Gas Pipeline Safety: Views on Proposed Legislation to Reauthorize Pipeline Safety Provisions
Released: 2006-08-04T00:00:00

Letter

Background

The United States has a 295,000-mile network of natural gas transmission pipelines that are owned and operated by approximately 900 operators. These pipelines are important to the nation because they transport nearly all the natural gas used, which provides about a quarter of the nation’s energy supply. Gas transmission pipelines typically move gas products over long distances from sources to communities and are primarily interstate. They generally deliver natural gas to local distribution pipelines, which distribute the gas to commercial and residential end-users. Local distribution companies may also operate small portions of transmission pipelines.

PHMSA administers the national regulatory program to ensure the safe transportation of natural gas and hazardous liquid by pipeline. In general, PHMSA retains full responsibility for inspecting and enforcing regulations on interstate pipelines, but it has arrangements with 48 states, the District of Columbia, and Puerto Rico to assist with overseeing intrastate pipelines. These states are currently authorized to receive reimbursement of up to 50 percent of the costs of their pipeline safety programs from PHMSA.

Traditionally, PHMSA has carried out its oversight role using minimum safety standards that were uniformly applied to all pipelines based on the “class location” of the pipeline. A pipeline’s class location—based on factors such as population within 660 feet of the pipeline—determines the applicable standards such as the thickness of the pipe required and the pressure at which it can operate. The Pipeline Safety Improvement Act of 2002 modified PHMSA’s traditional oversight approach by supplementing the minimum standards with a risk-based program for gas transmission pipelines. This program—termed “integrity management”—requires gas transmission pipeline operators to assess and mitigate safety threats, such as leaks or ruptures due to incorrect operation or corrosion, to pipeline segments that are located in highly populated or frequently used areas, such as parks. Specifically, operators are required to perform baseline assessments on half of the pipeline mileage located in these areas by December 2007, and the remainder by December 2012. Those pipeline segments potentially facing the greatest risks of failure from leaks or ruptures are to be assessed first. As of December 2005 (latest data available), 447 gas pipeline operators reported to PHMSA that about 20,000 miles of their pipelines (about 7 percent of all gas transmission pipeline miles) lie in highly populated or frequently used areas. Individual operators reported that they have as many as about 1,600 miles and as few as 0.02 miles of pipeline in these areas.

The 2002 act also requires that operators reassess these pipeline segments for safety threats at least every 7 years. Under flexibility provided by the act, PHMSA requires that operators reassess these pipeline segments for corrosion damage at least every 7 years in its implementing regulations, because corrosion is the most frequent cause of failures that can occur over time. (See fig. 1.) PHMSA’s regulations also incorporated, as mandatory, voluntary industry consensus standards on maximum reassessment intervals into these regulations for other types of safety threats. The industry standards require that operators reassess gas pipelines at least every 10, 15, or 20 years for all safety threats depending primarily on the condition of the pipelines and the pressure under which they operate. If conditions warrant, reassessments must occur more frequently. In addition, operators must perform prevention and mitigation activities—such as monitoring their pipelines for excavation or corrosion damage—on a continuing basis.

Gas Integrity Management Program Benefits Pipeline Safety

Operators are making good progress in assessing and repairing their pipelines, thereby improving the safety of their pipeline systems. As of December 2005, operators had assessed about 6,700 miles of their 20,000 miles—or about 33 percent—of pipelines located in highly populated or frequently used areas. This progress indicates that they are well on their way to meeting the requirement to conduct baseline assessments on 50 percent of their pipelines in these areas by December 2007. In addition to assessing their pipelines, operators are also making progress in fulfilling the requirement to repair problems found on their pipelines in highly populated or frequently used areas. In the 2 years that operators have reported the results of integrity management, they have completed 340 repairs that were immediately required and another 1,981 scheduled repairs in highly populated or frequently used areas. While it is not possible to determine how many of these needed repairs would have been identified without integrity management, it is clear that the requirement to routinely assess pipelines enables operators to identify problems that may otherwise go undetected. Furthermore, the benefits of integrity management expand beyond highly populated or frequently used areas because a large number of operators are using internal inspection tools to assess their pipelines. These tools must be inserted and removed from the pipelines at designated locations that often run through other areas. Consequently, operators reported having assessed about 44,000 miles of pipelines located outside highly populated or frequently used areas, representing about 15 percent of all gas transmission pipelines. While operators are not required to report to PHMSA the results of these expanded assessments, operators we spoke with said that they plan to make necessary repairs identified through the assessments regardless of where they are identified.

We estimate that the integrity management program should offer additional safety benefits over the minimum safety standards for up to 68 percent of the population living close to gas transmission pipelines. This estimate corresponds with PHMSA’s estimate of two-thirds of the population.

A number of representatives from pipeline industry organizations, state pipeline agencies, safety advocate groups, and operators that we contacted agree that integrity management benefits public safety because it requires all operators to systematically assess their pipelines to gain a comprehensive knowledge about the risks to their pipeline systems. Other benefits cited by operators include improved communications within their companies and more strategic resource allocation.

While the operators we contacted generally believe integrity management is beneficial, the program is not without its costs. For example, over half of the operators we spoke with said that they have hired additional staff or contractors as a result of the integrity management requirements. In addition, 19 of the operators we contacted (37 percent) were concerned about the level of documentation needed to support their gas integrity management programs. PHMSA requires operators to develop an integrity management program and provides a broad framework for the elements that should be included in the program. The regulations provide operators the flexibility to develop their programs to best suit their companies’ needs, but each operator must develop and document specific policies and procedures to demonstrate its commitment to compliance with and implementation of the integrity management program. Operators may use existing policies and procedures if they meet the requirements of integrity management. In addition, an operator must document any decisions made related to integrity management to demonstrate that it understands the threats to their pipelines and is systematically managing their pipelines for these threats. While the operators we contacted generally agreed with the need to document their policies and procedures, some said that the detailed documentation required for every decision is very time consuming and does not contribute to the safety of pipeline operations. In addition, a few operators expressed concern that they will not know if they have sufficient documentation until their programs have been inspected. Initial inspections of operators by PHMSA and state pipeline agencies have confirmed that some operators are experiencing difficulty with documentation but are generally doing well with assessments and repairs. According to PHMSA and state officials, as operators continue to develop and implement their integrity management programs and as they are provided feedback during inspections, the documentation issues identified during these initial inspections should be resolved.

Another concern raised by 33 (65 percent) of the operators is the requirement to reassess their pipelines for corrosion problems at least every 7 years. This issue is discussed in the following section.

The 7-year Reassessment Requirement Appears to be Conservative

Periodic reassessments of pipeline threats are beneficial because threats— such as the corrosive nature of the gas being transported—can change over time. However, the findings from baseline assessments conducted to date and the generally safe condition of gas transmission pipelines leads us to conclude that the 7-year requirement appears to be conservative. Through December 2005 (latest data available), 76 percent of the operators (182 of 241) reporting baseline assessment activity to PHMSA told the agency that their pipelines were in good condition, free of major defects, and requiring only minor repairs. (See fig. 2.) The remaining 59 operators found 340 problems requiring immediate repairs. About 60 percent of these problems occurred in seven operators’ pipelines. Since PHMSA does not require that operators tell it the nature of the problems found, we do not know how many, if any, were due to corrosion. These assessments covered about 6,700 miles, or about one-third of the nationwide total to be assessed.

It is encouraging that the majority of operators nationwide reported that they found few or no problems requiring immediate repairs, because operators are supposed to assess pipeline segments facing the greatest risk of failure from leaks or ruptures first, as required by the 2002 act. In addition, since operators are required to identify and repair significant problems, the overall safety and condition of the pipeline system should be enhanced before reassessments begin toward the end of the decade.

Regarding the industry’s overall safety record, over the past 5-1/2 years (from January 2001 through early July 2006), there were 143 corrosion- related incidents over the 295,000-mile transmission system (26 per year, on average)—none of which resulted in death or injury. Over the past 10- 1/2 years, 12 people have died and 3 have been injured in two corrosion- related incidents. Neither of these incidents occurred in a highly populated or frequently used area.

About 80 percent of the 52 operators that we contacted prefer that reassessment intervals be based on the condition and characteristics of the pipeline segment rather than on a prescriptive standard. About half of these operators (28) expressed a preference for the industry consensus standard developed by the American Society of Mechanical Engineers (ASME B31.8S-2004) for setting reassessment intervals for time-dependent threats because it incorporates a risk-based approach (for pipeline failure) and is based on science and engineering knowledge. This standard sets reassessment intervals at a maximum of 10 years for high-stress pipeline segments, 15 years for medium-stress segments, and 20 years for low- stress segments. Maximum reassessment intervals, such as those in the industry consensus standard, incorporate such risk concepts as built-in safety factors (e.g., wall stress, test pressure, or predicted failure), conditions, and potential consequences of a pipeline incident on a segment-by-segment basis. The maximum intervals of 10, 15, and 20 years are based on worst-case corrosion growth rates.

Industry consensus standards allow for maximum reassessment intervals for time-dependent threats of 10, 15, or 20 years only if the operator can adequately demonstrate that corrosion will not become a threat within the chosen time interval. If not, then the reassessment must occur sooner, perhaps at 7 or even 5 or fewer years. Furthermore, according to industry consensus standards, it typically takes longer than the 10, 15, or 20 years specified in the standard for corrosion problems to result in a leak or rupture.

The industry consensus standards were developed in 2001 and updated in 2004 based on, among other things, the experience and expertise of engineers, contractors, operators, local distribution companies, and pipeline manufacturers; more than 20 technical studies conducted by the Gas Technology Institute, ranging from pipeline design factors to natural gas pipeline risk management; and other industry consensus standards including the National Association of Corrosion Engineers standards, on topics such as corrosion. Contributors have been practicing aspects of risk-based assessments successfully for over 10 years. The ASME standard serves as a foundation for nearly every section of PHMSA’s integrity management regulations. The ASME standard was reviewed by the American National Standards Institute. The Institute found that the standard was developed in an environment of openness, balance, consensus, and due process and therefore approved it as an American National Standard.

While the mechanical engineering standards are voluntary for the industry, PHMSA incorporated them as mandatory in its gas transmission integrity management regulations. The mechanical engineering society’s standard for setting reassessment intervals is not the only industry consensus standard in PHMSA’s integrity management regulations. The regulations incorporate other industry consensus standards for assessing corrosion threats and for determining temporary reductions in operating pressure. In addition, it is federal policy to encourage the use of industry consensus standards: Congress expressed a preference for technical standards developed by consensus bodies over agency-unique standards in the National Technology Transfer and Advancement Act of 1995. The Office of Management and Budget’s Circular A-119 provides guidance to federal agencies on the use of voluntary consensus standards, including the attributes that define such standards.

Of the 52 operators we contacted, 44 had undertaken baseline assessments, and 23 of these have calculated their own reassessment intervals. Twenty of these 23 operators indicated that, based on the conditions they identified during their baseline assessments, they would reassess their pipelines at maximum intervals of 10, 15, or 20 years—as allowed by industry consensus standards—if the 7-year reassessment requirement were not in place. The remaining three operators told us that they would reassess their pipelines at intervals shorter than the industry consensus standards but longer than 7 years because of the condition of their pipelines. These results add weight to our assessment that the 7-year requirement appears to be conservative for most pipelines.

Safeguards Exist if an Alternative Standard for Corrosion Reassessments is Allowed

PHMSA and the state pipeline agencies plan to inspect all operators’ compliance with integrity management reassessment requirements, among other things, to ensure that operators continually and appropriately assess the conditions of their pipeline segments in highly populated or frequently used areas. These inspections should serve as a check as to whether operators have identified threats facing these pipeline segments and determined appropriate reassessment intervals. PHMSA and states have begun inspections and expect to complete most of the first round of inspections no later than 2009. As of June 2006, PHMSA has completed 20 of about 100 inspections and, as of January 2006, states have begun or completed about 117 of about 670 inspections. Initial results from these inspections show that operators are doing well in assessing their pipelines and making repairs, but, as discussed earlier, some need to better document their programs. Based on the initial inspection results to date, PHMSA and states did not find many issues that warranted enforcement actions.

Finally, it is important to note that, in addition to periodic reassessments, operators must perform prevention and mitigation activities on a continuing basis. PHMSA regulations require that all operators of pipelines, including those outside highly populated or frequently used areas, patrol their pipelines for excavation and other damage, survey for leakage, maintain valves, ensure that corrosion-preventing protections are working properly, and take other prevention and mitigation measures. (Attachment I summarizes results of our work to date on the expected availability of resources for pipeline reassessments and the likely impact of assessment activity (including reassessments) on the nation’s natural gas supply. We will discuss these topics in more detail in when we report on the 7-year reassessment requirement this fall.)

Increasing State Funding Appears Reasonable, but Funding Sources and Oversight Plans Would Need To Be Addressed

The Subcommittee’s draft bill proposes to increase the matching funds that PHMSA provides to states for pipeline safety program activities from a maximum of 50 percent to a maximum of 80 percent of a state’s pipeline safety program costs. The increased funding would offset states’ increased workload, such as activities related to gas transmission integrity management and other provisions in the 2002 act. All three legislative proposals also contain provisions, such as damage prevention programs, that could increase states’ workloads. Furthermore, state pipeline safety activities would increase if PHMSA implements its planned integrity management program for distribution pipelines. Our recent survey to state pipeline safety agencies about their integrity management oversight programs showed that 39 of 47 state agencies are experiencing challenges in staffing, which could require increased funding. For example, two state officials told us that state agencies are losing trained inspectors because the state salaries are typically lower than what operators pay. PHMSA proposes to implement the increased funding in 5 percent increments over a 6-year period starting in fiscal year 2008.

We believe that the proposed increase in state grants to offset expanded state activities appears reasonable, provided that appropriate funding sources are identified and that the activities are included in PHMSA’s oversight of state pipeline safety programs. According to PHMSA, the agency has several options for increasing funding for state grants, but has not developed a specific plan for how to provide additional funds. One option is for PHMSA to reprioritize its budget to channel additional funds from other activities, such as research, to states. Another option may be to increase user fees that are charged to pipeline companies. User fee assessments in fiscal year 2006 were about $150 per pipeline mile for natural gas transmission operators and about $76 per pipeline mile for hazardous liquid pipelines. All of these options involve tradeoffs among PHMSA’s pipeline safety oversight activities or could result in increased fees from the pipeline industry. Therefore, the effects of these options would need to be carefully analyzed in order to find a balanced solution.

According to PHMSA, the agency plans to monitor increased state pipeline safety activities through its current oversight approach, which consists of reviewing annual reports from states and field evaluations of state activities. States are required to submit documentation annually about their pipeline safety program activities for the previous year, including information on the state’s pipeline operators, inspections conducted, and enforcement of pipeline regulations. States are also required to submit a description of all ongoing and planned activities and an estimate of the total expenses for the next calendar year. PHMSA validates the information submitted by each state and attends at least one state inspection during field evaluations. As state pipeline safety activities expand, PHMSA would need to determine the best approach for including the new activities in its oversight of state pipeline safety programs.

Concluding Observations

The overall integrity management framework laid out in the Pipeline Safety Improvement Act is improving the safety of gas transmission pipelines. We have not identified issues that bring into question the basic framework of integrity management. Overall, we believe that PHMSA has done a good job in implementing the act. While we expect to make several recommendations to PHMSA when we complete our work, they will be aimed at incremental improvements, rather than major restructuring. Finally, regarding the 7-year reassessment requirement, our preliminary view is that these reassessment intervals should be based on technical data, risk factors, and engineering analyses rather than a prescribed term. We expect to make a recommendation to the Congress that the 2002 act be amended along these lines when we report on this issue. We expect to report to this Subcommittee and to other committees both on PHMSA’s implementation of integrity management and the 7-year reassessment requirement in September.

GAO Contact and Staff Acknowledgements

For further information on this statement, please contact Katherine Siggerud at (202) 512-2834 or siggerudk@gao.gov. Individuals making key contributions to this statement were Jennifer Clayborne, Anne Dilger, Seth Dykes, Maria Edelstein, Heather Frevert, Bert Japikse, Timothy Guinane, Matthew LaTour, James Ratzenberger, and Sara Vermillion.

Appendix: Availability of Resources to Conduct Reassessments and Possible Impacts on the Nation’s Natural Gas Supply

This appendix summarizes results of our work to date on the expected availability of resources for pipeline reassessments and the likely impact of assessment activity (including reassessments) on the nation’s natural gas supply.

Impact of Periodic Reassessments on Natural Gas Supply May be Less than Foreseen

As the Pipeline Safety Improvement Act of 2002 was being considered, INGAA analyzed the possible impact of requiring assessments and periodic reassessments and found that significant disruptions in the natural gas supply and considerable price increases could occur. A more moderate impact was predicted in three subsequent analyses—two reviews of the INGAA study performed for PHMSA by the John A. Volpe National Transportation Systems Center and by the Department of Energy during the congressional debate over the pipeline bill, and a post-act PHMSA evaluation of its implementing regulations. A waiver provision was included in the 2002 act after INGAA’s study was completed; this may serve as a safety valve if it appears that the natural gas supply may be disrupted. Finally, of the 44 natural gas pipeline operators that we contacted that had begun baseline assessments, 26 operators (59 percent) indicated that their assessments and repairs did not require them to shutdown their pipelines or reduce their operating pressure. Sixteen (36 percent) reported minor disruptions in their gas supply because they temporarily shut down pipelines and reduced operating pressure to conduct assessments or repairs. They told us that they used alternate gas sources, such as liquefied natural gas, to sustain their customers’ gas supply. The remaining two operators told us that they were not able to meet all their customers’ needs, but the customers were able to obtain natural gas from other sources.

This is a work of the U.S. government and is not subject to copyright protection in the United States. It may be reproduced and distributed in its entirety without further permission from GAO. However, because this work may contain copyrighted images or other material, permission from the copyright holder may be necessary if you wish to reproduce this material separately.