CROSS-BORDER MARINE POLLUTION: TRAGEDY AND TRIUMPHS

Written by Angela T. Howe¹

THE BORDER WATER POLLUTION TRAGEDY IN THREE PARTS

Chronic pollution crossing the U.S.-Mexico border South of San Diego and North of Tijuana is a decades-long problem that is growing increasingly dire. One hundred billion gallons of sewage flowed across the border in a recent five-year period, with 700 million gallons in September 2023 alone.² Pollution flows have been exacerbated by the atmospheric rivers battering the Pacific Ocean coastline in 2023, 2024, and 2025.³ Off the coast of San Diego, in the water and in the air, U.S. researchers have detected not only sewage indicator bacteria such as E. coli and enterococcus, but also enteroviruses, human norovirus, hepatitis A virus, and SARS-CoV2.⁴

The human and industrial sewage that is actively polluting some of the most beautiful coastline of Southern California highlights the failure of the U.S. International Boundary and Water Commission ("USIBWC") to address the sewage treatment and rampant pollution problem. The Tijuana Estuary is one of few remaining wetlands on the California coast and serves as a safe haven for numerous threatened and endangered species;⁵ it is also a natural buffer for climate change and coastal flooding. Climate change is expected to cause more extreme weather and storm events, which likely will further exacerbate the pollution problem.⁶ This serious threat to the environment, human health and climate resilience augers for making the redress of the Tijuana River Valley pollution a federal priority. Federal agencies, such as the USIBWC and United States Environmental Protection Agency ("EPA"), should swiftly and fully address the most egregious water quality violations in the nation.