The U.S. Environmental Protection Agency (EPA) announced on July 24th that the U.S. and Mexico have reached an agreement aimed at addressing the long-standing sewage crisis in the Tijuana River that has been a concern for both countries. For years, untreated sewage from Mexico has been flowing into Southern California, sparking widespread attention.
EPA Administrator Lee Zeldin and Mexico’s Secretary of Environment and Natural Resources Alicia Barcena Ibarra signed a memorandum of understanding in Mexico City. The sewage crisis in the Tijuana River Valley has persisted for decades, posing a challenging issue between the two nations. Despite long-term cooperation between the U.S. and Mexico on water resources and sewage issues, the rapid expansion of Tijuana city, coupled with insufficient infrastructure development and a lack of funding, has exacerbated the problem.
According to data from the U.S.-Mexico International Boundary and Water Commission (IBWC), the infrastructure in Tijuana city has long been overloaded, with millions of gallons of treated and untreated sewage flowing into the Tijuana River daily, ultimately discharging into the Pacific Ocean near San Diego. The IBWC has measured that the Tijuana River can discharge up to 50 million gallons of contaminated water per day, with about half being untreated raw sewage, and some being treated wastewater, groundwater, and tap water contaminated due to pipeline leaks.
The EPA stated that the issue has led to beach closures, deteriorating air quality, economic impacts in the region, and harm to the health of people in both countries. According to the EPA, the new agreement achieves three key priorities and milestones set by the Trump administration, which are crucial for fully resolving the crisis.
The agreement stipulates that Mexico has agreed to expedite the Tijuana sewage system upgrade project, with a total amount of $93 million. Mexico has also committed to immediately seek domestic funding to kickstart two construction projects within a year: one to divert 10 million gallons of treated wastewater daily from two sewage treatment plants that would have originally flowed into the Tijuana River, and the other is to repair a parallel gravity pipeline. The EPA noted that Mexico has agreed to complete other important water resources infrastructure projects before December 31, 2027, with some projects set to be completed four years ahead of schedule.
In exchange, the U.S. has agreed to release funding from the EPA’s Border Water Infrastructure Program that was previously withheld due to Mexico’s failure to fulfill other commitments, to be used for repairing a pumping station and the Tijuana River interceptor pipeline. The IBWC will also complete the expansion of the South Bay International Wastewater Treatment Plant by August, increasing its processing capacity from 25 million gallons per day to 35 million gallons.
The EPA announced that Mexico has also agreed to sign a new agreement by the end of the year; the new memorandum will incorporate at least 12 new actions deemed necessary by the U.S. to permanently end this crisis. The EPA also stated that within 100 days, both the U.S. and Mexico will comprehensively review all infrastructure project schedules to ensure that the related projects are completed in the shortest possible time.
Zeldin said, “The Trump administration is proud to bring this major environmental and national security victory to the residents of the San Diego area who have long suffered from sewage intrusion.” Ibarra also welcomed the agreement and posted on X, stating that the memorandum “strengthens cooperation between both sides in addressing environmental and health challenges at the northern Mexico border.” ◇