PHMSA regulations for both oil and gas pipelines require operators to provide protection against fault currents or lightning impacts on buried pipe.  See 49 C.F.R. parts 192.467(f); 195.575(e).  These rules obligate operators to electrically isolate buried or submerged pipelines from other metallic structures.  Examples of the types of interference that may occur include close proximity to the footings of electrical transmission line towers, ground cables or those areas subject to an unusual risk of lightning.  In those situations, insulating devices must be installed.  There is no established standard for the number or location of insulating devices, but a ‘rule of reason’ applies.  Operators should remember to monitor their systems for changes that may prompt consideration of this requirement.