Mexico is nearing completion on its new wastewater treatment plant near Tijuana, but once it’s turned on, it will be immediately overwhelmed by water that should have been treated in the United States.
The San Antonio de los Buenos Wastewater Treatment Plant is currently inoperable, so wastewater sent there is channeled into the ocean. The plant is being fully rebuilt with a capacity of 18 million gallons per day.
The $34 million project is being funded by Mexico, with civil works expected to be completed by October. It’s expected to be operational by the end of the year. The project being overseen by the Mexican Ministry of Defense (SEDENA).
“This is well on track to be completed by the end of the year,” said Doug Liden, an environmental engineer for the Environmental Protection Agency. He gave an update on Mexico’s projects at the August meeting of the San Diego Regional Water Quality Control Board.
Once the plant is turned on, it will be “immediately overwhelmed,” Liden said, because it will be flooded with wastewater that should have been treated at the US’s international treatment plant.
Because of the planned overwhelm, officials plan to bypass certain flows as they await the rehabilitation of the South Bay International Wastewater Treatment Plant on the US side of the border.
“There’s still much more work to be done to improve the flows at San Antonio de los Buenos, but the hope is that this will mark a significant improvement in the quality of water flows,” Liden said.
The United States also has projects underway, although officials recently announced more delays. An update on other projects curbing the ongoing Tijuana sewage crisis follows.
East Orientele/Collector
Status: Finished in 2023
Cost: $2 million (figures are in USD)
Mexico replaced 491 meters of pipes that had grown old and were at risk of causing sewage spills. It also built nine manholes.
Funds came solely from the Border Environment Infrastructure Fund (BEIF), a series of grants funded by the US Congress, allocated by the EPA, and distributed through the North American Development Bank.
PB Cila rehabilitation
Status: Finished in 2021
Cost: $4.4 million
This pump station’s small pipes were constantly clogged with garbage, rendering it inoperable. Mexico rehabilitated it by, among other things, installing pre-treatment systems as well as mechanical screens to prevent solid waste clogs.
Funding came from the Mexican government.
International Collector
Status: About 75% complete
Cost: $11 million
The international collector consolidates wastewater and diverts it to wastewater treatment plants – when it works. By replacing 5,176 meters of pipe and constructing 52 manholes, the collector should no longer experience leaks. Once it and related projects are complete, Mexico’s infrastructure will have an increased capacity: from 23 million to 34 million gallons per day, according to NADBank.
This project was funded by Mexico and is being overseen by the SEDENA. It’s expected to be completed next year.
Pressurized Line
Status: Partially funded
Cost: $16 million
This will replace a line that sends flows of river water from PBCILA/PB1 to the coast. Construction should be underway “fairly soon,” Liden said, pending some additional funding. This project will be paid for by Mexico.
Modernization of original gravity line
Status: Unfunded
Cost: $12 million
This will rehabilitate a gravity line to the coast. It will be funded entirely by Mexico.
Rehabilitation of Pump Stations
Status: In progress
Cost: $8.4 million (partially funded)
To create a wastewater removal system with a capacity of 300 liters per second, Mexico will rehabilitate the following pump stations: Los Laureles 1, Los Laureles 2, and Matadero.
Los Laureles 1 is 65% complete, with projected completion in October 2024. The other two are pending allocation of funding, with anticipated funds for the years 2025-2026. It will be funded entirely by Mexico.
Other projects
Some projects still require funding or are otherwise pending. They include: rehabilitating canal tubing, the Insurgentes Collector, the Poniente Collector, the Carranza Collector, The Orientele Interceptor, withdrawal of of treated wastewater flow from the Tijuana riverbed, wastewater treatment lines in the Sainz Canyon, gates on the Tijuana river to stop trash from clogging infrastructure, and a backup power supply to PB1.
Liden said he and his colleagues are continuing to work with Mexico to secure requisite funding.
