A program described by the Centers for Disease Control and Prevention (CDC) on its official public health portal tracks infectious disease activity by analyzing sewage samples collected from wastewater treatment facilities across the United States, including sites throughout Tennessee. The CDC's National Wastewater Surveillance System (NWSS), which expanded significantly during and after the COVID-19 pandemic, measures pathogen concentrations in untreated wastewater as a way to detect community-level disease trends before clinical testing data becomes available.
According to the CDC, wastewater surveillance can serve as an early indicator of rising infection rates because viral and bacterial genetic material shed by infected individuals appears in sewage systems days before those individuals may seek medical care or receive a positive test result. The agency notes the system currently monitors for a range of pathogens beyond SARS-CoV-2, including influenza, RSV, and mpox, with the network of participating utilities spanning urban centers and smaller municipalities alike.
In Tennessee, the Tennessee Department of Health (TDH) participates in the NWSS and has publicly reported wastewater data for service areas that include major population centers such as Nashville-Davidson County, Memphis, Knoxville, and Chattanooga, as well as some smaller communities in Middle and East Tennessee. The state's varied geography — from the Cumberland Plateau to the Mississippi River basin — means wastewater catchment areas can reflect disease burden across distinctly different population densities and demographic profiles, giving epidemiologists a more granular picture of how illness moves through the state.
For Tennessee residents and community planners who track infrastructure resilience, the wastewater surveillance program sits at the intersection of two critical systems: the state's public water and sewer infrastructure and its public health early-warning capacity. Tennessee's roughly 1,400 public water systems and its network of municipal wastewater treatment plants — many operated by utilities such as the Nashville Metro Water Services, Memphis Light Gas and Water, and the Knoxville Utilities Board — are the physical backbone that makes this kind of biological monitoring possible. Disruptions to those systems, whether from flooding events common along the Tennessee and Cumberland Rivers or from aging infrastructure, can affect both the quality of surveillance data collected and the ability of the TDH to detect emerging health threats in real time. Readers interested in how water system vulnerabilities factor into household preparedness planning may find background in our review of water filtration and storage options.
