St. Paul Completes First Pipe Bursting Project with Fusible PVC® Pipe

St. Paul Regional Water Services (SPRWS) typically installs ductile iron water mains using open-cut methods when expanding or upgrading its system. However, a unique situation required SPRWS to consider an alternative pipeline material using a new installation method to upgrade an existing 6-inch cast iron water main in a northwest neighborhood in the City of St. Paul. The existing water main along West Cottage Avenue - which provides access to a number of apartment complexes - needed to be replaced. Open-cut water main construction was not a favored option as the City would have needed to shut down West Cottage Avenue, causing a major disruption for its many residents.

As an alternative, pipe bursting was evaluated and approved as an acceptable solution for replacing the existing cast iron water main. Pipe bursting allowed SPRWS to utilize the existing water main alignment, upsize the existing pipe size, and maintain vehicular access along West Cottage Avenue. SPRWS evaluated both Fusible PVC® pipe and HDPE as material options for the bursting project. In order to compare the two materials on an equivalent inside diameter and pressure class basis, 8-inch DR18 Fusible PVC® pipe was bid against 10-inch DR9 HDPE.

Palda and Sons, Inc. was awarded the project by SPRWS and selected Red Pederson Utilities, Inc. (RPU) to perform the pipe bursting. RPU specializes in pipe bursting and has experience working with Fusible PVC® pipe. The Fusible PVC® pipe option minimized risk by reducing the amount of soil displacement required for the bursting process; a benefit which led to its selection as the material of choice to replace the existing 6-inch cast iron water main. Static pipe bursting equipment from TT Technologies was used to burst the existing main and pull in the new 8-inch Fusible PVC® pipe. The experienced crew from RPU completed the project quickly and efficiently, which minimized the amount of time the water main was out of service.

Temporary aboveground piping was used to maintain water service to the neighborhood's residents during construction of the new main. After the new 8-inch Fusible PVC® pipe was pulled into place, crews from SPRWS tapped the new main and reconnected the existing water services using standard PVC saddle taps. In total, the project required replacing 2,080 LF of 6-inch cast iron with 8-inch DR18 Fusible PVC® pipe. Graeme Chaple of SPRWS noted: "The project went well and we were happy with the product. The ease of use and familiarity we have with PVC would lead us to use Fusible PVC® pipe again in this type of application."

Pipeline Details and Project Summary
Project: West Cottage Avenue Pipe Bursting - St. Paul, MN
Length/Pipe Size: 2,080 LF - 8-inch DR18
Pressure Test: 150 psi for 2 hours
Installation: Pipe Bursting
Owner/Engineer: St. Paul Regional Water Services
Bursting Contractor: Red Pederson Utilities, Inc
General Contractor: Palda and Sons, Inc.
UGSI Contact: Dan Christensen (715) 206-0518

Pipe Bursting Equipment Staging

Feeding Bursting Rods Through Existing 6-inch Cast Iron

Fusible PVC® Pipe is Fused and Laid Out

Cutter and Expander Head are Attached to Pipe

Bursting Equipment is Pulled Through Existing 6-inch Cast Iron

Fusible PVC® Pipe is Pulled Through Existing 6-inch Cast Iron