A U.S. air and space agency says the Tijuana sewage crisis polluting Southern California beaches can be tracked by instruments in space.
In a study published on June 15, scientists tracked a Tijuana River plume using NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) instrument, built at the agency’s Jet Propulsion Laboratory to map minerals on Earth, which they say can further assist water quality management.
“[The findings] show a ‘smoking gun’ of sorts for wastewater in the Tijuana River plume,” said Eva Scrivner, the study’s lead author and doctoral student at the University of Connecticut, who led the study while at San Diego State University.
According to Scrivner, EMIT could be useful for filling data gaps around intensely polluted sites where traditional water sampling takes a lot of time and money, she said.
Christine Lee, a scientist at the Southern California laboratory and a coauthor of the study, agreed, noting that EMIT has the potential to complement water quality reports posted online.
“From orbit you are able to look down and see that a wastewater plume is extending into places you haven’t sampled,” Lee said. “It’s like a diagnostic at the doctor’s office that tells you, ‘Hey, let’s take a closer look at this.’”
Aboard the International Space Station, EMIT orbits Earth and observes sunlight by analyzing refined spatial resolutions through which scientists identify the respective unique spectral “fingerprint” of molecules, says NASA’s Earth Science News Team.
When scientists compared water samples from the Tijuana River to EMIT observations of the plume, they found an organism that can sicken humans and animals that ingest or inhale it deriving from a spectral fingerprint for phycocyanin, a pigment in cyanobacteria.
Water quality benefits
This study says scientists analyzed reflectance spectra of wastewater-seawater dilutions to investigate the potential to map and monitor water quality in the Tijuana River Estuary through field and satellite imaging spectroscopy.
“These results are promising for the use of spectroscopic sensors to map and monitor wastewater pollution in the Tijuana River Estuary and potentially, similarly polluted coastal and estuarine systems,” it says.
Imperial Beach Mayor Paloma Aguirre emphasized the need for infrastructure to protect the air, water, health and economy.
“When toxic wastewater pollution is so out of control that it’s visible from space, that’s no longer a local crisis—it’s a flashing red alert,” Aguirre said in a statement. “I hope this NASA report is a wake-up call for every level of government. The science is clear, the health risks are real, and seeing it all from space satellites just underscores what South County families are being forced to endure.”
