Prior to these wireless robots, PG&E engineers had no way of detecting small fractures or bad welds unless there was already a potentially dangerous leak.
"This is much less invasive obviously because this line runs under a creek bed. We would have had to dam the creek, excavate there to actually get to the line," said PG&E spokesperson Jason King.
Engineers can steer the mechanical snake through back to back 90 degree angle turns. It's also equipped with magnetic sensors that detect changes in the pipe's thickness.
"Yeah, and I'm happy that they're doing that right here because I live here," said Brentwood Resident Lizette Tapia.
Corrosion in gas lines is something Tapia became keenly aware of after the San Bruno pipeline explosion on Sept. 9, 2010.
"I hope this is a good robot, like it's not going to touch something and boom! Because that would be bad," said Tapia.
There needs to be oxygen mixed with natural gas for the robot's batteries to spark an explosion. That's why they suck out the oxygen in the launch chamber and fill it with nitrogen before sending it down.
On Friday, they found an inch of potentially corrosive water in the pipe. Draining the condensation is easy, but now they can focus on the section. Older survey methods like probing the line can be invasive.
This pipeline runs under the sidewalk which means prior to the robot, they would have had to drill holes in the sidewalk every 10 feet to survey the line.
Right now, hydro-static pressure testing and old fashioned probing are the predominant methods. But as the cost of technology goes down, PG&E will use more of these wireless robots to surgically survey the system.