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Natural gas service to facilities is a worry to consumers and local government because it has potential for fire and explosion. The National Electric Code and some state laws prohibit the use of natural gas service piping as a grounding electrode.
These facts may motivate people to isolate, or to avoid integrating, the natural gas service. Failing to integrate would actually be more dangerous.
The National Ocean and Atmospheric Administration (NOAA) recognizes the need for lightning protection of gas piping systems. Its page on lightning safety and lightning rods states that effective grounding and bonding is important to minimize "the chances for any sparks or side flashes" as lightning current flow is controlled.
The NEC makes provisions for bonding and grounding equipment and surfaces which may become energized. Natural gas service piping comes in from underground, where natural geomagnetic current flow already occurs, meaning that this piping is guaranteed to become energized. However, the NEC tends to emphasize the man-made opportunites for current flow. The reality is that where the current comes from is not as important as the fact of current flow occuring, because this is the hazard being controlled.
A grounding jumper must also be installed pipe-to-pipe around the meter on natural gas supply lines. If the meter is disconnected for maintanence or inspection, then the protection of electrical grounding will continue unaffected. This method is the same as for water supply meters and for piping where other electrical disconnects can occur, such as short runs of nonconductive piping between conductive piping. All of these cause the danger of missing ground, which the grounding jumper resolves.
Natural gas service to facilities creates concern and confusion because of the potential for current flow to ignite the supply of natural gas.
Properly and fully integrated systems at the ISBP will eliminate such concerns about explosion or fire. The natural gas service should be only a small part of a larger ISBP suite where a dedicated GES already exists.
There is actually more danger if the natural gas service is not integrated into the facility ISBP.
The principles of integrated systems bonding require that natural gas supply lines be bonded just as all other services are. The only trick here is to avoid using the natural gas supply lines as one of the few services represented at the ISBP to avoid the grounding system mistaking the natural gas bonding conductor for a grounding electrode. There should already be a dedicated GES and other sponsored services at the ISBP before integrating the natural gas supply line ground into the mix.
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