Locating Utilities Near Underground Storage Tanks At A State Prison In California
Ground Penetrating Radar Systems was tasked to locate all underground utilities within a designated area surrounding known underground storage tanks on the grounds of a State Prison.
The customer had been contracted to remove most of the pump and fuel feeding lines to the underground tanks; they also needed all underground utilities located along a proposed trench path to the new proposed fuel pump island. We scanned the entire proposed work area with both an EM locator and ground penetrating radar (GPR) and gave approximate depths when possible. On this site GPRS had some unique findings.
As you can see from the photographs, the gas line, which was located by the EM locator, takes an unexpected route near the connection point. In our experience a route like this usually indicates an existing underground item which had to be avoided. In this case, GPR did not show anything indicating an anomaly in the area such as a previous excavation area or other underground storage tank.
Also seen in the photographs is an electric line, also located with EM, running in an unexpected direction away from all near buildings. Upon further inspection we located electrical switch gear hundreds of yards away near another building. This is a good site to show that underground utilities, while usually predictable, should not be assumed to be in any certain location based on their above-ground indicators.
After GPRS completed scanning the area, the client was able to proceed safely with all their required tasks.
GPRS does not provide geophysical, geological, land surveying or engineering services. If you need such services, please contact an appropriate professional.