP is supported by the fact\nthat (a) the elements necessary to implement a distribution IMP have been\nidentified; (b) the threats have been identified; and (c) methods exist for operators\nto develop the elements. Operators may need additional guidance materials.\nThe Gas Piping Technology Committee should develop guidance to assist\noperators in determining (a) which threat prioritization methods, (b) which risk\ncontrol practices, and (c) which performance measures are most appropriate for\ntheir risk control program.\nThese findings provide assurance that the foundation for distribution integrity\nmanagement requirements is firm, and suggest areas in which additional guidance would\nbe useful. Special attention will likely need to be given to the needs of the smallest\noperators, who lack the resources to develop integrity management plans on their own.\n11 “Assuring the Integrity of Gas Distribution Pipeline Systems,” Report to the Congress, May 2005,\nSubmitted by Office of Pipeline Safety, Pipeline and Hazardous Materials Safety Administration, U.S.\nDepartment of Transportation, p. 3.\n\n<<<PAGE 16>>>\n\nIntegrity Management for Distribution Pipelines Phase 1 Investigations\n12\nPreventing Excavation Damage\nExcavation damage is the single most significant cause of incidents on distribution\npipeline systems. Many, perhaps most, incidents that result from excavation damage\noccur immediately, at the time the damage is inflicted. Thus, reducing incidents caused\nby this threat requires that the threat itself be reduced, i.e., that damage be prevented in\nthe first place.\nThe significance of this threat led to the establishment of a work/study group dedicated\nspecifically to considering ways in which excavation damage could be reduced.\nReducing the frequency of excavation damage requires changes in behavior by persons\nwho are not regulated by pipeline safety authorities, that is, contractors and others who\nperform excavation. Practical actions that operators can implement can have only limited\neffectiveness in reducing the frequency of damage events. It would be impractical to\nrequire that distribution pipeline operators monitor and restrict the activities of those\nconducting excavations near their pipelines. Instead, action is needed on a broader basis\nthan simply additional regulation imposed on pipeline operators.\nThe Excavation Damage Prevention Group reached four key findings in this area:\nExcavation damage poses by far the single greatest threat to distribution system\nsafety, reliability and integrity; therefore excavation damage prevention presents\nthe most significant opportunity for distribution pipeline safety improvements.\nStates with comprehensive damage prevention programs that include effective\nenforcement have a substantially lower probability of excavation damage to\npipeline facilities than states that do not. The lower probability of excavation\ndamage translates to a substantially lower risk of serious incidents and\nconsequences resulting from excavation damage to pipelines.\nA comprehensive damage prevention program requires nine important elements\nbe present and functional for the program to be effective. All stakeholders must\nparticipate in the excavation damage prevention process. The elements are:\n1. Enhanced communication between operators and excavators\n2. Fostering support and partnership of all stakeholders in all phases\n(enforcement, system improvement, etc.) of the program\n3. Operator’s use of performance measures for persons performing locating\nof pipelines and pipeline construction\n4. Partnership in employee training\n5. Partnership in public education\n6. Enforcement agencies’ role as partner and facilitator to help resolve\nissues\n7. 8. 9. Fair and consistent enforcement of the law\nUse of technology to improve all parts of the process\nAnalysis of data to continually evaluate/improve program effectiveness\n\n<<<PAGE 17>>>\n\nIntegrity Management for Distribution Pipelines Phase 1 Investigations\n13\nFederal Legislation is needed to support the development and implementation of\ndamage prevention programs that include effective enforcement as a part of the\nstate's pipeline safety program. This is consistent with the objectives of the state\npipeline safety programs, which are to ensure the safety of the public by\naddressing threats to the distribution infrastructure. The legislation will not be\neffective unless it includes provisions for ongoing funding such as federal grants\nto support these efforts. This funding is intended to be in addition to, and\nindependent of, existing federal funding of state pipeline safety programs12\n.\nAddressing these findings will help establish a situation in which those responsible for\nexcavation damage to pipelines will be required and motivated to modify behavior in a\nway that will reduce the frequency of such damage. As noted in the first key finding\nabove, this represents the greatest single opportunity for distribution pipeline safety\nimprovements.\nExcess Flow Valves\nExcess Flow Valves (EFV) are devices that can be installed in each service line and that\nmay shut off gas flow if the line is severed downstream of the valve. These valves\nrepresent a measure that may mitigate the consequences of some incidents if they occur\ndespite the preventive actions that may be taken to reduce the likelihood. ","truncated":true,"body_characters":583404}