As long as the proper depth is dug there should be no issue.Can a branch circuit to a generator be side by side with a natural gas pipe in the same trench?
Your adding a problem for both should either need worked on.
In that case why would you allow two conduits of electricity in the same trench? Or a conduit with communications cables in the same trench as the line voltage conduits?
But let's just say you're right:
How far apart would the trenches need to be? Or could you widen the trench so that the pipes were so many inches apart? And if so, how far apart would they need to be.