Wastewater Surveillance

The Wastewater Surveillance dashboard shows SARS-CoV-2 shed viral particles in sampled wastewater for communities. SARS-CoV-2 is the virus that causes COVID-19.

NH DHHS works with numerous partners to conduct wastewater SARS-CoV-2 surveillance. Samples are collected from wastewater treatment plants in participating jurisdictions to understand the prevalence of SARS-CoV-2 infections in our communities. People who are infected, with or without symptoms, shed viral particles in their waste. By monitoring wastewater we can measure the amount of SARS-CoV-2 viral fragments in a community wide sample to determine if the levels of the virus in that community are going up, down, or staying the same.

What is wastewater surveillance?

Wastewater surveillance is a powerful tool to estimate the amount of a pathogen, like SARS-CoV-2, in a community. This is particularly helpful for SARS-CoV-2 as home based testing has become more widely available and less testing is done in medical offices. Wastewater surveillance will be able to supplement the data reported to NH DHHS from medical offices and assist communities in making decisions to manage their risk of infection.

Data Limitations

Wastewater surveillance for viral detection of SARS-CoV-2 is still a developing field. Below are some important considerations to keep in mind. 

  • As valuable as wastewater surveillance is, it is not possible to reliably and accurately predict the total number of infected individuals in a community based on wastewater surveillance alone. This is why we also continue to include data reported from medical offices and laboratories. 
  • Wastewater surveillance will not necessarily represent homes that are on septic-based systems. Note: some wastewater treatment facilities accept waste from septic systems and this may impact results. 
  • Low levels of infection in a community may not be captured by wastewater surveillance if the quantity of SARS-CoV-2 falls below the limit of detection for laboratory analysis. 
  • Community-level wastewater surveillance at a wastewater treatment plant will not represent communities or facilities served by decentralized systems, such as prisons, universities, or hospitals that treat their own wastewater. 
  • Wastewater is a complex sample and variability in measured concentrations are expected due to environmental variability (rain or drought), day-to-day differences in wastewater flow rates, changes in population size (tourist and seasonal visitors), and laboratory tests used.  As such, trends are more reliable than individual data points because individual data points may reflect variability and should be interpreted in appropriate context and with caution.

Read more about the program here: https://www.dhhs.nh.gov/news-and-media/covid-19-wastewater-surveillance-program-launches-new-hampshire