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Wastewater Surveillance for COVID-19

Michigan COVID-19 Wastewater Testing Dashboard

Michigan COVID-19 SWEEP Sentinel Wastewater Dashboard

The State of Michigan SARS-CoV-2 Epidemiology - Wastewater Evaluation and Reporting Network is a wastewater monitoring project that uses locally coordinated projects to conduct surveillance for SARS-CoV-2 virus shed into Michigan public sewer systems. Coordinated by the Michigan Department of Health and Human Services (MDHHS), this network relies on local partnerships between local health departments (LHDs), Tribal communities, wastewater utilities, universities, and laboratories to gather wastewater samples, analyze them for the presence of SARS-CoV-2, and report and respond to the laboratory data.

  • MDHHS provides project coordination, data analysis, health education, and risk communication
  • Michigan Department of Environment, Great Lakes, and Energy (EGLE) provides scientific expertise and data management capacity for the network
  • Michigan State University (MSU) serves as the lead laboratory, standardizing laboratory testing and providing technical assistance
  • The local projects collect samples, conduct lab testing, and provide local data analysis, communications, and coordination

By operating multiple local projects under a single network, the SARS-CoV-2 wastewater sampling and analysis conducted is consistent, public health interpretation of results and risk communication is ensured, and data is systematically shared with local and state level public health officials and other stakeholders.

Network Goals and Activities

The overall goal of the network is to rapidly detect SARS-CoV-2, the virus that causes COVID-19 disease, in specific communities via wastewater testing. This is completed through the following activities:

  1. Establishment, maintenance, and coordination of the SEWER Network, in collaboration with participating stakeholders and local partnerships; 
  2. Ongoing sampling and analysis to detect SARS-CoV-2 virus in wastewater and monitor trends in results, and to quantify disease burden, within a community or at individual congregate sites; 
  3. Provision of timely and consistent wastewater data to support local public health responses, including clinical testing strategies and immunization efforts; 
  4. As applicable, utilize data to decrease the burden of testing on congregate facilities, such as prisons and long-term care facilities; and 
  5. Conduct internal and support external communications for the project. 

Timeline of COVID-19 wastewater surveillance activities in Michigan:

  • April 2020 through September 2020: Some sites in Michigan began voluntarily collecting samples of wastewater to test for SARS-CoV-2. These earlier samples were later supported via the pilot project through backdated funding.
  • October 1, 2020 through December 30, 2020: The State of Michigan COVID-19 Wastewater Surveillance Feasibility Pilot Project provided funding for 20 local projects to test wastewater for SARS-CoV-2 and determine the feasibility of this type of testing.
  • December 31, 2020 through May 2021: There was no State of Michigan-funded COVID-19 wastewater surveillance during this time; however, some local projects continued testing using their own funds and could voluntarily submit data to the State.
  • June 1, 2021 through July 31, 2023: Additional funding is being provided to the projects that participated in the pilot program to continue and expand COVID-19 wastewater surveillance in Michigan.

Michigan COVID-19 Wastewater Surveillance Pilot Project

In Fall 2020, MDHHS utilized $10 million from Michigan's allocation of the federal Coronavirus Relief Fund to conduct a wastewater surveillance feasibility pilot project for SARS-CoV-2. This was done through partnership with EGLE, MSU, and an existing statewide qPCR laboratory network. The pilot project tested samples from October-December 2020.

This project supported 20 local pilot projects, with testing conducted at 19 different academic, local health department, private, and local government laboratories. Approximately 280 locations were sampled in 41 counties, plus the City of Detroit, which represented 29 local health jurisdictions and 6 Tribal communities. Community-level surveillance was conducted at wastewater treatment plants and sewershed access points, while congregate facility surveillance was done at colleges and universities, K-12 schools, long-term care and assisted living facilities, adult foster cares, casinos, hospitals, and state and local correctional facilities.

The pilot project demonstrated that in a short timeframe, laboratories in all regions of the state were able to detect SARS-CoV-2 in wastewater via a standardized method and begin tracking trends. Many participating local health departments and universities were able to focus clinical testing recommendations and communication efforts when increased levels of the virus were detected in wastewater. Specific examples of successful outcomes from the pilot project are available in the COVID-19 Wastewater Surveillance Feasibility Pilot Project Success Stories.

Data from the pilot project can be viewed on the Michigan COVID-19 Wastewater Testing Dashboard.

Why is Michigan monitoring wastewater for the SARS-CoV-2 virus?

SARS-CoV-2 is easily spread from person-to-person and can cause serious illness and death. Public health agencies have been identifying individuals infected with SARS-CoV-2 and their close contacts to slow the spread of this virus in the community. This tracking occurs after a positive case has been identified, making it a challenge to get ahead of community spread and break the transmission cycle. 

Monitoring wastewater for SARS-CoV-2 can provide an early indicator for presence of disease in the community and can be used to track trends over time. This can be especially important as clinical testing rates decrease. SARS-CoV-2 virus can be detected in wastewater before infections lead to increases in clinical cases. See the graphic below for more information about how wastewater monitoring fits in with COVID-19 surveillance. 

This virus is shed in human feces for several weeks, including before people become ill and in individuals who are infected but not showing symptoms. Wastewater monitoring is one of the few ways in which public health agencies can understand SARS-CoV-2 transmission within these populations. This surveillance method is noninvasive and privacy-protecting, as it provides information about populations and not individuals.

An increase in SARS-CoV-2 detected in wastewater can alert public health agencies of a potential surge in cases in a specific community and allow additional precautions to be put in place to prevent the spread of the virus.

Waste Water infographic

Where is wastewater surveillance being conducted?

Through this network, wastewater surveillance is being conducted in 58 counties throughout Michigan, in both the upper and lower peninsulas. There are over 400 testing sites, which includes wastewater treatment plants and congregate settings.

Map showing community and congregate facility wastewater network sampling sites in Michigan as of July 2021.

Map showing community and congregate facility wastewater network sampling sites in Michigan as of October 2022. Sampling sites are subject to change.

Why are you testing at wastewater treatment plants and congregate settings?

This network includes surveillance at wastewater treatment plants and congregate facility sentinel locations. Wastewater treatment plant surveillance is used to evaluate trends of infection within the community contributing to the sewer system. These systems can represent several sewersheds that serve a larger interconnected population, such as dense urban areas, and provide community-level data for that region.

Targeted wastewater surveillance will be completed at congregate facilities, such as prisons/jails, long-term care and/or assisted living facilities, K-12 schools with in-person instruction, and universities. Targeted facility-level wastewater surveillance may provide a better understanding of how SARS-CoV-2 infections are distributed within a sewershed and allow for officials to take public health actions within that specific facility.

Who is involved in this project?

The Michigan Department of Health and Human Services is supporting 19 local pilot projects throughout the state. Partners include:

  • 36 local health departments
  • 5 Native American Tribal Nations
  • 18 public, private, and academic laboratories

Additional partners include EGLE, wastewater treatment agencies, colleges and universities, local municipalities, and other organizations with individual congregate facilities.

Where can I find wastewater testing results?

Results can be found on the Michigan COVID-19 Wastewater Testing Dashboard

What do the results mean?

The results can provide information on the presence or absence of infected individuals in the community and trends in the detected level of virus over time. Detecting SARS-CoV-2 in wastewater can depend on the sampling design, sensitivity of the test, and amount of virus being shed in the sampled community. If detected, it means there is at least one person in the community shedding the virus. If not detected, it could mean there is no virus in the sampled community or that the concentration of the virus in the sample is below the level that can be detected by the test.

Since COVID-19 wastewater surveillance is still a new and emerging field of study, it is important to monitor and observe the trends of SARS-CoV-2 detected in a community over time instead of looking at individual data points. A significant increase in the virus detected over time can show that cases may be increasing in a community. It is important to note that infected individuals can continue shedding the virus in feces for 20 to 30 days after they are no longer infectious, meaning decreases in the amount of virus detected in wastewater may lag behind clinical cases. Reviewing clinical case numbers, in conjunction with wastewater testing results, will allow community officials to make more informed decisions and take appropriate action.

For more information about how to view and interpret wastewater data from this project, please see the guide to wastewater data and interpretation.

How can I get a quick snapshot of current wastewater testing results and what they mean?

This network tests wastewater for SARS-CoV-2 at over 400 sites statewide, providing geographic coverage across the state and actionable local results. To give a regional and statewide overview of these efforts, the Sentinel Wastewater Epidemiology Evaluation Project (SWEEP) was added to provide a weekly analysis and interpretation of wastewater data from a subset of these monitoring sites.

20 wastewater treatment plants in 18 counties and the City of Detroit were selected to participate. These sites, referred to as sentinels, are distributed across the Michigan Economic Recovery Council (MERC) regions. MERC regions were developed by merging Michigan's Emergency Preparedness Regions and Michigan's labor sheds - the major areas of the state where people live and travel to work based on U.S. Department of Labor data - so that any outbreak resulting from a return to work could be handled effectively under public health laws.

The SWEEP data is updated weekly and is available on the Michigan COVID-19 SWEEP Sentinel Wastewater Dashboard, along with additional information about the SWEEP project.

What actions could be taken by local health departments if increases in the virus are detected?

If wastewater testing shows an increase in the level of SARS-CoV-2 at a specific site, local health departments may consider:

  • Alerting nearby hospitals, healthcare systems, clinics, and local physicians of a potential increase in cases;
  • Increasing communication and outreach efforts in communities where increased virus shedding has been found;
  • Increasing human clinical and/or wastewater testing in affected communities and adding additional testing locations, if necessary;
  • Continuing to evaluate and monitor clinical case data; and
  • Recommending additional restrictions, if necessary.

After an increase in the virus is detected, local health departments will continue studying the trends to monitor community transmission and to evaluate the effectiveness of any implemented prevention and response measures.

How can wastewater monitoring improve public health?

This wastewater monitoring network will help local public health agencies to:

  • Identify the presence of SARS-CoV-2 in a community and provide an early warning sign of an increase in cases;
  • Alert affected communities and local hospitals/public health response agencies more quickly;
  • Help measure the effectiveness of public health interventions, such as face covering mandates, business restrictions, isolation/quarantine, etc. by observing long term trends; and
  • Monitor populations at higher risk for COVID-19, such as those in congregate living facilities, and prevent further spread in these communities through early detection.

How is this COVID-19 wastewater surveillance project funded?

Funding for this project from June 2021 through July 31, 2023 comes from the Centers for Disease Control and Prevention's Epidemiology and Laboratory Capacity (ELC) Enhancing Detection Expansion grant supported through the Coronavirus Response and Relief Supplemental Appropriations Act of 2021 (P.L. 116-260).

Who should I contact for more information about COVID-19 wastewater surveillance in Michigan?

For questions or more information, please email MDHHS at

Additional Resources

COVID-19 Wastewater Resources for Local Health Departments

EGLE Michigan COVID-19 Wastewater Surveillance Pilot Project

Centers for Disease Control and Prevention (CDC) National Wastewater Surveillance System