I am having a trench dug that passes through our asphalt driveway (previously a public county road). I am running power to a pump house on the far side and want to run two water lines and sprinkler wire back to the main power side. The feeder wires to the pump house will be run in conduit. Water and power lines will be separated horizontally in the 12" wide, 30" deep trench. The sprinkler cable is rated for direct burial. Is the conduit for the feeders sufficient to meet code for separation between the 600-volt-rated feeders and the 30-volt-rated sprinkler cable or does the low voltage cable have to be run in its own separate conduit? I know sprinkler wire doesn't have to be that deep, but it seems like vertical layering in the same trench could make future repairs more complicated. Plus, I want them deeper so they are not damaged by repairing the driveway.
If I put the sprinkler wire in conduit just under the driveway portion of the trench, do I just leave the conduit ends open?