The amount of contaminated water laced with raw sewage that is flowing across the U.S.-Mexico border into San Diego County exceeded 44 billion gallons in 2023, the most on record in the last quarter-century.
This article has been reviewed according to Science X's editorial process and policies . Editors have highlighted the following attributes while ensuring the content's credibility: Mouth of Tijuana River. Credit: Wikimedia Commons Rickbramhall Creative Commons Attribution-Share Alike 4.0 International license. And this year's volumes could surpass all records should the region get more damaging rainstorms. As of June, the U.S. International Boundary and Water Commission (USIBWC) has recorded 33.55 billion gallons of polluted water, or flows, in the river, which makes its way into the Tijuana River Valley and the Pacific Ocean. That's enough water to fill 50,800 Olympic-size swimming pools. Flows are comprised of stormwater, groundwater and raw sewage. Rainstorms in the past couple years have brought staggering amounts of that polluted stew over the border into San Diego County, flooding some South Bay roads where people have had to be rescued, extending beach closures, and bringing sedimentation and trash to the Tijuana River Valley. A Jan. 22 storm filled a north levee near the South Bay International Wastewater Treatment Plant with more than 1,100 tons of debris. The IBWC finished cleaning it up in late May. The data was presented during a USIBWC Citizens Forum meeting, where agency officials gave updates on wastewater infrastructure projects on both sides of the U.S.-Mexico border that are expected to reduce the amount of untreated wastewater in the river. "There's a lot of moving pieces that we're monitoring and managing in order to address these transboundary flows and right now there's a lot of catchup work that needs to be done," said Commissioner Maria-Elena Giner, who heads the U.S. section of the binational agency. On the U.S. side, the IBWC is focused on repairing and expanding the South Bay plant. The 1997 facility has not been properly maintained for decades and is noncompliant with its Clean Water Act discharge permit. But it should reach…