The United States and Mexico are moving forward on a landmark agreement to end decades of sewage pollution in the Tijuana River. Infrastructure work under Minute 333, signed December 15, 2025, by the International Boundary and Water Commission, is now underway on both sides of the border.
Mexico has committed $46 million in 2026 and $47 million in 2027 to rehabilitate wastewater treatment channels, pumps, and backup power systems in Tijuana. The agreement also calls for a master water infrastructure plan for the city within six months. San Diego Union-Tribune and CalMatters have both reported on the implementation timeline.
On the U.S. side, the South Bay International Wastewater Treatment Plant expanded its capacity from 25 to 35 million gallons per day as of August 2025. A binational working group will assess building an ocean outfall system for the San Antonio de los Buenos treatment plant.
The agreement grew from a memorandum of understanding signed in July 2025 between EPA Administrator Lee Zeldin and Mexico’s Secretary of Environment Alicia Bárcena Ibarra. It creates a framework intended to eliminate 100 percent of cross-border river pollution.
For Imperial Beach residents and the broader South Bay community, the first major test comes with the construction of a sedimentation basin at Smuggler’s Gulch — a project scheduled for completion before the 2026-2027 rainy season.