The tunnel, which has an 18-foot diameter, is meant to catch overflowing water across the southwest portion of Hartford. Once the water enters the tunnel, it will be treated and then deposited into the Connecticut River. Even though the tunnel portion itself is complete, the project is not set to be functional until 2026 because the pump station isn’t finished. IRIS, the name given to the tunnel boring system, ends at the MDC’s retrieval facility on Talcott Road in West Hartford. The project is the first of its kind in Connecticut and is a major component of MDC’s Clean Water Project, required by U.S. Environmental Protection Agency. The MDC — which provides services to Bloomfield, East Hartford, Hartford, Newington, Rocky Hill, West Hartford, Wethersfield and Windsor — decided to build the historic tunnel after an attempt in 2006 to separate sewer and water operations in sections of Hartford.
https://www.stamfordadvocate.com/capitalregion/article/ct-hartford-underground-tunnel-mdc-iris-18612681.php