NTSB’s recent study on systemic weaknesses in gas pipeline safety

News media recently reported that the National Transportation Safety Board (NTSB) found continuing systemic weaknesses in gas pipeline safety. What does the NTSB have to say about where improvements are needed?

The NTSB and the gas pipeline integrity management rules

The NTSB is a congressionally-mandated transportation agency that operates independently to conduct objective accident investigations and safety studies, and advocates for implementation of safety recommendations. The NTSB does not conduct investigations of all pipeline incidents; it investigates those in which there is a fatality, substantial property damage, or significant environmental impact. In the past five years, the NTSB investigated three major gas transmission pipeline accidents in which operator and PHMSA oversight deficiencies were identified as concerns, occurring in Palm City, FL (2009), San Bruno, CA (2010), and Sissonville, WV (2012). These three accidents resulted in 8 deaths, over 50 injuries, and 41 homes destroyed with many more damaged.

The five-member NTSB Board held a meeting on Tuesday and soon after released an abstract of their recommendations. [The full study is now available here.] The study focuses on gas transmission pipelines within High Consequence Areas – basically, areas with higher population – and therefore must have in place an integrity management program. Only about 7% of the nearly 300,000 miles of gas transmission pipelines nationwide are required to have an integrity management program, though the industry says many more miles are inspected under integrity management than what the rules require.

The Pipeline and Hazardous Materials Safety Administration (PHMSA) gas pipeline integrity management program rules took effect in 2004. They require, among other things, that the pipeline operators inspect their gas pipelines at least every seven years, and have a program in place to assess risk and ensure their pipelines are safe and reliable. Integrity management rules are performance-based rather than prescriptive, and rely on the operator to have good and complete data that is continually evaluated. Pipeline operator integrity management programs are periodically inspected by PHMSA and/or state regulators to assess compliance. Theoretically, using integrity management, gas pipeline operators should be finding and addressing potential problems before they result in accidents. Clearly, that is not working as evidenced by the accidents mentioned, leading the NTSB to embark on their study.

The NTSB Study

The study highlights shortcomings of the gas transmission integrity management system, and underscores issues the Trust has been bringing up for years. [See our 2012 comments submitted to PHMSA on gas transmission line safety and our 2014 comments to PHMSA on improving the national pipeline mapping system.] The abstract from NTSB states, “there is no evidence that the overall occurrence of gas transmission pipeline incidents in HCA pipelines has declined.” The complexity of the integrity management programs require expertise in multiple technical disciplines from both operator personnel and pipeline inspectors, and PHMSA does not have the resources for guiding them. The thirty-three findings of the study are published in the abstract and are followed by twenty-eight recommendations.

In brief, many things need improvement, including much better geographic information so that inspectors and operators clearly know where pipelines and high consequence areas are, and all data is better integrated; better communication between state inspections lead by the National Association of Pipeline Safety Representatives and PHMSA; better use of in-line inspection tools and improved operation of the same; better threat identification and assessment methods, with PHMSA acting as a guide for pipeline operators and inspectors in this area; and generally stronger, clearer standards and criteria for both operator and inspector programs and personnel to raise the safety bar higher.

We sincerely hope that 2015 will be remembered not for more terrible pipeline accidents, but for safety improvements that are made in part when studies and recommendations like the NTSB’s are heeded.

New Natural Gas Pipelines and Proximity to Homes

We’ve had a couple inquires in the past few weeks from citizens who have property on or near which a new natural gas pipeline is being proposed. They have asked: 1) How close to homes can one of these pipelines be installed? and 2) What are the options to minimize the danger when developing pipelines in proximity to other structures if the pipeline were to rupture?

The answer to the first question is straightforward: There is no limitation on how close gas pipelines can be built to homes. The federal regulations say nothing about any minimum distance away from homes that pipeline installation must occur. There is language in the regulations that requires operators to generally protect the pipe from hazards, but often much is left up to the discretion of the operator. For example:

CFR §192.317(a), “The operator must take all practicable steps to protect each transmission line or main from washouts, floods, unstable soil, landslides, or other hazards that may cause the pipeline to move or to sustain abnormal loads….”


CFR §192.325(a), “Each transmission line must be installed with at least 12 inches (305 millimeters) of clearance from any other underground structure not associated with the transmission line. If this clearance cannot be attained, the transmission line must be protected from damage that might result from the proximity of the other structure.”

The second question leads to a longer answer. And one we cannot address without making mention of PIPA (the Pipelines and Informed Planning Alliance), a group made up of industry (including representatives from interstate natural gas pipeline operators), government, and public representatives that developed a set of recommended practices for development near existing pipelines. This group met for years to address the very real concerns of development and pipelines impacting one another and posing risks to one another. Recommended practices include things like: “Reduce Transmission Pipeline Risk in New Development for Residential, Mixed-Use, and Commercial Land Use,” which states in part:

“…it is prudent to design buildings and related facilities in a manner that mitigates the potential impacts on people and property from a transmission pipeline incident. Locating structures away from the pipeline right-of-way (ROW), incorporating more stringent building fire safety measures are examples of mitigation techniques that may improve public safety and limit damage to buildings or infrastructure in the event of a transmission pipeline incident.”

It is puzzling to us how the industry can see the importance of these types of recommendations, and not see the importance of turning them around to apply to the development of new pipelines near existing buildings. We have been pushing PIPA to be reinvigorated and tackle this issue, but as of yet it has not happened.

Risks in proximity to gas pipelines are relative to the size and pressure of the pipeline. “A Model for Sizing High Consequence Areas Associated with Natural Gas Pipelines” was published in 2000 by Mark Stephens of C-FER Technologies, and prepared for the Gas Research Institute [LINK]. This report gives detailed explanations and calculations that lead to a proposed hazard area radius as a function of line diameter and pressure (see Figure 2.4 in the report). The hazard area radius is basically the area in proximity to the pipeline within which there would be virtually no chance of survival if a pipeline rupture and fire were to happen, and it varies in size from about 100 feet to about 700 feet for a 6-inch to 42-inch pipeline, respectively. For example, A 26-inch, 600 psi natural gas pipeline would have an approximate 450 foot hazard area radius, according to the C-FER model. The model does not take into account things like wind, topography, and any protection such as berms or fire walls.

States and (if the state does not preempt them) local communities may adopt their own setbacks between pipelines and homes. No jurisdiction that we know of has adopted the C-FER hazard area as the basis of setbacks from natural gas pipelines, though it has often been discussed. For jurisdictions that have adopted some sort of setback or consultation ordinances, see this link.

A few of the ordinances accessed through our website link specifically discuss evacuation, and evacuation is also addressed in the PIPA recommendations. Language repeated in a number of recommendations is “…buildings should have a safe means of egress with exits located where they would not be made inaccessible by the impacts of a pipeline incident. Similarly, cul-de-sac streets should not be designed crossing a transmission pipeline as the only route of ingress or egress could be blocked during a pipeline incident.”

Some gas pipelines lie within High Consequence Areas – basically areas with higher population density – and operators of those pipelines are required to have an integrity management program that includes conducting risk management and regular assessment of the pipeline. Depending on the location, the pipeline may also be required to have thicker walls or more frequent valve spacing.

While we know of no instances where FERC has denied a new gas pipeline application, there are instances where the pipeline route has changed due to environmental, safety, or other concerns brought to light during the FERC proceedings.