Electromagnetic robotic tool used in Phase II to collect data on the pipe walls.

Since late spring 2020, a small crew of experts have been hard at work in the Highland Park neighborhood completing thorough inspection of two of our largest water mains in the distribution system. Transmission mains, referred to as “Rising Mains,” act like highways within our distribution system, carrying large volumes of water from one area of the system to another. The mains we are inspecting carry water from the Bruecken Pump Station to the reservoirs in Highland Park. Collected information and data will help PWSA engineers understand the condition of the pipes and determine needed repairs in the coming years.

Inspecting a long stretch of underground pipe is no easy feat. In Phase I, which occurred in May of this year, crews used a variety of remote technologies to access the pipe and collect measurements. Work began with a leak detection survey along the lengths of the pipes. Crews constructed access points along the pipe and used a tethered GPS tool that could be controlled from above ground and inspect the interior condition of the pipe. Crews also used a Smartball, which is a ball that is dropped into the pipe and can travel along the pipe collecting any evidence of leaks using acoustic sensors. 

Phase II, which took place later in the year, involved tools that would give even more detail for future work. Crews drained the pipe and sent a robot to “walk” the length of the pipe, using electromagnetic signals to test the thickness of the pipe. Knowing the thickness of the pipe indicates where the pipe has worn thin and may leak. 

This thorough inspection is crucial to the planning process for large infrastructure improvements like the future Rising Main Repair Project. Collecting more data means PWSA can target its repair work in the most efficient and cost-effective way. 

Learn more about PWSA water, sewer, and stormwater projects at pgh2o.com/projects-maintenance.