Photo courtesy of Indianapolis Dept. of Public Works
Treatment plant is set for completion next year; deep tunnel is set for a 2017 completion.

One month after awarding a $25-million sewerage-tunnel construction inspection contract amid a packed field of proposals, Indianapolis utility Citizens Energy Group will select a firm to build the $275-million project, with the low bidder 33% below the estimate.

On Sept. 29, AECOM Technology Corp. was awarded the inspection contract for the Deep Rock sewage overflow project. The Los Angeles-based firm bested competitors that included Parsons Brinckerhoff's Water Group, locally based American Structurepoint, Burgess & Niple and a Hunt/Parsons joint venture, among others, says utility spokeswoman Sarah Holsapple. AECOM designed the 18-ft-dia., 7.8-mile-long tunnel under a separate $17-million contract.

Indianapolis is undergoing a $1.7-billion upgrade as part of a 2006 federal consent decree (ENR 2/14 p. 24). Plans call for building four other storage tunnels. The collective system is meant to address the city's 7.8-billion gallons of yearly sewage overflow. AECOM is managing phase one of the 230-ft-deep, 54-million-gallon- capacity tunnel connecting two new wastewater treatment plants. The project also includes a 120-mgd capacity dewatering pump station.

The deep-tunnel contract, which bid on Aug. 11, attracted nine bidders with only 1.6% separating the top two submissions. A Shea-Kiewit joint venture is apparent the low bidder at $185.5 million, 33% below the engineer's estimate. Runner-up Flatiron Constructors submitted a $188.5-million bid, while less than 1% separated the next two bidders, the Judlau/Michels LLC JV and the team of Obayashi/WL Hailey.