Need to run approx 50' of RG6 coax, electrical line, and water line.

Water line will be PVC Sch40.
RG6 coax will be in light grey conduit (pvc ?)
110 electrical line will be in light grey conduit (pvc ?)

Can they all be in the same trench ?

As long as they are in their own piping you should not have a problem.

Chuck

Yes... As long as you meet the qualifications for the most stringent one.

Off the top of my head, I'm about 60% sure these are the numbers. Power conduit has to be 18" deep, low voltage stuff has no requirements other than it can't go in the same conduit as power. Water depth depended on your location. Irrigation lines that will be blown out in the winter have a much less stringent requirement than a water line: 6"? Sewer and water need to be separated by I think three feet. Gas needs to be 4' deep and separated from power by 4'.

Thanks guys