Ground Penetrating Radar Systems, Inc. (GPRS) was recently hired by a local contractor to utility scan various locations within Bruce Mansfield power plant for new utility pole installations. Each pole was to be set in place to run overhead electric lines for the plant. The scope of work was to scan 10’ x 10’ areas around each potential boring location. The client had already marked each location and the client performed a site walk down of all scan locations prior to work. This was the second of four phases the client was set to install. GPRS had already helped complete the first phase.

After the site overview, we began by marking out each scan area. This allows the client to have confidence in being able to move each potential location, if needed, knowing these areas were thoroughly scanned. Secondly, having a visual of the scan area. We then began EM scanning with radio detection equipment passively and all other methods available. We then setup and used our GPR (ground penetrating radar) unit. The unit used on site was 4000 SiR with a 400 mHz antenna. By way of our equipment and the procedures in place, we were able to successfully find known and unknown utilities within these areas. During the course of the shift, we successfully located utilities in line with 3 of the 7 potential borings. The pictures below will describe some of our findings:

The unknown pipe located here was found about 4.5 – 6’ in depth. Located with both EM and GPR.

This was a large pipe that reached into a restricted area.

The client’s potential boring (marked in orange) was to have an average depth of 7’

The client was able to move this boring to a safer location within the scan boundary.

This electric duct bank shown here, had six conduits at about 3’ in depth. Not locating this properly before drilling could have caused extreme harm.

Again, the client’s markings were right in line with this duct bank.

We advised the client on safer areas to move the locations to avoid these utilities within the scan boundaries.

This not only could have saved the client from any damage to conduits and piping, but also very health hazardous situations. The client redesigned their overhead scheme in these areas. The new locations were set in place within the scan boundary before drilling was set to start.

A third location was also moved during the locate. A small, non-conductive conduit was discovered with GPR in close proximity to the potential boring. Only with the use of grounding penetrating radar was conduit discovered.

Precautionary measures were used to relocate this boring.

GPRS continued in to locate in timely fashion to start the third phase of the project which helped the client further into their future scope.

In this case, we were able to help the contractor avoid any further damage to the existing conduits and piping. Even more importantly, prevent any injuries.

Prior to breaking any ground, have GPRS locate the utilities on site. Create a safer workplace for you and your employees. Contact Shaun Lucas, 412.852.3093 or shaun.lucas@gprsinc.com , for your next project.

GPRS does not provide geophysical, geological, land surveying or engineering services. If you need such services, please contact an appropriate professional.