A locator rod finds underground pipes. Living with a septic tank (which has a leach-field) will sooner or later require you to locate the plumbing to check for clogs or other failures in the lines. Homes w/ underground discharge lines eventually require some maintenance which requires locating the piping.
This simple locator rod with a handle has saved me from digging down 12” or more trying to locate a discharge line when it gets clogged and I need to find the termination point to repair it. I took a 48” piece of 3/8” standard ’cold rolled’ steel rod purchased at any hardware store or building supply and threaded 2” of one end w/a 3/8-16 die. The threading distance will need to be adjusted by the diameter of the handle you will attach to the top if the rod. I used a piece of pipe I had on hand but it could have been a wooden dowel or anything I wanted to cut about 10” long and attach w/2 3/8 nuts and washers.
The other end (the end going into the ground) I took and beat it w/a hammer on my vise but any heavy anvil works, my father’s choice was a sledge hammer head. After enough hammering the end of the rod will flatten and spread to create a ‘blade tip or a paddle foot’ a little wider than the rod.
The wider tip allows you to rotate the rod as you push it into the earth creating a slightly larger hole than the rod which reduces friction. This effect allows you to penetrate the ground w/less effort and have a better ‘feel’ of anything you will contact as you are probing around.