EPA releases first quarterly update on binational effort to resolve Tijuana River sewage crisis
EPA and the U.S. International Boundary and Water Commission (USIBWC) have issued their first quarterly public update on progress toward implementing a permanent, “100% solution” to the longstanding Tijuana River sewage crisis. The update is the first delivered under a Memorandum of Understanding (MOU) signed in July 2025 between EPA Administrator Lee Zeldin and Mexico’s Secretary of Environment Alicia Bárcena Ibarra.
“The Trump Administration committed to delivering an urgent and permanent 100% solution to the millions of people afflicted by this crisis,” Zeldin said in an EPA press release. “Our mission will not be accomplished until we reach the 100% solution.” He noted that the agencies have implemented the MOU “well ahead of the projected timeline.”
USIBWC Commissioner Chad McIntosh added that federal agencies are “making real progress on a 100% solution to permanently eliminate American exposure to Mexican sewage from the Tijuana River,” and emphasized ongoing coordination with Mexico as both countries advance infrastructure commitments.
According to EPA, major actions completed or underway include:
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A 10 mgd interim expansion of the South Bay International Wastewater Treatment Plant (SBIWTP)
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Mexico initiating construction of the first phase of the Tijuana River Gates and collection system
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A binational working group compressing project timelines by an additional nine months
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USIBWC completing a nanobubble ozonation pilot and planning a 50 mgd accelerated SBIWTP expansion
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EPA and Mexico’s SEMARNAT developing long-term operations and maintenance funding strategies
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Final negotiations for a new treaty “Minute” to guide future investments
The update also outlines Mexico’s planned 2026–2027 work—including collector rehabilitations, pump station upgrades, wastewater treatment plant improvements, and channel enclosures—to meet the December 31, 2027 deadline for completing all Minute 328 projects.
EPA and USIBWC plan to continue issuing quarterly updates as the U.S. and Mexico work toward a long-term, binational solution to reduce cross-border wastewater flows and safeguard public health in the San Diego–Tijuana region.
