Master Locators provided utility locating services at the Malvern Prep School as part of project involving renovations to the school campus. There were a couple different sites on campus where we located utilities for the purpose of excavation for storm water installation.

Our technicians followed our standard seven steps of locating, using three different pieces of equipment, to mark out all locatable utilities within the scope of work. The first site we located was in a parking lot and open field along the roadway on the Malvern Prep campus. We used GPR and EM scanning to locate several different utility lines including site lighting electric, storm, sanitary, and two unknown lines. One unknown was found using GPR, and the other with a split box. Water lines running through the scope were unlocatable.

The second area we located was outside one of the buildings on campus. We had access to a mechanical room in the basement of the building, where we were able to hook up to the fire service water line and domestic water line to attempt to locate the lines running out of the building. Unfortunately, we were unable to locate the domestic water line from the building, due to the fact that the line was non metallic and therefore we were not able to send a current down the line. Because of the very high utility congestion and rough debris and bricks within the scope, we were unable to get a good reading on the domestic water line or the fire service water line with GPR. The fire service water line was cast iron, but it would not pick up a current for us to locate it with EM.

Our technicians made another effort to locate the water lines by connecting the transmitter to the fire hydrant, where it was suspected that the fire service water line would tie into. However, the current wasn’t picking up any line heading towards the building. After a second attempt, we were able to use GPR to find the water line right where it came out of the building. We followed the line from where it started along the building, until the signal was lost. We picked it back up along the sidewalk and followed it back to the fire hydrant, ultimately finding success in locating the majority of the water line.

This project was a great example of the importance of using both EM and GPR to locate utility lines, as different methods work in different situations. By using both methods paired together, there is a greater chance that we will be able to locate any given utility line.

Deliverables: Mark Out

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