GPRS was hired by a directional drilling contractor to conduct a pre-construction video pipe inspection of all sanitary mains and laterals in conflict with the proposed path of new gas pipelines. The project is taking place at a large development in Milwaukee, Wisconsin, with over 200 single homes and will require multiple days to complete the CCTV video camera pipe inspection. This pre-inspection of the sanitary pipe was required by the township to document the conditions of the sewer system prior to construction. After the construction is completed, a post-construction video pipe inspection will take place to ensure that none of the sanitary mainlines or lateral pipes were damaged during the installation of the gas pipelines. This type of investigation is commonly referred to as Cross-Bore Mitigation.
To perform this investigation an Envirosight Lateral Launch CCTV Robotic Crawler was used. This equipment has multiple wheel size configurations that can be utilized, allowing the robot to traverse through pipes of varying sizes and materials. The camera head used during this project could pan and tilt 360 degrees, not only while in the main pipe but also while in the laterals, to ensure that each pipe is entirely inspected. Using approximately 40 manholes in the roads as access points, over 8000 linear feet of sewer pipes were inspected and any structural defects, operational defects and lateral tie-in points were documented. After the inspection of the sewer main is complete, each lateral pipe that is running in conflict with the proposed path of the work is inspected. This is achieved using the lateral launch technology on the robotic crawler; atop of the robot itself sits a push rod with a camera that is propelled into the lateral by a mechanism on the robot. The camera is pushed towards the house until it is past the scope of work, documenting the conditions inside the pipe along the way. During the course of the project, all of the mains and laterals inspected were located using electro-magnetic locating methods so that the mains and lateral pipes can be field marked with paint and flags. A sonde located in the camera head can also be located to pinpoint an exact location such as a lateral tie-point or damaged section of pipe. Over 115 laterals servicing the homes in conflict with the scope of work were identified, inspected, and marked. Each section of pipe is inspected using NASSCO standards and the client is provided with video camera logs of each run, while a NASSCO certified pipe inspection report is included, with photos of each observation which were made during the inspections.
With the video pipe inspection services provided by GPRS, our client can safely begin the work knowing that all sanitary mainlines and lateral pipes in conflict have been identified and marked. Locating of the pipelines prevents the striking of an unidentified pipe and also makes any potholing required much more efficient than digging blindly in search of the sewer pipe system. Documenting the condition of the pipes prior to the start of the directional drilling operations provides the client with protection against claims that they are responsible for any problems with pipes which were already compromised before any work took place. In the end, a pre-construction video pipe inspection will create a safer and more efficient job site, and also save the client from any costs ensued from damages caused during the course of the project.
Note: GPRS does not provide geophysical, geological, land surveying or engineering services. If you need such services, please contact an appropriate professional.