2024 Trenchless Technology Project of the Year Rehabilitation Honorable Mention – South Claiborne 48-in. Water Transmission Replacement
The Sewerage & Water Board of New Orleans (SWBNO) developed a comprehensive water transmission main replacement program after years of failures to its existing pipelines to improve water quality and low pressure concerns, eliminate failures due to poor soils and a high corrosive water table and cost of repairing breaks in their system.
Traversing along a six-lane major thoroughfare of New Orleans, the South Claiborne Water Transmission Main Replacement project included 4,440 ft of an existing 48-in. cast iron water transmission main that had experienced numerous failures in recent years. The work also included replacing numerous valves and branch connections.
In searching for a replacement method, SWBNO wanted a method that would maintain the community’s way of life as much as possible. This required a construction method that would limit lane closures, fast track the project schedule and maintain access to the numerous businesses along the project route.
South Claiborne Avenue is one of the most important thoroughfares within New Orleans connecting Jefferson Parish where the major airport is located, with Uptown, Central City and the Downtown area. In addition to major businesses, Claiborne Avenue includes one of the largest hospitals and numerous restaurants.
In addition, SWBNO hoped to select a new piping material that would not fail due to the same reasons the existing cast iron was failing. This required a new pipe that was both corrosion resistant and flexible. The area had extremely poor soils conditions with a high corrosive water table.
SWBNO contracted with Meyer Engineers, a Louisiana consulting engineering firm, to provide design, construction management and inspection services. The water utility ultimately selected the CompressionFit method. This decision was based on its success with previously completed projects, the method’s ability to meet its standard to maintain the community’s way of life during construction and familiarity with high-density polyethylene (HDPE) pipe’s corrosion resistance and flexible properties.
Murphy Pipeline Contractors (MPC) replaced just shy of one mile of 48-in. cast iron water main with new 48-in. HDPE DIPS DR 17 utilizing the CompressionFit technology. With a wall thickness of 3 in., the HDPE pipe can operate at 125 psi for operating pressures with the ability to handle surge events at 250 psi. Per ASTM F3508, this represents a Class 6 solution in its ability to handle all internal pressures and all external loads.
Why This Project Is Outstanding
The South Claiborne Water Transmission Main Replacement project represents the largest diameter, high pressure, fully structural pressure pipeline rehabilitation project completed in North America.
To MPC’s knowledge, no other trenchless method has ever completed a project requiring a fully structural solution at an operating pressure of 125 psi/surge pressure of 250 psi.
The project represents the largest diameter pipe rehabilitated in the world using the CompressionFit technology and largest in the world providing a Class 6 solution (per ASTM F3508).
With the 48-in. cast iron pipe being more than 100 years old and the operating history of this water transmission main, the SWBO needed a fully structural solution and as much flow capacity as possible. The utilization of DR 17 HDPE represents a pipe that is not dependent on the host pipe for any structural enhancement.
The project was successfully completed on time, and budget. The total scope of the project included installation of new 48-inch butterfly valves, new manholes for valve operation, new air relief valves and multiple branch connections and the 4,400 ft of HDPE pipe.
