US and Mexico Seal New Deal to Tackle Tijuana River Sewage Crisis

The United States and Mexico have signed a new agreement aimed at resolving the long-running sewage pollution crisis affecting the Tijuana River, the U.S. Environmental Protection Agency (EPA) announced on Monday. The deal seeks to address decades of untreated or partially treated wastewater flowing from Tijuana into the river, crossing the U.S. border and contaminating coastal waters near San Diego.

Under the agreement, the U.S. and Mexican sections of the International Boundary and Water Commission will advance a coordinated package of infrastructure upgrades, scientific research, enhanced water-quality monitoring, and long-term planning for the operation and maintenance of critical wastewater systems. The framework is designed to ensure the sewage infrastructure can keep pace with Tijuana’s continued population growth.

The agreement builds on momentum earlier this year, when EPA Administrator Lee Zeldin and Mexican Environment Minister Alicia Bárcena signed a memorandum of understanding committing Mexico to accelerate the use of $93 million in funding for improvements to Tijuana’s sewage network. Those projects include system upgrades and maintenance measures intended to reduce cross-border pollution and protect public health, coastal ecosystems, and shared marine resources on both sides of the border.

Cross-border wastewater infrastructure coordination between the US and Mexico is one of the more longstanding but underinvested aspects of the bilateral environmental relationship. The Tijuana River sewage crisis has affected coastal ecosystems and public health across the border for decades, with previous agreements repeatedly failing to deliver infrastructure sized to Tijuana's continued population growth.

The IBWC coordination framework combined with the earlier $93 million commitment for Mexican sewage infrastructure provides the financial and institutional architecture that meaningful improvement requires. However, delivery-capacity constraints - construction procurement, workforce availability, ongoing operational funding - will determine whether these commitments translate into measurable pollution reduction.

For water utilities, infrastructure operators, environmental consultancies and financial institutions supporting cross-border infrastructure investment, Cognitud's impact assessment, sustainability due diligence and CSR teams help clients evaluate bilateral infrastructure opportunities, structure long-term operation-and-maintenance arrangements, and prepare disclosures aligned with SDG 6, TNFD and jurisdictional water-quality frameworks that increasingly influence reputation and access to sustainable-finance for water-and-wastewater investment.