3/4" brass street 90 into bottom of hydrant, 18" galvinized nipple into that, then a PVC FIP or something similar, wrap the whole thing twice with 20 mil pipe tape up to ground level but skipping the brass body, then set the whole thing on a good sized rock or brick, put pea gravel in, then cover it up. If it's a 2' bury instead of 4' or more, I will drive a steel stake to ground level and tape it the entire length with the same tape.
Over kill? Probably.
1. When I say a PVC FIP of some sort or another. NEVER did I use just a plain PVC FIP. Worst case I use a Sch. 80 FIP with 2 ALL Stainless Steel hose clamps on the threaded end. My dad has been doing the 2 All SS clamps on underground FIPs as long as I can remember and to date we have not heard of any leaking.
What I have also done is put a metal coupling on the end of the nipple then screw in half of a 3/4" x 12 Sch. 80 PVC nipple.
2. These days I will put a 24" to 36" leader of PEX on instead of the galvinized nipple. What do you think about that?