City of Thornton, Colorado Reduces Rehabilitation Impact to Residents with Trenchless Slipline Installation

The City of Thornton, Colorado was incorporated in 1956 with a population of 8,640. Over the succeeding 56 years, the population has grown to over 121,000 and the oldest portions of the City's pipeline infrastructure are nearing the end of their useful lives. In 2010, an old and deteriorating 20-inch steel transmission line under Washington Street emerged as the top candidate for rehabilitation due to its failure frequency and annual cost to maintain; so the City started investigating rehabilitation options.

Because of the location of the failing 20-inch steel waterline beneath one of the City's busiest streets, the City's management team projected that conventional dig and replace construction would require shutting down the entire street for long periods. To avoid significant inconvenience to local businesses and residents, trenchless rehabilitation was selected as the most desirable solution. Several options were considered, including cured-in-place pipe (CIPP) and sliplining with Fusible PVC® pipe. In the end, a 16-inch DR21 Fusible C-905® slipline presented the most attractive solution for the following reasons:

BTrenchless was selected to perform the rehabilitation. Steve Jacques, VP of Operations, commented, "We love sliplining with Fusible PVC® pipe and wish that more people would recognize the benefits it provides. Spoils are greatly reduced from the project, we don't have to shut down the entire street, and it's fast! If you can get away with a slightly reduced inner diameter pipe, sliplining with Fusible PVC® pipe is a great solution."

Construction kicked-off in April 2012. Laydown room for the full 1,680 LF length of Fusible C-905® pipe presented a slight problem, so the pipe length was broken into three segments that were fused together as needed during the pull-back operation. Pull-back was accomplished with a TT Technologies hydraulic Grundoburst® 800G. Due to the ease and affordability of the project, the City of Thornton is planning a second phase in the fall of 2012.

Pipeline Details and Project Summary
Project/Location: Washington Street Waterline Rehab/Thornton, Colorado
Pipe Details: 1,680 LF of 16" DR21 Blue
Pressure Test: 150 psi for 2 hours
Owner/Engineer: Jason Pierce, former City of Thornton Project Engineer

Fusion Operations

Fused Pipe String

Pipe Insertion - Facing South

Pipe Entrance Pit - Facing North