Bergen Point Wastewater Treatment Plant Outfall Replacement Project
The Bergen Point Wastewater Treatment Plant Outfall Replacement Project in Babylon (Long Island, New York), in which OHLA participated through a joint venture, received the Underground Construction Association’s 2022 Project of the Year Award in the $50 million to $500 million category. It is one of the largest construction projects undertaken in Suffolk County in decades and OHLA’s first project on Long Island.
The project involved the construction of a 10-foot-diameter tunnel extending 2.6 miles beneath Great South Bay, excavated through a variety of soft soil conditions. The new tunnel replaces the existing outfall system and addresses concerns regarding the long-term reliability of the current pipeline while providing a significantly longer service life.
Construction was carried out using a slurry Tunnel Boring Machine (TBM), with the tunnel simultaneously lined using 48-inch-wide precast concrete segmental rings. The entry and exit shafts, reaching depths of between 80 and 100 feet, were constructed using ground-freezing techniques. The scope of works also included the replacement of pipes and valves at the existing Final Effluent Pump Station, further enhancing the resilience and operational reliability of the wastewater treatment system.