USIBWC announces contract to expand $600 million California WWTP project

The United States Section of the International Boundary and Water Commission (USIBWC) has awarded a contract for the design and construction of the rehabilitation and expansion of the South Bay International Wastewater Treatment Plant (SBIWTP) in San Diego, California.

The first phase, in the amount of $42.4 million, covers design for the full scope of the rehabilitation and expansion of SBIWTP and anticipates bringing clean, safe water to the local communities.

The USIBWC awarded the contract to PCL Construction of Long Beach, California. PCL selected Stantec Consulting Services, Inc. of San Diego as the design firm.

The project includes essential rehabilitation of existing infrastructure and capacity expansion to double current treatment capacity of 25 MGD to reach 50 MGD average flow, with a peak hydraulic flow capacity of 75 MGD.

This project is consistent with the binational agreement known as Minute No. 328, “Sanitation Infrastructure Projects in San Diego, California–Tijuana, Baja California for Immediate Implementation and for Future Development.”

The project is issued in partnership with the U.S. Environmental Protection Agency (EPA) and is implemented consistent with the 2020 United States-Mexico-Canada Implementation Act, and also funded from USIBWC’s annual appropriations.

The plant’s expansion, in combination with wastewater infrastructure improvements in Mexico under Minute 328, is intended to eliminate up to 90% of untreated wastewater reaching the coast, providing cleaner, safer water for local communities.

The project was awarded using the Progressive Design-Build contract delivery method consistent with government contracting practices and regulations. This contract delivery method allows for phasing construction to meet the project goals on available funding, shortens the construction schedule, minimizes risks and integrates input from construction experts during the design phase to increase quality and reduce the need for change orders.

The USIBWC anticipates the design to be completed in 20 months. The maximum timeline for construction is 5 years. The contractor expects to decrease this timeline by as much as 18 months through the innovative progressive design-build approach. The plant will remain in operation throughout the design and construction phases.

The USIBWC anticipates providing more definitive estimates of the full project cost and the construction schedule once the project reaches 30% to 60% design stage and plans to issue early construction packages during the design phase to enable some early construction work to start in 2024.

A key part of the early construction packages is site preparation work, including excavating the primary sedimentation tanks, relocating the site fence and installing shoring to protect utilities.

The full project cost, including design, construction, contingencies, project management and other support services, is estimated at $600 million.