A grout mix meant for soil stabilization found its way into a vitrified clay sewer main pipeline during supportive construction for subway tunneling. The slurry settled inside the pipe causing a serious blockage.

The grout was removed by Pacific Sewer Robotics who applied a 1000bar (14,500psi) controlled water blast from a remotely operated crawler with camera and steerable nozzle. Within a few days the sewer pipe was restored to its full capacity and undamaged