Successfully Navigating the Challenges of Emergency Interceptor Repair under the Wall Street of Whiskey

In 2018, Louisville, Kentucky’s wettest year on record, Louisville Metropolitan Sewer District (MSD) was faced with the daunting task of repairing the old Ohio River Interceptor (ORI), an 84-in. non circular combined sewer in the heart of downtown Louisville that carries 40 million gallons per day (MGD) of raw sewage during dry weather. Structural evaluation of the ORI concluded that sections under historic Main Street—downtown Louisville’s business, entertainment, and hospitality district—had significant concrete loss and was failing. The team, consisting of the Owner, Engineer, and Contractor collaboratively developed a repair solution for 1,400 linear feet (LF) that included a hydrogen sulfide (H2S)-resistant polyvinyl chloride (PVC) panel liner system that was easily installed to fit the unique shape of the sewer, maximizing hydraulic capacity of the repaired ORI. The structural repair included rebar and grout behind the liner. The repair solution required all upstream flows be diverted around the repair area. A temporary 40 MGD pump station and approximately 11,000 LF of 18-inch forcemain was strategically routed to minimize utility conflicts, traffic, and business impacts, and Main Street visibility. Prior to beginning rehabilitation work, a partial sewer collapse and related 60-ft diameter conical-shaped void below the pavement section was discovered approximately 80 ft into the ORI. The engineers quickly coordinated with contractors on structural design changes to accommodate a ring beam system to stabilize the tunnel for the first 165 ft and incorporated it into the permanent repair to maintain the original structural design’s internal diameter and prevent further loss of hydraulic capacity. Additionally, three consent decree required CSO connection improvement projects, located in the repair area, were added to the project to minimize impacts to stakeholders. Potential failure of the ORI put public safety, water quality, business operations, tourism, and MSD’s operations at risk. The cost-effective solution minimized disruption to downtown, minimized environmental impacts to the Ohio River, and was completed on schedule, saving the City and MSD millions of dollars. The repair has provided ratepayers with a safe, reliable sewer asset for the foreseeable future.