Bids for what is believed to be the most expensive project in the history of City Utilities were opened Thursday — and the lowest came in just under the estimate.
With a base bid of slightly more than $187.9 million, Kiewit-Seli Joint Venture was the apparent low bidder among five submissions to dig the city's proposed "Three Rivers Protection and Overflow Reduction Tunnel" and connecting shafts, which when compete in 2021 is expected to reduce the flow of untreated sewage into the rivers during heavy rain by about 90 percent. No information was immediately available about the firm, whose bid was slightly less than the estimate of $189 million. The next-lowest base bid came in at about $206 million.
City Utilities Director Kumar Menon said he was pleased with the bids and said the number of interested firms helped keep costs down. Similar projects in other cities have not been so fortunate, he said. City officials will spend the next several weeks analyzing the bids before awarding a contract.
But as The News-Sentinel reported last month, all of the bidding firms should be qualified to do the job because the city required interested firms to prove their qualifications in advance of being allowed to seek the contract.
The tunnel will begin at the city's Water Pollution Control plant and extend five miles 200 feet below the surface before terminating near Foster Park. By channeling materials currently handled by combined storm and sanitary sewers directly to the plant, the tunnel will prevent most so-called "combined sewer overflows" (CSOs) that occur during heavy rains. The federal government has required the city to reduce its CSOs.
Some bids for the project were awarded in 2014, including about $15 million in preliminary engineering contracts. Coming later will be bids for the machinery needed to lift the sewage from the tunnel into the treatment plant and for two larger vertical shafts: one near the Water Pollution Control plant on Dwenger Avenue that will allow machinery and workers into the tunnel and another near Foster Park that will be used to remove the equipment. Once the tunnel is complete, the entrance and exit shafts will be closed but will be accessible for maintenance needs. Machines used to bore the tunnel through bedrock can cost millions of dollars and must be assembled in the tunnel, Menon said.
The tunnel will be 16 feet in diameter, lined with concrete and able to handle 800 million gallons per day. The digging process itself will displace about 450,000 cubic yards of stone — enough to fill a football field 136 yards high. That's just a few feet shorter than Fort Wayne's tallest building, the I&M Power Center.