EnvironmentSaturday, November 7
A study traces a Tijuana River sewage chemical 22 miles north to La Jolla
The SDtoday team
A UC Riverside study in Scientific Reports found that waste dumped into the Tijuana River can travel underwater seven times farther than expected before reaching the air. Researchers tracked the sulfur compound dimethyl trisulfide to the Scripps Institution of Oceanography pier, and CBS News 8 reports the findings raise concern about the sewage's reach.
22 milesfrom the river's mouth to the Scripps pier in La Jolla
The compound is associated with decomposing organic matter and raw sewage. Air samples confirmed the Tijuana River as the main source.
Source: SanDiegoRed
The timing mattered. In summer 2024, the dry season, unusually large volumes of wastewater flowed through the river anyway, researchers explained.
The study found sewage chemicals traveled farther than thought
- 7 times
- farther than previously thought before reaching the air
- 4
- air sampling sites, from the river to La Jolla
- 42–55 million
- gallons a day entering the Pacific in 2024
Sources: SanDiegoRed, Imperial Valley Press Online
“It was already known that compounds from this waste could enter the air, but we didn't realize until now how far it could travel underwater before emerging.”
- Sampling: August and September 2024
- Reach: air quality degraded across a 20-mile radius, per SanDiegoRed
Sources: CBS News 8, SanDiegoRed, Imperial Valley Press Online