Federal border officials are calling for urgent repairs of a Southern California facility that treats sewage from Tijuana, Mexico, after the already deteriorating facility incurred additional damage from Tropical Storm Hilary.

The U.S. branch of the International Boundary and Water Commission (IBWC) announced Thursday that it has formulated an $8 million recovery plan for the facility, presented the previous day at a hearing of the San Diego Regional Water Quality Control Board.

“Tropical Storm Hilary exacerbated the vulnerabilities of an already at-risk treatment plant,” U.S. IBWC Commissioner Maria-Elena Giner said in a statement.

The region has long been battling cross-border wastewater woes, in which infrastructural mishaps and winter weather events have ushered raw sewage onto San Diego beaches. Funneling the flow is the Tijuana River Watershed, which travels from its origin in California into Mexico — passing through the dense urban environment of Tijuana — before reentering the U.S.

Tropical Storm Hilary took a toll on the wastewater facility that treats this water last month, “accelerating damage through excessive flows and incoming debris,” according to Giner.

The commissioner oversees the U.S. contingent of the IBWC, which is a federal government agency based in Texas that receives foreign policy guidance from the Department of State. Its Mexican counterpart, known as CILA, operates under the administrative supervision of the Mexican Ministry of Foreign Affairs.

Since the IBWC’s establishment by treaty in 1944, commissioners from the two countries have overseen the management of shared rivers, dams, storage reservoirs, sanitation facilities and conservation projects. 

The site affected by Hilary, the South Bay International Wastewater Treatment Plant, is a 25-million-gallon-per-day secondary treatment plant that discharges treated water into the Pacific Ocean — just west of the San Ysidro Port of Entry in San Diego County.

South Bay has treated sewage originating in Tijuana since 1999 — the result of a binational agreement, Minute 283, approved and jointly funded by the U.S. and Mexican governments.

The facility’s Hollister Street Pump Station, responsible for pumping transboundary flows into the plant, recently shut down when all four of its pumps became inoperable, the IBWC explained.

While efforts are underway to restore those operations, untreated sewage flows in the meantime can pass through the area’s canyons into the Tijuana River and Estuary, the agency warned.

The goal of the full South Bay rehabilitation project is to re-enable the facility to fully treat 25 million gallons per day of wastewater as well as meet discharge quality permit requirements, according to the IBWC.

The $8 million required to fulfill the plan will require the IBWC to realign other priorities by paying for the work from its salaries, expenses and construction budgets, the agency noted.

This sum adds to an existing $10 million in previously assigned contracts to address excess sewage flows that have been overwhelming the facility for more than a year, per the IBWC.

While achieving full compliance could take about nine months, incremental progress could occur alongside individual repairs, the agency noted. Some of the specific work aimed at recovering from Tropical Storm Hilary could be complete within 30-90 days, according to the IBWC.

“We want everyone to know we are working hard and have a plan to bring the plant back up to normal operations,” Giner said. “We are also making critically needed improvements to achieve water quality permit compliance.”  

In addition to this rehabilitative work, the IBWC in early August announced the advancement of a variety of sanitation projects for the region — the result of the binational Minute 328 agreement signed the previous summer.

The agency also said it would begin soliciting bids this fall for an initiative to both reduce transboundary water flows by 90 percent and double South Bay’s treatment capacity to 50 million gallons per day.

While costs of this project exceed existing finances by about $300 million, the IBWC noted that construction would occur in phases as more funds become available.