Cross Bores: The Unseen Danger

NASSCO-Certified GPRS Video Pipe Inspectors Can Find Cross Bores Before They Turn Deadly

Cross Bores: The Unseen Danger

NASSCO-Certified GPRS Video Pipe Inspectors Can Find Cross Bores Before They Turn Deadly
A cross bore between utility and water lines.
Cross bores such as this one are a deadly byproduct of trenchless technology. GPRS Video Pipe Inspections can help locate these dangerous subsurface anomalies before they cause injury or worse. 
“Cross bore mitigation is always our team’s biggest focus.” – Andy Jurski, GPRS Senior VPI Project Manager 

Cross bores are a deadly byproduct of progress. There could be one under your feet right now, a ticking time bomb set to go off at the slightest disturbance. 

Cross bores occur when an underground utility line accidentally pierces a sewer or septic line or another underground utility during trenchless, or horizontal, drilling. This method of installing utilities involves drilling into the ground to gouge out a route for the utility line to then be fed through. 

Trenchless technology causes far less ground disturbance than the costly and time-consuming excavations of yesteryear. However, it also comes with the risk of cross bores because the worker boring into the ground to set the utility line’s route can’t tell if their drill bit just pulverized rock or shattered a sewer line. 

The risk associated with cross bores is so high that many of the country’s leading power and gas providers are now requiring their contractors to have VPIs performed both before and after installing new underground utility lines. 

The best way to mitigate cross bores is for GPRS to conduct a Video (CCTV) Pipe Inspection. Our elite team of VPI Project Managers is certified by the National Association of Sewer Service Companies (NASSCO), meaning they’ve received the highest level of training on the most advanced and non-destructive methods to detect dangerous subsurface anomalies, including cross bores. 

Video Pipe Inspections, or sewer scope inspections, are exactly what they sound like; high-definition video cameras are attached to either remote-controlled robots or hand-fed lines, then inserted into sewer, water, and/or lateral lines to inspect them for cross bores and structural damage. 

A cross bore can lie undetected for years before any symptoms develop. The first indication of a cross bore might be as innocuous as a clogged drain in a home kitchen. Most of us would assume something was lodged in the sewer line and simply call a plumber to fix the problem. But if the blockage is caused by a utility line that is accidentally bored into the sewer line, and a mechanical rotary device is used to clear the obstruction, the resulting explosion or electrocution could cause injury, or worse. 

The Eldridge family got lucky when this situation played out at their Middletown, Ohio home. Vikki Gibson was watching her three grandchildren while her daughter, Mechelle Eldridge, was at work. A plumber was in the house trying to unclog a sewer line. 

The plumber had only been at the job a few minutes when he came running up the stairs yelling that Gibson had three minutes to get her grandchildren out of the house. The home went up in flames just seconds after everyone made it to safety, the result of the plumber inadvertently striking a gas line that had been bored into the sewer line. Gibson had to call her daughter and tell her that her house was gone. While of course, the most important outcome was that no lives were lost, the Eldridge family’s lives were forever altered by a utility contractor mistake that no one even knew had been made. 

A sewer line inspection later confirmed that the gas explosion was the result of a cross bore. 

While trenchless technology eliminates the need for expensive and time-consuming excavation, the ever-growing network of various underground utility and water lines means that it is vital for you to know what’s underneath you before you do anything that could potentially bring you into contact with this subsurface labyrinth. 

GPRS Video Pipe Inspection Project Managers perform an inspection at the University of Toledo.
GPRS’ NASSCO-certified Video Pipe Inspection Project Managers are trained to the highest standard possible and use only the most advanced equipment in our effort to eliminate all subsurface utility strikes. 

NASSCO’s mission is “To set industry standards for the assessment, maintenance, and rehabilitation of underground infrastructure, and to assure the continued acceptance and growth of trenchless technologies.” 

Through education, technical resources, and industry advocacy, the organization aims to increase awareness and provide viable solutions for aging underground infrastructure. 

GPRS’ VPI Project Managers go through NASSCO’s Pipeline Assessment Certification Program (PACP), Lateral Assessment Certification Program (LACP), and Manhole Assessment Certification Program (MACP) to learn how to consistently and accurately assess the condition of pipelines, laterals, and manholes. 

NASSCO’s goal for these training programs is to give inspectors the tools they need to do their job to the absolute highest standard, thus ensuring that pipeline systems can be assessed and maintained in a way that maintains efficient operation while also keeping people safe. Having the NASSCO stamp of approval is just one of the ways that GPRS reached a 99.8% accuracy rating for utility locating. 

GPRS Senior VPI Project Manager Andy Jurski explains that what sets GPRS’ VPIs apart is our team’s commitment to following NASSCO’s requirements regarding reportage. 

When GPRS Project Managers conduct a VPI, our clients receive a comprehensive package of information that includes detailed descriptions of any pipe defects found, and video footage and screenshots of those problems. The defects are ranked by severity and geolocated, so the client knows what needs to be addressed first and exactly where they need to dig. 

“With that certification, we’re going through coding the defects, and operational issues, and we’re giving our clients that data,” Jurski said. “Then they can provide that information to an engineer that is knowledgeable and experienced in sewer and water lines…” 

Jurski said that his team has worked with numerous utility companies on inspection projects of all sizes to ensure that new lines are installed safely without interfering with any existing utilities or pipes. 

“We go out and we do a full inspection, and we do a locate map, and then after the contractor comes through, we go out and do a post-inspection, just to show there was no damage caused, that they did not bore through a line,” he said. 

Jurski added that cross bore mitigation is “always our team’s biggest focus” when they are conducting VPIs. 

Cross bores must be front of mind for everyone working with underground utilities. Conducting video inspections of these lines both before and after any work is done is a vital step to ensuring that there are fewer of these incidental time bombs ticking away underneath us. 

GPRS locating services, including Video Pipe Inspection, help ensure that utilities are installed and maintained in a safe and efficient manner. It’s just one way we’re helping to Intelligently Visualize The Built World®. 

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