W.A. Rasic Construction, a leading California-based utility and heavy civil contractor, has been selected as a key subcontractor by Dragados USA for the Joint Water Pollution Control Plant (JWPCP) Effluent Outfall Tunnel—one of the most technically advanced and seismically resilient infrastructure projects currently underway in the United States.
The $630 million project, commissioned by the Los Angeles County Sanitation Districts (Sanitation Districts), aims to significantly upgrade the region’s wastewater discharge capabilities. With a planned completion in October 2026, the tunnel will span from the JWPCP Shaft Site in Carson to Royal Palms Beach in Rancho Palos Verdes, traveling as deep as 450 feet below ground.
As part of its subcontract, W.A. Rasic Construction will lead the installation of massive 144-inch (12-foot) diameter pipeline segments—critical to conveying treated effluent through the new tunnel. The pipe system will connect the existing JWPCP force main to the new tunnel shaft, facilitating long-term improvements in capacity, environmental protection, and seismic resilience.
W.A. Rasic Construction expressed pride in contributing its expertise to the landmark project, emphasizing the team's commitment to completing the complex scope with the highest safety, precision, and innovation standards.
Designed to meet the evolving needs of a growing population and the increasing severity of climate-driven storm events, the new outfall tunnel will provide redundancy for the region’s aging 1937 and 1958-era tunnels. It also marks the first use of a post-tensioned concrete segmental lining system in North America—an advanced engineering approach previously used only a few times globally.
Tunneling will be executed with a single-pass Tunnel Boring Machine (TBM), navigating soft ground and hard rock conditions, including sections passing through the Palos Verdes Fault Zone. The alignment’s varying depth and ground pressures—ranging from 1 to 9 bar—make it one of the most technically demanding tunneling operations in North America.
The tunnel project is a critical component of Southern California’s long-term infrastructure resilience strategy. The project directly supports the region’s climate adaptation goals and environmental stewardship mandates by improving outfall capacity and seismic durability.
W.A. Rasic Construction’s expertise in large-diameter pipeline installation and deep excavation makes the firm uniquely suited to handle the technical complexities of this assignment. The company’s work will also generate skilled trade jobs throughout the Los Angeles area, contributing to local economic growth while reinforcing the West Coast’s leadership in forward-looking utility infrastructure.