In summary
The Tijuana River in San Diego has sickened surfers, swimmers and Navy SEALS for decades. A new report explores ways to clean it up.
Authorities charged with cleaning up Tijuana River pollution should finish upgrades to wastewater plants on both sides of the border, fund operations and not just construction of those facilities, and plan for eventual wastewater reuse, a report issued today recommended.
Those are some key suggestions of the report “Tijuana River Contamination 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, former Commissioner of the U.S. International Boundary and Doug Liden, a former U.S. Environmental Protection Agency official, authored the report.
They offer an overview of how the cross-border river became one of the most polluted waterways in the country, recent efforts to fix that, and what’s still needed to clean it up.
“The persistent contamination of the Tijuana River and nearby Pacific coastline stems from historic chronic infrastructure failures, insufficient operations 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’s mostly concrete-lined on the Mexican side, but sprawls through natural floodplains and wetlands within the Tijuana River Valley on the U.S. side.
The U.S. and Mexico have managed it jointly through the International Boundary and Water Commission since 1944. The North American Free Trade Agreement, U.S. EPA Border Water Infrastructure Program and U.S. investment in Mexico helped pay for wastewater treatment, according to the report.
But wastewater capacity hasn’t kept pace with population growth in Tijuana, and deferred maintenance and deteriorating facilities led to “recurring failures and accelerated transboundary flows since 2016, eroding much of the progress achieved through prior binational efforts.”
Over the past decade sewage pollution from the Tijuana River has plagued Imperial Beach, Coronado and other parts of southern San Diego County, sickening swimmers and surfers, forcing beach closures and endangering Navy SEALs training in Coronado. The river also emits airborne toxins including foul-smelling hydrogen sulfide gas, which causes breathing problems and other ailments in neighboring communities.
Pathogens including fecal coliforms, E. coli, enterococci, and viruses cause gastrointestinal, respiratory, and skin illnesses, the report stated, 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 wastewater network and half of its pump stations need urgent repairs. Its population is projected to grow 40% by 2050, and demands for drinking water outpace interest in wastewater treatment, the report stated.
Infrastructure on the U.S. side was also crumbling. The South Bay International Wastewater Treatment Plant suffered from decades of deferred maintenance with more than a third of the facility in critical condition in 2022, the report stated.
The lack of consistent operations and maintenance funding, “resulted in a recurring cycle of system failures—where urgent fixes only occur following major operational disruptions” it stated.
To correct those failures, the U.S. and Mexico must stick with plans laid out in a series of treaties, or Minutes, agreed to through the International Boundary and Water Commission, the authors urged. They spell out 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.
Besides those investments, the U.S. must commit annual funding to maintenance and operations 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 discharged to the Tijuana River and offer lower charges for flows that are properly conveyed, the authors recommended.
While rainy weather increases flows of the river, the worst pollution occurs during dry conditions, so “eliminating dry-weather flows provides the greatest benefits at the lowest cost,” they noted.
Rather than simply managing runoff, facilities should clean it up to usable condition. “Wastewater reuse must remain the highest priority for future infrastructure,” the report stated.
And it urged transparency and public information, calling for a “joint binational communication strategy,” improving real-time monitoring and beach reports, and holding an annual “State of the River Forum.”
