The resolution of mitigation design problems associated with an AC a transmission line collocated with a natural gas pipeline is reviewed. Mitigation design was complicated by a high level of magnetic field coupling to the pipeline and high soil resistivity along the right-of-way. The results of the computer modeled simulation, which optimized the design for touch potential control, are presented. Problems encountered in the mitigation system installation are discussed. Validation of the
mitigation design was made by comparing voltage measurements made on the completed pipeline with values predicted by the computer simulation.
Keywords: ac interference, induced ac voltages, interference modeling, power line collocation, pipeline voltage mitigation, pipeline grounding