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CBP's Sampling of Tijuana Wastewater

Document Posting Date: 
August 7, 2018

The watershed of the Tijuana River flows from Mexico into the United States before entering the Pacific Ocean. This transboundary flow transfers a significant amount of raw sewage and other unknown contaminants, which have extremely high levels of bacteria.

This presence of wastewater and high levels of bacteria has caused beach closures at Imperial Beach, California for almost half of the year. Additionally, the river basin is uninhabited and a common route for illegal border crossings.  As such, U.S. Customs and Border Protection (CBP) must operate in this area to intercept such activity despite the presence of wastewater.  In 2017, CBP noticed an increasing presence of wastewater during dry weather and launched a response to mitigate the effects on the agency’s operations.

In January 2018, CBP conducted a six month water sampling effort to add to already existing data-sets collected by International Boundary and Water Commission (IBWC) and other past sampling efforts. Following this data set, CBP embarked on a subsequent six month sampling effort beginning in September 2018 to collect soil and water samples with the goal to better understand the impact of wastewater on CBP operations in the area. This data collection is intended to complement existing data, giving a potentially new perspective on the issue. 

The results of the second round of sampling data will be posted here at a future date.

Last modified: 
June 26, 2019