Municipalities across Vermont are collecting data on Covid levels in their wastewater. But that data isn’t showing up in state or national data systems, befuddling both government officials and contractors that are supposed to be working with the data.

In February, local wastewater treatment plants began announcing their participation in the U.S. Centers for Disease Control and Prevention’s wastewater surveillance program for Covid-19.

Public health officials and experts were excited to get access to a new type of Covid data as the number of PCR tests was declining. Some said wastewater surveillance, which measures the level of SARS-CoV-2 virus in a local sewer system, had the potential to be even more comprehensive than other data sources. 

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“It allows direct estimation of Covid-19 activity for everyone using a toilet that empties to a wastewater plant,” Timothy Plante, an assistant professor at the University of Vermont’s Larner College of Medicine, told VTDigger in April.

Months later, the CDC reports that 10 wastewater plants across the state are included in its National Wastewater Surveillance System, or NWSS.

Yet on the CDC website, and in Vermont Department of Health reports, the actual data showing viral levels and change over time is muddled and variable. In the past week, there was no data at all for the 10 participants in the program.

The health department had warned that there could be a pause in data collection as the national program transitioned to a new contractor, BioBot, in April. The company would be responsible for testing wastewater samples and releasing the results.

But health department officials told VTDigger via email this week that it’s now past time for BioBot to start reporting data again, and the state is puzzled about the pause.

“Our Health Surveillance team also noticed this apparent discrepancy in the data,” health department spokesperson Ben Truman said. “We have reached out to NWSS and to Biobot to find out why we don’t yet have trend data for some of these sites, and why some appear to go offline — such as Essex Junction, which had trend data for a few weeks and now do not.”

Several local officials at participating sites told VTDigger they had no idea their results weren’t appearing in state and national data sources. They had been receiving reports directly from BioBot for a month or more.

St. Albans, for example, had reports from BioBot dating back to May 24, according to Brian Willett, chief wastewater operator for the city. 

The ten sites participating in the program, according to the health department, are Bennington, Brighton, Essex Junction, Johnson, Morrisville, Newport city, St. Albans, St. Johnsbury, Troy and Jay’s combined sewershed and Winooski. 

It’s unclear exactly which sites are appearing in CDC data, because the agency lists three sites for Chittenden County — presumably including Essex Junction and Winooski — without specifying which is which. 

The 10 sites also include St. Johnsbury, which has not started collecting data because it is awaiting the arrival of the right kind of sampler to use for the program, project manager Jim Brimblecombe said.

But of the other nine sites, only five are displayed online. Four of those have some data, but not for the most recent week, and one has no data at all.

In response to questions from VTDigger about Vermont’s participation, Brian Katzowitz, a spokesperson for the CDC, said via email that “the majority of these (sites) are submitting data. It can take several weeks for enough data to be collected to calculate the metrics displayed on COVID Data Tracker. However, state, tribal, local, and territorial health departments will still be able to track COVID-19 in their communities and make public health decisions,” he wrote.

The agency did not respond to follow-up questions about which sites were listed on the CDC website, or why sites that had been submitting test results for more than a month were not appearing online.

Jennings Heussner, the government and business manager for BioBot, said he wasn’t sure why the data was missing, either. 

“I'm honestly not entirely sure of exactly why each site wouldn't be included,” he said.

He said that if sites are part of the program and sending BioBot sample kits, they should be on the CDC website “at some time or another.”

“At the end of the day, we are a contractor,” he said. “And we are doing all of the data generation, but we don't have any say about exactly how CDC uses the data once it's in their hands.”

Through the program, local wastewater officials are responsible for collecting sewage samples and sending those samples to BioBot labs via FedEx. 

Most program operators said the sample collection was not time-intensive. But Nate Fraser, chief operator at Springfield’s wastewater treatment plant, said the city passed on the chance to continue with the new contractor because the department found it too difficult to manage with its small staff.

“My staff is spread very thin on a normal day,” he said via email. “Collecting samples, labeling, washing the processed sample containers and packaging twice per week was taking time we felt was more beneficially used in other areas of our daily operation.”

Paradoxically, the only site in Vermont that doesn’t participate in the CDC data collection has also been the state’s most steady data source. The City of Burlington publishes data on a weekly basis of the viral level at its three wastewater treatment plants. 

Nancy Stetson, senior policy and data analyst for the city, said it has been reporting data since fall 2020 using a contractor who’s being paid with federal relief money. The city may be open to joining the CDC in the future, but for now, “we just have our own thing going,” she said.

That slice of data has proved useful for policymakers. The state health department and the Department of Financial Regulation have cited Burlington’s wastewater data in press conferences and reports.

Elaine Wang, the Winooski city manager, said she had noticed that when Burlington reported an uptick in wastewater data, cases in Winooski tended to rise. Wang began using Burlington’s wastewater reports to engage the city council to discuss mask mandates or other actions.

Timothy LaPara, a professor of civil engineering at the University of Minnesota, was one of the first researchers to study the ability to detect SARS-CoV-2 levels in wastewater. 

LaPara said wastewater levels aren’t a great way to determine exactly how many cases there are in your community, but they work well as a relative measure of whether the virus is trending up or down.

In fact, he believes that wastewater data is “the best way to track this disease.”

“All the other testing methods have catastrophic flaws,” LaPara said. Most people don’t get PCR testing when they’re asymptomatic, and antigen tests rarely get reported to state agencies. 

“There could be some problems with it that somebody could find somewhere, but it's trustworthy. It's the best we have,” he said.

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Erin Petenko is VTDigger's data and graphics reporter, bringing numbers to life to help Vermonters understand the state they live in.

View all stories by Erin Petenko

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