Recently I was asked to locate a buried water pipe under 2 feet of sand. The way I was able to do this was: two wires were buried next to the water pipe to operate a valve at the other end. I connected my detector to one of the wires and placed my ground rod as deep as I could in the sand. I began swinging my detector probe back and forth, until I heard a null in between the warbling sound of the detector. (you swing the probe across the buried wire) An oscillating/warbling sound is heard on either side of the buried wire and a null when you are directly over the wire. I was able to follow the null along the buried water pipe and trace its direction from the station back to its valve.

The trick to locating buried wires and sprinkler valves underground is getting to know your detector. Practice listening to know how your detector sounds tracking a known good wire. Listen carefully to the signal your detector is putting out and when the sound changes frequency or pitch, even very slightly, investigate why. When you are directly over the wire you are tracing, the sound you hear from the instrument will remain constant. As you move away from the wire, the signal will change in pitch and then get weaker as you get further away from the buried wire . This change is where you may find the problem you are looking for. When you get to a point where the signal stops or gets weak no matter which direction you turn, go back to the last place the signal was strong and dig. You should find a problem there.

About 2 years ago, I was asked to locate some buried sprinkler valves in a 5 acre park. There were 18 valves, according to the number of wires on the timer. The year before, a landscaping company tried to locate all of them, but could not find two valves. It took a couple of days. After some walking, digging, and communicating with each other by cell phone, we located all 18 of the valves with the detector shown above. Once we located all of the valves, we made a map of their locations. Needless to say, we would have never found some of the valves without some kind of detector. A few of the valves were buried more than a foot below the surface.