GPRS Project Manager Jason Houlberg had to get creative when tasked with locating an 18” sewer siphon in Daly City, California.
A siphon is a component of a wastewater collection system that runs under obstructions such as roads or tunnels. The siphon dips under the obstruction, and water is pulled through it by suction from the downstream end of the system.
Our client wanted to know if a siphon in their wastewater system ran down the road next to their property or through adjacent farmland.
GPRS typically uses remote-controlled rovers to conduct sewer scope inspections, which we also call video pipe inspections. We inspect your wastewater system for defects such as cross bores and inflow/infiltration (I/I), and simultaneously map the system using electromagnetic (EM) locators to detect sondes: instrument probes that are attached to the video pipe inspection equipment and allow for locating of unreachable subsurface utilities.
This method, however, wasn’t an option to locate the siphon.
“Siphons are challenging on their own, because they hold water at 100 percent with heavy flow,” Houlberg explained. “This means you can’t inspect a siphon with a sewer scope camera unless the line is dewatered, which was not an option in this case because the line was coming from an active sewer plant.”
To overcome this hurdle, Houlberg first deployed his push-fed sewer scope. This tool is usually utilized by GPRS Project Managers to inspect pipes too small for the remote-controlled rovers to traverse.
As with the rovers, the push-fed cameras are also equipped with sondes that allow for sewer mapping from the surface.
“As I inserted the [push-fed camera], everything seemed to be going smoothly,” Houlberg said. “At approximately 300 feet into the line, however, I could not locate the line any further. After pulling the line out, I found out it was tangling itself up inside the line.”
Houlberg also considered using ground penetrating radar to locate the siphon. However, the high water table in the area prohibited the radio waves emitted by a GPR unit from penetrating the soil and locating the siphon.
At this point, Houlberg reached into his bag of tricks. He tethered a sonde to a drift sock, or drift anchor: essentially a small parachute normally used by fishermen to slow or steer their boat without having to disturb nearby fish with a noisy motor.
Houlberg inserted his makeshift sewer inspection device into the line through a manhole, letting the flow of the wastewater carry it through the siphon that he was attempting to investigate. This allowed him to use his EM locator to detect the signal emitted from the sonde from the surface as it traveled through the siphon.
Thanks to Houlberg’s innovation and quick-thinking, he was able to determine that the siphon ran down the road and not through the farmland.
“The customer was in awe and had never heard of a method of locating sewer pipe with this kind of set-up,” Houlberg said. “He was pleased that we were able to locate the pipe, and extremely happy that the pipe was going down the road and not the farm property.”
At GPRS, we put our Project Managers through a stringent training program before they’re even allowed to step foot on a real jobsite. This training is built on the Subsurface Investigation Methodology (SIM), the industry-leading education program for utility locating, precision concrete scanning & imaging, video pipe inspection, and leak detection.
GPRS Project Managers are required to become SIM certified, which means completing at least 320 hours of field training and 80 hours of classroom training. PMs return to our state-of-the-art training facility in Sylvania, Ohio, during or after their second year on the job to further hone their skills and ensure they’re withholding GPRS’ reputation for unparalleled service.
To conduct sewer inspections, GPRS Project Managers also complete the certification programs offered by the National Association of Sewer Service Companies (NASSCO), which sets the industry standards for assessing, maintaining, and rehabilitating underground infrastructure.
All GPRS Project Managers are NASSCO trained and certified to provide NASSCO reports for our pipe inspections.
We are very proud of how our training program helps our Project Managers produce consistent, repeatable results when helping you Intelligently Visualize The Built World®. However, as Houlberg demonstrated, our PMs also have an unmatched ability to tailor our services to meet your needs, adapting to each specific situation to ensure your projects remain on time, on budget, and most importantly, safe.
What can we help you visualize? Click the links below to schedule a service or request a quote today!
Frequently Asked Questions
What is video pipe inspection (VPI)?
Video pipe inspection (VPI) is a sewer inspection service that utilizes CCTV video cameras attached to either remote-controlled rovers or push-fed cable to inspect wastewater systems for clogs, cross bores, structural faults and damages, and more. Through this process, we can also map your sewer system for use during future maintenance and renovation.
What size pipes can GPRS inspect?
Our elite VPI Project Managers can inspect pipes from 2” in diameter and up.
What deliverables does GPRS offer when conducting a VPI?
GPRS is proud to offer WinCan reporting to our video pipe inspection clients. Maintaining sewers starts with understanding sewer condition, and WinCan allows GPRS Project Managers to collect detailed, NASSCO-compliant inspection data. GPRS Project Managers not only inspect the interior condition of sewer pipes, laterals and manholes; they also provide a map of their location. The GPRS Mapping & Modeling Department can provide detailed GPS overlays and CAD files. Our detailed WinCan/NASSCO reports contain screenshots of the interior condition of the pipe segments that we inspect, as well as video file for further evaluation, documentation, and/or reference.
