USIBWC breaks ground on critical infrastructure at South Bay wastewater plant

The U.S. Section of the International Boundary and Water Commission (USIBWC) broke ground on September 30, 2024, on an infrastructure improvement project critical to the South Bay International Wastewater Treatment Plant’s rehabilitation, expansion and permit compliance.

The project to refurbish Junction Box 1 (JB-1) will install two new gates on an 8-foot-wide pipe that carries wastewater from Mexico to the plant.

The non-functioning JB-1 has impacted the plant since 2021. For the first time since then, the plant will be able to control how much wastewater it accepts, including during heavy rains, thereby protecting its equipment from damage and flooding, and meeting its treatment capacity limit of 25 MGD.

Reducing the inflow will make it possible for the plant to more efficiently treat water it sends into the Pacific Ocean through the 3.5-mile South Bay Ocean Outfall, once again achieving federal water quality standards on a consistent basis.

Repairs to JB-1 are included in the commitment the USIBWC made under the San Diego Regional Water Quality Control Board’s time schedule order issued in 2023.

The USIBWC awarded a $5,793,110 contract to rehabilitate JB-1 to Veolia Water West Operating Services Inc. of Boston, Massachusetts, which will use subcontractors WachsField Technologies of Scottsdale, Arizona, and J.R. Filanc Construction Co. of Escondido, California.

Meanwhile, progress is being made on plans to rehabilitate and expand the plant.

In August 2024, USIBWC announced it awarded a $42.4 million design contract to rehabilitate and expand the plant, doubling its current treatment capacity to 50 MGD of wastewater on an average day and 75 MGD at peak capacity.

USIBWC expects to issue early construction packages during the design phase so some expansion work can start in 2024.

The plant’s expansion, in combination with wastewater infrastructure improvements in Mexico under Minute 328, is intended to eliminate up to 90% of sewage reaching the coast.

The progress on rehabilitating JB-1 and expanding South Bay’s treatment capacity was made possible by a stream of federal funding supported by advocates, including members of Congress and local elected officials.

The USIBWC is working on four fronts to tackle the transboundary issue: Repairs to the South Bay plant; expansion of the plant; monitoring Mexico’s commitment on projects in Minute 328; and taking urgent action to ensure zero transboundary flows during the dry season.