Study launched to determine possible link between Mexican treatment plant and fecal contamination at Imperial Beach

SCCWRP and its partners have initiated a year-long study to investigate whether fecal contamination at Imperial Beach near the U.S.-Mexico border can be linked to primary-treated effluent being released into coastal waters by a Mexican wastewater treatment plant or to another specific source.

The study, which completed an initial round of field sampling in October, will use DNA sequencing technology to determine whether the microbial sewage community found at the San Antonio de Los Buenos treatment plant near Tijuana has a unique microbial community signature that may be used to identify pollution from the plant impacting Imperial Beach, about 10 miles north.

Researchers are sampling at multiple points along the northward route that the Mexican treatment plant’s effluent is hypothesized to be taking to reach Imperial Beach during times when strong ocean swells coming from the south push water north from Mexico.

Researchers also will examine whether unique microbial signatures can be traced to other specific sources, such as stormwater runoff entering the Tijuana River estuary that contains untreated human sewage.