Pump failure triggers limited cross-border wastewater bypass near Tijuana River

The International Boundary and Water Commission (U.S. Section) reported that a pump failure at Mexico’s PB1 station led to brief transboundary wastewater flows at Stewart’s Drain on March 14 and 15.

According to the agency, approximately 25,235 gallons bypassed the collector for about 1 hour and 15 minutes on March 14, followed by an additional 20,115 gallons over roughly 1 hour and 30 minutes on March 15.

In response, the International Boundary and Water Commission deployed three portable pumps to help contain and manage flows. Officials noted that wastewater remained localized—about 150 feet from the collector—and did not reach the Tijuana River Channel.

The South Bay International Wastewater Treatment Plant continued operating without disruption, receiving flows of approximately 30 million gallons per day during peak periods. No impacts to treatment operations were reported.

State officials, including the California Governor’s Office of Emergency Services, were notified of both incidents.