GRP Pipes Slipline Antiquated Wastewater Interceptor in Minnesota

The interceptor had no parallel pipe to redirect flow. Therefore, the chosen repair method needed to be implemented “in the wet” with wastewater flowing in the pipe. That left only two possible repair methods:

• Crown Repair involving excavating the entire length of the pipe, removing the brick arch and reconstructing the crown using cast-in-place concrete or precast concrete sections.
• Sliplining pipe within the interceptor sewer.

The option of crown repair was discarded because of the public disruption that excavation of the entire length of the pipe would cause, along with the length of time that would be needed to manufacture coated or lined precast sections, excavation and installation. Sliplining the pipe would require opening up sections of the existing brick arch for installation of the slipline pipe in segments. BC recommended sliplining the interceptor with GRP Pipe that would resist corrosion, stabilize the interceptor during construction activities, and extend its service life another 50 years. It would need to be corrosion resistant and fabricated quickly. Two prospective pipe manufacturers were contacted to provide prices.