NASSCO Report – Lafayette & White River Large Diameter Sewer Rehab Case Study

Citizens Energy Group owns and operates a wastewater collection system of roughly 3,000 miles of 8-in. to 120-in. sewers in Indianapolis (for all you race fans, that’s 1,200 laps around the Indianapolis Motor Speedway). Its approach to system rehabilitation is proactive, fixing sewers and manholes through targeted projects before they’re a problem.

Granite Inliner is a CIPP rehabilitation partner for Citizens and was excited to tackle the Lafayette & White River Large Diameter Sewer Rehabilitation Project in the summer of 2021. Quick Project facts:

•Over 4,100 lf of 42- to 54-in. sanitary interceptor sewer cleaning and CIPP lining

•The interceptor is 35 ft deep and within 200 ft of the White River

•8 MGD dry weather bypass

•Project crosses a golf course, two thoroughfares, heavily wooded areas, and an apartment construction jobsite

The project began in 2019 with a research assignment through Citizens’ Contractor Planning Partnership. Granite Inliner and Citizens worked collaboratively to plan every detail of the future project, thereby minimizing risk and ensuring readiness to proceed. Project funding came through for 2021, and construction began in June.

A bypass was constructed using a dedicated 18-in. HDPE discharge and scalable pump capacity. The bypass allowed for pipeline cleaning and televising to move forward, which was completed simultaneous to the creation of CIPP access points – removal of existing manhole cone sections to facilitate access for the massive liners. CIPP lining was completed in seven installations of custom-made inversion liners saturated at the contractor’s wet-out facility in Orleans, Indiana, and trucked to the jobsite to be processed with hot water.

The project went very smoothly despite some serious challenges. Success was the result of three key factors:

1.Communication: Surprises are fun on birthdays, but not so much in public construction. A communications plan was established in the early planning stages, identifying two key properties and stakeholders. First, Coffin Golf Course was home to both the bypass suction manhole and start of CIPP lining, the latter structure located at the base of the hole No. 5 tee box. Upfront conversations led to clear expectations, and the entire project was completed without impacting a single round of golf. The second property was a 400-plus unit apartment complex whose only entrance/exit driveway was also home to a key manhole atop the interceptor sewer. This one was a surprise considering the property was a vacant wooded lot during the planning phases. Collaboration with Indianapolis Business and Neighborhood Services was the key to creating right-of-way permits and traffic patterns that would keep workers and motorists safe and the driveway open.

2.Quality ingredients + great effort = superior performance: The project featured the use of a styrene-free vinyl ester resin for CIPP lining. The resin requires liners that are a little thicker than normal, and manhole spacing approaching 900 lf meant the liners would be extremely heavy for transport and handling. In 30 years and 35 million lf of liners installed, this project demanded the #1, #2 and #3 heaviest liners the Inliner team has ever transported. Special trailers were used and outfitted with custom decking to make the transport possible, and reinforced inversion equipment was utilized to get the liners in place. Vertically integrated processes from design to liner fabrication and reinforcement, to tube saturation and delivery through the complete installation process proved that a team can accomplish great things when everyone’s working in unison.

3.Luck never hurts: Let’s be honest, there was a fair amount of luck in the success recipe along with all that communication and planning. In the end, a safe and successful rehabilitation project is what really counts “This project was a huge success because of the planning and partnership that led to the delivery of a safe and successful project that will provide worry-free service for many years to come,” said Tim Shutters, supervisor, Underground Engineering & Construction, Citizens Energy Group.