Fusible PVC® Pipe Successfully Sliplined into Failing 24-inch Ductile Iron Water Main in Minnetonka

A bustling suburb located just eight miles east of Minneapolis, the City of Minnetonka derives its name - meaning "great water" - from the Dakota Indians. Appropriately, the City and its 50,000 residents take great pride in maintaining the region's majestic lakes and waterways, as well as its extensive water infrastructure. So when an existing 24-inch water main under Interstate 494 failed in late 2012, the City wasted little time enlisting the expertise of Advanced Engineering and Environmental Services, Inc. (AE2S) to design emergency repairs.

The existing 24-inch water main, mostly ductile iron, was located ten feet below the I-494 roadway, a major arterial loop around the Minneapolis metropolitan area. Replacing the water main via open-cut excavation was not a realistic option. The City and AE2S agreed that sliplining a new pipe into the 24-inch main would be the most practical installation method, considerably mitigating the inevitable disruptions along I-494. Bidding contractors were required to provide pricing for completing the project using either 20-inch DR25 Fusible C-905® pipe or 20-inch DR11 HDPE. Aaron Vollmer of AE2S noted, "The Fusible PVC® pipe option provided the least amount of flow area reduction from the existing water main."

Veit & Company, Inc. won the project and chose to complete the slipline with Fusible PVC® pipe. Due to the location of the existing water main, the project required a significant amount of excavation and shoring in order to access the leaking main. The cut slopes on both sides of I-494 extended more than twenty vertical feet above the roadway. Additionally, the locations of the pits for inserting and pulling the Fusible PVC® pipe were sandwiched between freeway ramps and frontage roads.

Pipeline Details and Project Summary
Project: Oakland Road/I-494 Water Main Repair - Minnetonka, MN
Length/Pipe Size: 260 LF of 20-inch DR25 Fusible C-905®
Pressure Test: 150 PSI for 2 Hours
Installation: Sliplining
Owner: City of Minnetonka
Engineer: Advanced Engineering and Environmental Services, Inc. (AE2S)
Contactor: Veit & Company, Inc.
UGSI Contact: Dan Christensen (715) 206-0518 dchristensen@undergroundsolutions.com

Excavation of 24-inch RCCP WM

Fusible PVC® Pipe Lowered Into Pit

Fusion Machine Lowered Into Pit

In-Pit Fusible PVC® Pipe Welding

>20-foot Deep Insertion Pit

Fusible PVC® Pipe Enters Host Pipe