2.12 Supply-line Separation

Excavator Project Owner Designer

Practice Statement:

When installing new direct-buried supply facilities in a common trench, a minimum of 12 in. radial separation is maintained between supply facilities, such as steam lines, plastic gas lines, other fuel lines, and direct-buried electrical supply lines. If 12 in. of separation cannot be feasibly attained at the time of installation, then mitigating measures are taken to protect lines against damage that might result from proximity to other structures. Examples may include the use of insulators, casing, shields, or spacers. If there is a conflict among any of the applicable regulations or standards regarding minimum separation, the most stringent are applied.6


  • National Electric Safety Code IEEE C2-2007 (2007 Edition)
  • Industry practices