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.