The City of Green Bay, Wisconsin is one of many municipalities that recently made a major upgrade to their primary water supply pipelines. The City’s existing Pre-stressed Concrete Cylinder Pipe (PCCP) line that connects the city’s intake structure on the shores of Lake Michigan to their water treatment facility is beginning to show its age and lack of reliability.
This PCCP pipeline and the City’s auxiliary well fields were not able to support Green Bay’s peak water demands and growing customer base. Green Bay needed to support their water supply sources by building a parallel transmission line to the failing PCCP line to provide them a more reliable access to their primary water source.
The project design by the City’s engineer, Alvord, Burdick & Howson, of Chicago, IL, specified pressure class 150 and 200 psi operation/performance requirements designed in accordance with AWWA standards. AWWA C200 Steel Water Pipe and AWWA C301 Pre-stressed Concrete Cylinder Pipe were specified as material alternates for the pipeline. The Steel Water Pipe alternate was bid low by the successful contractor, Garney Companies, from Kansas City, MO.
The Steel Water Pipe was specified with a cement-mortar lining per AWWA C205 and a bonded dielectric three-layer tape coating per AWWA C214. Rolled groove O-ring gasketed joints were utilized for the unrestrained joints and single lap-welded bell and spigot joints were used where joint restraint was required. The three-layer tape system provides a bonded dielectric corrosion resistant barrier coating on the pipeline, providing greater reliability for the future.
A significant and challenging portion of the pipeline had to be constructed through a swamp and wetlands area. This portion of the project had to be constructed during the winter months. Even then, during the coldest time of the year, water collected in the trenches, requiring equipment mats and timber support mats to move heavy equipment and materials to and through this marshy area. The lightweight and long (50 foot) lengths of the Steel Water Pipe, as well as the O-ring gasketed joints, help speed the pipe laying process through this difficult area of the project. Steve Swatek, VP of Garney Companies, said, “Steel Water Pipe is different from other water transmission pipe products in that the lightweight fifty foot pipe lengths allowed us to maximize our pipe laying production rates.” Steel pipe offered the best solutions to this project by adding reliability to Green Bay’s water system, overcoming wetlands installation issues for the contractor, and providing a quality, high performance pipeline for the future.