San Diego chamber releases binational roadmap for Tijuana River sewage crisis

Walker Armstrong, The San Diego Union-Tribune on Mar 11, 2026

By clicking submit, I authorize Arcamax and its affiliates to: (1) use, sell, and share my information for marketing purposes, including cross-context behavioral advertising, as described in our Privacy Policy , (2) add to information that I provide with other information like interests inferred from web page views, or data lawfully obtained from data brokers, such as past purchase or location data, or publicly available data, (3) contact me or enable others to contact me by email or other means with offers for different types of goods and services, and (4) retain my information while I am engaging with marketing messages that I receive and for a reasonable amount of time thereafter. I understand I can opt out at any time through an email that I receive, or by clicking here

The San Diego Regional Chamber of Commerce released a comprehensive binational report Wednesday outlining a five-pillar strategy to address the Tijuana River contamination crisis, a problem that has plagued South San Diego County communities for decades.

The report, commissioned by the Prebys Foundation, was authored by Doug Liden, a former U.S. Environmental Protection Agency official, and Maria Elena Giner, former commissioner of the U.S. International Boundary and Water Commission (IBWC).

The report frames an accounting of past failures as a necessary foundation for what it calls a clear, verifiable and actionable plan to finally end decades of transboundary pollution. Chris Cate, president and CEO of the San Diego Regional Chamber of Commerce, said the goal is to move the region from discussion to action.

“What changes today is not the urgency, it’s the clarity of the path forward,” Cate said.

Among its findings, the report documents that a federally owned wastewater treatment plant at the heart of the crisis received just $4 million in maintenance funding over an 11-year span, even as dry-weather sewage flows across the U.S.-Mexico border surged to record levels.

A 2022 condition assessment of the South Bay International Wastewater Treatment Plant, operated by the IBWC, found 36 percent of its assets in critical condition, requiring approximately $150 million in rehabilitation.

The report also found that Mexico has delivered approximately $51 million of a $144 million infrastructure commitment made under a 2022 binational agreement called Minute 328 — leaving roughly $93 million in unfunded pledges — while the United States has committed $650 million toward rehabilitation and expansion of the same treatment facility.

Signed in July 2022 under the Biden administration, Minute 328 committed approximately $474 million in binational funding toward doubling the capacity of the South Bay International Wastewater Treatment Plant and building a new treatment facility in Tijuana — with Mexico’s $144 million share described as a binding treaty obligation.

In December 2025, the Trump administration signed Minute 333, a follow-on agreement that for the first time includes operations and maintenance planning to account for Tijuana’s future population growth. The accord promised to hold Mexico accountable for infrastructure upgrades on their side of the border and does not obligate additional U.S. taxpayer funding.

The report identifies three root causes driving persistent contamination: chronic infrastructure failures, insufficient operations and maintenance funding, and fragmented binational governance.

Dry-weather transboundary flow days in the Tijuana River have surged from near-zero before 2016 to more than 100 days per year in 2023 and 2024. A study by the Scripps Institution of Oceanography estimated that more than 34,000 swimmers at Imperial Beach may have been sickened by contaminated ocean water in 2017 alone.

To address those root causes, the report proposes five mutually reinforcing pillars: reliable infrastructure funding, modernized operations and maintenance, strengthened governance, enhanced public transparency, and long-term water management and reuse planning.

Courtney Baltiyskyy, vice president of public policy at the YMCA of San Diego County and a member of the Tijuana River Coalition — an organization composed of more than 60 nonprofit and community-based organizations — said the pillared approach addresses gaps left previously untended under previous plans.

“There hasn’t ever been a comprehensive story and research that covers both US and Mexico and tells a future story of what’s really possible,” Baltiyskyy said. “Now we have a one stop for that.”

Imperial Beach Mayor Mitch McKay, speaking after the event, said he hoped the report addresses what he sees as an underexamined dimension of the crisis — the accumulated contamination already saturating the Tijuana River Valley, regardless of whether new flows are stopped.

“Once you source control that, stop it at the border or however, divert it — you still have that mess to clean up,” McKay said. “It’s been going on for 50 years.”