CSO separation largest public works project in history of Hoosier urban center
As a result of the creation of the CSO Control Policy of 1994, cities across the country were obligated by the Environmental Protection Association to lay out plans to eliminate the occasional fl ow of raw sewage into natural waterways. Most often, such overflows result from storm events that overwhelm combined sewer overflow systems.
Since then, according to Enesta Jones, spokesperson for the EPA, “most of the CSO permittees have chosen a comprehensive approach to long-term CSO controls, which includes multiple types of controls. Broad categories … include collection system controls, including sewer separation and inflow reduction; green infrastructure to reduce flows into the sewer system; and storage facilities and increasing treatment capability.”
In an attempt to manage sewer overflow, one of those cities is investing in a $150 million public works project — the largest in its history. The project will bring Fort Wayne, Ind., into compliance with EPA regulations and with the Department of Justice.
Fort Wayne City Utilities is designing a large tunnel and associated network of pipes in the bedrock below the feet of its 258,000 residents. Th is system, known as Tunnel Works, will collect and transport sewage from the combined sewer system to the treatment plant. Tunnel Works is the capstone project in Fort Wayne’s long-term control plan for reducing the amount of diluted sewage discharging into its three rivers annually.
Currently, the city’s sewage system is unable to handle great amounts of stormwater. About a third of its sewers are combined, and as usual with CSOs, when stormwater overwhelms them, the combination causes overflows. That’s why the tunnel is part of a $240 million project that includes an upgrade to the sewage treatment plant and construction of new storm sewer.
The tunnel system will begin south of Foster Park on the east side of the St. Marys River. It will run parallel to the St. Marys River, cross Swinney Park, go through downtown then run parallel to the Maumee River until it reaches the existing sewage treatment plant, located on the Maumee River east of North Anthony Boulevard.
The main tunnel will be approximately five miles long and lie 160 to 180 feet down in the bedrock. As part of Tunnel Works, a mile of consolidated sewers will also be constructed to collect combined sewage from the existing system and connect to shafts that will drop it 160 to 180 feet into the tunnel. Approximately two miles of sewer that will be shallower and smaller in diameter will connect to the south end of the tunnel.
More than 700 communities nationwide rely on CSO infrastructure, noted Frank Suarez, Fort Wayne City Utilities spokesperson. More than 100 of those municipalities are located in Indiana. Th e separation solution was viewed as “state of the art” at the time of the Clean Water Act, because experts used to believe the answer to pollution was dilution, Suarez said.
The reliance on CSOs was no longer viable for Fort Wayne anyway. It comes down to environmental and health concerns, Suarez said. “If there’s too much shared liquid, then it overflows in the rivers. Of course it happens.”
In fact, it happens about 70 times a year; a situation that causes significant pollution and prompted the EPA to give the city an “F” in water quality. Fort Wayne was ranked the sixth most polluted city in Indiana last year, based on data collected by the federal agency.
That’s bad news for residents who depend on the water for drinking and bathing. About 85 percent of Allen County households, including Fort Wayne, use water supplied by one of the 19 public water systems. The other 15 percent have their own wells.
The EPA mandated that the city come into compliance by the year 2025. By that year, the five-mile-long Deep Rock Tunnel along the Maumee will be capable of taking 90 percent of the unclean overflow to a water pollution control plant. According to Suarez, the project will nearly double the size of the plant.
The improved infrastructure will mean residents are better off in more than one way. Case in point: “This project will protect homes from flooding by an estimated 96 percent,” Suarez said. “Plus we’re keeping the 5 million gallons of overflow from going into the rivers.”
The health and protection of Fort Wayne’s three rivers is a hot-button issue, adding to the excitement surrounding the project, he noted. The Riverfront Fort Wayne project is a prime example. The initiative “envisions a revitalized downtown riverfront area that is a regional destination offering opportunities to experience nature, recreation, shopping, dining and entertainment in a whole new way.”
But such projects come at a cost, literally and figuratively. The CSO separation will be funded through rate increases through 2019 — a move that likely won’t be popular with taxpayers.
“From a national perspective, it can be a burden on the community when (projects like these) are unfunded; but it’s important for the future. It’s the right thing to do,” Suarez said.
The Deep Rock Tunnel project is in the design phase currently. Construction is expected to begin in 2017.
