Tuberculation Removal from a 20″ Sewer Main

Location: Northern California

Obstruction Type: Tuberculation
Pipe type: Ductile iron
Year: 2018
Region: Northern California

PSM was called to help remove tuberculation from a 20-inch ductile iron pipe that had suffered heavy degradation over its 60 years in place. Tuberculation is the byproduct of an iron-oxidizing bacteria that metabolizes ferrous iron, creating a buildup with a strong bond to the pipe.

The sewer main travels under a very busy freeway that could not be closed to allow for replacement or repair of the pipe. Rerouting would have called for more than a mile and a half of new pipe and installation of a pump station. Rather than shut down the road and replace the pipe, the client needed to remove the tuberculation without harming the existing pipe.

Our robotic, high-pressure system was able to eliminate the tuberculation and corrosion without causing any damage, clearing decades of buildup, debris, scale and rust. This allowed the client’s engineers to view the entire pipe and create a detailed action plan to re-line it, keeping it in service for years.

“This pipe has been waiting for the right solution for a few years,” the wastewater distribution director told us. “Now that it’s complete, we’re ready to move ahead with a good, solid repair plan.”