COVID-19 Wastewater Surveillance

Tracking the prevalence of COVID-19 among metro area residents

Consolidating wastewater surveillance

The State of Minnesota is updating and centralizing its COVID-19 wastewater reporting system. The updates will combine testing done in the metro area with a statewide monitoring system capable of detecting a variety of viruses in the general population, including COVID-19.

The Minnesota Department of Health (MDH) and the University of Minnesota’s Medical School are consolidating all wastewater monitoring in the state through the Center for Disease Control’s National Wastewater Surveillance System.

As a result, as of Sept. 1, the Met Council is discontinuing the work it embarked on, in partnership with the University of Minnesota Genomics Center (UMGC), to analyze and report findings on the prevalence of the SARS CoV-2 entering the Metro Plant in Saint Paul.

Wastewater surveillance of COVID-19 has become an important tool for monitoring trends with the virus, especially as the use of at-home tests has increased. Our Environmental Services division will continue to participate in this important partnership by continuing to provide samples from our nine wastewater treatment plants for analysis. 

Partnership benefits the region

Over recent years, the Met Council worked with UMGC to test and report weekly on the prevalence of the SARS-CoV-2 in wastewater from a large portion of the metro area. The University of Minnesota has also been monitoring 37 wastewater treatment plants across the state, including the metro, with a dashboard that is updated weekly and will continue to be updated.

This new approach is designed to be more sustainable and integrates early viral detection systems for Greater Minnesota. The MDH Public Health Laboratory will also implement a new assay to monitor for SARS-CoV-2 variants from wastewater.

“The work of analyzing and reporting on the prevalence of the SARS CoV-2 virus in the region’s wastewater has been important and rewarding,” said the Environmental Services director Leisa Thompson.

“We’ve learned so much about how wastewater surveillance can and will contribute to public health. The Council will continue to participate in this vital partnership, by continuing to provide samples from an abundance of wastewater that we collect and treat.”

Advancing the work of wastewater surveillance

The University of Minnesota is working with the MDH Public Health Laboratory to verify methods that will allow them to eventually add RSV, influenza A, and influenza B to wastewater monitoring. State health experts are hopeful the expansion to monitoring other viruses will provide useful signals that combined with other disease surveillance can help officials respond more effectively to disease threats.

“As we address the long-term management of COVID-19 in our communities, we are updating how wastewater surveillance is done in the state,” said Dr. Brooke Cunningham, Minnesota Commissioner of Health. “The new approach will provide better statewide data for COVID-19 as well as future monitoring for other viruses.”

"Going forward, the synergy between MDH and UMN will be a force multiplying effort that serves as an early warning system for pathogens that impact public health," said Mark Osborn, study lead and an assistant professor at the U of M Medical School.

From us to you

We extend special thanks to our partners at MDH, the University of Minnesota Genomics Center, and University of Minnesota Medical School project.

And we thank the public and interested parties across the country for entrusting us with this important data. We hope it was put to good use in making decisions that enhanced health and health care.

This week's data

The most recent data update includes samples taken August 21 – August 27, 2023. During this sampling period:

  • The weekly average viral RNA load in wastewater entering the Metro Plant increased by 18% this week compared to a week earlier.
  • XBB is the dominant variant in wastewater entering the plant.

See an interactive version of this information or download data

Total viral load

This graph shows the amount of SARS-CoV-2 viral RNA entering the Metro Plant each day (light blue dots) and averaged over the preceding 7 days (thick blue line). The gray area shows the number of new daily COVID-19 cases in the Metro Plant's service area, by sample collection date averaged over the preceding 7 days. The most recent case data (darker gray) are incomplete and subject to change. COVID-19 case data are from the Minnesota Department of Health. Last wastewater sample date was August 27, 2023.

Notes: Case data is not available after July 24, 2023. The Met Council ended wastewater monitoring on August 27, 2023. Monitoring of the Met Council’s wastewater continues through the University of Minnesota Medical School wastewater project.

This graph is interactive: hover over points for more information, or click and drag to zoom in.

This graph shows the amount of SARS-CoV-2 viral RNA entering the Metro Plant separately for each variant. The viral load for each variant is estimated by multiplying the total viral load by the frequency of that variant. Because measured frequencies do not always add to 100%, the sum of all variant loads may be slightly greater or less than the total viral load. The loads of Omicron BA.4 and BA.5 are shown as the sum (BA.4+BA.5) before May 31, 2022, and separately afterwards. Last wastewater sample date was August 27, 2023. The Met Council ended wastewater monitoring on August 27, 2023.

This graph is interactive: hover over points for more information, or click and drag to zoom in.

Download data

This graph shows the percentage of SARS-CoV-2 viral RNA that can be attributed to each variant. Variants are tracked by sequencing marker gene mutations on the SARS-CoV-2 viral genome. Omicron BA.4 and BA.5 are shown as the sum (BA.4+BA.5) before May 31, 2022, and separately afterwards. Because each variant is measured separately, variant frequencies do not always sum to 100%. Last sample date was August 27, 2023. The Met Council ended wastewater monitoring on August 27, 2023.

This graph is interactive: hover over points for more information, or click and drag to zoom in.

Download data

Learn more

Wastewater surveillance addresses need for public health data

The Met Council samples wastewater flowing into four of the region’s nine treatment plants. The most prevalent data come from the Metro Plant, which treats the wastewater of 66 communities in five counties. Scientists there initially launched the initiative to be of assistance to the health department in the fight against COVID-19.

For more information on wastewater surveillance for SARS-CoV-2, visit the CDC website.

The Met Council generated daily wastewater data from November 1, 2020 to August 27, 2023. The State of Minnesota has transitioned to having all wastewater monitoring accomplished through the National Wastewater Surveillance System and the University of Minnesota Medical School Wastewater Project.

Wastewater treatment is our primary business, but we are committed to helping to monitor the viral trends we’re experiencing. Wastewater surveillance has proven to be a valuable tool in the battle against COVID-19, and we are committed to continuing our efforts in this area.

Our observations are that, due to sometimes large variability in the day-to-day data, the weekly update gives a better picture of the developing trends than we would observe in a more frequent review of the data.

Viable (infectious) virus has not been detected in treated effluent from wastewater treatment plants. Modern wastewater treatment methods remove the virus before the treated water is discharged to receiving waters.

While SARS-CoV-2 can be shed in the feces of individuals with COVID-19 and discharged into wastewater collection systems, there is no evidence to date of COVID-19 infections arising from direct exposure to treated or untreated wastewater.

The Met Council does not provide guidance on health-related policy or procedures with respect to COVID-19. That information is conveyed by the Minnesota Department of Health and the national Centers for Disease Control and Prevention.