Mexico Bureau

U.S. AND MEXICO MOVE TO FIX A KEY PART OF TIJUANA'S FAILING SEWAGE SYSTEM
By Vicente Calderón / WaterToday Mexico Bureau

U.S. and Mexican officials gathered in Tijuana to announce the rehabilitation of a critical part of the city's wastewater system, in a new effort to solve the long-contested problem of transborder sewage pollution.

The ceremony, held on Monday, April 27, beside the aging pump station, marked the start of upgrades to two failing lift stations, PB1A and PB1B, which push wastewater from a larger pump station toward treatment plants — one on the coast of Baja California, the other just across the border in California.

When they fail — due to mechanical breakdowns, power outages or excess flow — sewage reaches the Tijuana River, which flows north through the San Ysidro communities and the Tijuana River Valley before emptying into the Pacific Ocean, triggering health complaints and repeated beach closures as far north as Imperial Beach, the southern-most city in San Diego County.

From PB-1, which sits along the highway running parallel to the international border, you can see across into U.S. territory the building that houses the South Bay International Wastewater Treatment Plant — a facility built several decades ago to manage the flow of contaminated water from a river that begins in Mexico and ends in the United States.

Despite more than two decades of repairs, international meetings and investment, complaints about sewage pollution persist on the U.S. side. The infrastructure was never built to handle a city that has grown exponentially. "The original infrastructure, designed almost 60 years ago, has been surpassed by the reality of our border, which never stops growing," said Mónica Vega, director of CESPT, Tijuana's water agency.

The $30.8 million rehabilitation is being funded in part by a $13.4 million non-reimbursable grant from the U.S. Environmental Protection Agency (EPA), channeled through the North American Development Bank (NADBANK). Mexico covers the rest.

At the same ceremony, NADBANK and CESPT signed a separate $4.2 million grant to replace nearly 11 kilometers of deteriorating sewer lines along the city's collection network. Mexico matches that amount dollar for dollar.

Both projects fall under Minute 333, a 2025 binational agreement between the boundary water commissions of both countries — though they were first conceived years earlier under Minute 328, signed in 2021. NADBANK has now directed over $32 million in EPA grants toward sanitation projects along the Tijuana River; Mexico has contributed nearly $60 million alongside them.

"Today we formalize a contract of non-reimbursable resources to advance work in the especially sensitive areas of the system," said John Beckham, NADBANK's managing director. "Works like these help prevent untreated discharges and protect the Tijuana River — a meeting point for our communities and our shared challenges."

The first phase of the rehabilitation will take at least 18 months. Officials from both countries are already celebrating. Once again.

"Today we are taking a decisive step in the modernization of the infrastructure that sustains the responsible management of wastewater in our state — and in the United States as well," said Baja California Governor Marina del Pilar Ávila Olmeda.