Can the gas line share the same trench with the electrical conduit? They are both branch circuits and are not on the service side.

I know it is not an NEC issue.

Thank you.

Niko:
Check locally IMHO.

Here in NJ it's not an issue as long as they are not 'side-by-side'.

You may have siesmic issues.

I agree with John. Local policy will dictate this and it may actually be the utilities driving it.

Pacific Gas & Electric does not permit it.

Underground natural gas delivery is by plastic.

No way will PG&E suffer compounding fires -- electric then gaseous.

Common trenches out my way are restricted to power, data, coax... with various horizons at least 12" apart -- sometimes more.

Fresh water, dark water, fire systems, and gas are not permitted in the common trench.

Customer side power is not permitted in the same horizon ( depth ) as utility lines. Utility power is always to be the deepest in the trench -- except if crossing.

Thanks guys.

I have emailed the plumbing inspector for advice.