How the US and Mexico can clean up the Tijuana River

from Deborah BrennanCalMatters

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Authorities tasked with cleaning up the Tijuana River’s pollution must complete upgrades to wastewater facilities on both sides of the border, fund operations, not just construction, of those facilities and plan for the eventual reuse of wastewater, a report released today recommends.

Those are some key takeaways from the report, “Tijuana River Pollution Crisis: A Five-Pillar Framework for Binational Solutions,” released today by the San Diego Regional Chamber of Commerce and the Prebys Foundation. Maria Elena Giner, a former U.S. border commissioner, and Doug Liden, a former U.S. Environmental Protection Agency official, authored the report.

They offer an overview of how the transboundary river became one of the nation’s most polluted waterways, recent efforts to fix it, and what’s still needed to clean it up.

“The continued pollution of the Tijuana River and the nearby Pacific coast stems from historic, chronic infrastructure failures, inadequate operation and maintenance, and fragmented binational governance,” the report states.

The Tijuana River watershed covers about 1,750 square miles, with nearly three-quarters of its area in Mexico and one-quarter in the United States, according to the report. It is mostly lined with concrete on the Mexican side, but extends through natural floodplains and wetlands in the Tijuana River Valley on the US side.

The US and Mexico have administered it jointly through the International Boundary and Water Commission since 1944. The North American Free Trade Agreement, the U.S. EPA’s Border Water Infrastructure Program and U.S. investments in Mexico have helped pay for the wastewater treatment, according to the report.

But wastewater capacity has not kept pace with Tijuana’s population growth, and delayed maintenance and deteriorating facilities have led to “recurring breakdowns and accelerated transboundary flows since 2016, undermining much of the progress achieved through previous binational efforts.”

For the past decade, sewage pollution from the Tijuana River has plagued Imperial Beach, Coronado and other parts of south San Diego County, nauseating swimmers and surfers, forcing beach closures and jeopardizing Navy SEAL training in Coronado. The river also emits airborne toxins, including foul-smelling hydrogen sulfide gas, which causes respiratory problems and other illnesses in neighboring communities.

Pathogens, including faecal coliforms, E. coli, enterococci and viruses, cause gastrointestinal, respiratory and skin diseases, the report said, creating “a chronic public health hazard for nearby communities and recreational users”. Water testing also found high levels of industrial metals, including copper, nickel and zinc.

Meanwhile, 75% of Tijuana’s sewer network and half of its pumping stations are in urgent need of repair. Its population is projected to grow by 40 percent by 2050, and demand for drinking water is outpacing interest in wastewater treatment, the report said.

The infrastructure on the US side was also crumbling. The South Bay International Wastewater Treatment Plant has suffered from decades of deferred maintenance, with more than a third of the facility in critical condition by 2022, the report found.

The lack of consistent operations and maintenance funding “has led to a repetitive cycle of system failures – where emergency fixes only occur after major operational disruptions,” it said.

To correct these failures, the U.S. and Mexico must adhere to plans laid out in a series of treaties or protocols agreed through the International Boundary and Water Commission, the authors urged. They explain how the two countries should cooperate to manage the river and how to expand the capacity of wastewater facilities to control sewage and other pollutants.

In addition to these investments, the US must commit annual funding for the maintenance and operation of the South Bay International Wastewater Treatment Plant. The International Boundary and Water Commission should consider a tiered fee structure that penalizes Mexican facilities for wastewater discharges into the Tijuana River and offer lower fees for flows that are properly diverted, the authors recommend.

While wet weather increases river flows, the worst pollution occurs during dry conditions, so “eliminating dry-weather flows provides the greatest benefits at the lowest cost,” they note.

Rather than simply managing runoff, facilities must clean it to a usable state. “Wastewater reuse must remain the highest priority for future infrastructure,” the report said.

And he called for transparency and public information, calling for a “joint bi-national communications strategy”, improving real-time beach monitoring and reporting and holding an annual “State of the River Forum”.

This article was originally published on CalMatters and is republished under Creative Commons Attribution-NonCommercial-No Derivatives license.