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Assistant Professor Cresten Mansfeldt joined the Environmental Engineering Department at the University of ŷ���ڱ���Ƶ Boulder last year, and he’s certainly had a very busy first year. Professor Mansfeldt researches applied microbiology, working in infrastructure and natural systems. He also teaches the Applied Microbiology, Toxicology, and Epidemiology courses in the Fall semester and Solid Waste in the Spring semester. 

When COVID-19 caused the campus to shut down in the spring, the campus planning team began formulating plans to reopen in the fall, which included a wastewater monitoring campaign for the sewer system on campus. Wastewater monitoring can be useful in early detection of potential COVID-19 outbreaks in a certain area. Mansfeldt's experience with wastewater made him the perfect candidate to take the lead on the project. Over the summer, he helped design and develop the reactor systems to collect samples. 

Fast forward to August 18th when the first monitoring station was switched on, just as students began to move back to campus. Now, there are 18 operational monitoring stations across campus and 23 in total. Each monitoring station fits into a black box with a red lid that’s about the same size as a standard cooler. A line runs down to the sewer and then a peristaltic pump, also known as a roller pump, pulls 10 to 15 liters of wastewater a day. The pumping system operates passively and can function even if the sewer is dry. Each sample station is checked twice every day: first by the sample collectors who gather 150 milliliters of wastewater and bring it back to the lab for testing, and second by the undergraduate team who replace the gel ice packs and the batteries in the pump, checking that the system is running smoothly. The ice packs are used to keep the samples at 4°C to preserve them; otherwise they may react and not be representative of the system. Then later on in the lab, the samples are run through bioconcentration, RNA extraction, and then finally a qPCR analysis to detect the SARS-CoV-2 signal. It’s a 12-hour process from the time a sample enters the lab to the time when the results are ready. Ultimately, what matters is how effective this form of monitoring is, and according to Mansfeldt, his team may actually use the monitoring system to track down individual cases on campus. Mansfeldt explained that this is possible because most of the sites are covering a range of 2 to 400 individuals, so it’s possible to track down an individual infection within a 24-hour monitoring period.

Mansfeldt doesn’t do all of this work alone. His team is made up of 27 people. He currently has a PhD student, lab technicians, masters students, and undergraduates who are responsible for collecting the samples and making sure the sampling stations are running smoothly. With the Boulder County Public Health (BCPH) order that limited gatherings for 18- to 22-year-olds and the fact that their work is deemed essential, the team takes extensive precautions to stay safe including wearing jumpsuits, goggles, facemasks and face shields. Although the BCPH order hasn’t impacted their daily monitoring routine, Mansfeldt says that it “altered the data somewhat because actually the wastewater data was indicating stabilization and potentially a slight decrease even before the substantial social distancing and Boulder County order came through.” If the wastewater data was indicating a plateau in infections after the post-Labor Day spike, one might question the point of the health order at all. However, Mansfeldt emphasizes that a plateau in the data may be an indicator of success for these programs because “instead of facing an exponential increase in cases, they [Boulder County] were already starting to hit a plateau and by putting in that extra effort you can really draw the cases down.”

So, are there tangible benefits to monitoring wastewater? Well, to put it simply, yes. Mansfeldt says “initially it was able to identify some of these individual cases...but as the rise in the number and the ubiquity in the number actually started to occur, the wastewater data found more strength in a community surveillance metric to say ‘are we on a general increase or general decrease?’” It’s meant to identify broader trends—specifically in on-campus housing, and it has been extremely effective in doing so.
When asked how his work on campus has affected his mindset and outlook when it comes to the pandemic as a whole, Mansfeldt was optimistic and straightforward saying, “pandemics are a lot of work...and although it is all consuming and then also very tiring at a lot of times, it’s also very inspiring.” 

As a researcher leading his first project tracking a specific virus, Mansfeldt appears to hold a lot of faith in humanity as a whole. He believes that as the stakes continuously rise, people will rise to meet them. People’s compassion, ability, curiosity, and drive will lead to a “just and fair system rather than something that’s just chaotically spreading.” While there’s a massive effort going into the campus monitoring campaigns, these initiatives are ultimately reflective of the effort of the students on a daily basis to adapt to a pandemic. Keeping things lighthearted, Mansfeldt says, “although it’s a very lonely time and can be very isolating, there are still people down in the sewer. You can just wave to us and we’ll wave back.” 

Photo courtesy of Cresten Mansfeldt