Transmission pipelines carry these products, sometimes  over hundreds of miles, to communities and large-volume users, such as  factories. PHMSA has  estimated there are more than 400,000 miles of hazardous liquid and  natural gas transmission pipelines across the United States. According to PHMSA, industry, and state officials, responding to either a  hazardous liquid or natural gas pipeline incident typically includes  detecting that an incident has occurred, coordinating with emergency  responders, and shutting down the affected pipeline segment. Officials from PHMSA and state  pipeline safety offices perform relatively minor roles during an incident, as  they rely on operators and emergency responders to take actions to  mitigate the consequences of such events. Incident Response Time Depends on Multiple Variables, Including the Use of Automated Valves

Multiple variables—some controllable by transmission pipeline  operators—can influence the ability of operators to respond quickly to an  incident, according to PHMSA officials, pipeline safety officials, and  industry stakeholders and operators. Ensuring a quick response is  important because according to pipeline operators and industry  stakeholders, reducing the amount of time it takes to respond to an  incident can reduce the amount of property and environmental damage  stemming from an incident and, in some cases, the number of fatalities  and injuries. As noted, one variable that influences operators’ response times to  incidents is the type of valve installed on the pipeline. These sources indicated that  the location of the valve, existing shutdown capabilities, proximity of  personnel to the valve’s location, the likelihood of an ignition, type of  product being transported, operating pressure, topography, and pipeline  diameter, among other factors, all play a role in determining the extent to  which an automated valve would be advantageous. Operators we met with are using a variety of methods for determining  whether to install automated valves that consider—on a case-by-case  basis—whether these valves will improve response time, the potential for  accidental closure, and monetary costs. Other  hazardous liquid pipeline operators said they used computer-based spill  modeling to determine whether the amount of product release would be  significantly reduced by installing an automated valve. Defining performance measures and targets for incident response can be  challenging, but one possible way for PHMSA to move toward a more  quantifiable, performance-based approach would be to develop strategies  to improve incident response based on nationwide data. For example,  performing an analysis of nationwide incident data—similar to PHMSA’s  current analyses of fatality and injury data—could help PHMSA determine  response times for different types of pipelines (based on characteristics  such as location, operating pressure, and diameter); identify trends; and  develop strategies to improve incident response. However, we found that  PHMSA does not have the reliable nationwide data on incident response  time data it would need to conduct such analyses. Specifically, the  response time data PHMSA currently collects are unreliable for two  reasons: (1) operators are not required to fill out certain time-related fields  in the PHMSA incident-reporting form and (2) when operators do provide  these data, they are interpreting the intended content of the data fields in  different ways. Our report recommended that PHMSA improve incident  response data and use these data to evaluate whether to implement a  performance-based framework for incident response times. PHMSA  agreed to consider this recommendation. For example, many of the operators we spoke with were unaware  of existing PHMSA enforcement and inspection guidance that could be  useful for operators in determining whether to install automated valves on  transmission pipelines. In addition, while PHMSA inspectors see  examples of how operators make decisions to install automated valves  during integrity management inspections, they do not formally collect this  information or share it with other operators. Given the variety of risk- based methods for making decisions about automated valves across the  operators we spoke with, we believe that both operators and inspectors  would benefit from exposure to some of the methods used by other  operators to make decisions on whether to install automated valves. Our  report recommended that PHMSA share guidance and information on  operators’ decision-making approaches to assist operators with these  determinations. Appendix I: Summary of Recent GAO Reports on Gathering Pipelines and Low-stress Transmission Pipelines

GAO recently issued two reports related to the safety of certain types of  pipelines. While the  consequences of a low-stress transmission pipeline failure are generally  not severe because these pipelines are more likely to leak than rupture,  the point at which a gas pipeline fails by rupture is uncertain and depends  on a number of factors in addition to pressure, such as the size or type of  defect and the materials used to conduct the pipeline.
Why GAO Did This Study

Pipelines are a relatively safe means of transporting natural gas and hazardous liquids; however, catastrophic incidents can and do occur. Such an incident occurred on December 11, 2012, near Sissonville, West Virginia, when a rupture of a natural gas transmission pipeline destroyed or damaged 9 homes and badly damaged a section of Interstate 77. Large-diameter transmission pipelines such as these that carry products over long distances from processing facilities to communities and large-volume users make up more than 400,000 miles of the 2.5 million mile natural gas and hazardous liquid pipeline network in the United States. The Department of Transportation's (DOT) Pipeline and Hazardous Materials Safety Administration (PHMSA), working in conjunction with state pipeline safety offices, oversees this network, which transports about 65 percent of the energy we consume.
The best way to ensure the safety of pipelines, and their surrounding communities, is to minimize the possibility of an incident occurring. PHMSA's regulations require pipeline operators to take appropriate preventive measures such as corrosion control and periodic assessments of pipeline integrity. To mitigate the consequences if an incident occurs, operators are also required to develop leak detection and emergency response plans. One mitigation measure operators can take is to install automated valves that, in the event of an incident, close automatically or can be closed remotely by operators in a control room. Such valves have been the topic of several National Transportation Safety Board (NTSB) recommendations since 1971 and a PHMSA report issued in October 2012.
As mandated in the Pipeline Safety, Regulatory Certainty, and Job Creation Act of 2011, we issued a January 2013 report on the ability of transmission pipeline operators to respond to a hazardous liquid or natural gas release from an existing pipeline segment. This statement is based on this report and addresses (1) variables that influence the ability of transmission pipeline operators to respond to incidents and (2) opportunities to improve these operators' responses to incidents. This statement also provides information from two other recent GAO reports on pipeline safety.

What GAO Found

Numerous variables--some of which are under operators' control--influence the ability of transmission pipeline operators to respond to incidents. For example, the location of response personnel and the use of manual or automated valves can affect the amount of time it takes for operators to respond to incidents. However, because the advantages and disadvantages of installing an automated valve are closely related to the specifics of the valve's location, it is appropriate that operators decide whether to install automated valves on a case-by-case basis. Several operators we spoke with have developed approaches to evaluate the advantages and disadvantages of installing automated valves, such as using spill-modeling software to estimate the potential amount of product released and extent of damage that would occur in the event of an incident.
One method PHMSA could use to improve operator response to incidents is to develop a performance-based approach for incident response times. While defining performance measures and targets for incident response can be challenging, PHMSA could move toward a performance-based approach by evaluating nationwide data to determine response times for different types of pipeline (based on location, operating pressure, and pipeline diameter, among other factors). First, though, PHMSA must improve the data it collects on incident response times. These data are not reliable because operators are not required to fill out certain time-related fields in the reporting form and because operators told us they interpret these data fields in different ways. Furthermore, while PHMSA conducts a variety of information-sharing activities, the agency does not formally collect or share evaluation approaches used by operators to decide whether to install automated valves, and not all operators we spoke with were aware of existing PHMSA guidance designed to assist operators in making these decisions. We recommended that PHMSA should: (1) improve incident response data and use those data to explore the feasibility of developing a performance-based approach for improving operators' responses to pipeline incidents and (2) assist operators in deciding whether to install automated valves by formally collecting and sharing evaluation approaches and ensuring operators are aware of existing guidance. PHMSA agreed to consider these recommendations.