The main purpose of this HVDC interference analysis project was to investigate the inductive and DC stray current effects of a few different HVDC transmission line systems during lightning-initiated faults as well as steady-state monopolar operations on adjacent metallic pipelines. Simulation forecasts in this project revealed different levels of DC stray current interference on nearby pipelines during monopolar operations based on the configuration of the HVDC system under study. Conversely, induced transient waveforms during fault scenarios were within the expected range compared to previous staged fault field measurements performed in the past project. Conducting these simulations will provide increased confidence when undertaking mitigation design by highlighting interference hot spots, therefore assisting with the design of more efficient mitigation systems to address both personnel safety and pipeline integrity concerns.