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This fall, when students in residence halls use the bathroom, they will be passively participating in important scientific research to keep campus safe. 

Researchers at CU Boulder are setting up an anonymous observational network to monitor the wastewater leaving residence halls on campus as part of an effort to detect and intercept community spread of COVID-19.

According to Cresten Mansfeldt, project lead and assistant professor of civil, environmental and architectural engineering at CU Boulder, between 40 and 80% of infected individuals shed the SARS-COV-2 virus that causes COVID-19. That means what we flush down the toilet can contain the virus. 

“It’s not a diagnosis, but could identify whether or not there are infections in certain areas of the campus,” said Mansfeldt. “It complements the entire framework being deployed at the university.” 

That framework also includes individual testing, contact tracing and enhanced ventilation on campus. 

The non-invasive wastewater surveillance system will be comprised of 23 sewer sampling stations on campus, run and tested by Mansfeldt and a team of 18 students and microbiologists. 

The most exciting part of the project is that it can provide an early warning, detecting infections almost a week before someone with COVID-19 might exhibit symptoms and need to seek medical attention. 

“In analyzing the sewage you have the potential to detect infections early—before people are actually showing symptoms and in asymptomatic individuals,” said Katie Reeves, PhD student in the Environmental Engineering Program. 

While it cannot identify individuals, this monitoring system can narrow down a potential infection from a sampling location. Individual testing resources can then be deployed to a specific residence hall or recommended for certain groups of students—catching and isolating the virus before it can spread throughout the community. 

Tracing the source of a signal 

Cresten Mansfeld examines a wastewater monitoring station, as part of an on-campus observational network to help identify emerging infections in residence halls. (Credit: Glenn Asakawa, CU Boulder)

Environmental engineering is no stranger to public health—in fact, the profession gained prominence because of it. 

In the 1970s, environmental engineering in the U.S. emerged as part of developing improved wastewater treatment systems and the cleanup of hazardous waste sites. Today, environmental engineers track various chemicals in wastewater, such as pharmaceuticals and illicit substances. 

But they also have the know-how to track viruses. In more recent history, they’ve even tracked polio in some communities through wastewater. 

“When our profession is functioning, it’s like a hidden safety structure,” Mansfeldt said. “Each time civilization and society grow, there has to be new innovation come online through our civil and environmental infrastructure.” 

The sampling stations Mansfeldt’s team are setting up are quite simple. A small pump and battery pull wastewater from the sewage system from 4 to 20 feet below into a secure container within a cooler over 24 hours, amounting to about 2 gallons a day. 

Each day, the team takes samples from these sites and performs PCR detection and amplification of the viral RNA—the same type of testing that is done on the samples collected from individuals through a nose swab for diagnostic testing.  

Any virus that a student sheds through wastewater will be detected in a station’s sample about 36 hours after they flush. 

Mansfeldt has previously monitored sewage so he was the perfect pick to lead the project at CU—even though this is only his second year ever as a professor.

The wastewater initiative was started by Roy Parker, professor of biochemistry, and the campus planning committee that oversaw the safe return to campus this fall. Once Mansfeldt was tapped to lead it, he received input and assistance from the Civil, Environmental, and Architectural Engineering Department faculty, staff and students; the Environmental Engineering Program; the Vice Chancellor’s Office of Integrity, Safety, and Compliance; the Facilities Management Team; the grounds team; Housing and Dining Services; Environmental Health and Safety; researchers across the Front Range, nation and the world; local device manufacturers and major scientific instrument suppliers. 

“It's been a rewarding and challenging learning experience,” said Mansfeldt. “But it's definitely not a single person campaign.”