Remote hose bib uphill from house

I want to add a ground-mounted hose bib at the front of our lot, about 20' away from the house and 30' above both the incoming water line and the lowest tap in the house.

Unfortunately, trenching to frost depth isn't feasible because the soil is mostly rock.

The best idea I can come up with is to run irrigation pipe in a shallow trench (6") and install a dump valve so the pipe can be drained before frost.

Is there any safe and legal way to make this work without needing an RPZ (or similar backflow preventer) that requires annual inspection?


Due to the backflow hazard, I'm not going to install this myself. I'm just trying to figure out if the installation is feasible before I call a plumber for an estimate. Travel time charges here are substantial.

Any hose thread mounted backflow valve will prevent the line from draining before freezing weather occurs. The backflow device will have to be before the drain point, which means your code requirements will determine whether you need an RPPBFP or a lesser "pressure backflow preventer".