Project Overview
The Mud Island Interceptor Rehabilitation Project involved installing cured-in-place pipe (CIPP) across approximately 2,400 linear feet (LF) of 60-inch diameter sewer main along the northern portion of the Mud Island Interceptor in Memphis, Tennessee.
Constructed in 1977, the monolithic reinforced concrete pipe functions as a critical trunk line within the city’s sanitary sewer network. Due to the short pipe segments and the diameter involved, the rehabilitation utilised an over-the-hole wet-out process combined with a water inversion and water cure installation.
CIPP Installation Approach
The project required three separate installations, with individual lengths ranging from 644 LF to 1,048 LF. A key challenge was maintaining service during rehabilitation, as the line conveys 47.5 million gallons per day (MGD) of flow.
To manage this, the team deployed a complex bypass pumping system including:
- Six diesel-driven critically-silenced CD400M pumps
- Four diesel-driven critically-silenced DPC300 pumps
The CD400M pumps drew flow through five 18-inch HDPE suction pipes, which discharged into a 48-inch diameter manifold. From there, the system conveyed flow through three 24-inch HDPE pipes running approximately 3,500 LF along a greenway before discharging into the Wolf River siphon.
Bypass Engineering Innovation
A distinctive element of the project was the method used to position the suction pipes. All five 18-inch suction lines were suspended within a 30-foot-deep, 60-inch-diameter drop structure.
By cutting 40° chamfers on the pipe ends, the suction lines were able to support their own weight, eliminating the need for a costly upstream tap. This approach resulted in an estimated saving of $100,000 for the owner.
Project Delivery
Installation of the 2,400 LF of 60-inch CIPP was completed in four weeks, meeting the programme requirements and achieving zero safety incidents.
The project demonstrates the effectiveness of standard polyester CIPP for large-diameter gravity pipelines and showcases how engineered bypass solutions can reduce cost and construction complexity.
Pipeline Details and Project Summary
Project: Front Street & Mud Island Interceptor Rehabilitation
Location: Memphis, Tennessee
Project Dates: April 2016 – January 2018
Pipe Length: 2,400 LF
Pipe Diameter: 60-inch
Existing Pipe Material: Reinforced concrete pipe
CIPP Type: Standard Polyester CIPP
Installation Method: Water inversion / water cure
Number of Installations: 3
Longest Pull: 1,048 LF
Pressure Rating: Gravity
Owner: City of Memphis, Tennessee
Engineer: Black & Veatch
