I have a sense of how I want to do this, but I'd like to get some advice from those of you who've been in the trade longer. So....

Roughing in for two hand sinks in the backyard of what will be a patio addition to a restaurant. The drain will be tied in to a stack that is within 5 ft once you enter the building. Given the low hydraulic load of the two hand sinks, my thoughts are to do this all in 2" PVC, my only concerns are how deep do I run the drains and the water lines, even though I'm going to install a heat trace. Further more, would you think it smart to build a conduit that will house the individual water lines, just to protect them from the elements? Is using 3/4" pex ok for this?

I'm going to put a clean out on the stack itself (currently isn't one; the guy in there before me was a hack) and a clean out before the drain enters the building outside. For the water lines, ill be building a flush able system by way of air compressor for the off season months.

If you need any additional info and ill include it, but if you have any advice or see flaws I'd really appreciate your help.

Thanks brothers and sisters