U.S. and Mexico Sign New Agreement to Tackle Longstanding Tijuana River Sewage Crisis

The United States and Mexico have signed a new bilateral agreement aimed at resolving the long-running sewage pollution crisis affecting the Tijuana River, according to a statement released Monday by the U.S. Environmental Protection Agency (EPA).

For decades, untreated and partially treated sewage from Tijuana, Mexico, has flowed into the Tijuana River, crossed the U.S. border, and emptied into the Pacific Ocean near San Diego. The issue has repeatedly strained relations between the two countries, sparked environmental concerns, and led to beach closures and public health warnings in Southern California.

Under the new agreement, the U.S. and Mexican sections of the International Boundary and Water Commission (IBWC) have committed to a series of coordinated actions designed to address both immediate and long-term challenges.

These include major infrastructure upgrades, expanded scientific research, enhanced water quality monitoring, and improved planning for the operation and maintenance of critical sewage and treatment systems.

The EPA said the agreement also takes future population growth in Tijuana into account, acknowledging that increased urban expansion has placed additional pressure on aging wastewater infrastructure. By incorporating long-term planning, both countries aim to prevent recurring pollution problems rather than relying on temporary fixes.

Earlier this year, momentum toward the new agreement was strengthened when EPA Administrator Lee Zeldin and Mexico’s Environment Minister, Alicia Bárcena, signed a memorandum of understanding. Under that deal, Mexico agreed to fast-track the use of approximately $93 million for critical upgrades to the Tijuana sewage system and to carry out multiple projects focused on sustainability, maintenance, and capacity expansion.

U.S. officials have described the latest agreement as a significant step toward protecting public health, preserving coastal ecosystems, and improving cross-border cooperation. Environmental advocates have also welcomed the development, while emphasizing the need for strict oversight and timely implementation.

As both countries move forward with the agreed projects, authorities say continued collaboration will be essential to finally resolving one of the most persistent environmental challenges along the U.S.-Mexico border.