Project: T153700 #3715

Utilities are under pressure to minimize separation between undergroundpipelines and overhead electric power lines. Ever increasing cost of landacquisition and usage force utilities to use narrow utility corridors, whereunderground pipelines are sharing the right of way (ROW) with high voltageoverhead power lines.

While electrical interactions (inductive, capacitive and conductive) are wellexplained during steady state and fault conditions, one extreme condition, when thesoil becomes ionized and direct arcing occurs between the high voltage tower/polefoundation and the underground pipeline is not well defined. Existing studies donot provide reliable assessment method(s) to establish a reliable but realisticseparation distance.

The objective of this project is to provide an assessment tool for determination ofsafe separation distance between high voltage power line tower/pole footings andunderground pipelines. This tool is to address arcing distance while alsoconsidering the following issues:

  • Corrosion of tower footings and grounding conductors.
  • Puncture of pipeline coatings due to faults.
  • Flashover damage to pipeline isolation flanges.
  • Possible hazardous step and touch potentials to pipeline and utility workers.