NASA EMIT Instrument Detects Sewage Contamination Off California Coast

NASA's EMIT instrument aboard the International Space Station has demonstrated the ability to detect wastewater contamination in the Tijuana River plume near Southern California by analyzing sunlight reflected from Earth. Originally designed to map mineral dust, EMIT's hyperspectral imaging technology can identify unique spectral fingerprints of pollutants such as phycocyanin, a pigment in cyanobacteria harmful to humans and wildlife. Researchers found that EMIT's satellite observations closely matched ground water sample measurements, confirming its potential to fill monitoring gaps where traditional water testing is limited by time or cost. The Tijuana River discharges millions of gallons of treated and untreated sewage annually, affecting densely populated areas and sensitive ecosystems along the U.S.-Mexico border. Scientists and NASA researchers view EMIT's capability as a promising new method for environmental monitoring and water quality assessment, providing a faster and broader diagnostic tool from space. This novel application expands EMIT's utility beyond its original mission to support terrestrial and atmospheric studies.