San Diego DA's office seeks info from Mexican government on potential Tijuana polluters

The San Diego County District Attorney’s Office is seeking records from the Mexican government to determine whether Tijuana-based industrial businesses might be contributing to cross-border pollution impacting San Diego County, announced Thursday.

While billions of gallons of sewage has flowed into the county via the Tijuana River on an annual basis, jeopardizing the health of South Bay residents, the D.A.’s Office cited a recent report from nonprofit environmental organization San Diego Coastkeeper that found industrial, chemical pollutants were also present in the water.

Among the chemicals detected were volatile and semi-volatile compounds such as heavy metals, pesticides, PFAs, acetone, phenols and benzoic acid.

San Diego Coastkeeper’s report, titled the 2025 Tijuana River Valley Water Quality Report, stated that the findings pointed to pollutants coming from Tijuana factories known as maquiladoras.

These factories were either dumping pollutants directly into surface waters or allowing them to enter the sanitary sewer system due to inadequate wastewater treatment at the factories, according to the report.

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San Diego County District Attorney Summer Stephan said the D.A.’s Office might be able to investigate these companies as they have U.S. parent companies or ownership interests.

To that end, the D.A.’s Office filed a request for records from Mexico’s Federal Attorney for Environmental Protection, also known as PROFEPA, the equivalent of the U.S. Environmental Protection Agency.

The D.A.’s request asks for records on environmental inspections, enforcement actions, sanctions, citizen complaints and potential sources of industrial pollution from January 2023 through September 2026.

It also seeks inspection reports, technical findings, administrative proceedings, fines, warnings, closures and records of complaints involving potential illegal discharges or improper handling of hazardous waste affecting the Tijuana and Alamar rivers.

Stephan said in a statement:

This request for information from the government of Mexico’s agency responsible for environmental laws is an important step to identify and gather evidence on the industries operating as maquiladoras with U.S. financial interests. We believe that when a company commits environmental violations that cross the border and continue to harm the water, air and people of San Diego County, those violations have consequences here that cannot be ignored. Just as we would pursue jurisdiction over a robbery that began in Mexico but continued into San Diego County, we believe the same principle should apply when environmental violations originating across the border continue to cause harm in our community.