How GPRS Utility Locating & Video Pipe Inspection Services Ensure Safe Construction

How GPRS Utility Locating & Video Pipe Inspection Services Ensure Safe Construction

A paper mill in south-central Ohio was expanding, and the contractor needed an accurate map of all subsurface utilities on the property to keep the project on time, on budget, and safe.

GPRS was able to locate and map all utilities on the site, so that the contractor could determine where it was safe to excavate, safe to build over the existing infrastructure, and what utilities would need to be relocated.

Inside a paper mill.
A paper mill in south-central Ohio was expanding, and the contractor need an accurate map of all subsurface utilities on the property to keep the project on time, on budget, and safe.

The paper mill is in Chillicothe, Ohio, about 45 miles south of Columbus along the Scioto River. Josh Domingues was one of the GPRS Project Managers (PMs) on the project, and he primarily relied on ground penetrating radar to locate and map the site’s buried utility lines.

“It was gas lines, communication lines, and electric duct banks,” Domingues said. “It was a flat [site] with gravel and some grass, and they were just extending the existing building.”

Ground penetrating radar (GPR) is a non-destructive detection and imaging technology which emits radio waves into the ground or within a surface such as concrete to visualize what is hidden within. When the waves encounter a subsurface object – metallic or non-metallic – they interact with it in a way that the GPR unit can detect. These interactions are displayed in a readout as a series of hyperbolas that vary in size and shape depending on the type of material the radio wave encountered.

A GPRS Project Manager uses ground penetrating radar to conduct a utility locate.
GPRS Project Managers use ground penetrating radar (GPR) to locate utilities underground and scan concrete for embedded conduit, post tension cable, and rebar.

It takes specialized training for a professional utility locator to interpret this data and provide you with accurate, actionable data on where you can and can’t dig.

The best training and specification for this kind of work is the Subsurface Investigation Methodology (SIM), which is what GPRS uses to train its PMs in conducting utility locating, precision concrete scanning, video (CCTV) pipe inspection, and leak detection services.

SIM teaches that the best way to ensure accurate, consistent data when investigating subsurface infrastructure is to utilize multiple technologies and a repeatable process. When a GPRS PM is conducting a utility locate, that means using both GPR and electromagnetic (EM) locating.

Unlike a GPR scanner, an EM locator can’t locate a buried pipe or cable; instead, it detects the electromagnetic signal radiating from the utility.

These signals can be created in several different ways:

  • An EM locator’s transmitter applying current to the pipe
  • Current flow in a live electrical cable
  • A conductive pipe acting as an antenna and re-radiating signals from stray electrical fields and communications transmissions
A GPRS Project Manager holding an EM locator and spray paint.
Electromagnetic (EM) locating is a complementary technology to ground penetrating radar when conducting utility locates.

Because an EM locator functions differently than GPR, the two technologies have different limitations and advantages and can therefore act as perfect complements to one another during a utility locate.

In Chillicothe, however, Domingues was able to rely heavily on his GPR scanner. This is because the sandy soil in the riverside city is conducive to GPR use, allowing for greater signal penetration as compared to the clay-rich soil more commonly found across Ohio.

“It was kind of weird [to see sandy soil] with it being Ohio, but we were able to see about 7-to-8 feet deep,” Domingues said.

A GPRS Project Manager lowers a remote-controlled sewer scope into a manhole.
GPRS’ video pipe inspection services utilize remote-controlled rovers and push-fed cameras to provide you with a comprehensive understanding of your storm and wastewater infrastructure.

In addition to utility locating, GPRS deployed our video pipe inspection (VPI) services to investigate and map the paper mill’s existing waste and stormwater infrastructure.

This sewer scope inspection service utilizes state-of-the-art, remote-controlled rovers equipped with CCTV cameras and sondes: instrument probes that allow GPRS Project Managers to ascertain the location of underground utilities from an inaccessible location. Push-fed cameras equipped with sondes are utilized to investigate pipes too small to access with the rovers.

GPRS inspects your sewer and storm lines for defects such as inflow/infiltration, cross bores, blockages, and other problems that could cause soil contamination, service interruptions, or worse.

GPRS VPI Project Managers are certified in the National Association of Sewer Service Companies’ (NASSCO) Pipeline Assessment Certification Program (PACP), Lateral Assessment Certification Program (LACP), and Manhole Assessment Certification Program (MACP) so they know how to consistently and accurately assess the condition of your pipelines, laterals, and manholes.

When you hire GPRS to conduct a sewer inspection, you receive comprehensive WinCan reporting that includes detailed descriptions of any pipe defects found, and video footage and screenshots of these problems. The defects are ranked by severity and geolocated, so you know what needs to be addressed first and exactly where you need to dig to conduct repairs.

With the information collected by our PMs, the contractor on the Chillicothe project was able to complete the expansion of the paper mill without causing costly and potentially dangerous subsurface damage.

At GPRS, we’re in pursuit of 100% subsurface damage prevention. From skyscrapers to sewer lines, we Intelligently Visualize The Built World® to keep your projects on time, on budget, and safe.

What can we help you visualize? Click below to schedule a service or request a quote today!

Frequently Asked Questions

Why is private utility locating important?

Striking a single buried utility while excavating costs, on average, $56,000 to repair, and it typically takes 6-8 weeks for that repair to be completed.

Calling 811 to have a one-call contractor provide you with the estimated locations of all public utilities on your job site is required by law, and simply a best practice for helping you avoid expensive and potentially dangerous subsurface damage. Public utilities, however, make up only about 40% of all buried infrastructure; the other 60% is private, and 811 does not locate private utilities. Hiring a professional private utility locating company is the best way to mitigate the risk of subsurface damage on your next project.

What do I get when GPRS conducts a utility locate?

Our Project Managers flag and paint our findings directly on the surface. This method of communication is the most accurate form of marking when excavation is expected to commence within a few days of service.

GPRS also uses a global positioning system (GPS) to collect data points of findings. We use this data to generate a plan, KMZ file, satellite overlay, or CAD file to permanently preserve results for future use.

Additionally, when you hire GPRS to complete a utility locate, you receive a complimentary SiteMap® Personal subscription. SiteMap® (patent pending), is GPRS’ cloud-based infrastructure mapping software solution that provides accurate existing condition documentation to protect your assets & people.

SiteMap® is a single source of truth for the field-verified data collected by our PMs, allowing you to securely access and share this information 24/7, from any computer, tablet, or mobile device.

Learn more about how SiteMap® can help you plan, design, manage, dig, and build better by clicking here to sign up for a personal, live SiteMap® demo today!