Wastewater surveillance has become a vital component of COVID-19 prevention. Campuses and cities do not have the data to determine if all positive cases are being detected. However, surveilling wastewater provides a picture of the approximate percentage of a population group that is shedding the virus via fecal matter. Therefore, the positive cases found via wastewater can be compared to the actual number of individuals with a positive nasal swab test. 

Working as support to COVID-19 prevention measures on campus, Sr. Vice Provost for Research and Graduate Education, Corinne Lengsfeld, shared the history and science behind this form of surveillance. Wastewater testing has been around for many years as a way to monitor for virus presence in water and sewage. It first emerged as a measure to identify hepatitis and polio cases. 

Wastewater research aims to identify a certain virus’s RNA remnants in order to shape information about a population’s infection rate. These findings can all be dependent on a virus’ progress in an individual’s body or their symptom severity. 

The idea was sparked to use this technology on campus a week prior to move-in. Wastewater testing was up and running just in time to welcome the first students to campus. 

After testing two of DU’s six major dorm buildings, it has now advanced to five dorms holding between 300 and 500 students each. Surveillance samples are taken three times each week with results available the following day. This quick turnaround time gives the COVID-19 task force ample opportunity to use current data to determine what action should be taken. 

Wastewater data has been proven to show the presence of coronavirus. This research is used in two ways. For one, it measures the virus prevalence found in wastewater surveillance against the number of positive cases that have been moved to quarantine. This allows the COVID-19 task force to ensure positive cases are quarantined and protect others living in the dorm. Second, this data also catches any high influxes of positive cases, enabling the task force to think of new ways to serve students and maintain safety. 

When it was first launched on campus, DU conducted wastewater surveillance using “grab samples.” This is a testing method in which wastewater is collected in a container from the central sewage line of a building. However, this method is problematic because it only collects samples of people using bathroom facilities within a particular 15-minute window. This can create skewed results.

Now, DU uses composite sampling. A composite sample is gathered by installing a device in the wastewater line that collects a small sample every 15 minutes until it reaches 60 samples. This allows for at least a 10-hour range of facility use to be present in the sample before it leaves for testing. 

DU is trying to use the most updated technologies to ensure accurate results. In addition, the university is working to expand its reach by helping other colleges implement wastewater surveillance and sharing the previously collected data at DU. 

Currently, both CU Boulder and CSU are using this testing method as well as many of the water municipalities in the Denver-metro area. Many other organizations are now also looking to start testing due to the high efficacy and low cost of the program. 

Lengsfeld claimed she has “always looked at controlling the virus from a multilayered strategy,” which included expanding the COVID-19 testing to include wastewater surveillance. While Lengsfeld was skeptical at first, she soon gained confidence in its success and ability to provide peace of mind. The greatest benefit, she said, is finding assurance that students are diligently wearing masks and physically distancing. 

Lengsfeld and other DU officials want students to know that there is no need to worry about walking by when workers set up surveillance in manholes on campus. This is because the virus deactivates in the wastewater. Lengsfeld also noted that she and other DU officials encourage community questions since those working to prevent the spread of the virus on campus want to be as transparent as possible. The DU community can access wastewater surveillance data, though officials are working to ensure that this information is provided in a digestible manner.

Lengsfeld also wants students and parents to know how encouraged she is by the wastewater data and the evidence of the caring community on campus. 

“I want to walk around and hand out prizes because there are so many people that are taking this seriously,” said Lengsfeld.

For information about COVID-19 at DU, see these resources.