by Thomas P. Healy
Citizens Energy Group (CEG) continues to make progress on the DigIndy project designed to clean up the city’s combined sewer overflow (CSO) network and improve water quality in Fall Creek and the White River.
One component of that work is the Fall Creek 06 (FC06) drop shaft construction site located east of Delaware Street between 28th Street and Fall Creek Parkway. According to Mike Miller, CEG’s manager of technical services and construction, the current work involves extending previously installed consolidation sewer infrastructure. “There are a number of CSO pipes that flow from north to south directly below the local streets in the area, including below Talbott Street, Washington Boulevard, New Jersey Street, and Central Avenue,” he said. Each of those pipes terminates in the northern bank of Fall Creek and contributes to degraded water quality.
In 2016, at the urging of Mapleton-Fall Creek Development Corporation and the City of Indianapolis, CEG installed diversion structures and consolidated those pipes into a central point located at the FC06 site. Although this work preceded completion of subsurface work on the Fall Creek Tunnel, it allowed for infrastructure improvements to 29th Street and reconfiguration of the “spider” intersection, and minimized disruption of the anticipated Central @ 29 project.
Miller said CEG’s tunneling contractor, the Shea-Kiewit Joint Venture, completed digging the 20,244-foot-long Fall Creek deep tunnel in April 2020. While the tunnel still needs to be lined with concrete, “the current work taking place at the FC06 site involves extending the previously installed consolidation sewer infrastructure down a drop shaft that connects to the deep tunnel located 240 feet directly below Fall Creek,” he said.
When the project is complete, Miller said overflows that would have previously flowed into Fall Creek will be diverted through the new consolidation sewers and down into the Fall Creek deep tunnel. “Once that combined sewage enters the deep tunnel system, it will flow by gravity all the way to CEG’s Southport Advanced Wastewater Treatment Plant, where it will be treated and released to the White River,” he said.
Miller said work at the FC06 site will continue for approximately the next six to eight months. “There are also a number of other similar sites located along Fall Creek Parkway that will be constructed over the course of the next three or four years,” he added.
According to Laura O’Brien, CEG’s corporate communications coordinator, the DigIndy Tunnel system is on track to be complete by the end of 2025.