GPRS Goes to Extreme Depths to Locate Pipes
Being experts in underground utility locating, we often get asked “How deep can you locate?” Well if anyone has asked that question before, or knows the industry, the answer usually comes back sounding a little political. The truth is, that different technologies have different limitations when it comes to depth, and different situations/parameters allow for much deeper depths or on the inverse much more depth restrictions. Long story shortened is, each situation is different, and you should call your local GPRS office to ask what we can do with your situation(s).
GPRS received a call a couple months back from a client that needed to locate a pipe that was 35-55 feet deep. In all honesty, they had no idea how deep the pipe was, but they felt it had to be pretty deep because another locating company had no success. The pipe was a plastic 4 inch leachate line at an active landfill in Southern California, and the client was worried that it was clogged. The leachate line was running at a downward 30-45 degree angle from the closest access point and it needed to be accessed about 120 feet away. Good news was that the grade of the land above ground also sloped down, but not at the same degree, thus the client had no idea on how deep the pipe really was.
A major benefit to GPRS having the VPI (video pipe inspection) division, is that they deal with inspecting sewers and storm drains that are very deep all the time. On occasion we have to locate those pipes, so we will use powerful battery powered beacons known as sondes. These sondes transmit a radio signal from inside the pipe and the project manager can locate that signal using a receiver which focuses on that same frequency.
Back to the leachate line, our project manager was equipped with a push camera reel, a powerful sonde, and our EM receiver. It was crucial to have the pushrod camera for this job as it would be important to know if the pipe turned or continued straight. We started by pushing the camera/sonde combo in only 15 ft, and with no issues it was located, already 11 ft deep, yikes. We continued 10 feet at a time, each time getting an accurate locate. Once the camera and sonde reached the needed length of 120 ft in, the camera was at a T intersection, and this was the point where the client needed to dig down and access the pipe. GPRS accurately located the sonde over 55 FT DEEP at this location, wow!
So hopefully if you enjoyed reading this, maybe you will get a little chuckle the next time you hear the question “How deep can you locate?” Or maybe you can enjoy what kind of answer you hear back from that question. Either way, remember that GPRS is here to help your project succeed.
GPRS does not provide geophysical, geological, land surveying or engineering services. If you need such services, please contact an appropriate professional. -