To better understand COVID-19 in North Carolina, NCDHHS is testing samples of wastewater from select wastewater treatment plants across the state to look for SARS-CoV-2, the virus that causes COVID-19. People with COVID-19 shed viral particles in their stool. These viral particles are pieces of the SARS-CoV-2 virus, which causes COVID-19 when still intact. In wastewater, the particles are no longer infectious but can still be measured. Testing wastewater for these viral particles allows us to track COVID-19 trends among people contributing to the wastewater. Data from these sites serve as a supplemental metric to understand the impacts of COVID-19 at the community level.
This project is a collaboration between the North Carolina Department of Health and Human Services, University of North Carolina system researchers, wastewater utilities, and public health departments.
Influenza and RSV: Levels of Influenza and RSV can also be detected in wastewater, but laboratory methods are still in development. From August 2022-May 2023, the NCWMN piloted wastewater testing for Influenza and RSV at 21 sites. Read the full report here.
*Note: COVID-19 cases in the sewershed are no longer being updated as of May 24, 2023. The COVID-19 Cases in the Sewershed graph reflects archived information.
To view the average COVID-19 virus copies found per person per week from participating North Carolina Wastewater treatment plants, please visit the Summary Dashboard.
To download tabular data displayed in the NCDHHS dashboards please go to Data Behind the Dashboards.
Why are we monitoring wastewater?
Wastewater monitoring is being used to follow COVID-19 trends within a community. People with COVID-19 illness shed the virus in their feces shortly after they are infected, often before they experience symptoms. People who are infected but never show symptoms can also shed the virus. By testing a community’s wastewater, we can measure the amount of the virus in a community-wide sample and see whether levels of the virus are increasing, decreasing, or staying the same. Public health officials can use this information to inform communities about COVID-19 trends at the local level.
How does wastewater monitoring work?
Participating wastewater utilities collect a wastewater sample (24-hour mixture, or composite) twice per week. Wastewater samples are analyzed in the laboratory to determine the amount of SARS-CoV-2 virus that is present. The amount of SARS-CoV-2 virus, measured as viral gene copies, can indicate if COVID-19 is increasing or decreasing in a community.
How can monitoring wastewater improve public health?
Wastewater monitoring can:
- Provide a community-wide sample to help track trends in levels of the virus.
- Sometimes serve as an early warning of increases in COVID-19 in communities.
- Provide information that can help local communities intervene act more quickly with strategies to slow COVID-19 spread.
Is there a risk of spreading COVID-19 through wastewater?
The SARS-CoV-2 virus, which causes COVID-19, breaks down quickly in the environment. Scientists have not found wastewater to be a pathway for disease transmission, although we can still measure the RNA fragments in the wastewater. Untreated wastewater can transmit other diseases, however, so staff collecting samples and conducting laboratory analysis must follow standard safety protocols, including the use of personal protective equipment and good hygiene practices.