As sewage continues to flow from Tijuana into the Pacific Ocean, officials last week gave an update on the extensive repairs underway to fix the problem – and on how much money is needed to finish projects.
The problem is all too familiar to Coronado and other South Bay residents: raw sewage from Tijuana overloads the crumbling infrastructure meant to process it, so instead, millions of gallons of untreated sewage spills into the ocean and the Tijuana River Valley.
In Imperial Beach, where the beach has been closed for more than 900 days, residents and visitors complain of a pungent smell. (Monitors are being installed to measure the impact.)
As Tijuana’s population explodes, neighborhoods whose homes are not connected to formal sewer lines exacerbate the problem of sewage in the river, which crosses the United States-Mexican border near San Ysidro. When it rains, water flushes trash into the valley, across the border, and either along the river banks or into the ocean.
Despite grassroots and political efforts to address the problem, and a slurry of funding that the United States and Mexican governments has allocated in the last two years, progress is slow, but moving forward.
The International Boundary and Water Commission gave an update on the status of requisite projects at a meeting of its San Diego Citizens’ Forum on July 10.
Last fall, the agency outlined a timeline for repairs, saying “incremental improvements” in water quality could be expected that year. An update in the spring revealed projects that were largely on schedule, with a slight delay for South Bay International Wastewater Treatment Plant (SBIWTP) expansion.
While beaches remain closed and repairs are still slogging forward, much has changed since that initial timeline, including an additional $156 million in federal funding to address the problem.
Here’s where the projects stand:
South Bay International Wastewater Treatment Plant Compliance
The infrastructure issues that cause the Tijuana sewage crisis are manifold, and their solutions complicated, but one of the largest projects is repairing and expanding the SBIWTP.
Under the Clean Water Act, no pollutants may be discharged into water in the United States without a permit. The IBWC holds such a permit for its treatment plant, but it is not complying with it. It has been sued for the violation, a case that is still working its way through the courts.
Officials say they hope to bring the plant back into compliance by August, a date that aligns with a timeline the IBWC gave last November. However, the plant will still need repairs and an expansion of its capacity from 25 to 50 million gallons of per day, with a peaking factor that can treat temporary flows of up to 75 MGD.
Between 2010 and 2021, only about $4 million was invested into the treatment plant that is meant to process waste sent across the border (via the international collector pipe), said IBWC Commissioner Maria-Elena Giner.
In the last 18 months, the agency has invested $30 million into the plant in effort to bring it into compliance with its permit. The IBWC does not only oversee sewage infrastructure related to Tijuana’s issues; it manages levees, dams, and sanitation along the entire US-Mexico border. Its budget for construction was about $211 million in 2022, more than double its 2019 budget of around $103 million.
The budget, IBWC officials have long said, has been strained. Rehabilitation and expansion of the SBIWTP is expected to cost around $1 billion.
Diverting so much of the agency’s funding to the treatment plant was “awkward” during meetings with managers of other infrastructure, said Morgan Rogers, area operations manager for the IBWC, but it needed to be done to push the plant back into compliance.
Problems with the treatment plant include its influent pumps, which greet wastewater brought from Mexico. In August 2023, only one of its six pumps were operational. Currently, five are operational, with four additional pumps on order.
The custom-made pumps are expensive, with price tags hitting a million dollars in some cases, and can take nine to eighteen months of lead time for procurement. By having spare pumps on hand, the IBWC hopes to avoid its treatment plant losing operability during large rain events. Tropical Storm Hilary, for example, severely damaged the already struggling plant.
All four pumps are expected to be operational by September.
In addition, the influent meters and valves have not been operational since 2017. Repairs are underway, and are expected to be completed in July.
Then comes the primary sedimentation tanks, which Rogers says are “key” to bringing the treatment plant into compliance. The plant has five of these tanks, and in March 2023, none were operational.
Currently, two are working, with a third expected to be complete in July. All are expected to be working by September.
Hollister Pump Station
The Hollister Pump Station is a part of the infrastructure of the SBIWTP, and it has flooded twice in the last year (in June and last August), pushing water into the streets of Imperial Beach. All four of its pumps are now operational, and an extra is on order.
Junction Box 1
Also a part of the SBIWTP, the junction box regulates how much liquid can flow into the wastewater treatment plant. Flow control is crucial to making sure the plant does not become overladen, Rogers said.
A contract for rehabilitation has been awarded, with 90% of the design expected by August and a projected completion date of February 2025.
SBIWTP Expansion
Once the international wastewater treatment plant is back in compliance with its wastewater permit, the work isn’t done: That simply means that it will no longer be spilling more pollutants than it is legally allowed to under the Clean Water Act.
The plant still must be expanded to double its treatment capacity from 25 million gallons per day to 50. The procurement phase for this project started in December 2023, and a contract award is expected in August. Design and construction is expected to begin immediately after.
It’s common for projects to spend a year or more in the design phase before construction begins, but Rogers said the plan is to begin construction as early as possible, though he did not comment on a projected completion date.
International Collector
This pipeline spans from Tijuana into San Diego and routes 16 percent of Mexico’s wastewater to the SBIWTP. Right now, it is fractured and leaking.
Those leaks contribute to dry-weather transboundary flows into the Tijuana River. Repairs on the collector, which include relining portions of the piping and replacing other portions, is expected to conclude by the end of summer 2024.
San Antonio de Los Buenos Wastewater Treatment Plant
The SAB, which sits south of the border, is being expanded by the Mexican government as a part of the $144 million the country committed to addressing the sewage crisis. The project has been fully funded, and construction began in February 2024.
When complete, its capacity will be 18 million gallons per day, and it is anticipated to treat about a third of Tijuana’s wastewater. With the plant inoperable, wastewater instead flowed into the ocean.
It’s expected to be completed in September, though Rogers cautioned that the US section of the IBWC found that goal “aggressive.” Still, he said that workers are working at all hours to expedite the project. Once online, it won’t address all of the wastewater, but it will mark a substantial improvement, Rogers said.
Other treaty-stipulated projects
When the US and Mexico executed Treaty Minute 328 in 2022, the countries outlined some projects that needed to be completed. Under the agreement, the United States pledged $300 million toward the problem (a number that has since been increased), while Mexico pledged $144 million. While the larger of those are outlined above, others remain.
Rehabilitation of the Poniente Interceptor, the Orientele Interceptor, the Insurgentes Collector, the Carranza Collector, the lift station and force main from Sainz Canyon to Arturo Herrerra Plant are all pending funding.
The first phase of reuse of effluent from the La Morita and Arturo Herrera plants are in the study phase, with the IBWC marking them as 20% complete in April.
Rehabilitation of PB Matadero and Laureles 1 and 2 is grouped as a single project and was reported at 28% complete in the April status report. Rehabilitation of Laureles 1 is underway, with Mexico reporting progress, but the other two projects are pending funding.
The Tijuana River gates, a series of 54 individual hoistable, steel gates that can be raised or lowered during high and low flow to control debris accumulation, are expected to be designed by Sept. 2024, with construction planned for early 2025.
A backup power supply for PB-1 is also planned, and the IBWC had a meeting scheduled with San Diego Gas and Electric in May 2024, but has not released an update on that project.
Encasing the open channel from PB-1A to the SAB is listed at 0% complete, but the IBWC did not comment on this project. Rehabilitation of the parallel gravity line and the Antiguo Force main we similarly listed at 0% complete.
