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Testing the Water

ROBOT HELPERS Scientists collect a wastewater sample from a robot at the University of California San Diego. ERIK JEPSEN—UC SAN DIEGO

If it’s flushed down the toilet, Rob Knight wants to know about it. He’s a researcher at the University of California San Diego. He specializes in microbes, the tiny organisms that live in your gut.

Knight is testing the university’s wastewater wastewater sewage; water that has been used (noun) The toilet overflowed and left wastewater on the floor. for the coronavirus that causes COVID-19. The virus can be found in pee and poop even before people show symptoms of the disease.

Knight uses a robot to sample the wastewater in a building’s pipes. If tests find the virus in those samples, people are warned to stay away. His team then gives COVID-19 tests to everyone who uses the building site. Anyone infected is removed from the building to help stop the spread.

READY TO TEST A scientist at UCSD carries a wastewater sample. It will be taken to a lab and tested for coronavirus.


The system has reduced cases of COVID-19 at the university. Samples testing positive dropped from around 80% in January to just 5% in the spring. It has “exceeded our wildest dreams,” Knight told TIME.

Imagine how this system could work for larger communities, like cities. If officials tested the wastewater in sewage plants, they’d know the virus was present before many people showed symptoms. By testing people in that area, they could identify infected people and advise them to stay home. This might stop an outbreak before it happened.

IN THE LAB Technicians at the University of Arizona are also testing wastewater.


Speedy Results

When outbreaks occur, wastewater analysis could save officials valuable time. It could “give hospitals and public health departments a warning of when to anticipate a surge in cases,” Paraic Kenny says. He’s a researcher for the Gundersen Health System, in La Crosse, Wisconsin.

In September 2020, the U.S. Centers for Disease Control and Prevention (CDC) launched a national wastewater surveillance surveillance THOMAS JACKSON—GETTY IMAGES having to do with watching someone or something (noun) Having surveillance cameras outside my home makes me feel safe. program. It aims to help control outbreaks and alert the CDC to the next coronavirus variant.

PROTECTING A COMMUNITY A treatment plant in San Diego collects wastewater samples for testing.


Currently, 33 states and four cities are uploading wastewater information to the CDC’s online database. Scientists analyze the data. Studies say officials could get results six days sooner than they would by testing people for COVID-19. “It’s enough time to really make a difference,” says Amy Kirby, who leads the CDC program.

This could be a way to fight infectious diseases in the future, Kirby says. The next dangerous virus could be picked up and managed more quickly—thanks to our pee and poop.